// SPDX-License-Identifier: GPL-2.0
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/*
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* ring buffer based function tracer
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*
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* Copyright (C) 2007-2012 Steven Rostedt <srostedt@redhat.com>
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* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
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*
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* Originally taken from the RT patch by:
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* Arnaldo Carvalho de Melo <acme@redhat.com>
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*
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* Based on code from the latency_tracer, that is:
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* Copyright (C) 2004-2006 Ingo Molnar
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* Copyright (C) 2004 Nadia Yvette Chambers
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*/
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#include <linux/ring_buffer.h>
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#include <generated/utsrelease.h>
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#include <linux/stacktrace.h>
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#include <linux/writeback.h>
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#include <linux/kallsyms.h>
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#include <linux/security.h>
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#include <linux/seq_file.h>
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#include <linux/notifier.h>
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#include <linux/irqflags.h>
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#include <linux/debugfs.h>
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#include <linux/tracefs.h>
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#include <linux/pagemap.h>
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#include <linux/hardirq.h>
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#include <linux/linkage.h>
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#include <linux/uaccess.h>
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#include <linux/vmalloc.h>
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#include <linux/ftrace.h>
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#include <linux/module.h>
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#include <linux/percpu.h>
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#include <linux/splice.h>
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#include <linux/kdebug.h>
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#include <linux/string.h>
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#include <linux/mount.h>
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#include <linux/rwsem.h>
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#include <linux/slab.h>
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#include <linux/ctype.h>
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#include <linux/init.h>
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#include <linux/poll.h>
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#include <linux/nmi.h>
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#include <linux/fs.h>
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#include <linux/trace.h>
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#include <linux/sched/clock.h>
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#include <linux/sched/rt.h>
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#include <linux/fsnotify.h>
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#include <linux/irq_work.h>
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#include <linux/workqueue.h>
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#include <trace/hooks/ftrace_dump.h>
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#include "trace.h"
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#include "trace_output.h"
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/*
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* On boot up, the ring buffer is set to the minimum size, so that
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* we do not waste memory on systems that are not using tracing.
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*/
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bool ring_buffer_expanded;
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/*
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* We need to change this state when a selftest is running.
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* A selftest will lurk into the ring-buffer to count the
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* entries inserted during the selftest although some concurrent
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* insertions into the ring-buffer such as trace_printk could occurred
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* at the same time, giving false positive or negative results.
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*/
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static bool __read_mostly tracing_selftest_running;
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/*
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* If boot-time tracing including tracers/events via kernel cmdline
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* is running, we do not want to run SELFTEST.
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*/
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bool __read_mostly tracing_selftest_disabled;
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#ifdef CONFIG_FTRACE_STARTUP_TEST
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void __init disable_tracing_selftest(const char *reason)
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{
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if (!tracing_selftest_disabled) {
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tracing_selftest_disabled = true;
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pr_info("Ftrace startup test is disabled due to %s\n", reason);
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}
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}
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#endif
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/* Pipe tracepoints to printk */
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struct trace_iterator *tracepoint_print_iter;
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int tracepoint_printk;
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static DEFINE_STATIC_KEY_FALSE(tracepoint_printk_key);
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/* For tracers that don't implement custom flags */
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static struct tracer_opt dummy_tracer_opt[] = {
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{ }
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};
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static int
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dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
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{
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return 0;
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}
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/*
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* To prevent the comm cache from being overwritten when no
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* tracing is active, only save the comm when a trace event
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* occurred.
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*/
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static DEFINE_PER_CPU(bool, trace_taskinfo_save);
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/*
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* Kill all tracing for good (never come back).
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* It is initialized to 1 but will turn to zero if the initialization
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* of the tracer is successful. But that is the only place that sets
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* this back to zero.
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*/
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static int tracing_disabled = 1;
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cpumask_var_t __read_mostly tracing_buffer_mask;
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/*
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* ftrace_dump_on_oops - variable to dump ftrace buffer on oops
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*
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* If there is an oops (or kernel panic) and the ftrace_dump_on_oops
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* is set, then ftrace_dump is called. This will output the contents
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* of the ftrace buffers to the console. This is very useful for
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* capturing traces that lead to crashes and outputing it to a
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* serial console.
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*
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* It is default off, but you can enable it with either specifying
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* "ftrace_dump_on_oops" in the kernel command line, or setting
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* /proc/sys/kernel/ftrace_dump_on_oops
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* Set 1 if you want to dump buffers of all CPUs
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* Set 2 if you want to dump the buffer of the CPU that triggered oops
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*/
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enum ftrace_dump_mode ftrace_dump_on_oops;
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/* When set, tracing will stop when a WARN*() is hit */
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int __disable_trace_on_warning;
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#ifdef CONFIG_TRACE_EVAL_MAP_FILE
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/* Map of enums to their values, for "eval_map" file */
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struct trace_eval_map_head {
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struct module *mod;
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unsigned long length;
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};
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union trace_eval_map_item;
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struct trace_eval_map_tail {
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/*
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* "end" is first and points to NULL as it must be different
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* than "mod" or "eval_string"
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*/
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union trace_eval_map_item *next;
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const char *end; /* points to NULL */
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};
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static DEFINE_MUTEX(trace_eval_mutex);
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/*
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* The trace_eval_maps are saved in an array with two extra elements,
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* one at the beginning, and one at the end. The beginning item contains
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* the count of the saved maps (head.length), and the module they
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* belong to if not built in (head.mod). The ending item contains a
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* pointer to the next array of saved eval_map items.
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*/
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union trace_eval_map_item {
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struct trace_eval_map map;
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struct trace_eval_map_head head;
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struct trace_eval_map_tail tail;
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};
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static union trace_eval_map_item *trace_eval_maps;
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#endif /* CONFIG_TRACE_EVAL_MAP_FILE */
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int tracing_set_tracer(struct trace_array *tr, const char *buf);
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static void ftrace_trace_userstack(struct trace_array *tr,
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struct trace_buffer *buffer,
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unsigned int trace_ctx);
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#define MAX_TRACER_SIZE 100
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static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
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static char *default_bootup_tracer;
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static bool allocate_snapshot;
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static int __init set_cmdline_ftrace(char *str)
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{
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strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
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default_bootup_tracer = bootup_tracer_buf;
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/* We are using ftrace early, expand it */
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ring_buffer_expanded = true;
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return 1;
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}
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__setup("ftrace=", set_cmdline_ftrace);
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static int __init set_ftrace_dump_on_oops(char *str)
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{
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if (*str++ != '=' || !*str) {
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ftrace_dump_on_oops = DUMP_ALL;
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return 1;
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}
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if (!strcmp("orig_cpu", str)) {
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ftrace_dump_on_oops = DUMP_ORIG;
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return 1;
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}
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return 0;
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}
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__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
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static int __init stop_trace_on_warning(char *str)
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{
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if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0))
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__disable_trace_on_warning = 1;
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return 1;
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}
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__setup("traceoff_on_warning", stop_trace_on_warning);
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static int __init boot_alloc_snapshot(char *str)
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{
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allocate_snapshot = true;
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/* We also need the main ring buffer expanded */
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ring_buffer_expanded = true;
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return 1;
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}
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__setup("alloc_snapshot", boot_alloc_snapshot);
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static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata;
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static int __init set_trace_boot_options(char *str)
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{
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strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
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return 1;
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}
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__setup("trace_options=", set_trace_boot_options);
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static char trace_boot_clock_buf[MAX_TRACER_SIZE] __initdata;
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static char *trace_boot_clock __initdata;
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static int __init set_trace_boot_clock(char *str)
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{
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strlcpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE);
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trace_boot_clock = trace_boot_clock_buf;
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return 1;
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}
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__setup("trace_clock=", set_trace_boot_clock);
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static int __init set_tracepoint_printk(char *str)
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{
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/* Ignore the "tp_printk_stop_on_boot" param */
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if (*str == '_')
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return 0;
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if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0))
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tracepoint_printk = 1;
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return 1;
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}
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__setup("tp_printk", set_tracepoint_printk);
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unsigned long long ns2usecs(u64 nsec)
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{
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nsec += 500;
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do_div(nsec, 1000);
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return nsec;
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}
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static void
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trace_process_export(struct trace_export *export,
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struct ring_buffer_event *event, int flag)
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{
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struct trace_entry *entry;
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unsigned int size = 0;
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if (export->flags & flag) {
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entry = ring_buffer_event_data(event);
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size = ring_buffer_event_length(event);
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export->write(export, entry, size);
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}
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}
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static DEFINE_MUTEX(ftrace_export_lock);
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static struct trace_export __rcu *ftrace_exports_list __read_mostly;
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static DEFINE_STATIC_KEY_FALSE(trace_function_exports_enabled);
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static DEFINE_STATIC_KEY_FALSE(trace_event_exports_enabled);
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static DEFINE_STATIC_KEY_FALSE(trace_marker_exports_enabled);
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static inline void ftrace_exports_enable(struct trace_export *export)
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{
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if (export->flags & TRACE_EXPORT_FUNCTION)
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static_branch_inc(&trace_function_exports_enabled);
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if (export->flags & TRACE_EXPORT_EVENT)
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static_branch_inc(&trace_event_exports_enabled);
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if (export->flags & TRACE_EXPORT_MARKER)
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static_branch_inc(&trace_marker_exports_enabled);
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}
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static inline void ftrace_exports_disable(struct trace_export *export)
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{
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if (export->flags & TRACE_EXPORT_FUNCTION)
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static_branch_dec(&trace_function_exports_enabled);
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if (export->flags & TRACE_EXPORT_EVENT)
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static_branch_dec(&trace_event_exports_enabled);
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if (export->flags & TRACE_EXPORT_MARKER)
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static_branch_dec(&trace_marker_exports_enabled);
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}
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static void ftrace_exports(struct ring_buffer_event *event, int flag)
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{
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struct trace_export *export;
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preempt_disable_notrace();
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export = rcu_dereference_raw_check(ftrace_exports_list);
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while (export) {
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trace_process_export(export, event, flag);
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export = rcu_dereference_raw_check(export->next);
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}
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preempt_enable_notrace();
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}
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static inline void
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add_trace_export(struct trace_export **list, struct trace_export *export)
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{
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rcu_assign_pointer(export->next, *list);
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/*
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* We are entering export into the list but another
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* CPU might be walking that list. We need to make sure
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* the export->next pointer is valid before another CPU sees
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* the export pointer included into the list.
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*/
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rcu_assign_pointer(*list, export);
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}
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static inline int
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rm_trace_export(struct trace_export **list, struct trace_export *export)
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{
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struct trace_export **p;
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for (p = list; *p != NULL; p = &(*p)->next)
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if (*p == export)
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break;
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if (*p != export)
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return -1;
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rcu_assign_pointer(*p, (*p)->next);
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return 0;
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}
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static inline void
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add_ftrace_export(struct trace_export **list, struct trace_export *export)
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{
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ftrace_exports_enable(export);
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add_trace_export(list, export);
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}
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static inline int
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rm_ftrace_export(struct trace_export **list, struct trace_export *export)
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{
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int ret;
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ret = rm_trace_export(list, export);
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ftrace_exports_disable(export);
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return ret;
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}
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int register_ftrace_export(struct trace_export *export)
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{
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if (WARN_ON_ONCE(!export->write))
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return -1;
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mutex_lock(&ftrace_export_lock);
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add_ftrace_export(&ftrace_exports_list, export);
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mutex_unlock(&ftrace_export_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(register_ftrace_export);
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int unregister_ftrace_export(struct trace_export *export)
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{
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int ret;
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mutex_lock(&ftrace_export_lock);
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ret = rm_ftrace_export(&ftrace_exports_list, export);
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mutex_unlock(&ftrace_export_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(unregister_ftrace_export);
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/* trace_flags holds trace_options default values */
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#define TRACE_DEFAULT_FLAGS \
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(FUNCTION_DEFAULT_FLAGS | \
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TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | \
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TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | \
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TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | \
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TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS)
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/* trace_options that are only supported by global_trace */
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#define TOP_LEVEL_TRACE_FLAGS (TRACE_ITER_PRINTK | \
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TRACE_ITER_PRINTK_MSGONLY | TRACE_ITER_RECORD_CMD)
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/* trace_flags that are default zero for instances */
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#define ZEROED_TRACE_FLAGS \
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(TRACE_ITER_EVENT_FORK | TRACE_ITER_FUNC_FORK)
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/*
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* The global_trace is the descriptor that holds the top-level tracing
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* buffers for the live tracing.
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*/
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static struct trace_array global_trace = {
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.trace_flags = TRACE_DEFAULT_FLAGS,
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};
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LIST_HEAD(ftrace_trace_arrays);
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int trace_array_get(struct trace_array *this_tr)
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{
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struct trace_array *tr;
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int ret = -ENODEV;
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mutex_lock(&trace_types_lock);
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list_for_each_entry(tr, &ftrace_trace_arrays, list) {
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if (tr == this_tr) {
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tr->ref++;
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ret = 0;
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break;
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}
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}
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mutex_unlock(&trace_types_lock);
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return ret;
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}
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static void __trace_array_put(struct trace_array *this_tr)
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{
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WARN_ON(!this_tr->ref);
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this_tr->ref--;
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}
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/**
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* trace_array_put - Decrement the reference counter for this trace array.
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*
|
* NOTE: Use this when we no longer need the trace array returned by
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* trace_array_get_by_name(). This ensures the trace array can be later
|
* destroyed.
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*
|
*/
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void trace_array_put(struct trace_array *this_tr)
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{
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if (!this_tr)
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return;
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mutex_lock(&trace_types_lock);
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__trace_array_put(this_tr);
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mutex_unlock(&trace_types_lock);
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}
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EXPORT_SYMBOL_GPL(trace_array_put);
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int tracing_check_open_get_tr(struct trace_array *tr)
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{
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int ret;
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ret = security_locked_down(LOCKDOWN_TRACEFS);
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if (ret)
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return ret;
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if (tracing_disabled)
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return -ENODEV;
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if (tr && trace_array_get(tr) < 0)
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return -ENODEV;
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return 0;
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}
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int call_filter_check_discard(struct trace_event_call *call, void *rec,
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struct trace_buffer *buffer,
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struct ring_buffer_event *event)
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{
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if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
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!filter_match_preds(call->filter, rec)) {
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__trace_event_discard_commit(buffer, event);
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return 1;
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}
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return 0;
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}
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void trace_free_pid_list(struct trace_pid_list *pid_list)
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{
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vfree(pid_list->pids);
|
kfree(pid_list);
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}
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/**
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* trace_find_filtered_pid - check if a pid exists in a filtered_pid list
|
* @filtered_pids: The list of pids to check
|
* @search_pid: The PID to find in @filtered_pids
|
*
|
* Returns true if @search_pid is fonud in @filtered_pids, and false otherwis.
|
*/
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bool
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trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)
|
{
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/*
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* If pid_max changed after filtered_pids was created, we
|
* by default ignore all pids greater than the previous pid_max.
|
*/
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if (search_pid >= filtered_pids->pid_max)
|
return false;
|
|
return test_bit(search_pid, filtered_pids->pids);
|
}
|
|
/**
|
* trace_ignore_this_task - should a task be ignored for tracing
|
* @filtered_pids: The list of pids to check
|
* @task: The task that should be ignored if not filtered
|
*
|
* Checks if @task should be traced or not from @filtered_pids.
|
* Returns true if @task should *NOT* be traced.
|
* Returns false if @task should be traced.
|
*/
|
bool
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trace_ignore_this_task(struct trace_pid_list *filtered_pids,
|
struct trace_pid_list *filtered_no_pids,
|
struct task_struct *task)
|
{
|
/*
|
* If filterd_no_pids is not empty, and the task's pid is listed
|
* in filtered_no_pids, then return true.
|
* Otherwise, if filtered_pids is empty, that means we can
|
* trace all tasks. If it has content, then only trace pids
|
* within filtered_pids.
|
*/
|
|
return (filtered_pids &&
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!trace_find_filtered_pid(filtered_pids, task->pid)) ||
|
(filtered_no_pids &&
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trace_find_filtered_pid(filtered_no_pids, task->pid));
|
}
|
|
/**
|
* trace_filter_add_remove_task - Add or remove a task from a pid_list
|
* @pid_list: The list to modify
|
* @self: The current task for fork or NULL for exit
|
* @task: The task to add or remove
|
*
|
* If adding a task, if @self is defined, the task is only added if @self
|
* is also included in @pid_list. This happens on fork and tasks should
|
* only be added when the parent is listed. If @self is NULL, then the
|
* @task pid will be removed from the list, which would happen on exit
|
* of a task.
|
*/
|
void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
|
struct task_struct *self,
|
struct task_struct *task)
|
{
|
if (!pid_list)
|
return;
|
|
/* For forks, we only add if the forking task is listed */
|
if (self) {
|
if (!trace_find_filtered_pid(pid_list, self->pid))
|
return;
|
}
|
|
/* Sorry, but we don't support pid_max changing after setting */
|
if (task->pid >= pid_list->pid_max)
|
return;
|
|
/* "self" is set for forks, and NULL for exits */
|
if (self)
|
set_bit(task->pid, pid_list->pids);
|
else
|
clear_bit(task->pid, pid_list->pids);
|
}
|
|
/**
|
* trace_pid_next - Used for seq_file to get to the next pid of a pid_list
|
* @pid_list: The pid list to show
|
* @v: The last pid that was shown (+1 the actual pid to let zero be displayed)
|
* @pos: The position of the file
|
*
|
* This is used by the seq_file "next" operation to iterate the pids
|
* listed in a trace_pid_list structure.
|
*
|
* Returns the pid+1 as we want to display pid of zero, but NULL would
|
* stop the iteration.
|
*/
|
void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos)
|
{
|
unsigned long pid = (unsigned long)v;
|
|
(*pos)++;
|
|
/* pid already is +1 of the actual prevous bit */
|
pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid);
|
|
/* Return pid + 1 to allow zero to be represented */
|
if (pid < pid_list->pid_max)
|
return (void *)(pid + 1);
|
|
return NULL;
|
}
|
|
/**
|
* trace_pid_start - Used for seq_file to start reading pid lists
|
* @pid_list: The pid list to show
|
* @pos: The position of the file
|
*
|
* This is used by seq_file "start" operation to start the iteration
|
* of listing pids.
|
*
|
* Returns the pid+1 as we want to display pid of zero, but NULL would
|
* stop the iteration.
|
*/
|
void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos)
|
{
|
unsigned long pid;
|
loff_t l = 0;
|
|
pid = find_first_bit(pid_list->pids, pid_list->pid_max);
|
if (pid >= pid_list->pid_max)
|
return NULL;
|
|
/* Return pid + 1 so that zero can be the exit value */
|
for (pid++; pid && l < *pos;
|
pid = (unsigned long)trace_pid_next(pid_list, (void *)pid, &l))
|
;
|
return (void *)pid;
|
}
|
|
/**
|
* trace_pid_show - show the current pid in seq_file processing
|
* @m: The seq_file structure to write into
|
* @v: A void pointer of the pid (+1) value to display
|
*
|
* Can be directly used by seq_file operations to display the current
|
* pid value.
|
*/
|
int trace_pid_show(struct seq_file *m, void *v)
|
{
|
unsigned long pid = (unsigned long)v - 1;
|
|
seq_printf(m, "%lu\n", pid);
|
return 0;
|
}
|
|
/* 128 should be much more than enough */
|
#define PID_BUF_SIZE 127
|
|
int trace_pid_write(struct trace_pid_list *filtered_pids,
|
struct trace_pid_list **new_pid_list,
|
const char __user *ubuf, size_t cnt)
|
{
|
struct trace_pid_list *pid_list;
|
struct trace_parser parser;
|
unsigned long val;
|
int nr_pids = 0;
|
ssize_t read = 0;
|
ssize_t ret = 0;
|
loff_t pos;
|
pid_t pid;
|
|
if (trace_parser_get_init(&parser, PID_BUF_SIZE + 1))
|
return -ENOMEM;
|
|
/*
|
* Always recreate a new array. The write is an all or nothing
|
* operation. Always create a new array when adding new pids by
|
* the user. If the operation fails, then the current list is
|
* not modified.
|
*/
|
pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
|
if (!pid_list) {
|
trace_parser_put(&parser);
|
return -ENOMEM;
|
}
|
|
pid_list->pid_max = READ_ONCE(pid_max);
|
|
/* Only truncating will shrink pid_max */
|
if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max)
|
pid_list->pid_max = filtered_pids->pid_max;
|
|
pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3);
|
if (!pid_list->pids) {
|
trace_parser_put(&parser);
|
kfree(pid_list);
|
return -ENOMEM;
|
}
|
|
if (filtered_pids) {
|
/* copy the current bits to the new max */
|
for_each_set_bit(pid, filtered_pids->pids,
|
filtered_pids->pid_max) {
|
set_bit(pid, pid_list->pids);
|
nr_pids++;
|
}
|
}
|
|
while (cnt > 0) {
|
|
pos = 0;
|
|
ret = trace_get_user(&parser, ubuf, cnt, &pos);
|
if (ret < 0 || !trace_parser_loaded(&parser))
|
break;
|
|
read += ret;
|
ubuf += ret;
|
cnt -= ret;
|
|
ret = -EINVAL;
|
if (kstrtoul(parser.buffer, 0, &val))
|
break;
|
if (val >= pid_list->pid_max)
|
break;
|
|
pid = (pid_t)val;
|
|
set_bit(pid, pid_list->pids);
|
nr_pids++;
|
|
trace_parser_clear(&parser);
|
ret = 0;
|
}
|
trace_parser_put(&parser);
|
|
if (ret < 0) {
|
trace_free_pid_list(pid_list);
|
return ret;
|
}
|
|
if (!nr_pids) {
|
/* Cleared the list of pids */
|
trace_free_pid_list(pid_list);
|
read = ret;
|
pid_list = NULL;
|
}
|
|
*new_pid_list = pid_list;
|
|
return read;
|
}
|
|
static u64 buffer_ftrace_now(struct array_buffer *buf, int cpu)
|
{
|
u64 ts;
|
|
/* Early boot up does not have a buffer yet */
|
if (!buf->buffer)
|
return trace_clock_local();
|
|
ts = ring_buffer_time_stamp(buf->buffer, cpu);
|
ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts);
|
|
return ts;
|
}
|
|
u64 ftrace_now(int cpu)
|
{
|
return buffer_ftrace_now(&global_trace.array_buffer, cpu);
|
}
|
|
/**
|
* tracing_is_enabled - Show if global_trace has been disabled
|
*
|
* Shows if the global trace has been enabled or not. It uses the
|
* mirror flag "buffer_disabled" to be used in fast paths such as for
|
* the irqsoff tracer. But it may be inaccurate due to races. If you
|
* need to know the accurate state, use tracing_is_on() which is a little
|
* slower, but accurate.
|
*/
|
int tracing_is_enabled(void)
|
{
|
/*
|
* For quick access (irqsoff uses this in fast path), just
|
* return the mirror variable of the state of the ring buffer.
|
* It's a little racy, but we don't really care.
|
*/
|
smp_rmb();
|
return !global_trace.buffer_disabled;
|
}
|
|
/*
|
* trace_buf_size is the size in bytes that is allocated
|
* for a buffer. Note, the number of bytes is always rounded
|
* to page size.
|
*
|
* This number is purposely set to a low number of 16384.
|
* If the dump on oops happens, it will be much appreciated
|
* to not have to wait for all that output. Anyway this can be
|
* boot time and run time configurable.
|
*/
|
#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */
|
|
static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
|
|
/* trace_types holds a link list of available tracers. */
|
static struct tracer *trace_types __read_mostly;
|
|
/*
|
* trace_types_lock is used to protect the trace_types list.
|
*/
|
DEFINE_MUTEX(trace_types_lock);
|
|
/*
|
* serialize the access of the ring buffer
|
*
|
* ring buffer serializes readers, but it is low level protection.
|
* The validity of the events (which returns by ring_buffer_peek() ..etc)
|
* are not protected by ring buffer.
|
*
|
* The content of events may become garbage if we allow other process consumes
|
* these events concurrently:
|
* A) the page of the consumed events may become a normal page
|
* (not reader page) in ring buffer, and this page will be rewrited
|
* by events producer.
|
* B) The page of the consumed events may become a page for splice_read,
|
* and this page will be returned to system.
|
*
|
* These primitives allow multi process access to different cpu ring buffer
|
* concurrently.
|
*
|
* These primitives don't distinguish read-only and read-consume access.
|
* Multi read-only access are also serialized.
|
*/
|
|
#ifdef CONFIG_SMP
|
static DECLARE_RWSEM(all_cpu_access_lock);
|
static DEFINE_PER_CPU(struct mutex, cpu_access_lock);
|
|
static inline void trace_access_lock(int cpu)
|
{
|
if (cpu == RING_BUFFER_ALL_CPUS) {
|
/* gain it for accessing the whole ring buffer. */
|
down_write(&all_cpu_access_lock);
|
} else {
|
/* gain it for accessing a cpu ring buffer. */
|
|
/* Firstly block other trace_access_lock(RING_BUFFER_ALL_CPUS). */
|
down_read(&all_cpu_access_lock);
|
|
/* Secondly block other access to this @cpu ring buffer. */
|
mutex_lock(&per_cpu(cpu_access_lock, cpu));
|
}
|
}
|
|
static inline void trace_access_unlock(int cpu)
|
{
|
if (cpu == RING_BUFFER_ALL_CPUS) {
|
up_write(&all_cpu_access_lock);
|
} else {
|
mutex_unlock(&per_cpu(cpu_access_lock, cpu));
|
up_read(&all_cpu_access_lock);
|
}
|
}
|
|
static inline void trace_access_lock_init(void)
|
{
|
int cpu;
|
|
for_each_possible_cpu(cpu)
|
mutex_init(&per_cpu(cpu_access_lock, cpu));
|
}
|
|
#else
|
|
static DEFINE_MUTEX(access_lock);
|
|
static inline void trace_access_lock(int cpu)
|
{
|
(void)cpu;
|
mutex_lock(&access_lock);
|
}
|
|
static inline void trace_access_unlock(int cpu)
|
{
|
(void)cpu;
|
mutex_unlock(&access_lock);
|
}
|
|
static inline void trace_access_lock_init(void)
|
{
|
}
|
|
#endif
|
|
#ifdef CONFIG_STACKTRACE
|
static void __ftrace_trace_stack(struct trace_buffer *buffer,
|
unsigned int trace_ctx,
|
int skip, struct pt_regs *regs);
|
static inline void ftrace_trace_stack(struct trace_array *tr,
|
struct trace_buffer *buffer,
|
unsigned int trace_ctx,
|
int skip, struct pt_regs *regs);
|
|
#else
|
static inline void __ftrace_trace_stack(struct trace_buffer *buffer,
|
unsigned int trace_ctx,
|
int skip, struct pt_regs *regs)
|
{
|
}
|
static inline void ftrace_trace_stack(struct trace_array *tr,
|
struct trace_buffer *buffer,
|
unsigned long trace_ctx,
|
int skip, struct pt_regs *regs)
|
{
|
}
|
|
#endif
|
|
static __always_inline void
|
trace_event_setup(struct ring_buffer_event *event,
|
int type, unsigned int trace_ctx)
|
{
|
struct trace_entry *ent = ring_buffer_event_data(event);
|
|
tracing_generic_entry_update(ent, type, trace_ctx);
|
}
|
|
static __always_inline struct ring_buffer_event *
|
__trace_buffer_lock_reserve(struct trace_buffer *buffer,
|
int type,
|
unsigned long len,
|
unsigned int trace_ctx)
|
{
|
struct ring_buffer_event *event;
|
|
event = ring_buffer_lock_reserve(buffer, len);
|
if (event != NULL)
|
trace_event_setup(event, type, trace_ctx);
|
|
return event;
|
}
|
|
void tracer_tracing_on(struct trace_array *tr)
|
{
|
if (tr->array_buffer.buffer)
|
ring_buffer_record_on(tr->array_buffer.buffer);
|
/*
|
* This flag is looked at when buffers haven't been allocated
|
* yet, or by some tracers (like irqsoff), that just want to
|
* know if the ring buffer has been disabled, but it can handle
|
* races of where it gets disabled but we still do a record.
|
* As the check is in the fast path of the tracers, it is more
|
* important to be fast than accurate.
|
*/
|
tr->buffer_disabled = 0;
|
/* Make the flag seen by readers */
|
smp_wmb();
|
}
|
|
/**
|
* tracing_on - enable tracing buffers
|
*
|
* This function enables tracing buffers that may have been
|
* disabled with tracing_off.
|
*/
|
void tracing_on(void)
|
{
|
tracer_tracing_on(&global_trace);
|
}
|
EXPORT_SYMBOL_GPL(tracing_on);
|
|
|
static __always_inline void
|
__buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *event)
|
{
|
__this_cpu_write(trace_taskinfo_save, true);
|
|
/* If this is the temp buffer, we need to commit fully */
|
if (this_cpu_read(trace_buffered_event) == event) {
|
/* Length is in event->array[0] */
|
ring_buffer_write(buffer, event->array[0], &event->array[1]);
|
/* Release the temp buffer */
|
this_cpu_dec(trace_buffered_event_cnt);
|
} else
|
ring_buffer_unlock_commit(buffer, event);
|
}
|
|
/**
|
* __trace_puts - write a constant string into the trace buffer.
|
* @ip: The address of the caller
|
* @str: The constant string to write
|
* @size: The size of the string.
|
*/
|
int __trace_puts(unsigned long ip, const char *str, int size)
|
{
|
struct ring_buffer_event *event;
|
struct trace_buffer *buffer;
|
struct print_entry *entry;
|
unsigned int trace_ctx;
|
int alloc;
|
|
if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
|
return 0;
|
|
if (unlikely(tracing_selftest_running || tracing_disabled))
|
return 0;
|
|
alloc = sizeof(*entry) + size + 2; /* possible \n added */
|
|
trace_ctx = tracing_gen_ctx();
|
buffer = global_trace.array_buffer.buffer;
|
ring_buffer_nest_start(buffer);
|
event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
|
trace_ctx);
|
if (!event) {
|
size = 0;
|
goto out;
|
}
|
|
entry = ring_buffer_event_data(event);
|
entry->ip = ip;
|
|
memcpy(&entry->buf, str, size);
|
|
/* Add a newline if necessary */
|
if (entry->buf[size - 1] != '\n') {
|
entry->buf[size] = '\n';
|
entry->buf[size + 1] = '\0';
|
} else
|
entry->buf[size] = '\0';
|
|
__buffer_unlock_commit(buffer, event);
|
ftrace_trace_stack(&global_trace, buffer, trace_ctx, 4, NULL);
|
out:
|
ring_buffer_nest_end(buffer);
|
return size;
|
}
|
EXPORT_SYMBOL_GPL(__trace_puts);
|
|
/**
|
* __trace_bputs - write the pointer to a constant string into trace buffer
|
* @ip: The address of the caller
|
* @str: The constant string to write to the buffer to
|
*/
|
int __trace_bputs(unsigned long ip, const char *str)
|
{
|
struct ring_buffer_event *event;
|
struct trace_buffer *buffer;
|
struct bputs_entry *entry;
|
unsigned int trace_ctx;
|
int size = sizeof(struct bputs_entry);
|
int ret = 0;
|
|
if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
|
return 0;
|
|
if (unlikely(tracing_selftest_running || tracing_disabled))
|
return 0;
|
|
trace_ctx = tracing_gen_ctx();
|
buffer = global_trace.array_buffer.buffer;
|
|
ring_buffer_nest_start(buffer);
|
event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
|
trace_ctx);
|
if (!event)
|
goto out;
|
|
entry = ring_buffer_event_data(event);
|
entry->ip = ip;
|
entry->str = str;
|
|
__buffer_unlock_commit(buffer, event);
|
ftrace_trace_stack(&global_trace, buffer, trace_ctx, 4, NULL);
|
|
ret = 1;
|
out:
|
ring_buffer_nest_end(buffer);
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(__trace_bputs);
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
static void tracing_snapshot_instance_cond(struct trace_array *tr,
|
void *cond_data)
|
{
|
struct tracer *tracer = tr->current_trace;
|
unsigned long flags;
|
|
if (in_nmi()) {
|
internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n");
|
internal_trace_puts("*** snapshot is being ignored ***\n");
|
return;
|
}
|
|
if (!tr->allocated_snapshot) {
|
internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n");
|
internal_trace_puts("*** stopping trace here! ***\n");
|
tracing_off();
|
return;
|
}
|
|
/* Note, snapshot can not be used when the tracer uses it */
|
if (tracer->use_max_tr) {
|
internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n");
|
internal_trace_puts("*** Can not use snapshot (sorry) ***\n");
|
return;
|
}
|
|
local_irq_save(flags);
|
update_max_tr(tr, current, smp_processor_id(), cond_data);
|
local_irq_restore(flags);
|
}
|
|
void tracing_snapshot_instance(struct trace_array *tr)
|
{
|
tracing_snapshot_instance_cond(tr, NULL);
|
}
|
|
/**
|
* tracing_snapshot - take a snapshot of the current buffer.
|
*
|
* This causes a swap between the snapshot buffer and the current live
|
* tracing buffer. You can use this to take snapshots of the live
|
* trace when some condition is triggered, but continue to trace.
|
*
|
* Note, make sure to allocate the snapshot with either
|
* a tracing_snapshot_alloc(), or by doing it manually
|
* with: echo 1 > /sys/kernel/debug/tracing/snapshot
|
*
|
* If the snapshot buffer is not allocated, it will stop tracing.
|
* Basically making a permanent snapshot.
|
*/
|
void tracing_snapshot(void)
|
{
|
struct trace_array *tr = &global_trace;
|
|
tracing_snapshot_instance(tr);
|
}
|
EXPORT_SYMBOL_GPL(tracing_snapshot);
|
|
/**
|
* tracing_snapshot_cond - conditionally take a snapshot of the current buffer.
|
* @tr: The tracing instance to snapshot
|
* @cond_data: The data to be tested conditionally, and possibly saved
|
*
|
* This is the same as tracing_snapshot() except that the snapshot is
|
* conditional - the snapshot will only happen if the
|
* cond_snapshot.update() implementation receiving the cond_data
|
* returns true, which means that the trace array's cond_snapshot
|
* update() operation used the cond_data to determine whether the
|
* snapshot should be taken, and if it was, presumably saved it along
|
* with the snapshot.
|
*/
|
void tracing_snapshot_cond(struct trace_array *tr, void *cond_data)
|
{
|
tracing_snapshot_instance_cond(tr, cond_data);
|
}
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond);
|
|
/**
|
* tracing_snapshot_cond_data - get the user data associated with a snapshot
|
* @tr: The tracing instance
|
*
|
* When the user enables a conditional snapshot using
|
* tracing_snapshot_cond_enable(), the user-defined cond_data is saved
|
* with the snapshot. This accessor is used to retrieve it.
|
*
|
* Should not be called from cond_snapshot.update(), since it takes
|
* the tr->max_lock lock, which the code calling
|
* cond_snapshot.update() has already done.
|
*
|
* Returns the cond_data associated with the trace array's snapshot.
|
*/
|
void *tracing_cond_snapshot_data(struct trace_array *tr)
|
{
|
void *cond_data = NULL;
|
|
local_irq_disable();
|
arch_spin_lock(&tr->max_lock);
|
|
if (tr->cond_snapshot)
|
cond_data = tr->cond_snapshot->cond_data;
|
|
arch_spin_unlock(&tr->max_lock);
|
local_irq_enable();
|
|
return cond_data;
|
}
|
EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data);
|
|
static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
|
struct array_buffer *size_buf, int cpu_id);
|
static void set_buffer_entries(struct array_buffer *buf, unsigned long val);
|
|
int tracing_alloc_snapshot_instance(struct trace_array *tr)
|
{
|
int ret;
|
|
if (!tr->allocated_snapshot) {
|
|
/* allocate spare buffer */
|
ret = resize_buffer_duplicate_size(&tr->max_buffer,
|
&tr->array_buffer, RING_BUFFER_ALL_CPUS);
|
if (ret < 0)
|
return ret;
|
|
tr->allocated_snapshot = true;
|
}
|
|
return 0;
|
}
|
|
static void free_snapshot(struct trace_array *tr)
|
{
|
/*
|
* We don't free the ring buffer. instead, resize it because
|
* The max_tr ring buffer has some state (e.g. ring->clock) and
|
* we want preserve it.
|
*/
|
ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS);
|
set_buffer_entries(&tr->max_buffer, 1);
|
tracing_reset_online_cpus(&tr->max_buffer);
|
tr->allocated_snapshot = false;
|
}
|
|
/**
|
* tracing_alloc_snapshot - allocate snapshot buffer.
|
*
|
* This only allocates the snapshot buffer if it isn't already
|
* allocated - it doesn't also take a snapshot.
|
*
|
* This is meant to be used in cases where the snapshot buffer needs
|
* to be set up for events that can't sleep but need to be able to
|
* trigger a snapshot.
|
*/
|
int tracing_alloc_snapshot(void)
|
{
|
struct trace_array *tr = &global_trace;
|
int ret;
|
|
ret = tracing_alloc_snapshot_instance(tr);
|
WARN_ON(ret < 0);
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
|
|
/**
|
* tracing_snapshot_alloc - allocate and take a snapshot of the current buffer.
|
*
|
* This is similar to tracing_snapshot(), but it will allocate the
|
* snapshot buffer if it isn't already allocated. Use this only
|
* where it is safe to sleep, as the allocation may sleep.
|
*
|
* This causes a swap between the snapshot buffer and the current live
|
* tracing buffer. You can use this to take snapshots of the live
|
* trace when some condition is triggered, but continue to trace.
|
*/
|
void tracing_snapshot_alloc(void)
|
{
|
int ret;
|
|
ret = tracing_alloc_snapshot();
|
if (ret < 0)
|
return;
|
|
tracing_snapshot();
|
}
|
EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);
|
|
/**
|
* tracing_snapshot_cond_enable - enable conditional snapshot for an instance
|
* @tr: The tracing instance
|
* @cond_data: User data to associate with the snapshot
|
* @update: Implementation of the cond_snapshot update function
|
*
|
* Check whether the conditional snapshot for the given instance has
|
* already been enabled, or if the current tracer is already using a
|
* snapshot; if so, return -EBUSY, else create a cond_snapshot and
|
* save the cond_data and update function inside.
|
*
|
* Returns 0 if successful, error otherwise.
|
*/
|
int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data,
|
cond_update_fn_t update)
|
{
|
struct cond_snapshot *cond_snapshot;
|
int ret = 0;
|
|
cond_snapshot = kzalloc(sizeof(*cond_snapshot), GFP_KERNEL);
|
if (!cond_snapshot)
|
return -ENOMEM;
|
|
cond_snapshot->cond_data = cond_data;
|
cond_snapshot->update = update;
|
|
mutex_lock(&trace_types_lock);
|
|
ret = tracing_alloc_snapshot_instance(tr);
|
if (ret)
|
goto fail_unlock;
|
|
if (tr->current_trace->use_max_tr) {
|
ret = -EBUSY;
|
goto fail_unlock;
|
}
|
|
/*
|
* The cond_snapshot can only change to NULL without the
|
* trace_types_lock. We don't care if we race with it going
|
* to NULL, but we want to make sure that it's not set to
|
* something other than NULL when we get here, which we can
|
* do safely with only holding the trace_types_lock and not
|
* having to take the max_lock.
|
*/
|
if (tr->cond_snapshot) {
|
ret = -EBUSY;
|
goto fail_unlock;
|
}
|
|
local_irq_disable();
|
arch_spin_lock(&tr->max_lock);
|
tr->cond_snapshot = cond_snapshot;
|
arch_spin_unlock(&tr->max_lock);
|
local_irq_enable();
|
|
mutex_unlock(&trace_types_lock);
|
|
return ret;
|
|
fail_unlock:
|
mutex_unlock(&trace_types_lock);
|
kfree(cond_snapshot);
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond_enable);
|
|
/**
|
* tracing_snapshot_cond_disable - disable conditional snapshot for an instance
|
* @tr: The tracing instance
|
*
|
* Check whether the conditional snapshot for the given instance is
|
* enabled; if so, free the cond_snapshot associated with it,
|
* otherwise return -EINVAL.
|
*
|
* Returns 0 if successful, error otherwise.
|
*/
|
int tracing_snapshot_cond_disable(struct trace_array *tr)
|
{
|
int ret = 0;
|
|
local_irq_disable();
|
arch_spin_lock(&tr->max_lock);
|
|
if (!tr->cond_snapshot)
|
ret = -EINVAL;
|
else {
|
kfree(tr->cond_snapshot);
|
tr->cond_snapshot = NULL;
|
}
|
|
arch_spin_unlock(&tr->max_lock);
|
local_irq_enable();
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable);
|
#else
|
void tracing_snapshot(void)
|
{
|
WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used");
|
}
|
EXPORT_SYMBOL_GPL(tracing_snapshot);
|
void tracing_snapshot_cond(struct trace_array *tr, void *cond_data)
|
{
|
WARN_ONCE(1, "Snapshot feature not enabled, but internal conditional snapshot used");
|
}
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond);
|
int tracing_alloc_snapshot(void)
|
{
|
WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used");
|
return -ENODEV;
|
}
|
EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
|
void tracing_snapshot_alloc(void)
|
{
|
/* Give warning */
|
tracing_snapshot();
|
}
|
EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);
|
void *tracing_cond_snapshot_data(struct trace_array *tr)
|
{
|
return NULL;
|
}
|
EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data);
|
int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update)
|
{
|
return -ENODEV;
|
}
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond_enable);
|
int tracing_snapshot_cond_disable(struct trace_array *tr)
|
{
|
return false;
|
}
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable);
|
#endif /* CONFIG_TRACER_SNAPSHOT */
|
|
void tracer_tracing_off(struct trace_array *tr)
|
{
|
if (tr->array_buffer.buffer)
|
ring_buffer_record_off(tr->array_buffer.buffer);
|
/*
|
* This flag is looked at when buffers haven't been allocated
|
* yet, or by some tracers (like irqsoff), that just want to
|
* know if the ring buffer has been disabled, but it can handle
|
* races of where it gets disabled but we still do a record.
|
* As the check is in the fast path of the tracers, it is more
|
* important to be fast than accurate.
|
*/
|
tr->buffer_disabled = 1;
|
/* Make the flag seen by readers */
|
smp_wmb();
|
}
|
|
/**
|
* tracing_off - turn off tracing buffers
|
*
|
* This function stops the tracing buffers from recording data.
|
* It does not disable any overhead the tracers themselves may
|
* be causing. This function simply causes all recording to
|
* the ring buffers to fail.
|
*/
|
void tracing_off(void)
|
{
|
tracer_tracing_off(&global_trace);
|
}
|
EXPORT_SYMBOL_GPL(tracing_off);
|
|
void disable_trace_on_warning(void)
|
{
|
if (__disable_trace_on_warning) {
|
trace_array_printk_buf(global_trace.array_buffer.buffer, _THIS_IP_,
|
"Disabling tracing due to warning\n");
|
tracing_off();
|
}
|
}
|
|
/**
|
* tracer_tracing_is_on - show real state of ring buffer enabled
|
* @tr : the trace array to know if ring buffer is enabled
|
*
|
* Shows real state of the ring buffer if it is enabled or not.
|
*/
|
bool tracer_tracing_is_on(struct trace_array *tr)
|
{
|
if (tr->array_buffer.buffer)
|
return ring_buffer_record_is_on(tr->array_buffer.buffer);
|
return !tr->buffer_disabled;
|
}
|
|
/**
|
* tracing_is_on - show state of ring buffers enabled
|
*/
|
int tracing_is_on(void)
|
{
|
return tracer_tracing_is_on(&global_trace);
|
}
|
EXPORT_SYMBOL_GPL(tracing_is_on);
|
|
static int __init set_buf_size(char *str)
|
{
|
unsigned long buf_size;
|
|
if (!str)
|
return 0;
|
buf_size = memparse(str, &str);
|
/*
|
* nr_entries can not be zero and the startup
|
* tests require some buffer space. Therefore
|
* ensure we have at least 4096 bytes of buffer.
|
*/
|
trace_buf_size = max(4096UL, buf_size);
|
return 1;
|
}
|
__setup("trace_buf_size=", set_buf_size);
|
|
static int __init set_tracing_thresh(char *str)
|
{
|
unsigned long threshold;
|
int ret;
|
|
if (!str)
|
return 0;
|
ret = kstrtoul(str, 0, &threshold);
|
if (ret < 0)
|
return 0;
|
tracing_thresh = threshold * 1000;
|
return 1;
|
}
|
__setup("tracing_thresh=", set_tracing_thresh);
|
|
unsigned long nsecs_to_usecs(unsigned long nsecs)
|
{
|
return nsecs / 1000;
|
}
|
|
/*
|
* TRACE_FLAGS is defined as a tuple matching bit masks with strings.
|
* It uses C(a, b) where 'a' is the eval (enum) name and 'b' is the string that
|
* matches it. By defining "C(a, b) b", TRACE_FLAGS becomes a list
|
* of strings in the order that the evals (enum) were defined.
|
*/
|
#undef C
|
#define C(a, b) b
|
|
/* These must match the bit postions in trace_iterator_flags */
|
static const char *trace_options[] = {
|
TRACE_FLAGS
|
NULL
|
};
|
|
static struct {
|
u64 (*func)(void);
|
const char *name;
|
int in_ns; /* is this clock in nanoseconds? */
|
} trace_clocks[] = {
|
{ trace_clock_local, "local", 1 },
|
{ trace_clock_global, "global", 1 },
|
{ trace_clock_counter, "counter", 0 },
|
{ trace_clock_jiffies, "uptime", 0 },
|
{ trace_clock, "perf", 1 },
|
{ ktime_get_mono_fast_ns, "mono", 1 },
|
{ ktime_get_raw_fast_ns, "mono_raw", 1 },
|
{ ktime_get_boot_fast_ns, "boot", 1 },
|
ARCH_TRACE_CLOCKS
|
};
|
|
bool trace_clock_in_ns(struct trace_array *tr)
|
{
|
if (trace_clocks[tr->clock_id].in_ns)
|
return true;
|
|
return false;
|
}
|
|
/*
|
* trace_parser_get_init - gets the buffer for trace parser
|
*/
|
int trace_parser_get_init(struct trace_parser *parser, int size)
|
{
|
memset(parser, 0, sizeof(*parser));
|
|
parser->buffer = kmalloc(size, GFP_KERNEL);
|
if (!parser->buffer)
|
return 1;
|
|
parser->size = size;
|
return 0;
|
}
|
|
/*
|
* trace_parser_put - frees the buffer for trace parser
|
*/
|
void trace_parser_put(struct trace_parser *parser)
|
{
|
kfree(parser->buffer);
|
parser->buffer = NULL;
|
}
|
|
/*
|
* trace_get_user - reads the user input string separated by space
|
* (matched by isspace(ch))
|
*
|
* For each string found the 'struct trace_parser' is updated,
|
* and the function returns.
|
*
|
* Returns number of bytes read.
|
*
|
* See kernel/trace/trace.h for 'struct trace_parser' details.
|
*/
|
int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
char ch;
|
size_t read = 0;
|
ssize_t ret;
|
|
if (!*ppos)
|
trace_parser_clear(parser);
|
|
ret = get_user(ch, ubuf++);
|
if (ret)
|
goto out;
|
|
read++;
|
cnt--;
|
|
/*
|
* The parser is not finished with the last write,
|
* continue reading the user input without skipping spaces.
|
*/
|
if (!parser->cont) {
|
/* skip white space */
|
while (cnt && isspace(ch)) {
|
ret = get_user(ch, ubuf++);
|
if (ret)
|
goto out;
|
read++;
|
cnt--;
|
}
|
|
parser->idx = 0;
|
|
/* only spaces were written */
|
if (isspace(ch) || !ch) {
|
*ppos += read;
|
ret = read;
|
goto out;
|
}
|
}
|
|
/* read the non-space input */
|
while (cnt && !isspace(ch) && ch) {
|
if (parser->idx < parser->size - 1)
|
parser->buffer[parser->idx++] = ch;
|
else {
|
ret = -EINVAL;
|
goto out;
|
}
|
ret = get_user(ch, ubuf++);
|
if (ret)
|
goto out;
|
read++;
|
cnt--;
|
}
|
|
/* We either got finished input or we have to wait for another call. */
|
if (isspace(ch) || !ch) {
|
parser->buffer[parser->idx] = 0;
|
parser->cont = false;
|
} else if (parser->idx < parser->size - 1) {
|
parser->cont = true;
|
parser->buffer[parser->idx++] = ch;
|
/* Make sure the parsed string always terminates with '\0'. */
|
parser->buffer[parser->idx] = 0;
|
} else {
|
ret = -EINVAL;
|
goto out;
|
}
|
|
*ppos += read;
|
ret = read;
|
|
out:
|
return ret;
|
}
|
|
/* TODO add a seq_buf_to_buffer() */
|
static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
|
{
|
int len;
|
|
if (trace_seq_used(s) <= s->seq.readpos)
|
return -EBUSY;
|
|
len = trace_seq_used(s) - s->seq.readpos;
|
if (cnt > len)
|
cnt = len;
|
memcpy(buf, s->buffer + s->seq.readpos, cnt);
|
|
s->seq.readpos += cnt;
|
return cnt;
|
}
|
|
unsigned long __read_mostly tracing_thresh;
|
static const struct file_operations tracing_max_lat_fops;
|
|
#if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
|
defined(CONFIG_FSNOTIFY)
|
|
static struct workqueue_struct *fsnotify_wq;
|
|
static void latency_fsnotify_workfn(struct work_struct *work)
|
{
|
struct trace_array *tr = container_of(work, struct trace_array,
|
fsnotify_work);
|
fsnotify_inode(tr->d_max_latency->d_inode, FS_MODIFY);
|
}
|
|
static void latency_fsnotify_workfn_irq(struct irq_work *iwork)
|
{
|
struct trace_array *tr = container_of(iwork, struct trace_array,
|
fsnotify_irqwork);
|
queue_work(fsnotify_wq, &tr->fsnotify_work);
|
}
|
|
static void trace_create_maxlat_file(struct trace_array *tr,
|
struct dentry *d_tracer)
|
{
|
INIT_WORK(&tr->fsnotify_work, latency_fsnotify_workfn);
|
init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq);
|
tr->d_max_latency = trace_create_file("tracing_max_latency", 0644,
|
d_tracer, &tr->max_latency,
|
&tracing_max_lat_fops);
|
}
|
|
__init static int latency_fsnotify_init(void)
|
{
|
fsnotify_wq = alloc_workqueue("tr_max_lat_wq",
|
WQ_UNBOUND | WQ_HIGHPRI, 0);
|
if (!fsnotify_wq) {
|
pr_err("Unable to allocate tr_max_lat_wq\n");
|
return -ENOMEM;
|
}
|
return 0;
|
}
|
|
late_initcall_sync(latency_fsnotify_init);
|
|
void latency_fsnotify(struct trace_array *tr)
|
{
|
if (!fsnotify_wq)
|
return;
|
/*
|
* We cannot call queue_work(&tr->fsnotify_work) from here because it's
|
* possible that we are called from __schedule() or do_idle(), which
|
* could cause a deadlock.
|
*/
|
irq_work_queue(&tr->fsnotify_irqwork);
|
}
|
|
/*
|
* (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \
|
* defined(CONFIG_FSNOTIFY)
|
*/
|
#else
|
|
#define trace_create_maxlat_file(tr, d_tracer) \
|
trace_create_file("tracing_max_latency", 0644, d_tracer, \
|
&tr->max_latency, &tracing_max_lat_fops)
|
|
#endif
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
/*
|
* Copy the new maximum trace into the separate maximum-trace
|
* structure. (this way the maximum trace is permanently saved,
|
* for later retrieval via /sys/kernel/tracing/tracing_max_latency)
|
*/
|
static void
|
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
|
{
|
struct array_buffer *trace_buf = &tr->array_buffer;
|
struct array_buffer *max_buf = &tr->max_buffer;
|
struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu);
|
struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu);
|
|
max_buf->cpu = cpu;
|
max_buf->time_start = data->preempt_timestamp;
|
|
max_data->saved_latency = tr->max_latency;
|
max_data->critical_start = data->critical_start;
|
max_data->critical_end = data->critical_end;
|
|
strncpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
|
max_data->pid = tsk->pid;
|
/*
|
* If tsk == current, then use current_uid(), as that does not use
|
* RCU. The irq tracer can be called out of RCU scope.
|
*/
|
if (tsk == current)
|
max_data->uid = current_uid();
|
else
|
max_data->uid = task_uid(tsk);
|
|
max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
|
max_data->policy = tsk->policy;
|
max_data->rt_priority = tsk->rt_priority;
|
|
/* record this tasks comm */
|
tracing_record_cmdline(tsk);
|
latency_fsnotify(tr);
|
}
|
|
/**
|
* update_max_tr - snapshot all trace buffers from global_trace to max_tr
|
* @tr: tracer
|
* @tsk: the task with the latency
|
* @cpu: The cpu that initiated the trace.
|
* @cond_data: User data associated with a conditional snapshot
|
*
|
* Flip the buffers between the @tr and the max_tr and record information
|
* about which task was the cause of this latency.
|
*/
|
void
|
update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
|
void *cond_data)
|
{
|
if (tr->stop_count)
|
return;
|
|
WARN_ON_ONCE(!irqs_disabled());
|
|
if (!tr->allocated_snapshot) {
|
/* Only the nop tracer should hit this when disabling */
|
WARN_ON_ONCE(tr->current_trace != &nop_trace);
|
return;
|
}
|
|
arch_spin_lock(&tr->max_lock);
|
|
/* Inherit the recordable setting from array_buffer */
|
if (ring_buffer_record_is_set_on(tr->array_buffer.buffer))
|
ring_buffer_record_on(tr->max_buffer.buffer);
|
else
|
ring_buffer_record_off(tr->max_buffer.buffer);
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data))
|
goto out_unlock;
|
#endif
|
swap(tr->array_buffer.buffer, tr->max_buffer.buffer);
|
|
__update_max_tr(tr, tsk, cpu);
|
|
out_unlock:
|
arch_spin_unlock(&tr->max_lock);
|
}
|
|
/**
|
* update_max_tr_single - only copy one trace over, and reset the rest
|
* @tr: tracer
|
* @tsk: task with the latency
|
* @cpu: the cpu of the buffer to copy.
|
*
|
* Flip the trace of a single CPU buffer between the @tr and the max_tr.
|
*/
|
void
|
update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
|
{
|
int ret;
|
|
if (tr->stop_count)
|
return;
|
|
WARN_ON_ONCE(!irqs_disabled());
|
if (!tr->allocated_snapshot) {
|
/* Only the nop tracer should hit this when disabling */
|
WARN_ON_ONCE(tr->current_trace != &nop_trace);
|
return;
|
}
|
|
arch_spin_lock(&tr->max_lock);
|
|
ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->array_buffer.buffer, cpu);
|
|
if (ret == -EBUSY) {
|
/*
|
* We failed to swap the buffer due to a commit taking
|
* place on this CPU. We fail to record, but we reset
|
* the max trace buffer (no one writes directly to it)
|
* and flag that it failed.
|
*/
|
trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_,
|
"Failed to swap buffers due to commit in progress\n");
|
}
|
|
WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY);
|
|
__update_max_tr(tr, tsk, cpu);
|
arch_spin_unlock(&tr->max_lock);
|
}
|
#endif /* CONFIG_TRACER_MAX_TRACE */
|
|
static int wait_on_pipe(struct trace_iterator *iter, int full)
|
{
|
/* Iterators are static, they should be filled or empty */
|
if (trace_buffer_iter(iter, iter->cpu_file))
|
return 0;
|
|
return ring_buffer_wait(iter->array_buffer->buffer, iter->cpu_file,
|
full);
|
}
|
|
#ifdef CONFIG_FTRACE_STARTUP_TEST
|
static bool selftests_can_run;
|
|
struct trace_selftests {
|
struct list_head list;
|
struct tracer *type;
|
};
|
|
static LIST_HEAD(postponed_selftests);
|
|
static int save_selftest(struct tracer *type)
|
{
|
struct trace_selftests *selftest;
|
|
selftest = kmalloc(sizeof(*selftest), GFP_KERNEL);
|
if (!selftest)
|
return -ENOMEM;
|
|
selftest->type = type;
|
list_add(&selftest->list, &postponed_selftests);
|
return 0;
|
}
|
|
static int run_tracer_selftest(struct tracer *type)
|
{
|
struct trace_array *tr = &global_trace;
|
struct tracer *saved_tracer = tr->current_trace;
|
int ret;
|
|
if (!type->selftest || tracing_selftest_disabled)
|
return 0;
|
|
/*
|
* If a tracer registers early in boot up (before scheduling is
|
* initialized and such), then do not run its selftests yet.
|
* Instead, run it a little later in the boot process.
|
*/
|
if (!selftests_can_run)
|
return save_selftest(type);
|
|
/*
|
* Run a selftest on this tracer.
|
* Here we reset the trace buffer, and set the current
|
* tracer to be this tracer. The tracer can then run some
|
* internal tracing to verify that everything is in order.
|
* If we fail, we do not register this tracer.
|
*/
|
tracing_reset_online_cpus(&tr->array_buffer);
|
|
tr->current_trace = type;
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
if (type->use_max_tr) {
|
/* If we expanded the buffers, make sure the max is expanded too */
|
if (ring_buffer_expanded)
|
ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size,
|
RING_BUFFER_ALL_CPUS);
|
tr->allocated_snapshot = true;
|
}
|
#endif
|
|
/* the test is responsible for initializing and enabling */
|
pr_info("Testing tracer %s: ", type->name);
|
ret = type->selftest(type, tr);
|
/* the test is responsible for resetting too */
|
tr->current_trace = saved_tracer;
|
if (ret) {
|
printk(KERN_CONT "FAILED!\n");
|
/* Add the warning after printing 'FAILED' */
|
WARN_ON(1);
|
return -1;
|
}
|
/* Only reset on passing, to avoid touching corrupted buffers */
|
tracing_reset_online_cpus(&tr->array_buffer);
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
if (type->use_max_tr) {
|
tr->allocated_snapshot = false;
|
|
/* Shrink the max buffer again */
|
if (ring_buffer_expanded)
|
ring_buffer_resize(tr->max_buffer.buffer, 1,
|
RING_BUFFER_ALL_CPUS);
|
}
|
#endif
|
|
printk(KERN_CONT "PASSED\n");
|
return 0;
|
}
|
|
static __init int init_trace_selftests(void)
|
{
|
struct trace_selftests *p, *n;
|
struct tracer *t, **last;
|
int ret;
|
|
selftests_can_run = true;
|
|
mutex_lock(&trace_types_lock);
|
|
if (list_empty(&postponed_selftests))
|
goto out;
|
|
pr_info("Running postponed tracer tests:\n");
|
|
tracing_selftest_running = true;
|
list_for_each_entry_safe(p, n, &postponed_selftests, list) {
|
/* This loop can take minutes when sanitizers are enabled, so
|
* lets make sure we allow RCU processing.
|
*/
|
cond_resched();
|
ret = run_tracer_selftest(p->type);
|
/* If the test fails, then warn and remove from available_tracers */
|
if (ret < 0) {
|
WARN(1, "tracer: %s failed selftest, disabling\n",
|
p->type->name);
|
last = &trace_types;
|
for (t = trace_types; t; t = t->next) {
|
if (t == p->type) {
|
*last = t->next;
|
break;
|
}
|
last = &t->next;
|
}
|
}
|
list_del(&p->list);
|
kfree(p);
|
}
|
tracing_selftest_running = false;
|
|
out:
|
mutex_unlock(&trace_types_lock);
|
|
return 0;
|
}
|
core_initcall(init_trace_selftests);
|
#else
|
static inline int run_tracer_selftest(struct tracer *type)
|
{
|
return 0;
|
}
|
#endif /* CONFIG_FTRACE_STARTUP_TEST */
|
|
static void add_tracer_options(struct trace_array *tr, struct tracer *t);
|
|
static void __init apply_trace_boot_options(void);
|
|
/**
|
* register_tracer - register a tracer with the ftrace system.
|
* @type: the plugin for the tracer
|
*
|
* Register a new plugin tracer.
|
*/
|
int __init register_tracer(struct tracer *type)
|
{
|
struct tracer *t;
|
int ret = 0;
|
|
if (!type->name) {
|
pr_info("Tracer must have a name\n");
|
return -1;
|
}
|
|
if (strlen(type->name) >= MAX_TRACER_SIZE) {
|
pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);
|
return -1;
|
}
|
|
if (security_locked_down(LOCKDOWN_TRACEFS)) {
|
pr_warn("Can not register tracer %s due to lockdown\n",
|
type->name);
|
return -EPERM;
|
}
|
|
mutex_lock(&trace_types_lock);
|
|
tracing_selftest_running = true;
|
|
for (t = trace_types; t; t = t->next) {
|
if (strcmp(type->name, t->name) == 0) {
|
/* already found */
|
pr_info("Tracer %s already registered\n",
|
type->name);
|
ret = -1;
|
goto out;
|
}
|
}
|
|
if (!type->set_flag)
|
type->set_flag = &dummy_set_flag;
|
if (!type->flags) {
|
/*allocate a dummy tracer_flags*/
|
type->flags = kmalloc(sizeof(*type->flags), GFP_KERNEL);
|
if (!type->flags) {
|
ret = -ENOMEM;
|
goto out;
|
}
|
type->flags->val = 0;
|
type->flags->opts = dummy_tracer_opt;
|
} else
|
if (!type->flags->opts)
|
type->flags->opts = dummy_tracer_opt;
|
|
/* store the tracer for __set_tracer_option */
|
type->flags->trace = type;
|
|
ret = run_tracer_selftest(type);
|
if (ret < 0)
|
goto out;
|
|
type->next = trace_types;
|
trace_types = type;
|
add_tracer_options(&global_trace, type);
|
|
out:
|
tracing_selftest_running = false;
|
mutex_unlock(&trace_types_lock);
|
|
if (ret || !default_bootup_tracer)
|
goto out_unlock;
|
|
if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
|
goto out_unlock;
|
|
printk(KERN_INFO "Starting tracer '%s'\n", type->name);
|
/* Do we want this tracer to start on bootup? */
|
tracing_set_tracer(&global_trace, type->name);
|
default_bootup_tracer = NULL;
|
|
apply_trace_boot_options();
|
|
/* disable other selftests, since this will break it. */
|
disable_tracing_selftest("running a tracer");
|
|
out_unlock:
|
return ret;
|
}
|
|
static void tracing_reset_cpu(struct array_buffer *buf, int cpu)
|
{
|
struct trace_buffer *buffer = buf->buffer;
|
|
if (!buffer)
|
return;
|
|
ring_buffer_record_disable(buffer);
|
|
/* Make sure all commits have finished */
|
synchronize_rcu();
|
ring_buffer_reset_cpu(buffer, cpu);
|
|
ring_buffer_record_enable(buffer);
|
}
|
|
void tracing_reset_online_cpus(struct array_buffer *buf)
|
{
|
struct trace_buffer *buffer = buf->buffer;
|
|
if (!buffer)
|
return;
|
|
ring_buffer_record_disable(buffer);
|
|
/* Make sure all commits have finished */
|
synchronize_rcu();
|
|
buf->time_start = buffer_ftrace_now(buf, buf->cpu);
|
|
ring_buffer_reset_online_cpus(buffer);
|
|
ring_buffer_record_enable(buffer);
|
}
|
|
/* Must have trace_types_lock held */
|
void tracing_reset_all_online_cpus(void)
|
{
|
struct trace_array *tr;
|
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
|
if (!tr->clear_trace)
|
continue;
|
tr->clear_trace = false;
|
tracing_reset_online_cpus(&tr->array_buffer);
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
tracing_reset_online_cpus(&tr->max_buffer);
|
#endif
|
}
|
}
|
|
/*
|
* The tgid_map array maps from pid to tgid; i.e. the value stored at index i
|
* is the tgid last observed corresponding to pid=i.
|
*/
|
static int *tgid_map;
|
|
/* The maximum valid index into tgid_map. */
|
static size_t tgid_map_max;
|
|
#define SAVED_CMDLINES_DEFAULT 128
|
#define NO_CMDLINE_MAP UINT_MAX
|
/*
|
* Preemption must be disabled before acquiring trace_cmdline_lock.
|
* The various trace_arrays' max_lock must be acquired in a context
|
* where interrupt is disabled.
|
*/
|
static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
|
struct saved_cmdlines_buffer {
|
unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
|
unsigned *map_cmdline_to_pid;
|
unsigned cmdline_num;
|
int cmdline_idx;
|
char *saved_cmdlines;
|
};
|
static struct saved_cmdlines_buffer *savedcmd;
|
|
static inline char *get_saved_cmdlines(int idx)
|
{
|
return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN];
|
}
|
|
static inline void set_cmdline(int idx, const char *cmdline)
|
{
|
strncpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
|
}
|
|
static int allocate_cmdlines_buffer(unsigned int val,
|
struct saved_cmdlines_buffer *s)
|
{
|
s->map_cmdline_to_pid = kmalloc_array(val,
|
sizeof(*s->map_cmdline_to_pid),
|
GFP_KERNEL);
|
if (!s->map_cmdline_to_pid)
|
return -ENOMEM;
|
|
s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);
|
if (!s->saved_cmdlines) {
|
kfree(s->map_cmdline_to_pid);
|
return -ENOMEM;
|
}
|
|
s->cmdline_idx = 0;
|
s->cmdline_num = val;
|
memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP,
|
sizeof(s->map_pid_to_cmdline));
|
memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP,
|
val * sizeof(*s->map_cmdline_to_pid));
|
|
return 0;
|
}
|
|
static int trace_create_savedcmd(void)
|
{
|
int ret;
|
|
savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL);
|
if (!savedcmd)
|
return -ENOMEM;
|
|
ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd);
|
if (ret < 0) {
|
kfree(savedcmd);
|
savedcmd = NULL;
|
return -ENOMEM;
|
}
|
|
return 0;
|
}
|
|
int is_tracing_stopped(void)
|
{
|
return global_trace.stop_count;
|
}
|
|
/**
|
* tracing_start - quick start of the tracer
|
*
|
* If tracing is enabled but was stopped by tracing_stop,
|
* this will start the tracer back up.
|
*/
|
void tracing_start(void)
|
{
|
struct trace_buffer *buffer;
|
unsigned long flags;
|
|
if (tracing_disabled)
|
return;
|
|
raw_spin_lock_irqsave(&global_trace.start_lock, flags);
|
if (--global_trace.stop_count) {
|
if (global_trace.stop_count < 0) {
|
/* Someone screwed up their debugging */
|
WARN_ON_ONCE(1);
|
global_trace.stop_count = 0;
|
}
|
goto out;
|
}
|
|
/* Prevent the buffers from switching */
|
arch_spin_lock(&global_trace.max_lock);
|
|
buffer = global_trace.array_buffer.buffer;
|
if (buffer)
|
ring_buffer_record_enable(buffer);
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
buffer = global_trace.max_buffer.buffer;
|
if (buffer)
|
ring_buffer_record_enable(buffer);
|
#endif
|
|
arch_spin_unlock(&global_trace.max_lock);
|
|
out:
|
raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
|
}
|
|
static void tracing_start_tr(struct trace_array *tr)
|
{
|
struct trace_buffer *buffer;
|
unsigned long flags;
|
|
if (tracing_disabled)
|
return;
|
|
/* If global, we need to also start the max tracer */
|
if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
|
return tracing_start();
|
|
raw_spin_lock_irqsave(&tr->start_lock, flags);
|
|
if (--tr->stop_count) {
|
if (tr->stop_count < 0) {
|
/* Someone screwed up their debugging */
|
WARN_ON_ONCE(1);
|
tr->stop_count = 0;
|
}
|
goto out;
|
}
|
|
buffer = tr->array_buffer.buffer;
|
if (buffer)
|
ring_buffer_record_enable(buffer);
|
|
out:
|
raw_spin_unlock_irqrestore(&tr->start_lock, flags);
|
}
|
|
/**
|
* tracing_stop - quick stop of the tracer
|
*
|
* Light weight way to stop tracing. Use in conjunction with
|
* tracing_start.
|
*/
|
void tracing_stop(void)
|
{
|
struct trace_buffer *buffer;
|
unsigned long flags;
|
|
raw_spin_lock_irqsave(&global_trace.start_lock, flags);
|
if (global_trace.stop_count++)
|
goto out;
|
|
/* Prevent the buffers from switching */
|
arch_spin_lock(&global_trace.max_lock);
|
|
buffer = global_trace.array_buffer.buffer;
|
if (buffer)
|
ring_buffer_record_disable(buffer);
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
buffer = global_trace.max_buffer.buffer;
|
if (buffer)
|
ring_buffer_record_disable(buffer);
|
#endif
|
|
arch_spin_unlock(&global_trace.max_lock);
|
|
out:
|
raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
|
}
|
|
static void tracing_stop_tr(struct trace_array *tr)
|
{
|
struct trace_buffer *buffer;
|
unsigned long flags;
|
|
/* If global, we need to also stop the max tracer */
|
if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
|
return tracing_stop();
|
|
raw_spin_lock_irqsave(&tr->start_lock, flags);
|
if (tr->stop_count++)
|
goto out;
|
|
buffer = tr->array_buffer.buffer;
|
if (buffer)
|
ring_buffer_record_disable(buffer);
|
|
out:
|
raw_spin_unlock_irqrestore(&tr->start_lock, flags);
|
}
|
|
static int trace_save_cmdline(struct task_struct *tsk)
|
{
|
unsigned tpid, idx;
|
|
/* treat recording of idle task as a success */
|
if (!tsk->pid)
|
return 1;
|
|
tpid = tsk->pid & (PID_MAX_DEFAULT - 1);
|
|
/*
|
* It's not the end of the world if we don't get
|
* the lock, but we also don't want to spin
|
* nor do we want to disable interrupts,
|
* so if we miss here, then better luck next time.
|
*
|
* This is called within the scheduler and wake up, so interrupts
|
* had better been disabled and run queue lock been held.
|
*/
|
lockdep_assert_preemption_disabled();
|
if (!arch_spin_trylock(&trace_cmdline_lock))
|
return 0;
|
|
idx = savedcmd->map_pid_to_cmdline[tpid];
|
if (idx == NO_CMDLINE_MAP) {
|
idx = (savedcmd->cmdline_idx + 1) % savedcmd->cmdline_num;
|
|
savedcmd->map_pid_to_cmdline[tpid] = idx;
|
savedcmd->cmdline_idx = idx;
|
}
|
|
savedcmd->map_cmdline_to_pid[idx] = tsk->pid;
|
set_cmdline(idx, tsk->comm);
|
|
arch_spin_unlock(&trace_cmdline_lock);
|
|
return 1;
|
}
|
|
static void __trace_find_cmdline(int pid, char comm[])
|
{
|
unsigned map;
|
int tpid;
|
|
if (!pid) {
|
strcpy(comm, "<idle>");
|
return;
|
}
|
|
if (WARN_ON_ONCE(pid < 0)) {
|
strcpy(comm, "<XXX>");
|
return;
|
}
|
|
tpid = pid & (PID_MAX_DEFAULT - 1);
|
map = savedcmd->map_pid_to_cmdline[tpid];
|
if (map != NO_CMDLINE_MAP) {
|
tpid = savedcmd->map_cmdline_to_pid[map];
|
if (tpid == pid) {
|
strlcpy(comm, get_saved_cmdlines(map), TASK_COMM_LEN);
|
return;
|
}
|
}
|
strcpy(comm, "<...>");
|
}
|
|
void trace_find_cmdline(int pid, char comm[])
|
{
|
preempt_disable();
|
arch_spin_lock(&trace_cmdline_lock);
|
|
__trace_find_cmdline(pid, comm);
|
|
arch_spin_unlock(&trace_cmdline_lock);
|
preempt_enable();
|
}
|
|
static int *trace_find_tgid_ptr(int pid)
|
{
|
/*
|
* Pairs with the smp_store_release in set_tracer_flag() to ensure that
|
* if we observe a non-NULL tgid_map then we also observe the correct
|
* tgid_map_max.
|
*/
|
int *map = smp_load_acquire(&tgid_map);
|
|
if (unlikely(!map || pid > tgid_map_max))
|
return NULL;
|
|
return &map[pid];
|
}
|
|
int trace_find_tgid(int pid)
|
{
|
int *ptr = trace_find_tgid_ptr(pid);
|
|
return ptr ? *ptr : 0;
|
}
|
|
static int trace_save_tgid(struct task_struct *tsk)
|
{
|
int *ptr;
|
|
/* treat recording of idle task as a success */
|
if (!tsk->pid)
|
return 1;
|
|
ptr = trace_find_tgid_ptr(tsk->pid);
|
if (!ptr)
|
return 0;
|
|
*ptr = tsk->tgid;
|
return 1;
|
}
|
|
static bool tracing_record_taskinfo_skip(int flags)
|
{
|
if (unlikely(!(flags & (TRACE_RECORD_CMDLINE | TRACE_RECORD_TGID))))
|
return true;
|
if (!__this_cpu_read(trace_taskinfo_save))
|
return true;
|
return false;
|
}
|
|
/**
|
* tracing_record_taskinfo - record the task info of a task
|
*
|
* @task: task to record
|
* @flags: TRACE_RECORD_CMDLINE for recording comm
|
* TRACE_RECORD_TGID for recording tgid
|
*/
|
void tracing_record_taskinfo(struct task_struct *task, int flags)
|
{
|
bool done;
|
|
if (tracing_record_taskinfo_skip(flags))
|
return;
|
|
/*
|
* Record as much task information as possible. If some fail, continue
|
* to try to record the others.
|
*/
|
done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(task);
|
done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(task);
|
|
/* If recording any information failed, retry again soon. */
|
if (!done)
|
return;
|
|
__this_cpu_write(trace_taskinfo_save, false);
|
}
|
|
/**
|
* tracing_record_taskinfo_sched_switch - record task info for sched_switch
|
*
|
* @prev: previous task during sched_switch
|
* @next: next task during sched_switch
|
* @flags: TRACE_RECORD_CMDLINE for recording comm
|
* TRACE_RECORD_TGID for recording tgid
|
*/
|
void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
|
struct task_struct *next, int flags)
|
{
|
bool done;
|
|
if (tracing_record_taskinfo_skip(flags))
|
return;
|
|
/*
|
* Record as much task information as possible. If some fail, continue
|
* to try to record the others.
|
*/
|
done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(prev);
|
done &= !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(next);
|
done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(prev);
|
done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(next);
|
|
/* If recording any information failed, retry again soon. */
|
if (!done)
|
return;
|
|
__this_cpu_write(trace_taskinfo_save, false);
|
}
|
|
/* Helpers to record a specific task information */
|
void tracing_record_cmdline(struct task_struct *task)
|
{
|
tracing_record_taskinfo(task, TRACE_RECORD_CMDLINE);
|
}
|
|
void tracing_record_tgid(struct task_struct *task)
|
{
|
tracing_record_taskinfo(task, TRACE_RECORD_TGID);
|
}
|
|
/*
|
* Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq
|
* overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function
|
* simplifies those functions and keeps them in sync.
|
*/
|
enum print_line_t trace_handle_return(struct trace_seq *s)
|
{
|
return trace_seq_has_overflowed(s) ?
|
TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
|
}
|
EXPORT_SYMBOL_GPL(trace_handle_return);
|
|
static unsigned short migration_disable_value(void)
|
{
|
#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT)
|
return current->migration_disabled;
|
#else
|
return 0;
|
#endif
|
}
|
|
unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status)
|
{
|
unsigned int trace_flags = irqs_status;
|
unsigned int pc;
|
|
pc = preempt_count();
|
|
if (pc & NMI_MASK)
|
trace_flags |= TRACE_FLAG_NMI;
|
if (pc & HARDIRQ_MASK)
|
trace_flags |= TRACE_FLAG_HARDIRQ;
|
if (in_serving_softirq())
|
trace_flags |= TRACE_FLAG_SOFTIRQ;
|
|
if (tif_need_resched())
|
trace_flags |= TRACE_FLAG_NEED_RESCHED;
|
if (test_preempt_need_resched())
|
trace_flags |= TRACE_FLAG_PREEMPT_RESCHED;
|
|
#ifdef CONFIG_PREEMPT_LAZY
|
if (need_resched_lazy())
|
trace_flags |= TRACE_FLAG_NEED_RESCHED_LAZY;
|
#endif
|
|
return (pc & 0xff) |
|
(migration_disable_value() & 0xff) << 8 |
|
(preempt_lazy_count() & 0xff) << 16 |
|
(trace_flags << 24);
|
}
|
|
struct ring_buffer_event *
|
trace_buffer_lock_reserve(struct trace_buffer *buffer,
|
int type,
|
unsigned long len,
|
unsigned int trace_ctx)
|
{
|
return __trace_buffer_lock_reserve(buffer, type, len, trace_ctx);
|
}
|
|
DEFINE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
|
DEFINE_PER_CPU(int, trace_buffered_event_cnt);
|
static int trace_buffered_event_ref;
|
|
/**
|
* trace_buffered_event_enable - enable buffering events
|
*
|
* When events are being filtered, it is quicker to use a temporary
|
* buffer to write the event data into if there's a likely chance
|
* that it will not be committed. The discard of the ring buffer
|
* is not as fast as committing, and is much slower than copying
|
* a commit.
|
*
|
* When an event is to be filtered, allocate per cpu buffers to
|
* write the event data into, and if the event is filtered and discarded
|
* it is simply dropped, otherwise, the entire data is to be committed
|
* in one shot.
|
*/
|
void trace_buffered_event_enable(void)
|
{
|
struct ring_buffer_event *event;
|
struct page *page;
|
int cpu;
|
|
WARN_ON_ONCE(!mutex_is_locked(&event_mutex));
|
|
if (trace_buffered_event_ref++)
|
return;
|
|
for_each_tracing_cpu(cpu) {
|
page = alloc_pages_node(cpu_to_node(cpu),
|
GFP_KERNEL | __GFP_NORETRY, 0);
|
if (!page)
|
goto failed;
|
|
event = page_address(page);
|
memset(event, 0, sizeof(*event));
|
|
per_cpu(trace_buffered_event, cpu) = event;
|
|
preempt_disable();
|
if (cpu == smp_processor_id() &&
|
__this_cpu_read(trace_buffered_event) !=
|
per_cpu(trace_buffered_event, cpu))
|
WARN_ON_ONCE(1);
|
preempt_enable();
|
}
|
|
return;
|
failed:
|
trace_buffered_event_disable();
|
}
|
|
static void enable_trace_buffered_event(void *data)
|
{
|
/* Probably not needed, but do it anyway */
|
smp_rmb();
|
this_cpu_dec(trace_buffered_event_cnt);
|
}
|
|
static void disable_trace_buffered_event(void *data)
|
{
|
this_cpu_inc(trace_buffered_event_cnt);
|
}
|
|
/**
|
* trace_buffered_event_disable - disable buffering events
|
*
|
* When a filter is removed, it is faster to not use the buffered
|
* events, and to commit directly into the ring buffer. Free up
|
* the temp buffers when there are no more users. This requires
|
* special synchronization with current events.
|
*/
|
void trace_buffered_event_disable(void)
|
{
|
int cpu;
|
|
WARN_ON_ONCE(!mutex_is_locked(&event_mutex));
|
|
if (WARN_ON_ONCE(!trace_buffered_event_ref))
|
return;
|
|
if (--trace_buffered_event_ref)
|
return;
|
|
preempt_disable();
|
/* For each CPU, set the buffer as used. */
|
smp_call_function_many(tracing_buffer_mask,
|
disable_trace_buffered_event, NULL, 1);
|
preempt_enable();
|
|
/* Wait for all current users to finish */
|
synchronize_rcu();
|
|
for_each_tracing_cpu(cpu) {
|
free_page((unsigned long)per_cpu(trace_buffered_event, cpu));
|
per_cpu(trace_buffered_event, cpu) = NULL;
|
}
|
/*
|
* Make sure trace_buffered_event is NULL before clearing
|
* trace_buffered_event_cnt.
|
*/
|
smp_wmb();
|
|
preempt_disable();
|
/* Do the work on each cpu */
|
smp_call_function_many(tracing_buffer_mask,
|
enable_trace_buffered_event, NULL, 1);
|
preempt_enable();
|
}
|
|
static struct trace_buffer *temp_buffer;
|
|
struct ring_buffer_event *
|
trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
|
struct trace_event_file *trace_file,
|
int type, unsigned long len,
|
unsigned int trace_ctx)
|
{
|
struct ring_buffer_event *entry;
|
int val;
|
|
*current_rb = trace_file->tr->array_buffer.buffer;
|
|
if (!ring_buffer_time_stamp_abs(*current_rb) && (trace_file->flags &
|
(EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
|
(entry = this_cpu_read(trace_buffered_event))) {
|
/* Try to use the per cpu buffer first */
|
val = this_cpu_inc_return(trace_buffered_event_cnt);
|
if ((len < (PAGE_SIZE - sizeof(*entry) - sizeof(entry->array[0]))) && val == 1) {
|
trace_event_setup(entry, type, trace_ctx);
|
entry->array[0] = len;
|
return entry;
|
}
|
this_cpu_dec(trace_buffered_event_cnt);
|
}
|
|
entry = __trace_buffer_lock_reserve(*current_rb,
|
type, len, trace_ctx);
|
/*
|
* If tracing is off, but we have triggers enabled
|
* we still need to look at the event data. Use the temp_buffer
|
* to store the trace event for the trigger to use. It's recursive
|
* safe and will not be recorded anywhere.
|
*/
|
if (!entry && trace_file->flags & EVENT_FILE_FL_TRIGGER_COND) {
|
*current_rb = temp_buffer;
|
entry = __trace_buffer_lock_reserve(*current_rb, type, len,
|
trace_ctx);
|
}
|
return entry;
|
}
|
EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve);
|
|
static DEFINE_RAW_SPINLOCK(tracepoint_iter_lock);
|
static DEFINE_MUTEX(tracepoint_printk_mutex);
|
|
static void output_printk(struct trace_event_buffer *fbuffer)
|
{
|
struct trace_event_call *event_call;
|
struct trace_event_file *file;
|
struct trace_event *event;
|
unsigned long flags;
|
struct trace_iterator *iter = tracepoint_print_iter;
|
|
/* We should never get here if iter is NULL */
|
if (WARN_ON_ONCE(!iter))
|
return;
|
|
event_call = fbuffer->trace_file->event_call;
|
if (!event_call || !event_call->event.funcs ||
|
!event_call->event.funcs->trace)
|
return;
|
|
file = fbuffer->trace_file;
|
if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
|
(unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
|
!filter_match_preds(file->filter, fbuffer->entry)))
|
return;
|
|
event = &fbuffer->trace_file->event_call->event;
|
|
raw_spin_lock_irqsave(&tracepoint_iter_lock, flags);
|
trace_seq_init(&iter->seq);
|
iter->ent = fbuffer->entry;
|
event_call->event.funcs->trace(iter, 0, event);
|
trace_seq_putc(&iter->seq, 0);
|
printk("%s", iter->seq.buffer);
|
|
raw_spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
|
}
|
|
int tracepoint_printk_sysctl(struct ctl_table *table, int write,
|
void *buffer, size_t *lenp,
|
loff_t *ppos)
|
{
|
int save_tracepoint_printk;
|
int ret;
|
|
mutex_lock(&tracepoint_printk_mutex);
|
save_tracepoint_printk = tracepoint_printk;
|
|
ret = proc_dointvec(table, write, buffer, lenp, ppos);
|
|
/*
|
* This will force exiting early, as tracepoint_printk
|
* is always zero when tracepoint_printk_iter is not allocated
|
*/
|
if (!tracepoint_print_iter)
|
tracepoint_printk = 0;
|
|
if (save_tracepoint_printk == tracepoint_printk)
|
goto out;
|
|
if (tracepoint_printk)
|
static_key_enable(&tracepoint_printk_key.key);
|
else
|
static_key_disable(&tracepoint_printk_key.key);
|
|
out:
|
mutex_unlock(&tracepoint_printk_mutex);
|
|
return ret;
|
}
|
|
void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
|
{
|
if (static_key_false(&tracepoint_printk_key.key))
|
output_printk(fbuffer);
|
|
if (static_branch_unlikely(&trace_event_exports_enabled))
|
ftrace_exports(fbuffer->event, TRACE_EXPORT_EVENT);
|
event_trigger_unlock_commit_regs(fbuffer->trace_file, fbuffer->buffer,
|
fbuffer->event, fbuffer->entry,
|
fbuffer->trace_ctx, fbuffer->regs);
|
}
|
EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
|
|
/*
|
* Skip 3:
|
*
|
* trace_buffer_unlock_commit_regs()
|
* trace_event_buffer_commit()
|
* trace_event_raw_event_xxx()
|
*/
|
# define STACK_SKIP 3
|
|
void trace_buffer_unlock_commit_regs(struct trace_array *tr,
|
struct trace_buffer *buffer,
|
struct ring_buffer_event *event,
|
unsigned int trace_ctx,
|
struct pt_regs *regs)
|
{
|
__buffer_unlock_commit(buffer, event);
|
|
/*
|
* If regs is not set, then skip the necessary functions.
|
* Note, we can still get here via blktrace, wakeup tracer
|
* and mmiotrace, but that's ok if they lose a function or
|
* two. They are not that meaningful.
|
*/
|
ftrace_trace_stack(tr, buffer, trace_ctx, regs ? 0 : STACK_SKIP, regs);
|
ftrace_trace_userstack(tr, buffer, trace_ctx);
|
}
|
|
/*
|
* Similar to trace_buffer_unlock_commit_regs() but do not dump stack.
|
*/
|
void
|
trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
|
struct ring_buffer_event *event)
|
{
|
__buffer_unlock_commit(buffer, event);
|
}
|
|
void
|
trace_function(struct trace_array *tr, unsigned long ip, unsigned long
|
parent_ip, unsigned int trace_ctx)
|
{
|
struct trace_event_call *call = &event_function;
|
struct trace_buffer *buffer = tr->array_buffer.buffer;
|
struct ring_buffer_event *event;
|
struct ftrace_entry *entry;
|
|
event = __trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
|
trace_ctx);
|
if (!event)
|
return;
|
entry = ring_buffer_event_data(event);
|
entry->ip = ip;
|
entry->parent_ip = parent_ip;
|
|
if (!call_filter_check_discard(call, entry, buffer, event)) {
|
if (static_branch_unlikely(&trace_function_exports_enabled))
|
ftrace_exports(event, TRACE_EXPORT_FUNCTION);
|
__buffer_unlock_commit(buffer, event);
|
}
|
}
|
|
#ifdef CONFIG_STACKTRACE
|
|
/* Allow 4 levels of nesting: normal, softirq, irq, NMI */
|
#define FTRACE_KSTACK_NESTING 4
|
|
#define FTRACE_KSTACK_ENTRIES (PAGE_SIZE / FTRACE_KSTACK_NESTING)
|
|
struct ftrace_stack {
|
unsigned long calls[FTRACE_KSTACK_ENTRIES];
|
};
|
|
|
struct ftrace_stacks {
|
struct ftrace_stack stacks[FTRACE_KSTACK_NESTING];
|
};
|
|
static DEFINE_PER_CPU(struct ftrace_stacks, ftrace_stacks);
|
static DEFINE_PER_CPU(int, ftrace_stack_reserve);
|
|
static void __ftrace_trace_stack(struct trace_buffer *buffer,
|
unsigned int trace_ctx,
|
int skip, struct pt_regs *regs)
|
{
|
struct trace_event_call *call = &event_kernel_stack;
|
struct ring_buffer_event *event;
|
unsigned int size, nr_entries;
|
struct ftrace_stack *fstack;
|
struct stack_entry *entry;
|
int stackidx;
|
|
/*
|
* Add one, for this function and the call to save_stack_trace()
|
* If regs is set, then these functions will not be in the way.
|
*/
|
#ifndef CONFIG_UNWINDER_ORC
|
if (!regs)
|
skip++;
|
#endif
|
|
preempt_disable_notrace();
|
|
stackidx = __this_cpu_inc_return(ftrace_stack_reserve) - 1;
|
|
/* This should never happen. If it does, yell once and skip */
|
if (WARN_ON_ONCE(stackidx >= FTRACE_KSTACK_NESTING))
|
goto out;
|
|
/*
|
* The above __this_cpu_inc_return() is 'atomic' cpu local. An
|
* interrupt will either see the value pre increment or post
|
* increment. If the interrupt happens pre increment it will have
|
* restored the counter when it returns. We just need a barrier to
|
* keep gcc from moving things around.
|
*/
|
barrier();
|
|
fstack = this_cpu_ptr(ftrace_stacks.stacks) + stackidx;
|
size = ARRAY_SIZE(fstack->calls);
|
|
if (regs) {
|
nr_entries = stack_trace_save_regs(regs, fstack->calls,
|
size, skip);
|
} else {
|
nr_entries = stack_trace_save(fstack->calls, size, skip);
|
}
|
|
size = nr_entries * sizeof(unsigned long);
|
event = __trace_buffer_lock_reserve(buffer, TRACE_STACK,
|
(sizeof(*entry) - sizeof(entry->caller)) + size,
|
trace_ctx);
|
if (!event)
|
goto out;
|
entry = ring_buffer_event_data(event);
|
|
memcpy(&entry->caller, fstack->calls, size);
|
entry->size = nr_entries;
|
|
if (!call_filter_check_discard(call, entry, buffer, event))
|
__buffer_unlock_commit(buffer, event);
|
|
out:
|
/* Again, don't let gcc optimize things here */
|
barrier();
|
__this_cpu_dec(ftrace_stack_reserve);
|
preempt_enable_notrace();
|
|
}
|
|
static inline void ftrace_trace_stack(struct trace_array *tr,
|
struct trace_buffer *buffer,
|
unsigned int trace_ctx,
|
int skip, struct pt_regs *regs)
|
{
|
if (!(tr->trace_flags & TRACE_ITER_STACKTRACE))
|
return;
|
|
__ftrace_trace_stack(buffer, trace_ctx, skip, regs);
|
}
|
|
void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
|
int skip)
|
{
|
struct trace_buffer *buffer = tr->array_buffer.buffer;
|
|
if (rcu_is_watching()) {
|
__ftrace_trace_stack(buffer, trace_ctx, skip, NULL);
|
return;
|
}
|
|
/*
|
* When an NMI triggers, RCU is enabled via rcu_nmi_enter(),
|
* but if the above rcu_is_watching() failed, then the NMI
|
* triggered someplace critical, and rcu_irq_enter() should
|
* not be called from NMI.
|
*/
|
if (unlikely(in_nmi()))
|
return;
|
|
rcu_irq_enter_irqson();
|
__ftrace_trace_stack(buffer, trace_ctx, skip, NULL);
|
rcu_irq_exit_irqson();
|
}
|
|
/**
|
* trace_dump_stack - record a stack back trace in the trace buffer
|
* @skip: Number of functions to skip (helper handlers)
|
*/
|
void trace_dump_stack(int skip)
|
{
|
if (tracing_disabled || tracing_selftest_running)
|
return;
|
|
#ifndef CONFIG_UNWINDER_ORC
|
/* Skip 1 to skip this function. */
|
skip++;
|
#endif
|
__ftrace_trace_stack(global_trace.array_buffer.buffer,
|
tracing_gen_ctx(), skip, NULL);
|
}
|
EXPORT_SYMBOL_GPL(trace_dump_stack);
|
|
#ifdef CONFIG_USER_STACKTRACE_SUPPORT
|
static DEFINE_PER_CPU(int, user_stack_count);
|
|
static void
|
ftrace_trace_userstack(struct trace_array *tr,
|
struct trace_buffer *buffer, unsigned int trace_ctx)
|
{
|
struct trace_event_call *call = &event_user_stack;
|
struct ring_buffer_event *event;
|
struct userstack_entry *entry;
|
|
if (!(tr->trace_flags & TRACE_ITER_USERSTACKTRACE))
|
return;
|
|
/*
|
* NMIs can not handle page faults, even with fix ups.
|
* The save user stack can (and often does) fault.
|
*/
|
if (unlikely(in_nmi()))
|
return;
|
|
/*
|
* prevent recursion, since the user stack tracing may
|
* trigger other kernel events.
|
*/
|
preempt_disable();
|
if (__this_cpu_read(user_stack_count))
|
goto out;
|
|
__this_cpu_inc(user_stack_count);
|
|
event = __trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
|
sizeof(*entry), trace_ctx);
|
if (!event)
|
goto out_drop_count;
|
entry = ring_buffer_event_data(event);
|
|
entry->tgid = current->tgid;
|
memset(&entry->caller, 0, sizeof(entry->caller));
|
|
stack_trace_save_user(entry->caller, FTRACE_STACK_ENTRIES);
|
if (!call_filter_check_discard(call, entry, buffer, event))
|
__buffer_unlock_commit(buffer, event);
|
|
out_drop_count:
|
__this_cpu_dec(user_stack_count);
|
out:
|
preempt_enable();
|
}
|
#else /* CONFIG_USER_STACKTRACE_SUPPORT */
|
static void ftrace_trace_userstack(struct trace_array *tr,
|
struct trace_buffer *buffer,
|
unsigned int trace_ctx)
|
{
|
}
|
#endif /* !CONFIG_USER_STACKTRACE_SUPPORT */
|
|
#endif /* CONFIG_STACKTRACE */
|
|
/* created for use with alloc_percpu */
|
struct trace_buffer_struct {
|
int nesting;
|
char buffer[4][TRACE_BUF_SIZE];
|
};
|
|
static struct trace_buffer_struct __percpu *trace_percpu_buffer;
|
|
/*
|
* Thise allows for lockless recording. If we're nested too deeply, then
|
* this returns NULL.
|
*/
|
static char *get_trace_buf(void)
|
{
|
struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer);
|
|
if (!trace_percpu_buffer || buffer->nesting >= 4)
|
return NULL;
|
|
buffer->nesting++;
|
|
/* Interrupts must see nesting incremented before we use the buffer */
|
barrier();
|
return &buffer->buffer[buffer->nesting - 1][0];
|
}
|
|
static void put_trace_buf(void)
|
{
|
/* Don't let the decrement of nesting leak before this */
|
barrier();
|
this_cpu_dec(trace_percpu_buffer->nesting);
|
}
|
|
static int alloc_percpu_trace_buffer(void)
|
{
|
struct trace_buffer_struct __percpu *buffers;
|
|
if (trace_percpu_buffer)
|
return 0;
|
|
buffers = alloc_percpu(struct trace_buffer_struct);
|
if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer"))
|
return -ENOMEM;
|
|
trace_percpu_buffer = buffers;
|
return 0;
|
}
|
|
static int buffers_allocated;
|
|
void trace_printk_init_buffers(void)
|
{
|
if (buffers_allocated)
|
return;
|
|
if (alloc_percpu_trace_buffer())
|
return;
|
|
/* trace_printk() is for debug use only. Don't use it in production. */
|
|
pr_warn("\n");
|
pr_warn("**********************************************************\n");
|
pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
|
pr_warn("** **\n");
|
pr_warn("** trace_printk() being used. Allocating extra memory. **\n");
|
pr_warn("** **\n");
|
pr_warn("** This means that this is a DEBUG kernel and it is **\n");
|
pr_warn("** unsafe for production use. **\n");
|
pr_warn("** **\n");
|
pr_warn("** If you see this message and you are not debugging **\n");
|
pr_warn("** the kernel, report this immediately to your vendor! **\n");
|
pr_warn("** **\n");
|
pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
|
pr_warn("**********************************************************\n");
|
|
/* Expand the buffers to set size */
|
tracing_update_buffers();
|
|
buffers_allocated = 1;
|
|
/*
|
* trace_printk_init_buffers() can be called by modules.
|
* If that happens, then we need to start cmdline recording
|
* directly here. If the global_trace.buffer is already
|
* allocated here, then this was called by module code.
|
*/
|
if (global_trace.array_buffer.buffer)
|
tracing_start_cmdline_record();
|
}
|
EXPORT_SYMBOL_GPL(trace_printk_init_buffers);
|
|
void trace_printk_start_comm(void)
|
{
|
/* Start tracing comms if trace printk is set */
|
if (!buffers_allocated)
|
return;
|
tracing_start_cmdline_record();
|
}
|
|
static void trace_printk_start_stop_comm(int enabled)
|
{
|
if (!buffers_allocated)
|
return;
|
|
if (enabled)
|
tracing_start_cmdline_record();
|
else
|
tracing_stop_cmdline_record();
|
}
|
|
/**
|
* trace_vbprintk - write binary msg to tracing buffer
|
* @ip: The address of the caller
|
* @fmt: The string format to write to the buffer
|
* @args: Arguments for @fmt
|
*/
|
int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
|
{
|
struct trace_event_call *call = &event_bprint;
|
struct ring_buffer_event *event;
|
struct trace_buffer *buffer;
|
struct trace_array *tr = &global_trace;
|
struct bprint_entry *entry;
|
unsigned int trace_ctx;
|
char *tbuffer;
|
int len = 0, size;
|
|
if (unlikely(tracing_selftest_running || tracing_disabled))
|
return 0;
|
|
/* Don't pollute graph traces with trace_vprintk internals */
|
pause_graph_tracing();
|
|
trace_ctx = tracing_gen_ctx();
|
preempt_disable_notrace();
|
|
tbuffer = get_trace_buf();
|
if (!tbuffer) {
|
len = 0;
|
goto out_nobuffer;
|
}
|
|
len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args);
|
|
if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0)
|
goto out_put;
|
|
size = sizeof(*entry) + sizeof(u32) * len;
|
buffer = tr->array_buffer.buffer;
|
ring_buffer_nest_start(buffer);
|
event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
|
trace_ctx);
|
if (!event)
|
goto out;
|
entry = ring_buffer_event_data(event);
|
entry->ip = ip;
|
entry->fmt = fmt;
|
|
memcpy(entry->buf, tbuffer, sizeof(u32) * len);
|
if (!call_filter_check_discard(call, entry, buffer, event)) {
|
__buffer_unlock_commit(buffer, event);
|
ftrace_trace_stack(tr, buffer, trace_ctx, 6, NULL);
|
}
|
|
out:
|
ring_buffer_nest_end(buffer);
|
out_put:
|
put_trace_buf();
|
|
out_nobuffer:
|
preempt_enable_notrace();
|
unpause_graph_tracing();
|
|
return len;
|
}
|
EXPORT_SYMBOL_GPL(trace_vbprintk);
|
|
__printf(3, 0)
|
static int
|
__trace_array_vprintk(struct trace_buffer *buffer,
|
unsigned long ip, const char *fmt, va_list args)
|
{
|
struct trace_event_call *call = &event_print;
|
struct ring_buffer_event *event;
|
int len = 0, size;
|
struct print_entry *entry;
|
unsigned int trace_ctx;
|
char *tbuffer;
|
|
if (tracing_disabled || tracing_selftest_running)
|
return 0;
|
|
/* Don't pollute graph traces with trace_vprintk internals */
|
pause_graph_tracing();
|
|
trace_ctx = tracing_gen_ctx();
|
preempt_disable_notrace();
|
|
|
tbuffer = get_trace_buf();
|
if (!tbuffer) {
|
len = 0;
|
goto out_nobuffer;
|
}
|
|
len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args);
|
|
size = sizeof(*entry) + len + 1;
|
ring_buffer_nest_start(buffer);
|
event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
|
trace_ctx);
|
if (!event)
|
goto out;
|
entry = ring_buffer_event_data(event);
|
entry->ip = ip;
|
|
memcpy(&entry->buf, tbuffer, len + 1);
|
if (!call_filter_check_discard(call, entry, buffer, event)) {
|
__buffer_unlock_commit(buffer, event);
|
ftrace_trace_stack(&global_trace, buffer, trace_ctx, 6, NULL);
|
}
|
|
out:
|
ring_buffer_nest_end(buffer);
|
put_trace_buf();
|
|
out_nobuffer:
|
preempt_enable_notrace();
|
unpause_graph_tracing();
|
|
return len;
|
}
|
|
__printf(3, 0)
|
int trace_array_vprintk(struct trace_array *tr,
|
unsigned long ip, const char *fmt, va_list args)
|
{
|
return __trace_array_vprintk(tr->array_buffer.buffer, ip, fmt, args);
|
}
|
|
/**
|
* trace_array_printk - Print a message to a specific instance
|
* @tr: The instance trace_array descriptor
|
* @ip: The instruction pointer that this is called from.
|
* @fmt: The format to print (printf format)
|
*
|
* If a subsystem sets up its own instance, they have the right to
|
* printk strings into their tracing instance buffer using this
|
* function. Note, this function will not write into the top level
|
* buffer (use trace_printk() for that), as writing into the top level
|
* buffer should only have events that can be individually disabled.
|
* trace_printk() is only used for debugging a kernel, and should not
|
* be ever encorporated in normal use.
|
*
|
* trace_array_printk() can be used, as it will not add noise to the
|
* top level tracing buffer.
|
*
|
* Note, trace_array_init_printk() must be called on @tr before this
|
* can be used.
|
*/
|
__printf(3, 0)
|
int trace_array_printk(struct trace_array *tr,
|
unsigned long ip, const char *fmt, ...)
|
{
|
int ret;
|
va_list ap;
|
|
if (!tr)
|
return -ENOENT;
|
|
/* This is only allowed for created instances */
|
if (tr == &global_trace)
|
return 0;
|
|
if (!(tr->trace_flags & TRACE_ITER_PRINTK))
|
return 0;
|
|
va_start(ap, fmt);
|
ret = trace_array_vprintk(tr, ip, fmt, ap);
|
va_end(ap);
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(trace_array_printk);
|
|
/**
|
* trace_array_init_printk - Initialize buffers for trace_array_printk()
|
* @tr: The trace array to initialize the buffers for
|
*
|
* As trace_array_printk() only writes into instances, they are OK to
|
* have in the kernel (unlike trace_printk()). This needs to be called
|
* before trace_array_printk() can be used on a trace_array.
|
*/
|
int trace_array_init_printk(struct trace_array *tr)
|
{
|
if (!tr)
|
return -ENOENT;
|
|
/* This is only allowed for created instances */
|
if (tr == &global_trace)
|
return -EINVAL;
|
|
return alloc_percpu_trace_buffer();
|
}
|
EXPORT_SYMBOL_GPL(trace_array_init_printk);
|
|
__printf(3, 4)
|
int trace_array_printk_buf(struct trace_buffer *buffer,
|
unsigned long ip, const char *fmt, ...)
|
{
|
int ret;
|
va_list ap;
|
|
if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
|
return 0;
|
|
va_start(ap, fmt);
|
ret = __trace_array_vprintk(buffer, ip, fmt, ap);
|
va_end(ap);
|
return ret;
|
}
|
|
__printf(2, 0)
|
int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
|
{
|
return trace_array_vprintk(&global_trace, ip, fmt, args);
|
}
|
EXPORT_SYMBOL_GPL(trace_vprintk);
|
|
static void trace_iterator_increment(struct trace_iterator *iter)
|
{
|
struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu);
|
|
iter->idx++;
|
if (buf_iter)
|
ring_buffer_iter_advance(buf_iter);
|
}
|
|
static struct trace_entry *
|
peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
|
unsigned long *lost_events)
|
{
|
struct ring_buffer_event *event;
|
struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu);
|
|
if (buf_iter) {
|
event = ring_buffer_iter_peek(buf_iter, ts);
|
if (lost_events)
|
*lost_events = ring_buffer_iter_dropped(buf_iter) ?
|
(unsigned long)-1 : 0;
|
} else {
|
event = ring_buffer_peek(iter->array_buffer->buffer, cpu, ts,
|
lost_events);
|
}
|
|
if (event) {
|
iter->ent_size = ring_buffer_event_length(event);
|
return ring_buffer_event_data(event);
|
}
|
iter->ent_size = 0;
|
return NULL;
|
}
|
|
static struct trace_entry *
|
__find_next_entry(struct trace_iterator *iter, int *ent_cpu,
|
unsigned long *missing_events, u64 *ent_ts)
|
{
|
struct trace_buffer *buffer = iter->array_buffer->buffer;
|
struct trace_entry *ent, *next = NULL;
|
unsigned long lost_events = 0, next_lost = 0;
|
int cpu_file = iter->cpu_file;
|
u64 next_ts = 0, ts;
|
int next_cpu = -1;
|
int next_size = 0;
|
int cpu;
|
|
/*
|
* If we are in a per_cpu trace file, don't bother by iterating over
|
* all cpu and peek directly.
|
*/
|
if (cpu_file > RING_BUFFER_ALL_CPUS) {
|
if (ring_buffer_empty_cpu(buffer, cpu_file))
|
return NULL;
|
ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events);
|
if (ent_cpu)
|
*ent_cpu = cpu_file;
|
|
return ent;
|
}
|
|
for_each_tracing_cpu(cpu) {
|
|
if (ring_buffer_empty_cpu(buffer, cpu))
|
continue;
|
|
ent = peek_next_entry(iter, cpu, &ts, &lost_events);
|
|
/*
|
* Pick the entry with the smallest timestamp:
|
*/
|
if (ent && (!next || ts < next_ts)) {
|
next = ent;
|
next_cpu = cpu;
|
next_ts = ts;
|
next_lost = lost_events;
|
next_size = iter->ent_size;
|
}
|
}
|
|
iter->ent_size = next_size;
|
|
if (ent_cpu)
|
*ent_cpu = next_cpu;
|
|
if (ent_ts)
|
*ent_ts = next_ts;
|
|
if (missing_events)
|
*missing_events = next_lost;
|
|
return next;
|
}
|
|
#define STATIC_TEMP_BUF_SIZE 128
|
static char static_temp_buf[STATIC_TEMP_BUF_SIZE] __aligned(4);
|
|
/* Find the next real entry, without updating the iterator itself */
|
struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
|
int *ent_cpu, u64 *ent_ts)
|
{
|
/* __find_next_entry will reset ent_size */
|
int ent_size = iter->ent_size;
|
struct trace_entry *entry;
|
|
/*
|
* If called from ftrace_dump(), then the iter->temp buffer
|
* will be the static_temp_buf and not created from kmalloc.
|
* If the entry size is greater than the buffer, we can
|
* not save it. Just return NULL in that case. This is only
|
* used to add markers when two consecutive events' time
|
* stamps have a large delta. See trace_print_lat_context()
|
*/
|
if (iter->temp == static_temp_buf &&
|
STATIC_TEMP_BUF_SIZE < ent_size)
|
return NULL;
|
|
/*
|
* The __find_next_entry() may call peek_next_entry(), which may
|
* call ring_buffer_peek() that may make the contents of iter->ent
|
* undefined. Need to copy iter->ent now.
|
*/
|
if (iter->ent && iter->ent != iter->temp) {
|
if ((!iter->temp || iter->temp_size < iter->ent_size) &&
|
!WARN_ON_ONCE(iter->temp == static_temp_buf)) {
|
void *temp;
|
temp = kmalloc(iter->ent_size, GFP_KERNEL);
|
if (!temp)
|
return NULL;
|
kfree(iter->temp);
|
iter->temp = temp;
|
iter->temp_size = iter->ent_size;
|
}
|
memcpy(iter->temp, iter->ent, iter->ent_size);
|
iter->ent = iter->temp;
|
}
|
entry = __find_next_entry(iter, ent_cpu, NULL, ent_ts);
|
/* Put back the original ent_size */
|
iter->ent_size = ent_size;
|
|
return entry;
|
}
|
|
/* Find the next real entry, and increment the iterator to the next entry */
|
void *trace_find_next_entry_inc(struct trace_iterator *iter)
|
{
|
iter->ent = __find_next_entry(iter, &iter->cpu,
|
&iter->lost_events, &iter->ts);
|
|
if (iter->ent)
|
trace_iterator_increment(iter);
|
|
return iter->ent ? iter : NULL;
|
}
|
|
static void trace_consume(struct trace_iterator *iter)
|
{
|
ring_buffer_consume(iter->array_buffer->buffer, iter->cpu, &iter->ts,
|
&iter->lost_events);
|
}
|
|
static void *s_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
struct trace_iterator *iter = m->private;
|
int i = (int)*pos;
|
void *ent;
|
|
WARN_ON_ONCE(iter->leftover);
|
|
(*pos)++;
|
|
/* can't go backwards */
|
if (iter->idx > i)
|
return NULL;
|
|
if (iter->idx < 0)
|
ent = trace_find_next_entry_inc(iter);
|
else
|
ent = iter;
|
|
while (ent && iter->idx < i)
|
ent = trace_find_next_entry_inc(iter);
|
|
iter->pos = *pos;
|
|
return ent;
|
}
|
|
void tracing_iter_reset(struct trace_iterator *iter, int cpu)
|
{
|
struct ring_buffer_iter *buf_iter;
|
unsigned long entries = 0;
|
u64 ts;
|
|
per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = 0;
|
|
buf_iter = trace_buffer_iter(iter, cpu);
|
if (!buf_iter)
|
return;
|
|
ring_buffer_iter_reset(buf_iter);
|
|
/*
|
* We could have the case with the max latency tracers
|
* that a reset never took place on a cpu. This is evident
|
* by the timestamp being before the start of the buffer.
|
*/
|
while (ring_buffer_iter_peek(buf_iter, &ts)) {
|
if (ts >= iter->array_buffer->time_start)
|
break;
|
entries++;
|
ring_buffer_iter_advance(buf_iter);
|
}
|
|
per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = entries;
|
}
|
|
/*
|
* The current tracer is copied to avoid a global locking
|
* all around.
|
*/
|
static void *s_start(struct seq_file *m, loff_t *pos)
|
{
|
struct trace_iterator *iter = m->private;
|
struct trace_array *tr = iter->tr;
|
int cpu_file = iter->cpu_file;
|
void *p = NULL;
|
loff_t l = 0;
|
int cpu;
|
|
/*
|
* copy the tracer to avoid using a global lock all around.
|
* iter->trace is a copy of current_trace, the pointer to the
|
* name may be used instead of a strcmp(), as iter->trace->name
|
* will point to the same string as current_trace->name.
|
*/
|
mutex_lock(&trace_types_lock);
|
if (unlikely(tr->current_trace && iter->trace->name != tr->current_trace->name))
|
*iter->trace = *tr->current_trace;
|
mutex_unlock(&trace_types_lock);
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
if (iter->snapshot && iter->trace->use_max_tr)
|
return ERR_PTR(-EBUSY);
|
#endif
|
|
if (*pos != iter->pos) {
|
iter->ent = NULL;
|
iter->cpu = 0;
|
iter->idx = -1;
|
|
if (cpu_file == RING_BUFFER_ALL_CPUS) {
|
for_each_tracing_cpu(cpu)
|
tracing_iter_reset(iter, cpu);
|
} else
|
tracing_iter_reset(iter, cpu_file);
|
|
iter->leftover = 0;
|
for (p = iter; p && l < *pos; p = s_next(m, p, &l))
|
;
|
|
} else {
|
/*
|
* If we overflowed the seq_file before, then we want
|
* to just reuse the trace_seq buffer again.
|
*/
|
if (iter->leftover)
|
p = iter;
|
else {
|
l = *pos - 1;
|
p = s_next(m, p, &l);
|
}
|
}
|
|
trace_event_read_lock();
|
trace_access_lock(cpu_file);
|
return p;
|
}
|
|
static void s_stop(struct seq_file *m, void *p)
|
{
|
struct trace_iterator *iter = m->private;
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
if (iter->snapshot && iter->trace->use_max_tr)
|
return;
|
#endif
|
|
trace_access_unlock(iter->cpu_file);
|
trace_event_read_unlock();
|
}
|
|
static void
|
get_total_entries_cpu(struct array_buffer *buf, unsigned long *total,
|
unsigned long *entries, int cpu)
|
{
|
unsigned long count;
|
|
count = ring_buffer_entries_cpu(buf->buffer, cpu);
|
/*
|
* If this buffer has skipped entries, then we hold all
|
* entries for the trace and we need to ignore the
|
* ones before the time stamp.
|
*/
|
if (per_cpu_ptr(buf->data, cpu)->skipped_entries) {
|
count -= per_cpu_ptr(buf->data, cpu)->skipped_entries;
|
/* total is the same as the entries */
|
*total = count;
|
} else
|
*total = count +
|
ring_buffer_overrun_cpu(buf->buffer, cpu);
|
*entries = count;
|
}
|
|
static void
|
get_total_entries(struct array_buffer *buf,
|
unsigned long *total, unsigned long *entries)
|
{
|
unsigned long t, e;
|
int cpu;
|
|
*total = 0;
|
*entries = 0;
|
|
for_each_tracing_cpu(cpu) {
|
get_total_entries_cpu(buf, &t, &e, cpu);
|
*total += t;
|
*entries += e;
|
}
|
}
|
|
unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu)
|
{
|
unsigned long total, entries;
|
|
if (!tr)
|
tr = &global_trace;
|
|
get_total_entries_cpu(&tr->array_buffer, &total, &entries, cpu);
|
|
return entries;
|
}
|
|
unsigned long trace_total_entries(struct trace_array *tr)
|
{
|
unsigned long total, entries;
|
|
if (!tr)
|
tr = &global_trace;
|
|
get_total_entries(&tr->array_buffer, &total, &entries);
|
|
return entries;
|
}
|
|
static void print_lat_help_header(struct seq_file *m)
|
{
|
seq_puts(m, "# _--------=> CPU# \n"
|
"# / _-------=> irqs-off \n"
|
"# | / _------=> need-resched \n"
|
"# || / _-----=> need-resched-lazy\n"
|
"# ||| / _----=> hardirq/softirq \n"
|
"# |||| / _---=> preempt-depth \n"
|
"# ||||| / _--=> preempt-lazy-depth\n"
|
"# |||||| / _-=> migrate-disable \n"
|
"# ||||||| / delay \n"
|
"# cmd pid |||||||| time | caller \n"
|
"# \\ / |||||||| \\ | / \n");
|
}
|
|
static void print_event_info(struct array_buffer *buf, struct seq_file *m)
|
{
|
unsigned long total;
|
unsigned long entries;
|
|
get_total_entries(buf, &total, &entries);
|
seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n",
|
entries, total, num_online_cpus());
|
seq_puts(m, "#\n");
|
}
|
|
static void print_func_help_header(struct array_buffer *buf, struct seq_file *m,
|
unsigned int flags)
|
{
|
bool tgid = flags & TRACE_ITER_RECORD_TGID;
|
|
print_event_info(buf, m);
|
|
seq_printf(m, "# TASK-PID %s CPU# TIMESTAMP FUNCTION\n", tgid ? " TGID " : "");
|
seq_printf(m, "# | | %s | | |\n", tgid ? " | " : "");
|
}
|
|
static void print_func_help_header_irq(struct array_buffer *buf, struct seq_file *m,
|
unsigned int flags)
|
{
|
bool tgid = flags & TRACE_ITER_RECORD_TGID;
|
const char *space = " ";
|
int prec = tgid ? 12 : 2;
|
|
print_event_info(buf, m);
|
|
seq_printf(m, "# %.*s _-------=> irqs-off\n", prec, space);
|
seq_printf(m, "# %.*s / _------=> need-resched\n", prec, space);
|
seq_printf(m, "# %.*s| / _-----=> need-resched-lazy\n", prec, space);
|
seq_printf(m, "# %.*s|| / _----=> hardirq/softirq\n", prec, space);
|
seq_printf(m, "# %.*s||| / _---=> preempt-depth\n", prec, space);
|
seq_printf(m, "# %.*s|||| / _--=> preempt-lazy-depth\n", prec, space);
|
seq_printf(m, "# %.*s||||| / _-=> migrate-disable\n", prec, space);
|
seq_printf(m, "# %.*s|||||| / delay\n", prec, space);
|
seq_printf(m, "# TASK-PID %.*s CPU# ||||||| TIMESTAMP FUNCTION\n", prec, " TGID ");
|
seq_printf(m, "# | | %.*s | ||||||| | |\n", prec, " | ");
|
}
|
|
void
|
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
|
{
|
unsigned long sym_flags = (global_trace.trace_flags & TRACE_ITER_SYM_MASK);
|
struct array_buffer *buf = iter->array_buffer;
|
struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu);
|
struct tracer *type = iter->trace;
|
unsigned long entries;
|
unsigned long total;
|
const char *name = "preemption";
|
|
name = type->name;
|
|
get_total_entries(buf, &total, &entries);
|
|
seq_printf(m, "# %s latency trace v1.1.5 on %s\n",
|
name, UTS_RELEASE);
|
seq_puts(m, "# -----------------------------------"
|
"---------------------------------\n");
|
seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |"
|
" (M:%s VP:%d, KP:%d, SP:%d HP:%d",
|
nsecs_to_usecs(data->saved_latency),
|
entries,
|
total,
|
buf->cpu,
|
#if defined(CONFIG_PREEMPT_NONE)
|
"server",
|
#elif defined(CONFIG_PREEMPT_VOLUNTARY)
|
"desktop",
|
#elif defined(CONFIG_PREEMPT)
|
"preempt",
|
#elif defined(CONFIG_PREEMPT_RT)
|
"preempt_rt",
|
#else
|
"unknown",
|
#endif
|
/* These are reserved for later use */
|
0, 0, 0, 0);
|
#ifdef CONFIG_SMP
|
seq_printf(m, " #P:%d)\n", num_online_cpus());
|
#else
|
seq_puts(m, ")\n");
|
#endif
|
seq_puts(m, "# -----------------\n");
|
seq_printf(m, "# | task: %.16s-%d "
|
"(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
|
data->comm, data->pid,
|
from_kuid_munged(seq_user_ns(m), data->uid), data->nice,
|
data->policy, data->rt_priority);
|
seq_puts(m, "# -----------------\n");
|
|
if (data->critical_start) {
|
seq_puts(m, "# => started at: ");
|
seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
|
trace_print_seq(m, &iter->seq);
|
seq_puts(m, "\n# => ended at: ");
|
seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
|
trace_print_seq(m, &iter->seq);
|
seq_puts(m, "\n#\n");
|
}
|
|
seq_puts(m, "#\n");
|
}
|
|
static void test_cpu_buff_start(struct trace_iterator *iter)
|
{
|
struct trace_seq *s = &iter->seq;
|
struct trace_array *tr = iter->tr;
|
|
if (!(tr->trace_flags & TRACE_ITER_ANNOTATE))
|
return;
|
|
if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
|
return;
|
|
if (cpumask_available(iter->started) &&
|
cpumask_test_cpu(iter->cpu, iter->started))
|
return;
|
|
if (per_cpu_ptr(iter->array_buffer->data, iter->cpu)->skipped_entries)
|
return;
|
|
if (cpumask_available(iter->started))
|
cpumask_set_cpu(iter->cpu, iter->started);
|
|
/* Don't print started cpu buffer for the first entry of the trace */
|
if (iter->idx > 1)
|
trace_seq_printf(s, "##### CPU %u buffer started ####\n",
|
iter->cpu);
|
}
|
|
static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
|
{
|
struct trace_array *tr = iter->tr;
|
struct trace_seq *s = &iter->seq;
|
unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);
|
struct trace_entry *entry;
|
struct trace_event *event;
|
|
entry = iter->ent;
|
|
test_cpu_buff_start(iter);
|
|
event = ftrace_find_event(entry->type);
|
|
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT)
|
trace_print_lat_context(iter);
|
else
|
trace_print_context(iter);
|
}
|
|
if (trace_seq_has_overflowed(s))
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
if (event)
|
return event->funcs->trace(iter, sym_flags, event);
|
|
trace_seq_printf(s, "Unknown type %d\n", entry->type);
|
|
return trace_handle_return(s);
|
}
|
|
static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
|
{
|
struct trace_array *tr = iter->tr;
|
struct trace_seq *s = &iter->seq;
|
struct trace_entry *entry;
|
struct trace_event *event;
|
|
entry = iter->ent;
|
|
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO)
|
trace_seq_printf(s, "%d %d %llu ",
|
entry->pid, iter->cpu, iter->ts);
|
|
if (trace_seq_has_overflowed(s))
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
event = ftrace_find_event(entry->type);
|
if (event)
|
return event->funcs->raw(iter, 0, event);
|
|
trace_seq_printf(s, "%d ?\n", entry->type);
|
|
return trace_handle_return(s);
|
}
|
|
static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
|
{
|
struct trace_array *tr = iter->tr;
|
struct trace_seq *s = &iter->seq;
|
unsigned char newline = '\n';
|
struct trace_entry *entry;
|
struct trace_event *event;
|
|
entry = iter->ent;
|
|
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
|
SEQ_PUT_HEX_FIELD(s, entry->pid);
|
SEQ_PUT_HEX_FIELD(s, iter->cpu);
|
SEQ_PUT_HEX_FIELD(s, iter->ts);
|
if (trace_seq_has_overflowed(s))
|
return TRACE_TYPE_PARTIAL_LINE;
|
}
|
|
event = ftrace_find_event(entry->type);
|
if (event) {
|
enum print_line_t ret = event->funcs->hex(iter, 0, event);
|
if (ret != TRACE_TYPE_HANDLED)
|
return ret;
|
}
|
|
SEQ_PUT_FIELD(s, newline);
|
|
return trace_handle_return(s);
|
}
|
|
static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
|
{
|
struct trace_array *tr = iter->tr;
|
struct trace_seq *s = &iter->seq;
|
struct trace_entry *entry;
|
struct trace_event *event;
|
|
entry = iter->ent;
|
|
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
|
SEQ_PUT_FIELD(s, entry->pid);
|
SEQ_PUT_FIELD(s, iter->cpu);
|
SEQ_PUT_FIELD(s, iter->ts);
|
if (trace_seq_has_overflowed(s))
|
return TRACE_TYPE_PARTIAL_LINE;
|
}
|
|
event = ftrace_find_event(entry->type);
|
return event ? event->funcs->binary(iter, 0, event) :
|
TRACE_TYPE_HANDLED;
|
}
|
|
int trace_empty(struct trace_iterator *iter)
|
{
|
struct ring_buffer_iter *buf_iter;
|
int cpu;
|
|
/* If we are looking at one CPU buffer, only check that one */
|
if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
|
cpu = iter->cpu_file;
|
buf_iter = trace_buffer_iter(iter, cpu);
|
if (buf_iter) {
|
if (!ring_buffer_iter_empty(buf_iter))
|
return 0;
|
} else {
|
if (!ring_buffer_empty_cpu(iter->array_buffer->buffer, cpu))
|
return 0;
|
}
|
return 1;
|
}
|
|
for_each_tracing_cpu(cpu) {
|
buf_iter = trace_buffer_iter(iter, cpu);
|
if (buf_iter) {
|
if (!ring_buffer_iter_empty(buf_iter))
|
return 0;
|
} else {
|
if (!ring_buffer_empty_cpu(iter->array_buffer->buffer, cpu))
|
return 0;
|
}
|
}
|
|
return 1;
|
}
|
|
/* Called with trace_event_read_lock() held. */
|
enum print_line_t print_trace_line(struct trace_iterator *iter)
|
{
|
struct trace_array *tr = iter->tr;
|
unsigned long trace_flags = tr->trace_flags;
|
enum print_line_t ret;
|
|
if (iter->lost_events) {
|
if (iter->lost_events == (unsigned long)-1)
|
trace_seq_printf(&iter->seq, "CPU:%d [LOST EVENTS]\n",
|
iter->cpu);
|
else
|
trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
|
iter->cpu, iter->lost_events);
|
if (trace_seq_has_overflowed(&iter->seq))
|
return TRACE_TYPE_PARTIAL_LINE;
|
}
|
|
if (iter->trace && iter->trace->print_line) {
|
ret = iter->trace->print_line(iter);
|
if (ret != TRACE_TYPE_UNHANDLED)
|
return ret;
|
}
|
|
if (iter->ent->type == TRACE_BPUTS &&
|
trace_flags & TRACE_ITER_PRINTK &&
|
trace_flags & TRACE_ITER_PRINTK_MSGONLY)
|
return trace_print_bputs_msg_only(iter);
|
|
if (iter->ent->type == TRACE_BPRINT &&
|
trace_flags & TRACE_ITER_PRINTK &&
|
trace_flags & TRACE_ITER_PRINTK_MSGONLY)
|
return trace_print_bprintk_msg_only(iter);
|
|
if (iter->ent->type == TRACE_PRINT &&
|
trace_flags & TRACE_ITER_PRINTK &&
|
trace_flags & TRACE_ITER_PRINTK_MSGONLY)
|
return trace_print_printk_msg_only(iter);
|
|
if (trace_flags & TRACE_ITER_BIN)
|
return print_bin_fmt(iter);
|
|
if (trace_flags & TRACE_ITER_HEX)
|
return print_hex_fmt(iter);
|
|
if (trace_flags & TRACE_ITER_RAW)
|
return print_raw_fmt(iter);
|
|
return print_trace_fmt(iter);
|
}
|
|
void trace_latency_header(struct seq_file *m)
|
{
|
struct trace_iterator *iter = m->private;
|
struct trace_array *tr = iter->tr;
|
|
/* print nothing if the buffers are empty */
|
if (trace_empty(iter))
|
return;
|
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT)
|
print_trace_header(m, iter);
|
|
if (!(tr->trace_flags & TRACE_ITER_VERBOSE))
|
print_lat_help_header(m);
|
}
|
|
void trace_default_header(struct seq_file *m)
|
{
|
struct trace_iterator *iter = m->private;
|
struct trace_array *tr = iter->tr;
|
unsigned long trace_flags = tr->trace_flags;
|
|
if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
|
return;
|
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
|
/* print nothing if the buffers are empty */
|
if (trace_empty(iter))
|
return;
|
print_trace_header(m, iter);
|
if (!(trace_flags & TRACE_ITER_VERBOSE))
|
print_lat_help_header(m);
|
} else {
|
if (!(trace_flags & TRACE_ITER_VERBOSE)) {
|
if (trace_flags & TRACE_ITER_IRQ_INFO)
|
print_func_help_header_irq(iter->array_buffer,
|
m, trace_flags);
|
else
|
print_func_help_header(iter->array_buffer, m,
|
trace_flags);
|
}
|
}
|
}
|
|
static void test_ftrace_alive(struct seq_file *m)
|
{
|
if (!ftrace_is_dead())
|
return;
|
seq_puts(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n"
|
"# MAY BE MISSING FUNCTION EVENTS\n");
|
}
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
static void show_snapshot_main_help(struct seq_file *m)
|
{
|
seq_puts(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n"
|
"# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"
|
"# Takes a snapshot of the main buffer.\n"
|
"# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)\n"
|
"# (Doesn't have to be '2' works with any number that\n"
|
"# is not a '0' or '1')\n");
|
}
|
|
static void show_snapshot_percpu_help(struct seq_file *m)
|
{
|
seq_puts(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n");
|
#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
|
seq_puts(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"
|
"# Takes a snapshot of the main buffer for this cpu.\n");
|
#else
|
seq_puts(m, "# echo 1 > snapshot : Not supported with this kernel.\n"
|
"# Must use main snapshot file to allocate.\n");
|
#endif
|
seq_puts(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n"
|
"# (Doesn't have to be '2' works with any number that\n"
|
"# is not a '0' or '1')\n");
|
}
|
|
static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter)
|
{
|
if (iter->tr->allocated_snapshot)
|
seq_puts(m, "#\n# * Snapshot is allocated *\n#\n");
|
else
|
seq_puts(m, "#\n# * Snapshot is freed *\n#\n");
|
|
seq_puts(m, "# Snapshot commands:\n");
|
if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
|
show_snapshot_main_help(m);
|
else
|
show_snapshot_percpu_help(m);
|
}
|
#else
|
/* Should never be called */
|
static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { }
|
#endif
|
|
static int s_show(struct seq_file *m, void *v)
|
{
|
struct trace_iterator *iter = v;
|
int ret;
|
|
if (iter->ent == NULL) {
|
if (iter->tr) {
|
seq_printf(m, "# tracer: %s\n", iter->trace->name);
|
seq_puts(m, "#\n");
|
test_ftrace_alive(m);
|
}
|
if (iter->snapshot && trace_empty(iter))
|
print_snapshot_help(m, iter);
|
else if (iter->trace && iter->trace->print_header)
|
iter->trace->print_header(m);
|
else
|
trace_default_header(m);
|
|
} else if (iter->leftover) {
|
/*
|
* If we filled the seq_file buffer earlier, we
|
* want to just show it now.
|
*/
|
ret = trace_print_seq(m, &iter->seq);
|
|
/* ret should this time be zero, but you never know */
|
iter->leftover = ret;
|
|
} else {
|
print_trace_line(iter);
|
ret = trace_print_seq(m, &iter->seq);
|
/*
|
* If we overflow the seq_file buffer, then it will
|
* ask us for this data again at start up.
|
* Use that instead.
|
* ret is 0 if seq_file write succeeded.
|
* -1 otherwise.
|
*/
|
iter->leftover = ret;
|
}
|
|
return 0;
|
}
|
|
/*
|
* Should be used after trace_array_get(), trace_types_lock
|
* ensures that i_cdev was already initialized.
|
*/
|
static inline int tracing_get_cpu(struct inode *inode)
|
{
|
if (inode->i_cdev) /* See trace_create_cpu_file() */
|
return (long)inode->i_cdev - 1;
|
return RING_BUFFER_ALL_CPUS;
|
}
|
|
static const struct seq_operations tracer_seq_ops = {
|
.start = s_start,
|
.next = s_next,
|
.stop = s_stop,
|
.show = s_show,
|
};
|
|
static struct trace_iterator *
|
__tracing_open(struct inode *inode, struct file *file, bool snapshot)
|
{
|
struct trace_array *tr = inode->i_private;
|
struct trace_iterator *iter;
|
int cpu;
|
|
if (tracing_disabled)
|
return ERR_PTR(-ENODEV);
|
|
iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter));
|
if (!iter)
|
return ERR_PTR(-ENOMEM);
|
|
iter->buffer_iter = kcalloc(nr_cpu_ids, sizeof(*iter->buffer_iter),
|
GFP_KERNEL);
|
if (!iter->buffer_iter)
|
goto release;
|
|
/*
|
* trace_find_next_entry() may need to save off iter->ent.
|
* It will place it into the iter->temp buffer. As most
|
* events are less than 128, allocate a buffer of that size.
|
* If one is greater, then trace_find_next_entry() will
|
* allocate a new buffer to adjust for the bigger iter->ent.
|
* It's not critical if it fails to get allocated here.
|
*/
|
iter->temp = kmalloc(128, GFP_KERNEL);
|
if (iter->temp)
|
iter->temp_size = 128;
|
|
/*
|
* We make a copy of the current tracer to avoid concurrent
|
* changes on it while we are reading.
|
*/
|
mutex_lock(&trace_types_lock);
|
iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL);
|
if (!iter->trace)
|
goto fail;
|
|
*iter->trace = *tr->current_trace;
|
|
if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL))
|
goto fail;
|
|
iter->tr = tr;
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
/* Currently only the top directory has a snapshot */
|
if (tr->current_trace->print_max || snapshot)
|
iter->array_buffer = &tr->max_buffer;
|
else
|
#endif
|
iter->array_buffer = &tr->array_buffer;
|
iter->snapshot = snapshot;
|
iter->pos = -1;
|
iter->cpu_file = tracing_get_cpu(inode);
|
mutex_init(&iter->mutex);
|
|
/* Notify the tracer early; before we stop tracing. */
|
if (iter->trace->open)
|
iter->trace->open(iter);
|
|
/* Annotate start of buffers if we had overruns */
|
if (ring_buffer_overruns(iter->array_buffer->buffer))
|
iter->iter_flags |= TRACE_FILE_ANNOTATE;
|
|
/* Output in nanoseconds only if we are using a clock in nanoseconds. */
|
if (trace_clocks[tr->clock_id].in_ns)
|
iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
|
|
/*
|
* If pause-on-trace is enabled, then stop the trace while
|
* dumping, unless this is the "snapshot" file
|
*/
|
if (!iter->snapshot && (tr->trace_flags & TRACE_ITER_PAUSE_ON_TRACE))
|
tracing_stop_tr(tr);
|
|
if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
|
for_each_tracing_cpu(cpu) {
|
iter->buffer_iter[cpu] =
|
ring_buffer_read_prepare(iter->array_buffer->buffer,
|
cpu, GFP_KERNEL);
|
}
|
ring_buffer_read_prepare_sync();
|
for_each_tracing_cpu(cpu) {
|
ring_buffer_read_start(iter->buffer_iter[cpu]);
|
tracing_iter_reset(iter, cpu);
|
}
|
} else {
|
cpu = iter->cpu_file;
|
iter->buffer_iter[cpu] =
|
ring_buffer_read_prepare(iter->array_buffer->buffer,
|
cpu, GFP_KERNEL);
|
ring_buffer_read_prepare_sync();
|
ring_buffer_read_start(iter->buffer_iter[cpu]);
|
tracing_iter_reset(iter, cpu);
|
}
|
|
mutex_unlock(&trace_types_lock);
|
|
return iter;
|
|
fail:
|
mutex_unlock(&trace_types_lock);
|
kfree(iter->trace);
|
kfree(iter->temp);
|
kfree(iter->buffer_iter);
|
release:
|
seq_release_private(inode, file);
|
return ERR_PTR(-ENOMEM);
|
}
|
|
int tracing_open_generic(struct inode *inode, struct file *filp)
|
{
|
int ret;
|
|
ret = tracing_check_open_get_tr(NULL);
|
if (ret)
|
return ret;
|
|
filp->private_data = inode->i_private;
|
return 0;
|
}
|
|
bool tracing_is_disabled(void)
|
{
|
return (tracing_disabled) ? true: false;
|
}
|
|
/*
|
* Open and update trace_array ref count.
|
* Must have the current trace_array passed to it.
|
*/
|
int tracing_open_generic_tr(struct inode *inode, struct file *filp)
|
{
|
struct trace_array *tr = inode->i_private;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
filp->private_data = inode->i_private;
|
|
return 0;
|
}
|
|
static int tracing_release(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
struct seq_file *m = file->private_data;
|
struct trace_iterator *iter;
|
int cpu;
|
|
if (!(file->f_mode & FMODE_READ)) {
|
trace_array_put(tr);
|
return 0;
|
}
|
|
/* Writes do not use seq_file */
|
iter = m->private;
|
mutex_lock(&trace_types_lock);
|
|
for_each_tracing_cpu(cpu) {
|
if (iter->buffer_iter[cpu])
|
ring_buffer_read_finish(iter->buffer_iter[cpu]);
|
}
|
|
if (iter->trace && iter->trace->close)
|
iter->trace->close(iter);
|
|
if (!iter->snapshot && tr->stop_count)
|
/* reenable tracing if it was previously enabled */
|
tracing_start_tr(tr);
|
|
__trace_array_put(tr);
|
|
mutex_unlock(&trace_types_lock);
|
|
mutex_destroy(&iter->mutex);
|
free_cpumask_var(iter->started);
|
kfree(iter->temp);
|
kfree(iter->trace);
|
kfree(iter->buffer_iter);
|
seq_release_private(inode, file);
|
|
return 0;
|
}
|
|
static int tracing_release_generic_tr(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
|
trace_array_put(tr);
|
return 0;
|
}
|
|
static int tracing_single_release_tr(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
|
trace_array_put(tr);
|
|
return single_release(inode, file);
|
}
|
|
static int tracing_open(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
struct trace_iterator *iter;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
/* If this file was open for write, then erase contents */
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
|
int cpu = tracing_get_cpu(inode);
|
struct array_buffer *trace_buf = &tr->array_buffer;
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
if (tr->current_trace->print_max)
|
trace_buf = &tr->max_buffer;
|
#endif
|
|
if (cpu == RING_BUFFER_ALL_CPUS)
|
tracing_reset_online_cpus(trace_buf);
|
else
|
tracing_reset_cpu(trace_buf, cpu);
|
}
|
|
if (file->f_mode & FMODE_READ) {
|
iter = __tracing_open(inode, file, false);
|
if (IS_ERR(iter))
|
ret = PTR_ERR(iter);
|
else if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
|
iter->iter_flags |= TRACE_FILE_LAT_FMT;
|
}
|
|
if (ret < 0)
|
trace_array_put(tr);
|
|
return ret;
|
}
|
|
/*
|
* Some tracers are not suitable for instance buffers.
|
* A tracer is always available for the global array (toplevel)
|
* or if it explicitly states that it is.
|
*/
|
static bool
|
trace_ok_for_array(struct tracer *t, struct trace_array *tr)
|
{
|
return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances;
|
}
|
|
/* Find the next tracer that this trace array may use */
|
static struct tracer *
|
get_tracer_for_array(struct trace_array *tr, struct tracer *t)
|
{
|
while (t && !trace_ok_for_array(t, tr))
|
t = t->next;
|
|
return t;
|
}
|
|
static void *
|
t_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
struct trace_array *tr = m->private;
|
struct tracer *t = v;
|
|
(*pos)++;
|
|
if (t)
|
t = get_tracer_for_array(tr, t->next);
|
|
return t;
|
}
|
|
static void *t_start(struct seq_file *m, loff_t *pos)
|
{
|
struct trace_array *tr = m->private;
|
struct tracer *t;
|
loff_t l = 0;
|
|
mutex_lock(&trace_types_lock);
|
|
t = get_tracer_for_array(tr, trace_types);
|
for (; t && l < *pos; t = t_next(m, t, &l))
|
;
|
|
return t;
|
}
|
|
static void t_stop(struct seq_file *m, void *p)
|
{
|
mutex_unlock(&trace_types_lock);
|
}
|
|
static int t_show(struct seq_file *m, void *v)
|
{
|
struct tracer *t = v;
|
|
if (!t)
|
return 0;
|
|
seq_puts(m, t->name);
|
if (t->next)
|
seq_putc(m, ' ');
|
else
|
seq_putc(m, '\n');
|
|
return 0;
|
}
|
|
static const struct seq_operations show_traces_seq_ops = {
|
.start = t_start,
|
.next = t_next,
|
.stop = t_stop,
|
.show = t_show,
|
};
|
|
static int show_traces_open(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
struct seq_file *m;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
ret = seq_open(file, &show_traces_seq_ops);
|
if (ret) {
|
trace_array_put(tr);
|
return ret;
|
}
|
|
m = file->private_data;
|
m->private = tr;
|
|
return 0;
|
}
|
|
static int show_traces_release(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
|
trace_array_put(tr);
|
return seq_release(inode, file);
|
}
|
|
static ssize_t
|
tracing_write_stub(struct file *filp, const char __user *ubuf,
|
size_t count, loff_t *ppos)
|
{
|
return count;
|
}
|
|
loff_t tracing_lseek(struct file *file, loff_t offset, int whence)
|
{
|
int ret;
|
|
if (file->f_mode & FMODE_READ)
|
ret = seq_lseek(file, offset, whence);
|
else
|
file->f_pos = ret = 0;
|
|
return ret;
|
}
|
|
static const struct file_operations tracing_fops = {
|
.open = tracing_open,
|
.read = seq_read,
|
.write = tracing_write_stub,
|
.llseek = tracing_lseek,
|
.release = tracing_release,
|
};
|
|
static const struct file_operations show_traces_fops = {
|
.open = show_traces_open,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = show_traces_release,
|
};
|
|
static ssize_t
|
tracing_cpumask_read(struct file *filp, char __user *ubuf,
|
size_t count, loff_t *ppos)
|
{
|
struct trace_array *tr = file_inode(filp)->i_private;
|
char *mask_str;
|
int len;
|
|
len = snprintf(NULL, 0, "%*pb\n",
|
cpumask_pr_args(tr->tracing_cpumask)) + 1;
|
mask_str = kmalloc(len, GFP_KERNEL);
|
if (!mask_str)
|
return -ENOMEM;
|
|
len = snprintf(mask_str, len, "%*pb\n",
|
cpumask_pr_args(tr->tracing_cpumask));
|
if (len >= count) {
|
count = -EINVAL;
|
goto out_err;
|
}
|
count = simple_read_from_buffer(ubuf, count, ppos, mask_str, len);
|
|
out_err:
|
kfree(mask_str);
|
|
return count;
|
}
|
|
int tracing_set_cpumask(struct trace_array *tr,
|
cpumask_var_t tracing_cpumask_new)
|
{
|
int cpu;
|
|
if (!tr)
|
return -EINVAL;
|
|
local_irq_disable();
|
arch_spin_lock(&tr->max_lock);
|
for_each_tracing_cpu(cpu) {
|
/*
|
* Increase/decrease the disabled counter if we are
|
* about to flip a bit in the cpumask:
|
*/
|
if (cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
|
!cpumask_test_cpu(cpu, tracing_cpumask_new)) {
|
atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled);
|
ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu);
|
}
|
if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
|
cpumask_test_cpu(cpu, tracing_cpumask_new)) {
|
atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled);
|
ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu);
|
}
|
}
|
arch_spin_unlock(&tr->max_lock);
|
local_irq_enable();
|
|
cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new);
|
|
return 0;
|
}
|
|
static ssize_t
|
tracing_cpumask_write(struct file *filp, const char __user *ubuf,
|
size_t count, loff_t *ppos)
|
{
|
struct trace_array *tr = file_inode(filp)->i_private;
|
cpumask_var_t tracing_cpumask_new;
|
int err;
|
|
if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
|
return -ENOMEM;
|
|
err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
|
if (err)
|
goto err_free;
|
|
err = tracing_set_cpumask(tr, tracing_cpumask_new);
|
if (err)
|
goto err_free;
|
|
free_cpumask_var(tracing_cpumask_new);
|
|
return count;
|
|
err_free:
|
free_cpumask_var(tracing_cpumask_new);
|
|
return err;
|
}
|
|
static const struct file_operations tracing_cpumask_fops = {
|
.open = tracing_open_generic_tr,
|
.read = tracing_cpumask_read,
|
.write = tracing_cpumask_write,
|
.release = tracing_release_generic_tr,
|
.llseek = generic_file_llseek,
|
};
|
|
static int tracing_trace_options_show(struct seq_file *m, void *v)
|
{
|
struct tracer_opt *trace_opts;
|
struct trace_array *tr = m->private;
|
u32 tracer_flags;
|
int i;
|
|
mutex_lock(&trace_types_lock);
|
tracer_flags = tr->current_trace->flags->val;
|
trace_opts = tr->current_trace->flags->opts;
|
|
for (i = 0; trace_options[i]; i++) {
|
if (tr->trace_flags & (1 << i))
|
seq_printf(m, "%s\n", trace_options[i]);
|
else
|
seq_printf(m, "no%s\n", trace_options[i]);
|
}
|
|
for (i = 0; trace_opts[i].name; i++) {
|
if (tracer_flags & trace_opts[i].bit)
|
seq_printf(m, "%s\n", trace_opts[i].name);
|
else
|
seq_printf(m, "no%s\n", trace_opts[i].name);
|
}
|
mutex_unlock(&trace_types_lock);
|
|
return 0;
|
}
|
|
static int __set_tracer_option(struct trace_array *tr,
|
struct tracer_flags *tracer_flags,
|
struct tracer_opt *opts, int neg)
|
{
|
struct tracer *trace = tracer_flags->trace;
|
int ret;
|
|
ret = trace->set_flag(tr, tracer_flags->val, opts->bit, !neg);
|
if (ret)
|
return ret;
|
|
if (neg)
|
tracer_flags->val &= ~opts->bit;
|
else
|
tracer_flags->val |= opts->bit;
|
return 0;
|
}
|
|
/* Try to assign a tracer specific option */
|
static int set_tracer_option(struct trace_array *tr, char *cmp, int neg)
|
{
|
struct tracer *trace = tr->current_trace;
|
struct tracer_flags *tracer_flags = trace->flags;
|
struct tracer_opt *opts = NULL;
|
int i;
|
|
for (i = 0; tracer_flags->opts[i].name; i++) {
|
opts = &tracer_flags->opts[i];
|
|
if (strcmp(cmp, opts->name) == 0)
|
return __set_tracer_option(tr, trace->flags, opts, neg);
|
}
|
|
return -EINVAL;
|
}
|
|
/* Some tracers require overwrite to stay enabled */
|
int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set)
|
{
|
if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set)
|
return -1;
|
|
return 0;
|
}
|
|
int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
|
{
|
int *map;
|
|
if ((mask == TRACE_ITER_RECORD_TGID) ||
|
(mask == TRACE_ITER_RECORD_CMD))
|
lockdep_assert_held(&event_mutex);
|
|
/* do nothing if flag is already set */
|
if (!!(tr->trace_flags & mask) == !!enabled)
|
return 0;
|
|
/* Give the tracer a chance to approve the change */
|
if (tr->current_trace->flag_changed)
|
if (tr->current_trace->flag_changed(tr, mask, !!enabled))
|
return -EINVAL;
|
|
if (enabled)
|
tr->trace_flags |= mask;
|
else
|
tr->trace_flags &= ~mask;
|
|
if (mask == TRACE_ITER_RECORD_CMD)
|
trace_event_enable_cmd_record(enabled);
|
|
if (mask == TRACE_ITER_RECORD_TGID) {
|
if (!tgid_map) {
|
tgid_map_max = pid_max;
|
map = kvcalloc(tgid_map_max + 1, sizeof(*tgid_map),
|
GFP_KERNEL);
|
|
/*
|
* Pairs with smp_load_acquire() in
|
* trace_find_tgid_ptr() to ensure that if it observes
|
* the tgid_map we just allocated then it also observes
|
* the corresponding tgid_map_max value.
|
*/
|
smp_store_release(&tgid_map, map);
|
}
|
if (!tgid_map) {
|
tr->trace_flags &= ~TRACE_ITER_RECORD_TGID;
|
return -ENOMEM;
|
}
|
|
trace_event_enable_tgid_record(enabled);
|
}
|
|
if (mask == TRACE_ITER_EVENT_FORK)
|
trace_event_follow_fork(tr, enabled);
|
|
if (mask == TRACE_ITER_FUNC_FORK)
|
ftrace_pid_follow_fork(tr, enabled);
|
|
if (mask == TRACE_ITER_OVERWRITE) {
|
ring_buffer_change_overwrite(tr->array_buffer.buffer, enabled);
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled);
|
#endif
|
}
|
|
if (mask == TRACE_ITER_PRINTK) {
|
trace_printk_start_stop_comm(enabled);
|
trace_printk_control(enabled);
|
}
|
|
return 0;
|
}
|
|
int trace_set_options(struct trace_array *tr, char *option)
|
{
|
char *cmp;
|
int neg = 0;
|
int ret;
|
size_t orig_len = strlen(option);
|
int len;
|
|
cmp = strstrip(option);
|
|
len = str_has_prefix(cmp, "no");
|
if (len)
|
neg = 1;
|
|
cmp += len;
|
|
mutex_lock(&event_mutex);
|
mutex_lock(&trace_types_lock);
|
|
ret = match_string(trace_options, -1, cmp);
|
/* If no option could be set, test the specific tracer options */
|
if (ret < 0)
|
ret = set_tracer_option(tr, cmp, neg);
|
else
|
ret = set_tracer_flag(tr, 1 << ret, !neg);
|
|
mutex_unlock(&trace_types_lock);
|
mutex_unlock(&event_mutex);
|
|
/*
|
* If the first trailing whitespace is replaced with '\0' by strstrip,
|
* turn it back into a space.
|
*/
|
if (orig_len > strlen(option))
|
option[strlen(option)] = ' ';
|
|
return ret;
|
}
|
|
static void __init apply_trace_boot_options(void)
|
{
|
char *buf = trace_boot_options_buf;
|
char *option;
|
|
while (true) {
|
option = strsep(&buf, ",");
|
|
if (!option)
|
break;
|
|
if (*option)
|
trace_set_options(&global_trace, option);
|
|
/* Put back the comma to allow this to be called again */
|
if (buf)
|
*(buf - 1) = ',';
|
}
|
}
|
|
static ssize_t
|
tracing_trace_options_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct seq_file *m = filp->private_data;
|
struct trace_array *tr = m->private;
|
char buf[64];
|
int ret;
|
|
if (cnt >= sizeof(buf))
|
return -EINVAL;
|
|
if (copy_from_user(buf, ubuf, cnt))
|
return -EFAULT;
|
|
buf[cnt] = 0;
|
|
ret = trace_set_options(tr, buf);
|
if (ret < 0)
|
return ret;
|
|
*ppos += cnt;
|
|
return cnt;
|
}
|
|
static int tracing_trace_options_open(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
ret = single_open(file, tracing_trace_options_show, inode->i_private);
|
if (ret < 0)
|
trace_array_put(tr);
|
|
return ret;
|
}
|
|
static const struct file_operations tracing_iter_fops = {
|
.open = tracing_trace_options_open,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = tracing_single_release_tr,
|
.write = tracing_trace_options_write,
|
};
|
|
static const char readme_msg[] =
|
"tracing mini-HOWTO:\n\n"
|
"# echo 0 > tracing_on : quick way to disable tracing\n"
|
"# echo 1 > tracing_on : quick way to re-enable tracing\n\n"
|
" Important files:\n"
|
" trace\t\t\t- The static contents of the buffer\n"
|
"\t\t\t To clear the buffer write into this file: echo > trace\n"
|
" trace_pipe\t\t- A consuming read to see the contents of the buffer\n"
|
" current_tracer\t- function and latency tracers\n"
|
" available_tracers\t- list of configured tracers for current_tracer\n"
|
" error_log\t- error log for failed commands (that support it)\n"
|
" buffer_size_kb\t- view and modify size of per cpu buffer\n"
|
" buffer_total_size_kb - view total size of all cpu buffers\n\n"
|
" trace_clock\t\t-change the clock used to order events\n"
|
" local: Per cpu clock but may not be synced across CPUs\n"
|
" global: Synced across CPUs but slows tracing down.\n"
|
" counter: Not a clock, but just an increment\n"
|
" uptime: Jiffy counter from time of boot\n"
|
" perf: Same clock that perf events use\n"
|
#ifdef CONFIG_X86_64
|
" x86-tsc: TSC cycle counter\n"
|
#endif
|
"\n timestamp_mode\t-view the mode used to timestamp events\n"
|
" delta: Delta difference against a buffer-wide timestamp\n"
|
" absolute: Absolute (standalone) timestamp\n"
|
"\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n"
|
"\n trace_marker_raw\t\t- Writes into this file writes binary data into the kernel buffer\n"
|
" tracing_cpumask\t- Limit which CPUs to trace\n"
|
" instances\t\t- Make sub-buffers with: mkdir instances/foo\n"
|
"\t\t\t Remove sub-buffer with rmdir\n"
|
" trace_options\t\t- Set format or modify how tracing happens\n"
|
"\t\t\t Disable an option by prefixing 'no' to the\n"
|
"\t\t\t option name\n"
|
" saved_cmdlines_size\t- echo command number in here to store comm-pid list\n"
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
"\n available_filter_functions - list of functions that can be filtered on\n"
|
" set_ftrace_filter\t- echo function name in here to only trace these\n"
|
"\t\t\t functions\n"
|
"\t accepts: func_full_name or glob-matching-pattern\n"
|
"\t modules: Can select a group via module\n"
|
"\t Format: :mod:<module-name>\n"
|
"\t example: echo :mod:ext3 > set_ftrace_filter\n"
|
"\t triggers: a command to perform when function is hit\n"
|
"\t Format: <function>:<trigger>[:count]\n"
|
"\t trigger: traceon, traceoff\n"
|
"\t\t enable_event:<system>:<event>\n"
|
"\t\t disable_event:<system>:<event>\n"
|
#ifdef CONFIG_STACKTRACE
|
"\t\t stacktrace\n"
|
#endif
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
"\t\t snapshot\n"
|
#endif
|
"\t\t dump\n"
|
"\t\t cpudump\n"
|
"\t example: echo do_fault:traceoff > set_ftrace_filter\n"
|
"\t echo do_trap:traceoff:3 > set_ftrace_filter\n"
|
"\t The first one will disable tracing every time do_fault is hit\n"
|
"\t The second will disable tracing at most 3 times when do_trap is hit\n"
|
"\t The first time do trap is hit and it disables tracing, the\n"
|
"\t counter will decrement to 2. If tracing is already disabled,\n"
|
"\t the counter will not decrement. It only decrements when the\n"
|
"\t trigger did work\n"
|
"\t To remove trigger without count:\n"
|
"\t echo '!<function>:<trigger> > set_ftrace_filter\n"
|
"\t To remove trigger with a count:\n"
|
"\t echo '!<function>:<trigger>:0 > set_ftrace_filter\n"
|
" set_ftrace_notrace\t- echo function name in here to never trace.\n"
|
"\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
|
"\t modules: Can select a group via module command :mod:\n"
|
"\t Does not accept triggers\n"
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
#ifdef CONFIG_FUNCTION_TRACER
|
" set_ftrace_pid\t- Write pid(s) to only function trace those pids\n"
|
"\t\t (function)\n"
|
" set_ftrace_notrace_pid\t- Write pid(s) to not function trace those pids\n"
|
"\t\t (function)\n"
|
#endif
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
" set_graph_function\t- Trace the nested calls of a function (function_graph)\n"
|
" set_graph_notrace\t- Do not trace the nested calls of a function (function_graph)\n"
|
" max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n"
|
#endif
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
"\n snapshot\t\t- Like 'trace' but shows the content of the static\n"
|
"\t\t\t snapshot buffer. Read the contents for more\n"
|
"\t\t\t information\n"
|
#endif
|
#ifdef CONFIG_STACK_TRACER
|
" stack_trace\t\t- Shows the max stack trace when active\n"
|
" stack_max_size\t- Shows current max stack size that was traced\n"
|
"\t\t\t Write into this file to reset the max size (trigger a\n"
|
"\t\t\t new trace)\n"
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
" stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace\n"
|
"\t\t\t traces\n"
|
#endif
|
#endif /* CONFIG_STACK_TRACER */
|
#ifdef CONFIG_DYNAMIC_EVENTS
|
" dynamic_events\t\t- Create/append/remove/show the generic dynamic events\n"
|
"\t\t\t Write into this file to define/undefine new trace events.\n"
|
#endif
|
#ifdef CONFIG_KPROBE_EVENTS
|
" kprobe_events\t\t- Create/append/remove/show the kernel dynamic events\n"
|
"\t\t\t Write into this file to define/undefine new trace events.\n"
|
#endif
|
#ifdef CONFIG_UPROBE_EVENTS
|
" uprobe_events\t\t- Create/append/remove/show the userspace dynamic events\n"
|
"\t\t\t Write into this file to define/undefine new trace events.\n"
|
#endif
|
#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
|
"\t accepts: event-definitions (one definition per line)\n"
|
"\t Format: p[:[<group>/]<event>] <place> [<args>]\n"
|
"\t r[maxactive][:[<group>/]<event>] <place> [<args>]\n"
|
#ifdef CONFIG_HIST_TRIGGERS
|
"\t s:[synthetic/]<event> <field> [<field>]\n"
|
#endif
|
"\t -:[<group>/]<event>\n"
|
#ifdef CONFIG_KPROBE_EVENTS
|
"\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
|
"place (kretprobe): [<module>:]<symbol>[+<offset>]%return|<memaddr>\n"
|
#endif
|
#ifdef CONFIG_UPROBE_EVENTS
|
" place (uprobe): <path>:<offset>[%return][(ref_ctr_offset)]\n"
|
#endif
|
"\t args: <name>=fetcharg[:type]\n"
|
"\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n"
|
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
|
"\t $stack<index>, $stack, $retval, $comm, $arg<N>,\n"
|
#else
|
"\t $stack<index>, $stack, $retval, $comm,\n"
|
#endif
|
"\t +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n"
|
"\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n"
|
"\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n"
|
"\t <type>\\[<array-size>\\]\n"
|
#ifdef CONFIG_HIST_TRIGGERS
|
"\t field: <stype> <name>;\n"
|
"\t stype: u8/u16/u32/u64, s8/s16/s32/s64, pid_t,\n"
|
"\t [unsigned] char/int/long\n"
|
#endif
|
#endif
|
" events/\t\t- Directory containing all trace event subsystems:\n"
|
" enable\t\t- Write 0/1 to enable/disable tracing of all events\n"
|
" events/<system>/\t- Directory containing all trace events for <system>:\n"
|
" enable\t\t- Write 0/1 to enable/disable tracing of all <system>\n"
|
"\t\t\t events\n"
|
" filter\t\t- If set, only events passing filter are traced\n"
|
" events/<system>/<event>/\t- Directory containing control files for\n"
|
"\t\t\t <event>:\n"
|
" enable\t\t- Write 0/1 to enable/disable tracing of <event>\n"
|
" filter\t\t- If set, only events passing filter are traced\n"
|
" trigger\t\t- If set, a command to perform when event is hit\n"
|
"\t Format: <trigger>[:count][if <filter>]\n"
|
"\t trigger: traceon, traceoff\n"
|
"\t enable_event:<system>:<event>\n"
|
"\t disable_event:<system>:<event>\n"
|
#ifdef CONFIG_HIST_TRIGGERS
|
"\t enable_hist:<system>:<event>\n"
|
"\t disable_hist:<system>:<event>\n"
|
#endif
|
#ifdef CONFIG_STACKTRACE
|
"\t\t stacktrace\n"
|
#endif
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
"\t\t snapshot\n"
|
#endif
|
#ifdef CONFIG_HIST_TRIGGERS
|
"\t\t hist (see below)\n"
|
#endif
|
"\t example: echo traceoff > events/block/block_unplug/trigger\n"
|
"\t echo traceoff:3 > events/block/block_unplug/trigger\n"
|
"\t echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > \\\n"
|
"\t events/block/block_unplug/trigger\n"
|
"\t The first disables tracing every time block_unplug is hit.\n"
|
"\t The second disables tracing the first 3 times block_unplug is hit.\n"
|
"\t The third enables the kmalloc event the first 3 times block_unplug\n"
|
"\t is hit and has value of greater than 1 for the 'nr_rq' event field.\n"
|
"\t Like function triggers, the counter is only decremented if it\n"
|
"\t enabled or disabled tracing.\n"
|
"\t To remove a trigger without a count:\n"
|
"\t echo '!<trigger> > <system>/<event>/trigger\n"
|
"\t To remove a trigger with a count:\n"
|
"\t echo '!<trigger>:0 > <system>/<event>/trigger\n"
|
"\t Filters can be ignored when removing a trigger.\n"
|
#ifdef CONFIG_HIST_TRIGGERS
|
" hist trigger\t- If set, event hits are aggregated into a hash table\n"
|
"\t Format: hist:keys=<field1[,field2,...]>\n"
|
"\t [:values=<field1[,field2,...]>]\n"
|
"\t [:sort=<field1[,field2,...]>]\n"
|
"\t [:size=#entries]\n"
|
"\t [:pause][:continue][:clear]\n"
|
"\t [:name=histname1]\n"
|
"\t [:<handler>.<action>]\n"
|
"\t [if <filter>]\n\n"
|
"\t Note, special fields can be used as well:\n"
|
"\t common_timestamp - to record current timestamp\n"
|
"\t common_cpu - to record the CPU the event happened on\n"
|
"\n"
|
"\t When a matching event is hit, an entry is added to a hash\n"
|
"\t table using the key(s) and value(s) named, and the value of a\n"
|
"\t sum called 'hitcount' is incremented. Keys and values\n"
|
"\t correspond to fields in the event's format description. Keys\n"
|
"\t can be any field, or the special string 'stacktrace'.\n"
|
"\t Compound keys consisting of up to two fields can be specified\n"
|
"\t by the 'keys' keyword. Values must correspond to numeric\n"
|
"\t fields. Sort keys consisting of up to two fields can be\n"
|
"\t specified using the 'sort' keyword. The sort direction can\n"
|
"\t be modified by appending '.descending' or '.ascending' to a\n"
|
"\t sort field. The 'size' parameter can be used to specify more\n"
|
"\t or fewer than the default 2048 entries for the hashtable size.\n"
|
"\t If a hist trigger is given a name using the 'name' parameter,\n"
|
"\t its histogram data will be shared with other triggers of the\n"
|
"\t same name, and trigger hits will update this common data.\n\n"
|
"\t Reading the 'hist' file for the event will dump the hash\n"
|
"\t table in its entirety to stdout. If there are multiple hist\n"
|
"\t triggers attached to an event, there will be a table for each\n"
|
"\t trigger in the output. The table displayed for a named\n"
|
"\t trigger will be the same as any other instance having the\n"
|
"\t same name. The default format used to display a given field\n"
|
"\t can be modified by appending any of the following modifiers\n"
|
"\t to the field name, as applicable:\n\n"
|
"\t .hex display a number as a hex value\n"
|
"\t .sym display an address as a symbol\n"
|
"\t .sym-offset display an address as a symbol and offset\n"
|
"\t .execname display a common_pid as a program name\n"
|
"\t .syscall display a syscall id as a syscall name\n"
|
"\t .log2 display log2 value rather than raw number\n"
|
"\t .usecs display a common_timestamp in microseconds\n\n"
|
"\t The 'pause' parameter can be used to pause an existing hist\n"
|
"\t trigger or to start a hist trigger but not log any events\n"
|
"\t until told to do so. 'continue' can be used to start or\n"
|
"\t restart a paused hist trigger.\n\n"
|
"\t The 'clear' parameter will clear the contents of a running\n"
|
"\t hist trigger and leave its current paused/active state\n"
|
"\t unchanged.\n\n"
|
"\t The enable_hist and disable_hist triggers can be used to\n"
|
"\t have one event conditionally start and stop another event's\n"
|
"\t already-attached hist trigger. The syntax is analogous to\n"
|
"\t the enable_event and disable_event triggers.\n\n"
|
"\t Hist trigger handlers and actions are executed whenever a\n"
|
"\t a histogram entry is added or updated. They take the form:\n\n"
|
"\t <handler>.<action>\n\n"
|
"\t The available handlers are:\n\n"
|
"\t onmatch(matching.event) - invoke on addition or update\n"
|
"\t onmax(var) - invoke if var exceeds current max\n"
|
"\t onchange(var) - invoke action if var changes\n\n"
|
"\t The available actions are:\n\n"
|
"\t trace(<synthetic_event>,param list) - generate synthetic event\n"
|
"\t save(field,...) - save current event fields\n"
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
"\t snapshot() - snapshot the trace buffer\n\n"
|
#endif
|
#ifdef CONFIG_SYNTH_EVENTS
|
" events/synthetic_events\t- Create/append/remove/show synthetic events\n"
|
"\t Write into this file to define/undefine new synthetic events.\n"
|
"\t example: echo 'myevent u64 lat; char name[]' >> synthetic_events\n"
|
#endif
|
#endif
|
;
|
|
static ssize_t
|
tracing_readme_read(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
return simple_read_from_buffer(ubuf, cnt, ppos,
|
readme_msg, strlen(readme_msg));
|
}
|
|
static const struct file_operations tracing_readme_fops = {
|
.open = tracing_open_generic,
|
.read = tracing_readme_read,
|
.llseek = generic_file_llseek,
|
};
|
|
static void *saved_tgids_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
int pid = ++(*pos);
|
|
return trace_find_tgid_ptr(pid);
|
}
|
|
static void *saved_tgids_start(struct seq_file *m, loff_t *pos)
|
{
|
int pid = *pos;
|
|
return trace_find_tgid_ptr(pid);
|
}
|
|
static void saved_tgids_stop(struct seq_file *m, void *v)
|
{
|
}
|
|
static int saved_tgids_show(struct seq_file *m, void *v)
|
{
|
int *entry = (int *)v;
|
int pid = entry - tgid_map;
|
int tgid = *entry;
|
|
if (tgid == 0)
|
return SEQ_SKIP;
|
|
seq_printf(m, "%d %d\n", pid, tgid);
|
return 0;
|
}
|
|
static const struct seq_operations tracing_saved_tgids_seq_ops = {
|
.start = saved_tgids_start,
|
.stop = saved_tgids_stop,
|
.next = saved_tgids_next,
|
.show = saved_tgids_show,
|
};
|
|
static int tracing_saved_tgids_open(struct inode *inode, struct file *filp)
|
{
|
int ret;
|
|
ret = tracing_check_open_get_tr(NULL);
|
if (ret)
|
return ret;
|
|
return seq_open(filp, &tracing_saved_tgids_seq_ops);
|
}
|
|
|
static const struct file_operations tracing_saved_tgids_fops = {
|
.open = tracing_saved_tgids_open,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = seq_release,
|
};
|
|
static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
unsigned int *ptr = v;
|
|
if (*pos || m->count)
|
ptr++;
|
|
(*pos)++;
|
|
for (; ptr < &savedcmd->map_cmdline_to_pid[savedcmd->cmdline_num];
|
ptr++) {
|
if (*ptr == -1 || *ptr == NO_CMDLINE_MAP)
|
continue;
|
|
return ptr;
|
}
|
|
return NULL;
|
}
|
|
static void *saved_cmdlines_start(struct seq_file *m, loff_t *pos)
|
{
|
void *v;
|
loff_t l = 0;
|
|
preempt_disable();
|
arch_spin_lock(&trace_cmdline_lock);
|
|
v = &savedcmd->map_cmdline_to_pid[0];
|
while (l <= *pos) {
|
v = saved_cmdlines_next(m, v, &l);
|
if (!v)
|
return NULL;
|
}
|
|
return v;
|
}
|
|
static void saved_cmdlines_stop(struct seq_file *m, void *v)
|
{
|
arch_spin_unlock(&trace_cmdline_lock);
|
preempt_enable();
|
}
|
|
static int saved_cmdlines_show(struct seq_file *m, void *v)
|
{
|
char buf[TASK_COMM_LEN];
|
unsigned int *pid = v;
|
|
__trace_find_cmdline(*pid, buf);
|
seq_printf(m, "%d %s\n", *pid, buf);
|
return 0;
|
}
|
|
static const struct seq_operations tracing_saved_cmdlines_seq_ops = {
|
.start = saved_cmdlines_start,
|
.next = saved_cmdlines_next,
|
.stop = saved_cmdlines_stop,
|
.show = saved_cmdlines_show,
|
};
|
|
static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp)
|
{
|
int ret;
|
|
ret = tracing_check_open_get_tr(NULL);
|
if (ret)
|
return ret;
|
|
return seq_open(filp, &tracing_saved_cmdlines_seq_ops);
|
}
|
|
static const struct file_operations tracing_saved_cmdlines_fops = {
|
.open = tracing_saved_cmdlines_open,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = seq_release,
|
};
|
|
static ssize_t
|
tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
char buf[64];
|
int r;
|
|
preempt_disable();
|
arch_spin_lock(&trace_cmdline_lock);
|
r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num);
|
arch_spin_unlock(&trace_cmdline_lock);
|
preempt_enable();
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
}
|
|
static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
|
{
|
kfree(s->saved_cmdlines);
|
kfree(s->map_cmdline_to_pid);
|
kfree(s);
|
}
|
|
static int tracing_resize_saved_cmdlines(unsigned int val)
|
{
|
struct saved_cmdlines_buffer *s, *savedcmd_temp;
|
|
s = kmalloc(sizeof(*s), GFP_KERNEL);
|
if (!s)
|
return -ENOMEM;
|
|
if (allocate_cmdlines_buffer(val, s) < 0) {
|
kfree(s);
|
return -ENOMEM;
|
}
|
|
preempt_disable();
|
arch_spin_lock(&trace_cmdline_lock);
|
savedcmd_temp = savedcmd;
|
savedcmd = s;
|
arch_spin_unlock(&trace_cmdline_lock);
|
preempt_enable();
|
free_saved_cmdlines_buffer(savedcmd_temp);
|
|
return 0;
|
}
|
|
static ssize_t
|
tracing_saved_cmdlines_size_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
unsigned long val;
|
int ret;
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
if (ret)
|
return ret;
|
|
/* must have at least 1 entry or less than PID_MAX_DEFAULT */
|
if (!val || val > PID_MAX_DEFAULT)
|
return -EINVAL;
|
|
ret = tracing_resize_saved_cmdlines((unsigned int)val);
|
if (ret < 0)
|
return ret;
|
|
*ppos += cnt;
|
|
return cnt;
|
}
|
|
static const struct file_operations tracing_saved_cmdlines_size_fops = {
|
.open = tracing_open_generic,
|
.read = tracing_saved_cmdlines_size_read,
|
.write = tracing_saved_cmdlines_size_write,
|
};
|
|
#ifdef CONFIG_TRACE_EVAL_MAP_FILE
|
static union trace_eval_map_item *
|
update_eval_map(union trace_eval_map_item *ptr)
|
{
|
if (!ptr->map.eval_string) {
|
if (ptr->tail.next) {
|
ptr = ptr->tail.next;
|
/* Set ptr to the next real item (skip head) */
|
ptr++;
|
} else
|
return NULL;
|
}
|
return ptr;
|
}
|
|
static void *eval_map_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
union trace_eval_map_item *ptr = v;
|
|
/*
|
* Paranoid! If ptr points to end, we don't want to increment past it.
|
* This really should never happen.
|
*/
|
(*pos)++;
|
ptr = update_eval_map(ptr);
|
if (WARN_ON_ONCE(!ptr))
|
return NULL;
|
|
ptr++;
|
ptr = update_eval_map(ptr);
|
|
return ptr;
|
}
|
|
static void *eval_map_start(struct seq_file *m, loff_t *pos)
|
{
|
union trace_eval_map_item *v;
|
loff_t l = 0;
|
|
mutex_lock(&trace_eval_mutex);
|
|
v = trace_eval_maps;
|
if (v)
|
v++;
|
|
while (v && l < *pos) {
|
v = eval_map_next(m, v, &l);
|
}
|
|
return v;
|
}
|
|
static void eval_map_stop(struct seq_file *m, void *v)
|
{
|
mutex_unlock(&trace_eval_mutex);
|
}
|
|
static int eval_map_show(struct seq_file *m, void *v)
|
{
|
union trace_eval_map_item *ptr = v;
|
|
seq_printf(m, "%s %ld (%s)\n",
|
ptr->map.eval_string, ptr->map.eval_value,
|
ptr->map.system);
|
|
return 0;
|
}
|
|
static const struct seq_operations tracing_eval_map_seq_ops = {
|
.start = eval_map_start,
|
.next = eval_map_next,
|
.stop = eval_map_stop,
|
.show = eval_map_show,
|
};
|
|
static int tracing_eval_map_open(struct inode *inode, struct file *filp)
|
{
|
int ret;
|
|
ret = tracing_check_open_get_tr(NULL);
|
if (ret)
|
return ret;
|
|
return seq_open(filp, &tracing_eval_map_seq_ops);
|
}
|
|
static const struct file_operations tracing_eval_map_fops = {
|
.open = tracing_eval_map_open,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = seq_release,
|
};
|
|
static inline union trace_eval_map_item *
|
trace_eval_jmp_to_tail(union trace_eval_map_item *ptr)
|
{
|
/* Return tail of array given the head */
|
return ptr + ptr->head.length + 1;
|
}
|
|
static void
|
trace_insert_eval_map_file(struct module *mod, struct trace_eval_map **start,
|
int len)
|
{
|
struct trace_eval_map **stop;
|
struct trace_eval_map **map;
|
union trace_eval_map_item *map_array;
|
union trace_eval_map_item *ptr;
|
|
stop = start + len;
|
|
/*
|
* The trace_eval_maps contains the map plus a head and tail item,
|
* where the head holds the module and length of array, and the
|
* tail holds a pointer to the next list.
|
*/
|
map_array = kmalloc_array(len + 2, sizeof(*map_array), GFP_KERNEL);
|
if (!map_array) {
|
pr_warn("Unable to allocate trace eval mapping\n");
|
return;
|
}
|
|
mutex_lock(&trace_eval_mutex);
|
|
if (!trace_eval_maps)
|
trace_eval_maps = map_array;
|
else {
|
ptr = trace_eval_maps;
|
for (;;) {
|
ptr = trace_eval_jmp_to_tail(ptr);
|
if (!ptr->tail.next)
|
break;
|
ptr = ptr->tail.next;
|
|
}
|
ptr->tail.next = map_array;
|
}
|
map_array->head.mod = mod;
|
map_array->head.length = len;
|
map_array++;
|
|
for (map = start; (unsigned long)map < (unsigned long)stop; map++) {
|
map_array->map = **map;
|
map_array++;
|
}
|
memset(map_array, 0, sizeof(*map_array));
|
|
mutex_unlock(&trace_eval_mutex);
|
}
|
|
static void trace_create_eval_file(struct dentry *d_tracer)
|
{
|
trace_create_file("eval_map", 0444, d_tracer,
|
NULL, &tracing_eval_map_fops);
|
}
|
|
#else /* CONFIG_TRACE_EVAL_MAP_FILE */
|
static inline void trace_create_eval_file(struct dentry *d_tracer) { }
|
static inline void trace_insert_eval_map_file(struct module *mod,
|
struct trace_eval_map **start, int len) { }
|
#endif /* !CONFIG_TRACE_EVAL_MAP_FILE */
|
|
static void trace_insert_eval_map(struct module *mod,
|
struct trace_eval_map **start, int len)
|
{
|
struct trace_eval_map **map;
|
|
if (len <= 0)
|
return;
|
|
map = start;
|
|
trace_event_eval_update(map, len);
|
|
trace_insert_eval_map_file(mod, start, len);
|
}
|
|
static ssize_t
|
tracing_set_trace_read(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct trace_array *tr = filp->private_data;
|
char buf[MAX_TRACER_SIZE+2];
|
int r;
|
|
mutex_lock(&trace_types_lock);
|
r = sprintf(buf, "%s\n", tr->current_trace->name);
|
mutex_unlock(&trace_types_lock);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
}
|
|
int tracer_init(struct tracer *t, struct trace_array *tr)
|
{
|
tracing_reset_online_cpus(&tr->array_buffer);
|
return t->init(tr);
|
}
|
|
static void set_buffer_entries(struct array_buffer *buf, unsigned long val)
|
{
|
int cpu;
|
|
for_each_tracing_cpu(cpu)
|
per_cpu_ptr(buf->data, cpu)->entries = val;
|
}
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
/* resize @tr's buffer to the size of @size_tr's entries */
|
static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
|
struct array_buffer *size_buf, int cpu_id)
|
{
|
int cpu, ret = 0;
|
|
if (cpu_id == RING_BUFFER_ALL_CPUS) {
|
for_each_tracing_cpu(cpu) {
|
ret = ring_buffer_resize(trace_buf->buffer,
|
per_cpu_ptr(size_buf->data, cpu)->entries, cpu);
|
if (ret < 0)
|
break;
|
per_cpu_ptr(trace_buf->data, cpu)->entries =
|
per_cpu_ptr(size_buf->data, cpu)->entries;
|
}
|
} else {
|
ret = ring_buffer_resize(trace_buf->buffer,
|
per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id);
|
if (ret == 0)
|
per_cpu_ptr(trace_buf->data, cpu_id)->entries =
|
per_cpu_ptr(size_buf->data, cpu_id)->entries;
|
}
|
|
return ret;
|
}
|
#endif /* CONFIG_TRACER_MAX_TRACE */
|
|
static int __tracing_resize_ring_buffer(struct trace_array *tr,
|
unsigned long size, int cpu)
|
{
|
int ret;
|
|
/*
|
* If kernel or user changes the size of the ring buffer
|
* we use the size that was given, and we can forget about
|
* expanding it later.
|
*/
|
ring_buffer_expanded = true;
|
|
/* May be called before buffers are initialized */
|
if (!tr->array_buffer.buffer)
|
return 0;
|
|
ret = ring_buffer_resize(tr->array_buffer.buffer, size, cpu);
|
if (ret < 0)
|
return ret;
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL) ||
|
!tr->current_trace->use_max_tr)
|
goto out;
|
|
ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu);
|
if (ret < 0) {
|
int r = resize_buffer_duplicate_size(&tr->array_buffer,
|
&tr->array_buffer, cpu);
|
if (r < 0) {
|
/*
|
* AARGH! We are left with different
|
* size max buffer!!!!
|
* The max buffer is our "snapshot" buffer.
|
* When a tracer needs a snapshot (one of the
|
* latency tracers), it swaps the max buffer
|
* with the saved snap shot. We succeeded to
|
* update the size of the main buffer, but failed to
|
* update the size of the max buffer. But when we tried
|
* to reset the main buffer to the original size, we
|
* failed there too. This is very unlikely to
|
* happen, but if it does, warn and kill all
|
* tracing.
|
*/
|
WARN_ON(1);
|
tracing_disabled = 1;
|
}
|
return ret;
|
}
|
|
if (cpu == RING_BUFFER_ALL_CPUS)
|
set_buffer_entries(&tr->max_buffer, size);
|
else
|
per_cpu_ptr(tr->max_buffer.data, cpu)->entries = size;
|
|
out:
|
#endif /* CONFIG_TRACER_MAX_TRACE */
|
|
if (cpu == RING_BUFFER_ALL_CPUS)
|
set_buffer_entries(&tr->array_buffer, size);
|
else
|
per_cpu_ptr(tr->array_buffer.data, cpu)->entries = size;
|
|
return ret;
|
}
|
|
ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
|
unsigned long size, int cpu_id)
|
{
|
int ret = size;
|
|
mutex_lock(&trace_types_lock);
|
|
if (cpu_id != RING_BUFFER_ALL_CPUS) {
|
/* make sure, this cpu is enabled in the mask */
|
if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) {
|
ret = -EINVAL;
|
goto out;
|
}
|
}
|
|
ret = __tracing_resize_ring_buffer(tr, size, cpu_id);
|
if (ret < 0)
|
ret = -ENOMEM;
|
|
out:
|
mutex_unlock(&trace_types_lock);
|
|
return ret;
|
}
|
|
|
/**
|
* tracing_update_buffers - used by tracing facility to expand ring buffers
|
*
|
* To save on memory when the tracing is never used on a system with it
|
* configured in. The ring buffers are set to a minimum size. But once
|
* a user starts to use the tracing facility, then they need to grow
|
* to their default size.
|
*
|
* This function is to be called when a tracer is about to be used.
|
*/
|
int tracing_update_buffers(void)
|
{
|
int ret = 0;
|
|
mutex_lock(&trace_types_lock);
|
if (!ring_buffer_expanded)
|
ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size,
|
RING_BUFFER_ALL_CPUS);
|
mutex_unlock(&trace_types_lock);
|
|
return ret;
|
}
|
|
struct trace_option_dentry;
|
|
static void
|
create_trace_option_files(struct trace_array *tr, struct tracer *tracer);
|
|
/*
|
* Used to clear out the tracer before deletion of an instance.
|
* Must have trace_types_lock held.
|
*/
|
static void tracing_set_nop(struct trace_array *tr)
|
{
|
if (tr->current_trace == &nop_trace)
|
return;
|
|
tr->current_trace->enabled--;
|
|
if (tr->current_trace->reset)
|
tr->current_trace->reset(tr);
|
|
tr->current_trace = &nop_trace;
|
}
|
|
static bool tracer_options_updated;
|
|
static void add_tracer_options(struct trace_array *tr, struct tracer *t)
|
{
|
/* Only enable if the directory has been created already. */
|
if (!tr->dir)
|
return;
|
|
/* Only create trace option files after update_tracer_options finish */
|
if (!tracer_options_updated)
|
return;
|
|
create_trace_option_files(tr, t);
|
}
|
|
int tracing_set_tracer(struct trace_array *tr, const char *buf)
|
{
|
struct tracer *t;
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
bool had_max_tr;
|
#endif
|
int ret = 0;
|
|
mutex_lock(&trace_types_lock);
|
|
if (!ring_buffer_expanded) {
|
ret = __tracing_resize_ring_buffer(tr, trace_buf_size,
|
RING_BUFFER_ALL_CPUS);
|
if (ret < 0)
|
goto out;
|
ret = 0;
|
}
|
|
for (t = trace_types; t; t = t->next) {
|
if (strcmp(t->name, buf) == 0)
|
break;
|
}
|
if (!t) {
|
ret = -EINVAL;
|
goto out;
|
}
|
if (t == tr->current_trace)
|
goto out;
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
if (t->use_max_tr) {
|
local_irq_disable();
|
arch_spin_lock(&tr->max_lock);
|
if (tr->cond_snapshot)
|
ret = -EBUSY;
|
arch_spin_unlock(&tr->max_lock);
|
local_irq_enable();
|
if (ret)
|
goto out;
|
}
|
#endif
|
/* Some tracers won't work on kernel command line */
|
if (system_state < SYSTEM_RUNNING && t->noboot) {
|
pr_warn("Tracer '%s' is not allowed on command line, ignored\n",
|
t->name);
|
goto out;
|
}
|
|
/* Some tracers are only allowed for the top level buffer */
|
if (!trace_ok_for_array(t, tr)) {
|
ret = -EINVAL;
|
goto out;
|
}
|
|
/* If trace pipe files are being read, we can't change the tracer */
|
if (tr->trace_ref) {
|
ret = -EBUSY;
|
goto out;
|
}
|
|
trace_branch_disable();
|
|
tr->current_trace->enabled--;
|
|
if (tr->current_trace->reset)
|
tr->current_trace->reset(tr);
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
had_max_tr = tr->current_trace->use_max_tr;
|
|
/* Current trace needs to be nop_trace before synchronize_rcu */
|
tr->current_trace = &nop_trace;
|
|
if (had_max_tr && !t->use_max_tr) {
|
/*
|
* We need to make sure that the update_max_tr sees that
|
* current_trace changed to nop_trace to keep it from
|
* swapping the buffers after we resize it.
|
* The update_max_tr is called from interrupts disabled
|
* so a synchronized_sched() is sufficient.
|
*/
|
synchronize_rcu();
|
free_snapshot(tr);
|
}
|
|
if (t->use_max_tr && !tr->allocated_snapshot) {
|
ret = tracing_alloc_snapshot_instance(tr);
|
if (ret < 0)
|
goto out;
|
}
|
#else
|
tr->current_trace = &nop_trace;
|
#endif
|
|
if (t->init) {
|
ret = tracer_init(t, tr);
|
if (ret)
|
goto out;
|
}
|
|
tr->current_trace = t;
|
tr->current_trace->enabled++;
|
trace_branch_enable(tr);
|
out:
|
mutex_unlock(&trace_types_lock);
|
|
return ret;
|
}
|
|
static ssize_t
|
tracing_set_trace_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct trace_array *tr = filp->private_data;
|
char buf[MAX_TRACER_SIZE+1];
|
int i;
|
size_t ret;
|
int err;
|
|
ret = cnt;
|
|
if (cnt > MAX_TRACER_SIZE)
|
cnt = MAX_TRACER_SIZE;
|
|
if (copy_from_user(buf, ubuf, cnt))
|
return -EFAULT;
|
|
buf[cnt] = 0;
|
|
/* strip ending whitespace. */
|
for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
|
buf[i] = 0;
|
|
err = tracing_set_tracer(tr, buf);
|
if (err)
|
return err;
|
|
*ppos += ret;
|
|
return ret;
|
}
|
|
static ssize_t
|
tracing_nsecs_read(unsigned long *ptr, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
char buf[64];
|
int r;
|
|
r = snprintf(buf, sizeof(buf), "%ld\n",
|
*ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
|
if (r > sizeof(buf))
|
r = sizeof(buf);
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
}
|
|
static ssize_t
|
tracing_nsecs_write(unsigned long *ptr, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
unsigned long val;
|
int ret;
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
if (ret)
|
return ret;
|
|
*ptr = val * 1000;
|
|
return cnt;
|
}
|
|
static ssize_t
|
tracing_thresh_read(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
return tracing_nsecs_read(&tracing_thresh, ubuf, cnt, ppos);
|
}
|
|
static ssize_t
|
tracing_thresh_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct trace_array *tr = filp->private_data;
|
int ret;
|
|
mutex_lock(&trace_types_lock);
|
ret = tracing_nsecs_write(&tracing_thresh, ubuf, cnt, ppos);
|
if (ret < 0)
|
goto out;
|
|
if (tr->current_trace->update_thresh) {
|
ret = tr->current_trace->update_thresh(tr);
|
if (ret < 0)
|
goto out;
|
}
|
|
ret = cnt;
|
out:
|
mutex_unlock(&trace_types_lock);
|
|
return ret;
|
}
|
|
#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
|
|
static ssize_t
|
tracing_max_lat_read(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
return tracing_nsecs_read(filp->private_data, ubuf, cnt, ppos);
|
}
|
|
static ssize_t
|
tracing_max_lat_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
return tracing_nsecs_write(filp->private_data, ubuf, cnt, ppos);
|
}
|
|
#endif
|
|
static int tracing_open_pipe(struct inode *inode, struct file *filp)
|
{
|
struct trace_array *tr = inode->i_private;
|
struct trace_iterator *iter;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
mutex_lock(&trace_types_lock);
|
|
/* create a buffer to store the information to pass to userspace */
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
if (!iter) {
|
ret = -ENOMEM;
|
__trace_array_put(tr);
|
goto out;
|
}
|
|
trace_seq_init(&iter->seq);
|
iter->trace = tr->current_trace;
|
|
if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
|
ret = -ENOMEM;
|
goto fail;
|
}
|
|
/* trace pipe does not show start of buffer */
|
cpumask_setall(iter->started);
|
|
if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
|
iter->iter_flags |= TRACE_FILE_LAT_FMT;
|
|
/* Output in nanoseconds only if we are using a clock in nanoseconds. */
|
if (trace_clocks[tr->clock_id].in_ns)
|
iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
|
|
iter->tr = tr;
|
iter->array_buffer = &tr->array_buffer;
|
iter->cpu_file = tracing_get_cpu(inode);
|
mutex_init(&iter->mutex);
|
filp->private_data = iter;
|
|
if (iter->trace->pipe_open)
|
iter->trace->pipe_open(iter);
|
|
nonseekable_open(inode, filp);
|
|
tr->trace_ref++;
|
out:
|
mutex_unlock(&trace_types_lock);
|
return ret;
|
|
fail:
|
kfree(iter);
|
__trace_array_put(tr);
|
mutex_unlock(&trace_types_lock);
|
return ret;
|
}
|
|
static int tracing_release_pipe(struct inode *inode, struct file *file)
|
{
|
struct trace_iterator *iter = file->private_data;
|
struct trace_array *tr = inode->i_private;
|
|
mutex_lock(&trace_types_lock);
|
|
tr->trace_ref--;
|
|
if (iter->trace->pipe_close)
|
iter->trace->pipe_close(iter);
|
|
mutex_unlock(&trace_types_lock);
|
|
free_cpumask_var(iter->started);
|
mutex_destroy(&iter->mutex);
|
kfree(iter);
|
|
trace_array_put(tr);
|
|
return 0;
|
}
|
|
static __poll_t
|
trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table)
|
{
|
struct trace_array *tr = iter->tr;
|
|
/* Iterators are static, they should be filled or empty */
|
if (trace_buffer_iter(iter, iter->cpu_file))
|
return EPOLLIN | EPOLLRDNORM;
|
|
if (tr->trace_flags & TRACE_ITER_BLOCK)
|
/*
|
* Always select as readable when in blocking mode
|
*/
|
return EPOLLIN | EPOLLRDNORM;
|
else
|
return ring_buffer_poll_wait(iter->array_buffer->buffer, iter->cpu_file,
|
filp, poll_table, iter->tr->buffer_percent);
|
}
|
|
static __poll_t
|
tracing_poll_pipe(struct file *filp, poll_table *poll_table)
|
{
|
struct trace_iterator *iter = filp->private_data;
|
|
return trace_poll(iter, filp, poll_table);
|
}
|
|
/* Must be called with iter->mutex held. */
|
static int tracing_wait_pipe(struct file *filp)
|
{
|
struct trace_iterator *iter = filp->private_data;
|
int ret;
|
|
while (trace_empty(iter)) {
|
|
if ((filp->f_flags & O_NONBLOCK)) {
|
return -EAGAIN;
|
}
|
|
/*
|
* We block until we read something and tracing is disabled.
|
* We still block if tracing is disabled, but we have never
|
* read anything. This allows a user to cat this file, and
|
* then enable tracing. But after we have read something,
|
* we give an EOF when tracing is again disabled.
|
*
|
* iter->pos will be 0 if we haven't read anything.
|
*/
|
if (!tracer_tracing_is_on(iter->tr) && iter->pos)
|
break;
|
|
mutex_unlock(&iter->mutex);
|
|
ret = wait_on_pipe(iter, 0);
|
|
mutex_lock(&iter->mutex);
|
|
if (ret)
|
return ret;
|
}
|
|
return 1;
|
}
|
|
/*
|
* Consumer reader.
|
*/
|
static ssize_t
|
tracing_read_pipe(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct trace_iterator *iter = filp->private_data;
|
ssize_t sret;
|
|
/*
|
* Avoid more than one consumer on a single file descriptor
|
* This is just a matter of traces coherency, the ring buffer itself
|
* is protected.
|
*/
|
mutex_lock(&iter->mutex);
|
|
/* return any leftover data */
|
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
|
if (sret != -EBUSY)
|
goto out;
|
|
trace_seq_init(&iter->seq);
|
|
if (iter->trace->read) {
|
sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
|
if (sret)
|
goto out;
|
}
|
|
waitagain:
|
sret = tracing_wait_pipe(filp);
|
if (sret <= 0)
|
goto out;
|
|
/* stop when tracing is finished */
|
if (trace_empty(iter)) {
|
sret = 0;
|
goto out;
|
}
|
|
if (cnt >= PAGE_SIZE)
|
cnt = PAGE_SIZE - 1;
|
|
/* reset all but tr, trace, and overruns */
|
memset(&iter->seq, 0,
|
sizeof(struct trace_iterator) -
|
offsetof(struct trace_iterator, seq));
|
cpumask_clear(iter->started);
|
trace_seq_init(&iter->seq);
|
iter->pos = -1;
|
|
trace_event_read_lock();
|
trace_access_lock(iter->cpu_file);
|
while (trace_find_next_entry_inc(iter) != NULL) {
|
enum print_line_t ret;
|
int save_len = iter->seq.seq.len;
|
|
ret = print_trace_line(iter);
|
if (ret == TRACE_TYPE_PARTIAL_LINE) {
|
/* don't print partial lines */
|
iter->seq.seq.len = save_len;
|
break;
|
}
|
if (ret != TRACE_TYPE_NO_CONSUME)
|
trace_consume(iter);
|
|
if (trace_seq_used(&iter->seq) >= cnt)
|
break;
|
|
/*
|
* Setting the full flag means we reached the trace_seq buffer
|
* size and we should leave by partial output condition above.
|
* One of the trace_seq_* functions is not used properly.
|
*/
|
WARN_ONCE(iter->seq.full, "full flag set for trace type %d",
|
iter->ent->type);
|
}
|
trace_access_unlock(iter->cpu_file);
|
trace_event_read_unlock();
|
|
/* Now copy what we have to the user */
|
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
|
if (iter->seq.seq.readpos >= trace_seq_used(&iter->seq))
|
trace_seq_init(&iter->seq);
|
|
/*
|
* If there was nothing to send to user, in spite of consuming trace
|
* entries, go back to wait for more entries.
|
*/
|
if (sret == -EBUSY)
|
goto waitagain;
|
|
out:
|
mutex_unlock(&iter->mutex);
|
|
return sret;
|
}
|
|
static void tracing_spd_release_pipe(struct splice_pipe_desc *spd,
|
unsigned int idx)
|
{
|
__free_page(spd->pages[idx]);
|
}
|
|
static size_t
|
tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
|
{
|
size_t count;
|
int save_len;
|
int ret;
|
|
/* Seq buffer is page-sized, exactly what we need. */
|
for (;;) {
|
save_len = iter->seq.seq.len;
|
ret = print_trace_line(iter);
|
|
if (trace_seq_has_overflowed(&iter->seq)) {
|
iter->seq.seq.len = save_len;
|
break;
|
}
|
|
/*
|
* This should not be hit, because it should only
|
* be set if the iter->seq overflowed. But check it
|
* anyway to be safe.
|
*/
|
if (ret == TRACE_TYPE_PARTIAL_LINE) {
|
iter->seq.seq.len = save_len;
|
break;
|
}
|
|
count = trace_seq_used(&iter->seq) - save_len;
|
if (rem < count) {
|
rem = 0;
|
iter->seq.seq.len = save_len;
|
break;
|
}
|
|
if (ret != TRACE_TYPE_NO_CONSUME)
|
trace_consume(iter);
|
rem -= count;
|
if (!trace_find_next_entry_inc(iter)) {
|
rem = 0;
|
iter->ent = NULL;
|
break;
|
}
|
}
|
|
return rem;
|
}
|
|
static ssize_t tracing_splice_read_pipe(struct file *filp,
|
loff_t *ppos,
|
struct pipe_inode_info *pipe,
|
size_t len,
|
unsigned int flags)
|
{
|
struct page *pages_def[PIPE_DEF_BUFFERS];
|
struct partial_page partial_def[PIPE_DEF_BUFFERS];
|
struct trace_iterator *iter = filp->private_data;
|
struct splice_pipe_desc spd = {
|
.pages = pages_def,
|
.partial = partial_def,
|
.nr_pages = 0, /* This gets updated below. */
|
.nr_pages_max = PIPE_DEF_BUFFERS,
|
.ops = &default_pipe_buf_ops,
|
.spd_release = tracing_spd_release_pipe,
|
};
|
ssize_t ret;
|
size_t rem;
|
unsigned int i;
|
|
if (splice_grow_spd(pipe, &spd))
|
return -ENOMEM;
|
|
mutex_lock(&iter->mutex);
|
|
if (iter->trace->splice_read) {
|
ret = iter->trace->splice_read(iter, filp,
|
ppos, pipe, len, flags);
|
if (ret)
|
goto out_err;
|
}
|
|
ret = tracing_wait_pipe(filp);
|
if (ret <= 0)
|
goto out_err;
|
|
if (!iter->ent && !trace_find_next_entry_inc(iter)) {
|
ret = -EFAULT;
|
goto out_err;
|
}
|
|
trace_event_read_lock();
|
trace_access_lock(iter->cpu_file);
|
|
/* Fill as many pages as possible. */
|
for (i = 0, rem = len; i < spd.nr_pages_max && rem; i++) {
|
spd.pages[i] = alloc_page(GFP_KERNEL);
|
if (!spd.pages[i])
|
break;
|
|
rem = tracing_fill_pipe_page(rem, iter);
|
|
/* Copy the data into the page, so we can start over. */
|
ret = trace_seq_to_buffer(&iter->seq,
|
page_address(spd.pages[i]),
|
trace_seq_used(&iter->seq));
|
if (ret < 0) {
|
__free_page(spd.pages[i]);
|
break;
|
}
|
spd.partial[i].offset = 0;
|
spd.partial[i].len = trace_seq_used(&iter->seq);
|
|
trace_seq_init(&iter->seq);
|
}
|
|
trace_access_unlock(iter->cpu_file);
|
trace_event_read_unlock();
|
mutex_unlock(&iter->mutex);
|
|
spd.nr_pages = i;
|
|
if (i)
|
ret = splice_to_pipe(pipe, &spd);
|
else
|
ret = 0;
|
out:
|
splice_shrink_spd(&spd);
|
return ret;
|
|
out_err:
|
mutex_unlock(&iter->mutex);
|
goto out;
|
}
|
|
static ssize_t
|
tracing_entries_read(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct inode *inode = file_inode(filp);
|
struct trace_array *tr = inode->i_private;
|
int cpu = tracing_get_cpu(inode);
|
char buf[64];
|
int r = 0;
|
ssize_t ret;
|
|
mutex_lock(&trace_types_lock);
|
|
if (cpu == RING_BUFFER_ALL_CPUS) {
|
int cpu, buf_size_same;
|
unsigned long size;
|
|
size = 0;
|
buf_size_same = 1;
|
/* check if all cpu sizes are same */
|
for_each_tracing_cpu(cpu) {
|
/* fill in the size from first enabled cpu */
|
if (size == 0)
|
size = per_cpu_ptr(tr->array_buffer.data, cpu)->entries;
|
if (size != per_cpu_ptr(tr->array_buffer.data, cpu)->entries) {
|
buf_size_same = 0;
|
break;
|
}
|
}
|
|
if (buf_size_same) {
|
if (!ring_buffer_expanded)
|
r = sprintf(buf, "%lu (expanded: %lu)\n",
|
size >> 10,
|
trace_buf_size >> 10);
|
else
|
r = sprintf(buf, "%lu\n", size >> 10);
|
} else
|
r = sprintf(buf, "X\n");
|
} else
|
r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10);
|
|
mutex_unlock(&trace_types_lock);
|
|
ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
return ret;
|
}
|
|
static ssize_t
|
tracing_entries_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct inode *inode = file_inode(filp);
|
struct trace_array *tr = inode->i_private;
|
unsigned long val;
|
int ret;
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
if (ret)
|
return ret;
|
|
/* must have at least 1 entry */
|
if (!val)
|
return -EINVAL;
|
|
/* value is in KB */
|
val <<= 10;
|
ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode));
|
if (ret < 0)
|
return ret;
|
|
*ppos += cnt;
|
|
return cnt;
|
}
|
|
static ssize_t
|
tracing_total_entries_read(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct trace_array *tr = filp->private_data;
|
char buf[64];
|
int r, cpu;
|
unsigned long size = 0, expanded_size = 0;
|
|
mutex_lock(&trace_types_lock);
|
for_each_tracing_cpu(cpu) {
|
size += per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10;
|
if (!ring_buffer_expanded)
|
expanded_size += trace_buf_size >> 10;
|
}
|
if (ring_buffer_expanded)
|
r = sprintf(buf, "%lu\n", size);
|
else
|
r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size);
|
mutex_unlock(&trace_types_lock);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
}
|
|
static ssize_t
|
tracing_free_buffer_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
/*
|
* There is no need to read what the user has written, this function
|
* is just to make sure that there is no error when "echo" is used
|
*/
|
|
*ppos += cnt;
|
|
return cnt;
|
}
|
|
static int
|
tracing_free_buffer_release(struct inode *inode, struct file *filp)
|
{
|
struct trace_array *tr = inode->i_private;
|
|
/* disable tracing ? */
|
if (tr->trace_flags & TRACE_ITER_STOP_ON_FREE)
|
tracer_tracing_off(tr);
|
/* resize the ring buffer to 0 */
|
tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS);
|
|
trace_array_put(tr);
|
|
return 0;
|
}
|
|
static ssize_t
|
tracing_mark_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *fpos)
|
{
|
struct trace_array *tr = filp->private_data;
|
struct ring_buffer_event *event;
|
enum event_trigger_type tt = ETT_NONE;
|
struct trace_buffer *buffer;
|
struct print_entry *entry;
|
ssize_t written;
|
int size;
|
int len;
|
|
/* Used in tracing_mark_raw_write() as well */
|
#define FAULTED_STR "<faulted>"
|
#define FAULTED_SIZE (sizeof(FAULTED_STR) - 1) /* '\0' is already accounted for */
|
|
if (tracing_disabled)
|
return -EINVAL;
|
|
if (!(tr->trace_flags & TRACE_ITER_MARKERS))
|
return -EINVAL;
|
|
if (cnt > TRACE_BUF_SIZE)
|
cnt = TRACE_BUF_SIZE;
|
|
BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE);
|
|
size = sizeof(*entry) + cnt + 2; /* add '\0' and possible '\n' */
|
|
/* If less than "<faulted>", then make sure we can still add that */
|
if (cnt < FAULTED_SIZE)
|
size += FAULTED_SIZE - cnt;
|
|
buffer = tr->array_buffer.buffer;
|
event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
|
tracing_gen_ctx());
|
if (unlikely(!event))
|
/* Ring buffer disabled, return as if not open for write */
|
return -EBADF;
|
|
entry = ring_buffer_event_data(event);
|
entry->ip = _THIS_IP_;
|
|
len = __copy_from_user_inatomic(&entry->buf, ubuf, cnt);
|
if (len) {
|
memcpy(&entry->buf, FAULTED_STR, FAULTED_SIZE);
|
cnt = FAULTED_SIZE;
|
written = -EFAULT;
|
} else
|
written = cnt;
|
|
if (tr->trace_marker_file && !list_empty(&tr->trace_marker_file->triggers)) {
|
/* do not add \n before testing triggers, but add \0 */
|
entry->buf[cnt] = '\0';
|
tt = event_triggers_call(tr->trace_marker_file, entry, event);
|
}
|
|
if (entry->buf[cnt - 1] != '\n') {
|
entry->buf[cnt] = '\n';
|
entry->buf[cnt + 1] = '\0';
|
} else
|
entry->buf[cnt] = '\0';
|
|
if (static_branch_unlikely(&trace_marker_exports_enabled))
|
ftrace_exports(event, TRACE_EXPORT_MARKER);
|
__buffer_unlock_commit(buffer, event);
|
|
if (tt)
|
event_triggers_post_call(tr->trace_marker_file, tt);
|
|
if (written > 0)
|
*fpos += written;
|
|
return written;
|
}
|
|
/* Limit it for now to 3K (including tag) */
|
#define RAW_DATA_MAX_SIZE (1024*3)
|
|
static ssize_t
|
tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *fpos)
|
{
|
struct trace_array *tr = filp->private_data;
|
struct ring_buffer_event *event;
|
struct trace_buffer *buffer;
|
struct raw_data_entry *entry;
|
ssize_t written;
|
int size;
|
int len;
|
|
#define FAULT_SIZE_ID (FAULTED_SIZE + sizeof(int))
|
|
if (tracing_disabled)
|
return -EINVAL;
|
|
if (!(tr->trace_flags & TRACE_ITER_MARKERS))
|
return -EINVAL;
|
|
/* The marker must at least have a tag id */
|
if (cnt < sizeof(unsigned int) || cnt > RAW_DATA_MAX_SIZE)
|
return -EINVAL;
|
|
if (cnt > TRACE_BUF_SIZE)
|
cnt = TRACE_BUF_SIZE;
|
|
BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE);
|
|
size = sizeof(*entry) + cnt;
|
if (cnt < FAULT_SIZE_ID)
|
size += FAULT_SIZE_ID - cnt;
|
|
buffer = tr->array_buffer.buffer;
|
event = __trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size,
|
tracing_gen_ctx());
|
if (!event)
|
/* Ring buffer disabled, return as if not open for write */
|
return -EBADF;
|
|
entry = ring_buffer_event_data(event);
|
|
len = __copy_from_user_inatomic(&entry->id, ubuf, cnt);
|
if (len) {
|
entry->id = -1;
|
memcpy(&entry->buf, FAULTED_STR, FAULTED_SIZE);
|
written = -EFAULT;
|
} else
|
written = cnt;
|
|
__buffer_unlock_commit(buffer, event);
|
|
if (written > 0)
|
*fpos += written;
|
|
return written;
|
}
|
|
static int tracing_clock_show(struct seq_file *m, void *v)
|
{
|
struct trace_array *tr = m->private;
|
int i;
|
|
for (i = 0; i < ARRAY_SIZE(trace_clocks); i++)
|
seq_printf(m,
|
"%s%s%s%s", i ? " " : "",
|
i == tr->clock_id ? "[" : "", trace_clocks[i].name,
|
i == tr->clock_id ? "]" : "");
|
seq_putc(m, '\n');
|
|
return 0;
|
}
|
|
int tracing_set_clock(struct trace_array *tr, const char *clockstr)
|
{
|
int i;
|
|
for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) {
|
if (strcmp(trace_clocks[i].name, clockstr) == 0)
|
break;
|
}
|
if (i == ARRAY_SIZE(trace_clocks))
|
return -EINVAL;
|
|
mutex_lock(&trace_types_lock);
|
|
tr->clock_id = i;
|
|
ring_buffer_set_clock(tr->array_buffer.buffer, trace_clocks[i].func);
|
|
/*
|
* New clock may not be consistent with the previous clock.
|
* Reset the buffer so that it doesn't have incomparable timestamps.
|
*/
|
tracing_reset_online_cpus(&tr->array_buffer);
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
if (tr->max_buffer.buffer)
|
ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
|
tracing_reset_online_cpus(&tr->max_buffer);
|
#endif
|
|
mutex_unlock(&trace_types_lock);
|
|
return 0;
|
}
|
|
static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *fpos)
|
{
|
struct seq_file *m = filp->private_data;
|
struct trace_array *tr = m->private;
|
char buf[64];
|
const char *clockstr;
|
int ret;
|
|
if (cnt >= sizeof(buf))
|
return -EINVAL;
|
|
if (copy_from_user(buf, ubuf, cnt))
|
return -EFAULT;
|
|
buf[cnt] = 0;
|
|
clockstr = strstrip(buf);
|
|
ret = tracing_set_clock(tr, clockstr);
|
if (ret)
|
return ret;
|
|
*fpos += cnt;
|
|
return cnt;
|
}
|
|
static int tracing_clock_open(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
ret = single_open(file, tracing_clock_show, inode->i_private);
|
if (ret < 0)
|
trace_array_put(tr);
|
|
return ret;
|
}
|
|
static int tracing_time_stamp_mode_show(struct seq_file *m, void *v)
|
{
|
struct trace_array *tr = m->private;
|
|
mutex_lock(&trace_types_lock);
|
|
if (ring_buffer_time_stamp_abs(tr->array_buffer.buffer))
|
seq_puts(m, "delta [absolute]\n");
|
else
|
seq_puts(m, "[delta] absolute\n");
|
|
mutex_unlock(&trace_types_lock);
|
|
return 0;
|
}
|
|
static int tracing_time_stamp_mode_open(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
ret = single_open(file, tracing_time_stamp_mode_show, inode->i_private);
|
if (ret < 0)
|
trace_array_put(tr);
|
|
return ret;
|
}
|
|
int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs)
|
{
|
int ret = 0;
|
|
mutex_lock(&trace_types_lock);
|
|
if (abs && tr->time_stamp_abs_ref++)
|
goto out;
|
|
if (!abs) {
|
if (WARN_ON_ONCE(!tr->time_stamp_abs_ref)) {
|
ret = -EINVAL;
|
goto out;
|
}
|
|
if (--tr->time_stamp_abs_ref)
|
goto out;
|
}
|
|
ring_buffer_set_time_stamp_abs(tr->array_buffer.buffer, abs);
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
if (tr->max_buffer.buffer)
|
ring_buffer_set_time_stamp_abs(tr->max_buffer.buffer, abs);
|
#endif
|
out:
|
mutex_unlock(&trace_types_lock);
|
|
return ret;
|
}
|
|
struct ftrace_buffer_info {
|
struct trace_iterator iter;
|
void *spare;
|
unsigned int spare_cpu;
|
unsigned int read;
|
};
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
static int tracing_snapshot_open(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
struct trace_iterator *iter;
|
struct seq_file *m;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
if (file->f_mode & FMODE_READ) {
|
iter = __tracing_open(inode, file, true);
|
if (IS_ERR(iter))
|
ret = PTR_ERR(iter);
|
} else {
|
/* Writes still need the seq_file to hold the private data */
|
ret = -ENOMEM;
|
m = kzalloc(sizeof(*m), GFP_KERNEL);
|
if (!m)
|
goto out;
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
if (!iter) {
|
kfree(m);
|
goto out;
|
}
|
ret = 0;
|
|
iter->tr = tr;
|
iter->array_buffer = &tr->max_buffer;
|
iter->cpu_file = tracing_get_cpu(inode);
|
m->private = iter;
|
file->private_data = m;
|
}
|
out:
|
if (ret < 0)
|
trace_array_put(tr);
|
|
return ret;
|
}
|
|
static ssize_t
|
tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
struct seq_file *m = filp->private_data;
|
struct trace_iterator *iter = m->private;
|
struct trace_array *tr = iter->tr;
|
unsigned long val;
|
int ret;
|
|
ret = tracing_update_buffers();
|
if (ret < 0)
|
return ret;
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
if (ret)
|
return ret;
|
|
mutex_lock(&trace_types_lock);
|
|
if (tr->current_trace->use_max_tr) {
|
ret = -EBUSY;
|
goto out;
|
}
|
|
local_irq_disable();
|
arch_spin_lock(&tr->max_lock);
|
if (tr->cond_snapshot)
|
ret = -EBUSY;
|
arch_spin_unlock(&tr->max_lock);
|
local_irq_enable();
|
if (ret)
|
goto out;
|
|
switch (val) {
|
case 0:
|
if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
|
ret = -EINVAL;
|
break;
|
}
|
if (tr->allocated_snapshot)
|
free_snapshot(tr);
|
break;
|
case 1:
|
/* Only allow per-cpu swap if the ring buffer supports it */
|
#ifndef CONFIG_RING_BUFFER_ALLOW_SWAP
|
if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
|
ret = -EINVAL;
|
break;
|
}
|
#endif
|
if (tr->allocated_snapshot)
|
ret = resize_buffer_duplicate_size(&tr->max_buffer,
|
&tr->array_buffer, iter->cpu_file);
|
else
|
ret = tracing_alloc_snapshot_instance(tr);
|
if (ret < 0)
|
break;
|
local_irq_disable();
|
/* Now, we're going to swap */
|
if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
|
update_max_tr(tr, current, smp_processor_id(), NULL);
|
else
|
update_max_tr_single(tr, current, iter->cpu_file);
|
local_irq_enable();
|
break;
|
default:
|
if (tr->allocated_snapshot) {
|
if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
|
tracing_reset_online_cpus(&tr->max_buffer);
|
else
|
tracing_reset_cpu(&tr->max_buffer, iter->cpu_file);
|
}
|
break;
|
}
|
|
if (ret >= 0) {
|
*ppos += cnt;
|
ret = cnt;
|
}
|
out:
|
mutex_unlock(&trace_types_lock);
|
return ret;
|
}
|
|
static int tracing_snapshot_release(struct inode *inode, struct file *file)
|
{
|
struct seq_file *m = file->private_data;
|
int ret;
|
|
ret = tracing_release(inode, file);
|
|
if (file->f_mode & FMODE_READ)
|
return ret;
|
|
/* If write only, the seq_file is just a stub */
|
if (m)
|
kfree(m->private);
|
kfree(m);
|
|
return 0;
|
}
|
|
static int tracing_buffers_open(struct inode *inode, struct file *filp);
|
static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf,
|
size_t count, loff_t *ppos);
|
static int tracing_buffers_release(struct inode *inode, struct file *file);
|
static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos,
|
struct pipe_inode_info *pipe, size_t len, unsigned int flags);
|
|
static int snapshot_raw_open(struct inode *inode, struct file *filp)
|
{
|
struct ftrace_buffer_info *info;
|
int ret;
|
|
/* The following checks for tracefs lockdown */
|
ret = tracing_buffers_open(inode, filp);
|
if (ret < 0)
|
return ret;
|
|
info = filp->private_data;
|
|
if (info->iter.trace->use_max_tr) {
|
tracing_buffers_release(inode, filp);
|
return -EBUSY;
|
}
|
|
info->iter.snapshot = true;
|
info->iter.array_buffer = &info->iter.tr->max_buffer;
|
|
return ret;
|
}
|
|
#endif /* CONFIG_TRACER_SNAPSHOT */
|
|
|
static const struct file_operations tracing_thresh_fops = {
|
.open = tracing_open_generic,
|
.read = tracing_thresh_read,
|
.write = tracing_thresh_write,
|
.llseek = generic_file_llseek,
|
};
|
|
#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
|
static const struct file_operations tracing_max_lat_fops = {
|
.open = tracing_open_generic,
|
.read = tracing_max_lat_read,
|
.write = tracing_max_lat_write,
|
.llseek = generic_file_llseek,
|
};
|
#endif
|
|
static const struct file_operations set_tracer_fops = {
|
.open = tracing_open_generic,
|
.read = tracing_set_trace_read,
|
.write = tracing_set_trace_write,
|
.llseek = generic_file_llseek,
|
};
|
|
static const struct file_operations tracing_pipe_fops = {
|
.open = tracing_open_pipe,
|
.poll = tracing_poll_pipe,
|
.read = tracing_read_pipe,
|
.splice_read = tracing_splice_read_pipe,
|
.release = tracing_release_pipe,
|
.llseek = no_llseek,
|
};
|
|
static const struct file_operations tracing_entries_fops = {
|
.open = tracing_open_generic_tr,
|
.read = tracing_entries_read,
|
.write = tracing_entries_write,
|
.llseek = generic_file_llseek,
|
.release = tracing_release_generic_tr,
|
};
|
|
static const struct file_operations tracing_total_entries_fops = {
|
.open = tracing_open_generic_tr,
|
.read = tracing_total_entries_read,
|
.llseek = generic_file_llseek,
|
.release = tracing_release_generic_tr,
|
};
|
|
static const struct file_operations tracing_free_buffer_fops = {
|
.open = tracing_open_generic_tr,
|
.write = tracing_free_buffer_write,
|
.release = tracing_free_buffer_release,
|
};
|
|
static const struct file_operations tracing_mark_fops = {
|
.open = tracing_open_generic_tr,
|
.write = tracing_mark_write,
|
.llseek = generic_file_llseek,
|
.release = tracing_release_generic_tr,
|
};
|
|
static const struct file_operations tracing_mark_raw_fops = {
|
.open = tracing_open_generic_tr,
|
.write = tracing_mark_raw_write,
|
.llseek = generic_file_llseek,
|
.release = tracing_release_generic_tr,
|
};
|
|
static const struct file_operations trace_clock_fops = {
|
.open = tracing_clock_open,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = tracing_single_release_tr,
|
.write = tracing_clock_write,
|
};
|
|
static const struct file_operations trace_time_stamp_mode_fops = {
|
.open = tracing_time_stamp_mode_open,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = tracing_single_release_tr,
|
};
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
static const struct file_operations snapshot_fops = {
|
.open = tracing_snapshot_open,
|
.read = seq_read,
|
.write = tracing_snapshot_write,
|
.llseek = tracing_lseek,
|
.release = tracing_snapshot_release,
|
};
|
|
static const struct file_operations snapshot_raw_fops = {
|
.open = snapshot_raw_open,
|
.read = tracing_buffers_read,
|
.release = tracing_buffers_release,
|
.splice_read = tracing_buffers_splice_read,
|
.llseek = no_llseek,
|
};
|
|
#endif /* CONFIG_TRACER_SNAPSHOT */
|
|
#define TRACING_LOG_ERRS_MAX 8
|
#define TRACING_LOG_LOC_MAX 128
|
|
#define CMD_PREFIX " Command: "
|
|
struct err_info {
|
const char **errs; /* ptr to loc-specific array of err strings */
|
u8 type; /* index into errs -> specific err string */
|
u8 pos; /* MAX_FILTER_STR_VAL = 256 */
|
u64 ts;
|
};
|
|
struct tracing_log_err {
|
struct list_head list;
|
struct err_info info;
|
char loc[TRACING_LOG_LOC_MAX]; /* err location */
|
char cmd[MAX_FILTER_STR_VAL]; /* what caused err */
|
};
|
|
static DEFINE_MUTEX(tracing_err_log_lock);
|
|
static struct tracing_log_err *get_tracing_log_err(struct trace_array *tr)
|
{
|
struct tracing_log_err *err;
|
|
if (tr->n_err_log_entries < TRACING_LOG_ERRS_MAX) {
|
err = kzalloc(sizeof(*err), GFP_KERNEL);
|
if (!err)
|
err = ERR_PTR(-ENOMEM);
|
else
|
tr->n_err_log_entries++;
|
|
return err;
|
}
|
|
err = list_first_entry(&tr->err_log, struct tracing_log_err, list);
|
list_del(&err->list);
|
|
return err;
|
}
|
|
/**
|
* err_pos - find the position of a string within a command for error careting
|
* @cmd: The tracing command that caused the error
|
* @str: The string to position the caret at within @cmd
|
*
|
* Finds the position of the first occurence of @str within @cmd. The
|
* return value can be passed to tracing_log_err() for caret placement
|
* within @cmd.
|
*
|
* Returns the index within @cmd of the first occurence of @str or 0
|
* if @str was not found.
|
*/
|
unsigned int err_pos(char *cmd, const char *str)
|
{
|
char *found;
|
|
if (WARN_ON(!strlen(cmd)))
|
return 0;
|
|
found = strstr(cmd, str);
|
if (found)
|
return found - cmd;
|
|
return 0;
|
}
|
|
/**
|
* tracing_log_err - write an error to the tracing error log
|
* @tr: The associated trace array for the error (NULL for top level array)
|
* @loc: A string describing where the error occurred
|
* @cmd: The tracing command that caused the error
|
* @errs: The array of loc-specific static error strings
|
* @type: The index into errs[], which produces the specific static err string
|
* @pos: The position the caret should be placed in the cmd
|
*
|
* Writes an error into tracing/error_log of the form:
|
*
|
* <loc>: error: <text>
|
* Command: <cmd>
|
* ^
|
*
|
* tracing/error_log is a small log file containing the last
|
* TRACING_LOG_ERRS_MAX errors (8). Memory for errors isn't allocated
|
* unless there has been a tracing error, and the error log can be
|
* cleared and have its memory freed by writing the empty string in
|
* truncation mode to it i.e. echo > tracing/error_log.
|
*
|
* NOTE: the @errs array along with the @type param are used to
|
* produce a static error string - this string is not copied and saved
|
* when the error is logged - only a pointer to it is saved. See
|
* existing callers for examples of how static strings are typically
|
* defined for use with tracing_log_err().
|
*/
|
void tracing_log_err(struct trace_array *tr,
|
const char *loc, const char *cmd,
|
const char **errs, u8 type, u8 pos)
|
{
|
struct tracing_log_err *err;
|
|
if (!tr)
|
tr = &global_trace;
|
|
mutex_lock(&tracing_err_log_lock);
|
err = get_tracing_log_err(tr);
|
if (PTR_ERR(err) == -ENOMEM) {
|
mutex_unlock(&tracing_err_log_lock);
|
return;
|
}
|
|
snprintf(err->loc, TRACING_LOG_LOC_MAX, "%s: error: ", loc);
|
snprintf(err->cmd, MAX_FILTER_STR_VAL,"\n" CMD_PREFIX "%s\n", cmd);
|
|
err->info.errs = errs;
|
err->info.type = type;
|
err->info.pos = pos;
|
err->info.ts = local_clock();
|
|
list_add_tail(&err->list, &tr->err_log);
|
mutex_unlock(&tracing_err_log_lock);
|
}
|
|
static void clear_tracing_err_log(struct trace_array *tr)
|
{
|
struct tracing_log_err *err, *next;
|
|
mutex_lock(&tracing_err_log_lock);
|
list_for_each_entry_safe(err, next, &tr->err_log, list) {
|
list_del(&err->list);
|
kfree(err);
|
}
|
|
tr->n_err_log_entries = 0;
|
mutex_unlock(&tracing_err_log_lock);
|
}
|
|
static void *tracing_err_log_seq_start(struct seq_file *m, loff_t *pos)
|
{
|
struct trace_array *tr = m->private;
|
|
mutex_lock(&tracing_err_log_lock);
|
|
return seq_list_start(&tr->err_log, *pos);
|
}
|
|
static void *tracing_err_log_seq_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
struct trace_array *tr = m->private;
|
|
return seq_list_next(v, &tr->err_log, pos);
|
}
|
|
static void tracing_err_log_seq_stop(struct seq_file *m, void *v)
|
{
|
mutex_unlock(&tracing_err_log_lock);
|
}
|
|
static void tracing_err_log_show_pos(struct seq_file *m, u8 pos)
|
{
|
u8 i;
|
|
for (i = 0; i < sizeof(CMD_PREFIX) - 1; i++)
|
seq_putc(m, ' ');
|
for (i = 0; i < pos; i++)
|
seq_putc(m, ' ');
|
seq_puts(m, "^\n");
|
}
|
|
static int tracing_err_log_seq_show(struct seq_file *m, void *v)
|
{
|
struct tracing_log_err *err = v;
|
|
if (err) {
|
const char *err_text = err->info.errs[err->info.type];
|
u64 sec = err->info.ts;
|
u32 nsec;
|
|
nsec = do_div(sec, NSEC_PER_SEC);
|
seq_printf(m, "[%5llu.%06u] %s%s", sec, nsec / 1000,
|
err->loc, err_text);
|
seq_printf(m, "%s", err->cmd);
|
tracing_err_log_show_pos(m, err->info.pos);
|
}
|
|
return 0;
|
}
|
|
static const struct seq_operations tracing_err_log_seq_ops = {
|
.start = tracing_err_log_seq_start,
|
.next = tracing_err_log_seq_next,
|
.stop = tracing_err_log_seq_stop,
|
.show = tracing_err_log_seq_show
|
};
|
|
static int tracing_err_log_open(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
int ret = 0;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
/* If this file was opened for write, then erase contents */
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC))
|
clear_tracing_err_log(tr);
|
|
if (file->f_mode & FMODE_READ) {
|
ret = seq_open(file, &tracing_err_log_seq_ops);
|
if (!ret) {
|
struct seq_file *m = file->private_data;
|
m->private = tr;
|
} else {
|
trace_array_put(tr);
|
}
|
}
|
return ret;
|
}
|
|
static ssize_t tracing_err_log_write(struct file *file,
|
const char __user *buffer,
|
size_t count, loff_t *ppos)
|
{
|
return count;
|
}
|
|
static int tracing_err_log_release(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
|
trace_array_put(tr);
|
|
if (file->f_mode & FMODE_READ)
|
seq_release(inode, file);
|
|
return 0;
|
}
|
|
static const struct file_operations tracing_err_log_fops = {
|
.open = tracing_err_log_open,
|
.write = tracing_err_log_write,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = tracing_err_log_release,
|
};
|
|
static int tracing_buffers_open(struct inode *inode, struct file *filp)
|
{
|
struct trace_array *tr = inode->i_private;
|
struct ftrace_buffer_info *info;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
info = kvzalloc(sizeof(*info), GFP_KERNEL);
|
if (!info) {
|
trace_array_put(tr);
|
return -ENOMEM;
|
}
|
|
mutex_lock(&trace_types_lock);
|
|
info->iter.tr = tr;
|
info->iter.cpu_file = tracing_get_cpu(inode);
|
info->iter.trace = tr->current_trace;
|
info->iter.array_buffer = &tr->array_buffer;
|
info->spare = NULL;
|
/* Force reading ring buffer for first read */
|
info->read = (unsigned int)-1;
|
|
filp->private_data = info;
|
|
tr->trace_ref++;
|
|
mutex_unlock(&trace_types_lock);
|
|
ret = nonseekable_open(inode, filp);
|
if (ret < 0)
|
trace_array_put(tr);
|
|
return ret;
|
}
|
|
static __poll_t
|
tracing_buffers_poll(struct file *filp, poll_table *poll_table)
|
{
|
struct ftrace_buffer_info *info = filp->private_data;
|
struct trace_iterator *iter = &info->iter;
|
|
return trace_poll(iter, filp, poll_table);
|
}
|
|
static ssize_t
|
tracing_buffers_read(struct file *filp, char __user *ubuf,
|
size_t count, loff_t *ppos)
|
{
|
struct ftrace_buffer_info *info = filp->private_data;
|
struct trace_iterator *iter = &info->iter;
|
ssize_t ret = 0;
|
ssize_t size;
|
|
if (!count)
|
return 0;
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
if (iter->snapshot && iter->tr->current_trace->use_max_tr)
|
return -EBUSY;
|
#endif
|
|
if (!info->spare) {
|
info->spare = ring_buffer_alloc_read_page(iter->array_buffer->buffer,
|
iter->cpu_file);
|
if (IS_ERR(info->spare)) {
|
ret = PTR_ERR(info->spare);
|
info->spare = NULL;
|
} else {
|
info->spare_cpu = iter->cpu_file;
|
}
|
}
|
if (!info->spare)
|
return ret;
|
|
/* Do we have previous read data to read? */
|
if (info->read < PAGE_SIZE)
|
goto read;
|
|
again:
|
trace_access_lock(iter->cpu_file);
|
ret = ring_buffer_read_page(iter->array_buffer->buffer,
|
&info->spare,
|
count,
|
iter->cpu_file, 0);
|
trace_access_unlock(iter->cpu_file);
|
|
if (ret < 0) {
|
if (trace_empty(iter)) {
|
if ((filp->f_flags & O_NONBLOCK))
|
return -EAGAIN;
|
|
ret = wait_on_pipe(iter, 0);
|
if (ret)
|
return ret;
|
|
goto again;
|
}
|
return 0;
|
}
|
|
info->read = 0;
|
read:
|
size = PAGE_SIZE - info->read;
|
if (size > count)
|
size = count;
|
|
ret = copy_to_user(ubuf, info->spare + info->read, size);
|
if (ret == size)
|
return -EFAULT;
|
|
size -= ret;
|
|
*ppos += size;
|
info->read += size;
|
|
return size;
|
}
|
|
static int tracing_buffers_release(struct inode *inode, struct file *file)
|
{
|
struct ftrace_buffer_info *info = file->private_data;
|
struct trace_iterator *iter = &info->iter;
|
|
mutex_lock(&trace_types_lock);
|
|
iter->tr->trace_ref--;
|
|
__trace_array_put(iter->tr);
|
|
if (info->spare)
|
ring_buffer_free_read_page(iter->array_buffer->buffer,
|
info->spare_cpu, info->spare);
|
kvfree(info);
|
|
mutex_unlock(&trace_types_lock);
|
|
return 0;
|
}
|
|
struct buffer_ref {
|
struct trace_buffer *buffer;
|
void *page;
|
int cpu;
|
refcount_t refcount;
|
};
|
|
static void buffer_ref_release(struct buffer_ref *ref)
|
{
|
if (!refcount_dec_and_test(&ref->refcount))
|
return;
|
ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->page);
|
kfree(ref);
|
}
|
|
static void buffer_pipe_buf_release(struct pipe_inode_info *pipe,
|
struct pipe_buffer *buf)
|
{
|
struct buffer_ref *ref = (struct buffer_ref *)buf->private;
|
|
buffer_ref_release(ref);
|
buf->private = 0;
|
}
|
|
static bool buffer_pipe_buf_get(struct pipe_inode_info *pipe,
|
struct pipe_buffer *buf)
|
{
|
struct buffer_ref *ref = (struct buffer_ref *)buf->private;
|
|
if (refcount_read(&ref->refcount) > INT_MAX/2)
|
return false;
|
|
refcount_inc(&ref->refcount);
|
return true;
|
}
|
|
/* Pipe buffer operations for a buffer. */
|
static const struct pipe_buf_operations buffer_pipe_buf_ops = {
|
.release = buffer_pipe_buf_release,
|
.get = buffer_pipe_buf_get,
|
};
|
|
/*
|
* Callback from splice_to_pipe(), if we need to release some pages
|
* at the end of the spd in case we error'ed out in filling the pipe.
|
*/
|
static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i)
|
{
|
struct buffer_ref *ref =
|
(struct buffer_ref *)spd->partial[i].private;
|
|
buffer_ref_release(ref);
|
spd->partial[i].private = 0;
|
}
|
|
static ssize_t
|
tracing_buffers_splice_read(struct file *file, loff_t *ppos,
|
struct pipe_inode_info *pipe, size_t len,
|
unsigned int flags)
|
{
|
struct ftrace_buffer_info *info = file->private_data;
|
struct trace_iterator *iter = &info->iter;
|
struct partial_page partial_def[PIPE_DEF_BUFFERS];
|
struct page *pages_def[PIPE_DEF_BUFFERS];
|
struct splice_pipe_desc spd = {
|
.pages = pages_def,
|
.partial = partial_def,
|
.nr_pages_max = PIPE_DEF_BUFFERS,
|
.ops = &buffer_pipe_buf_ops,
|
.spd_release = buffer_spd_release,
|
};
|
struct buffer_ref *ref;
|
int entries, i;
|
ssize_t ret = 0;
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
if (iter->snapshot && iter->tr->current_trace->use_max_tr)
|
return -EBUSY;
|
#endif
|
|
if (*ppos & (PAGE_SIZE - 1))
|
return -EINVAL;
|
|
if (len & (PAGE_SIZE - 1)) {
|
if (len < PAGE_SIZE)
|
return -EINVAL;
|
len &= PAGE_MASK;
|
}
|
|
if (splice_grow_spd(pipe, &spd))
|
return -ENOMEM;
|
|
again:
|
trace_access_lock(iter->cpu_file);
|
entries = ring_buffer_entries_cpu(iter->array_buffer->buffer, iter->cpu_file);
|
|
for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) {
|
struct page *page;
|
int r;
|
|
ref = kzalloc(sizeof(*ref), GFP_KERNEL);
|
if (!ref) {
|
ret = -ENOMEM;
|
break;
|
}
|
|
refcount_set(&ref->refcount, 1);
|
ref->buffer = iter->array_buffer->buffer;
|
ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file);
|
if (IS_ERR(ref->page)) {
|
ret = PTR_ERR(ref->page);
|
ref->page = NULL;
|
kfree(ref);
|
break;
|
}
|
ref->cpu = iter->cpu_file;
|
|
r = ring_buffer_read_page(ref->buffer, &ref->page,
|
len, iter->cpu_file, 1);
|
if (r < 0) {
|
ring_buffer_free_read_page(ref->buffer, ref->cpu,
|
ref->page);
|
kfree(ref);
|
break;
|
}
|
|
page = virt_to_page(ref->page);
|
|
spd.pages[i] = page;
|
spd.partial[i].len = PAGE_SIZE;
|
spd.partial[i].offset = 0;
|
spd.partial[i].private = (unsigned long)ref;
|
spd.nr_pages++;
|
*ppos += PAGE_SIZE;
|
|
entries = ring_buffer_entries_cpu(iter->array_buffer->buffer, iter->cpu_file);
|
}
|
|
trace_access_unlock(iter->cpu_file);
|
spd.nr_pages = i;
|
|
/* did we read anything? */
|
if (!spd.nr_pages) {
|
if (ret)
|
goto out;
|
|
ret = -EAGAIN;
|
if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK))
|
goto out;
|
|
ret = wait_on_pipe(iter, iter->tr->buffer_percent);
|
if (ret)
|
goto out;
|
|
goto again;
|
}
|
|
ret = splice_to_pipe(pipe, &spd);
|
out:
|
splice_shrink_spd(&spd);
|
|
return ret;
|
}
|
|
static const struct file_operations tracing_buffers_fops = {
|
.open = tracing_buffers_open,
|
.read = tracing_buffers_read,
|
.poll = tracing_buffers_poll,
|
.release = tracing_buffers_release,
|
.splice_read = tracing_buffers_splice_read,
|
.llseek = no_llseek,
|
};
|
|
static ssize_t
|
tracing_stats_read(struct file *filp, char __user *ubuf,
|
size_t count, loff_t *ppos)
|
{
|
struct inode *inode = file_inode(filp);
|
struct trace_array *tr = inode->i_private;
|
struct array_buffer *trace_buf = &tr->array_buffer;
|
int cpu = tracing_get_cpu(inode);
|
struct trace_seq *s;
|
unsigned long cnt;
|
unsigned long long t;
|
unsigned long usec_rem;
|
|
s = kmalloc(sizeof(*s), GFP_KERNEL);
|
if (!s)
|
return -ENOMEM;
|
|
trace_seq_init(s);
|
|
cnt = ring_buffer_entries_cpu(trace_buf->buffer, cpu);
|
trace_seq_printf(s, "entries: %ld\n", cnt);
|
|
cnt = ring_buffer_overrun_cpu(trace_buf->buffer, cpu);
|
trace_seq_printf(s, "overrun: %ld\n", cnt);
|
|
cnt = ring_buffer_commit_overrun_cpu(trace_buf->buffer, cpu);
|
trace_seq_printf(s, "commit overrun: %ld\n", cnt);
|
|
cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu);
|
trace_seq_printf(s, "bytes: %ld\n", cnt);
|
|
if (trace_clocks[tr->clock_id].in_ns) {
|
/* local or global for trace_clock */
|
t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu));
|
usec_rem = do_div(t, USEC_PER_SEC);
|
trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n",
|
t, usec_rem);
|
|
t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer, cpu));
|
usec_rem = do_div(t, USEC_PER_SEC);
|
trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem);
|
} else {
|
/* counter or tsc mode for trace_clock */
|
trace_seq_printf(s, "oldest event ts: %llu\n",
|
ring_buffer_oldest_event_ts(trace_buf->buffer, cpu));
|
|
trace_seq_printf(s, "now ts: %llu\n",
|
ring_buffer_time_stamp(trace_buf->buffer, cpu));
|
}
|
|
cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu);
|
trace_seq_printf(s, "dropped events: %ld\n", cnt);
|
|
cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu);
|
trace_seq_printf(s, "read events: %ld\n", cnt);
|
|
count = simple_read_from_buffer(ubuf, count, ppos,
|
s->buffer, trace_seq_used(s));
|
|
kfree(s);
|
|
return count;
|
}
|
|
static const struct file_operations tracing_stats_fops = {
|
.open = tracing_open_generic_tr,
|
.read = tracing_stats_read,
|
.llseek = generic_file_llseek,
|
.release = tracing_release_generic_tr,
|
};
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
static ssize_t
|
tracing_read_dyn_info(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
ssize_t ret;
|
char *buf;
|
int r;
|
|
/* 256 should be plenty to hold the amount needed */
|
buf = kmalloc(256, GFP_KERNEL);
|
if (!buf)
|
return -ENOMEM;
|
|
r = scnprintf(buf, 256, "%ld pages:%ld groups: %ld\n",
|
ftrace_update_tot_cnt,
|
ftrace_number_of_pages,
|
ftrace_number_of_groups);
|
|
ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
kfree(buf);
|
return ret;
|
}
|
|
static const struct file_operations tracing_dyn_info_fops = {
|
.open = tracing_open_generic,
|
.read = tracing_read_dyn_info,
|
.llseek = generic_file_llseek,
|
};
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
#if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE)
|
static void
|
ftrace_snapshot(unsigned long ip, unsigned long parent_ip,
|
struct trace_array *tr, struct ftrace_probe_ops *ops,
|
void *data)
|
{
|
tracing_snapshot_instance(tr);
|
}
|
|
static void
|
ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip,
|
struct trace_array *tr, struct ftrace_probe_ops *ops,
|
void *data)
|
{
|
struct ftrace_func_mapper *mapper = data;
|
long *count = NULL;
|
|
if (mapper)
|
count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
|
|
if (count) {
|
|
if (*count <= 0)
|
return;
|
|
(*count)--;
|
}
|
|
tracing_snapshot_instance(tr);
|
}
|
|
static int
|
ftrace_snapshot_print(struct seq_file *m, unsigned long ip,
|
struct ftrace_probe_ops *ops, void *data)
|
{
|
struct ftrace_func_mapper *mapper = data;
|
long *count = NULL;
|
|
seq_printf(m, "%ps:", (void *)ip);
|
|
seq_puts(m, "snapshot");
|
|
if (mapper)
|
count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
|
|
if (count)
|
seq_printf(m, ":count=%ld\n", *count);
|
else
|
seq_puts(m, ":unlimited\n");
|
|
return 0;
|
}
|
|
static int
|
ftrace_snapshot_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
|
unsigned long ip, void *init_data, void **data)
|
{
|
struct ftrace_func_mapper *mapper = *data;
|
|
if (!mapper) {
|
mapper = allocate_ftrace_func_mapper();
|
if (!mapper)
|
return -ENOMEM;
|
*data = mapper;
|
}
|
|
return ftrace_func_mapper_add_ip(mapper, ip, init_data);
|
}
|
|
static void
|
ftrace_snapshot_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
|
unsigned long ip, void *data)
|
{
|
struct ftrace_func_mapper *mapper = data;
|
|
if (!ip) {
|
if (!mapper)
|
return;
|
free_ftrace_func_mapper(mapper, NULL);
|
return;
|
}
|
|
ftrace_func_mapper_remove_ip(mapper, ip);
|
}
|
|
static struct ftrace_probe_ops snapshot_probe_ops = {
|
.func = ftrace_snapshot,
|
.print = ftrace_snapshot_print,
|
};
|
|
static struct ftrace_probe_ops snapshot_count_probe_ops = {
|
.func = ftrace_count_snapshot,
|
.print = ftrace_snapshot_print,
|
.init = ftrace_snapshot_init,
|
.free = ftrace_snapshot_free,
|
};
|
|
static int
|
ftrace_trace_snapshot_callback(struct trace_array *tr, struct ftrace_hash *hash,
|
char *glob, char *cmd, char *param, int enable)
|
{
|
struct ftrace_probe_ops *ops;
|
void *count = (void *)-1;
|
char *number;
|
int ret;
|
|
if (!tr)
|
return -ENODEV;
|
|
/* hash funcs only work with set_ftrace_filter */
|
if (!enable)
|
return -EINVAL;
|
|
ops = param ? &snapshot_count_probe_ops : &snapshot_probe_ops;
|
|
if (glob[0] == '!')
|
return unregister_ftrace_function_probe_func(glob+1, tr, ops);
|
|
if (!param)
|
goto out_reg;
|
|
number = strsep(¶m, ":");
|
|
if (!strlen(number))
|
goto out_reg;
|
|
/*
|
* We use the callback data field (which is a pointer)
|
* as our counter.
|
*/
|
ret = kstrtoul(number, 0, (unsigned long *)&count);
|
if (ret)
|
return ret;
|
|
out_reg:
|
ret = tracing_alloc_snapshot_instance(tr);
|
if (ret < 0)
|
goto out;
|
|
ret = register_ftrace_function_probe(glob, tr, ops, count);
|
|
out:
|
return ret < 0 ? ret : 0;
|
}
|
|
static struct ftrace_func_command ftrace_snapshot_cmd = {
|
.name = "snapshot",
|
.func = ftrace_trace_snapshot_callback,
|
};
|
|
static __init int register_snapshot_cmd(void)
|
{
|
return register_ftrace_command(&ftrace_snapshot_cmd);
|
}
|
#else
|
static inline __init int register_snapshot_cmd(void) { return 0; }
|
#endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */
|
|
static struct dentry *tracing_get_dentry(struct trace_array *tr)
|
{
|
if (WARN_ON(!tr->dir))
|
return ERR_PTR(-ENODEV);
|
|
/* Top directory uses NULL as the parent */
|
if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
|
return NULL;
|
|
/* All sub buffers have a descriptor */
|
return tr->dir;
|
}
|
|
static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu)
|
{
|
struct dentry *d_tracer;
|
|
if (tr->percpu_dir)
|
return tr->percpu_dir;
|
|
d_tracer = tracing_get_dentry(tr);
|
if (IS_ERR(d_tracer))
|
return NULL;
|
|
tr->percpu_dir = tracefs_create_dir("per_cpu", d_tracer);
|
|
MEM_FAIL(!tr->percpu_dir,
|
"Could not create tracefs directory 'per_cpu/%d'\n", cpu);
|
|
return tr->percpu_dir;
|
}
|
|
static struct dentry *
|
trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent,
|
void *data, long cpu, const struct file_operations *fops)
|
{
|
struct dentry *ret = trace_create_file(name, mode, parent, data, fops);
|
|
if (ret) /* See tracing_get_cpu() */
|
d_inode(ret)->i_cdev = (void *)(cpu + 1);
|
return ret;
|
}
|
|
static void
|
tracing_init_tracefs_percpu(struct trace_array *tr, long cpu)
|
{
|
struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu);
|
struct dentry *d_cpu;
|
char cpu_dir[30]; /* 30 characters should be more than enough */
|
|
if (!d_percpu)
|
return;
|
|
snprintf(cpu_dir, 30, "cpu%ld", cpu);
|
d_cpu = tracefs_create_dir(cpu_dir, d_percpu);
|
if (!d_cpu) {
|
pr_warn("Could not create tracefs '%s' entry\n", cpu_dir);
|
return;
|
}
|
|
/* per cpu trace_pipe */
|
trace_create_cpu_file("trace_pipe", 0444, d_cpu,
|
tr, cpu, &tracing_pipe_fops);
|
|
/* per cpu trace */
|
trace_create_cpu_file("trace", 0644, d_cpu,
|
tr, cpu, &tracing_fops);
|
|
trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu,
|
tr, cpu, &tracing_buffers_fops);
|
|
trace_create_cpu_file("stats", 0444, d_cpu,
|
tr, cpu, &tracing_stats_fops);
|
|
trace_create_cpu_file("buffer_size_kb", 0444, d_cpu,
|
tr, cpu, &tracing_entries_fops);
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
trace_create_cpu_file("snapshot", 0644, d_cpu,
|
tr, cpu, &snapshot_fops);
|
|
trace_create_cpu_file("snapshot_raw", 0444, d_cpu,
|
tr, cpu, &snapshot_raw_fops);
|
#endif
|
}
|
|
#ifdef CONFIG_FTRACE_SELFTEST
|
/* Let selftest have access to static functions in this file */
|
#include "trace_selftest.c"
|
#endif
|
|
static ssize_t
|
trace_options_read(struct file *filp, char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
struct trace_option_dentry *topt = filp->private_data;
|
char *buf;
|
|
if (topt->flags->val & topt->opt->bit)
|
buf = "1\n";
|
else
|
buf = "0\n";
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
|
}
|
|
static ssize_t
|
trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
struct trace_option_dentry *topt = filp->private_data;
|
unsigned long val;
|
int ret;
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
if (ret)
|
return ret;
|
|
if (val != 0 && val != 1)
|
return -EINVAL;
|
|
if (!!(topt->flags->val & topt->opt->bit) != val) {
|
mutex_lock(&trace_types_lock);
|
ret = __set_tracer_option(topt->tr, topt->flags,
|
topt->opt, !val);
|
mutex_unlock(&trace_types_lock);
|
if (ret)
|
return ret;
|
}
|
|
*ppos += cnt;
|
|
return cnt;
|
}
|
|
|
static const struct file_operations trace_options_fops = {
|
.open = tracing_open_generic,
|
.read = trace_options_read,
|
.write = trace_options_write,
|
.llseek = generic_file_llseek,
|
};
|
|
/*
|
* In order to pass in both the trace_array descriptor as well as the index
|
* to the flag that the trace option file represents, the trace_array
|
* has a character array of trace_flags_index[], which holds the index
|
* of the bit for the flag it represents. index[0] == 0, index[1] == 1, etc.
|
* The address of this character array is passed to the flag option file
|
* read/write callbacks.
|
*
|
* In order to extract both the index and the trace_array descriptor,
|
* get_tr_index() uses the following algorithm.
|
*
|
* idx = *ptr;
|
*
|
* As the pointer itself contains the address of the index (remember
|
* index[1] == 1).
|
*
|
* Then to get the trace_array descriptor, by subtracting that index
|
* from the ptr, we get to the start of the index itself.
|
*
|
* ptr - idx == &index[0]
|
*
|
* Then a simple container_of() from that pointer gets us to the
|
* trace_array descriptor.
|
*/
|
static void get_tr_index(void *data, struct trace_array **ptr,
|
unsigned int *pindex)
|
{
|
*pindex = *(unsigned char *)data;
|
|
*ptr = container_of(data - *pindex, struct trace_array,
|
trace_flags_index);
|
}
|
|
static ssize_t
|
trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
void *tr_index = filp->private_data;
|
struct trace_array *tr;
|
unsigned int index;
|
char *buf;
|
|
get_tr_index(tr_index, &tr, &index);
|
|
if (tr->trace_flags & (1 << index))
|
buf = "1\n";
|
else
|
buf = "0\n";
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
|
}
|
|
static ssize_t
|
trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
void *tr_index = filp->private_data;
|
struct trace_array *tr;
|
unsigned int index;
|
unsigned long val;
|
int ret;
|
|
get_tr_index(tr_index, &tr, &index);
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
if (ret)
|
return ret;
|
|
if (val != 0 && val != 1)
|
return -EINVAL;
|
|
mutex_lock(&event_mutex);
|
mutex_lock(&trace_types_lock);
|
ret = set_tracer_flag(tr, 1 << index, val);
|
mutex_unlock(&trace_types_lock);
|
mutex_unlock(&event_mutex);
|
|
if (ret < 0)
|
return ret;
|
|
*ppos += cnt;
|
|
return cnt;
|
}
|
|
static const struct file_operations trace_options_core_fops = {
|
.open = tracing_open_generic,
|
.read = trace_options_core_read,
|
.write = trace_options_core_write,
|
.llseek = generic_file_llseek,
|
};
|
|
struct dentry *trace_create_file(const char *name,
|
umode_t mode,
|
struct dentry *parent,
|
void *data,
|
const struct file_operations *fops)
|
{
|
struct dentry *ret;
|
|
ret = tracefs_create_file(name, mode, parent, data, fops);
|
if (!ret)
|
pr_warn("Could not create tracefs '%s' entry\n", name);
|
|
return ret;
|
}
|
|
|
static struct dentry *trace_options_init_dentry(struct trace_array *tr)
|
{
|
struct dentry *d_tracer;
|
|
if (tr->options)
|
return tr->options;
|
|
d_tracer = tracing_get_dentry(tr);
|
if (IS_ERR(d_tracer))
|
return NULL;
|
|
tr->options = tracefs_create_dir("options", d_tracer);
|
if (!tr->options) {
|
pr_warn("Could not create tracefs directory 'options'\n");
|
return NULL;
|
}
|
|
return tr->options;
|
}
|
|
static void
|
create_trace_option_file(struct trace_array *tr,
|
struct trace_option_dentry *topt,
|
struct tracer_flags *flags,
|
struct tracer_opt *opt)
|
{
|
struct dentry *t_options;
|
|
t_options = trace_options_init_dentry(tr);
|
if (!t_options)
|
return;
|
|
topt->flags = flags;
|
topt->opt = opt;
|
topt->tr = tr;
|
|
topt->entry = trace_create_file(opt->name, 0644, t_options, topt,
|
&trace_options_fops);
|
|
}
|
|
static void
|
create_trace_option_files(struct trace_array *tr, struct tracer *tracer)
|
{
|
struct trace_option_dentry *topts;
|
struct trace_options *tr_topts;
|
struct tracer_flags *flags;
|
struct tracer_opt *opts;
|
int cnt;
|
int i;
|
|
if (!tracer)
|
return;
|
|
flags = tracer->flags;
|
|
if (!flags || !flags->opts)
|
return;
|
|
/*
|
* If this is an instance, only create flags for tracers
|
* the instance may have.
|
*/
|
if (!trace_ok_for_array(tracer, tr))
|
return;
|
|
for (i = 0; i < tr->nr_topts; i++) {
|
/* Make sure there's no duplicate flags. */
|
if (WARN_ON_ONCE(tr->topts[i].tracer->flags == tracer->flags))
|
return;
|
}
|
|
opts = flags->opts;
|
|
for (cnt = 0; opts[cnt].name; cnt++)
|
;
|
|
topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL);
|
if (!topts)
|
return;
|
|
tr_topts = krealloc(tr->topts, sizeof(*tr->topts) * (tr->nr_topts + 1),
|
GFP_KERNEL);
|
if (!tr_topts) {
|
kfree(topts);
|
return;
|
}
|
|
tr->topts = tr_topts;
|
tr->topts[tr->nr_topts].tracer = tracer;
|
tr->topts[tr->nr_topts].topts = topts;
|
tr->nr_topts++;
|
|
for (cnt = 0; opts[cnt].name; cnt++) {
|
create_trace_option_file(tr, &topts[cnt], flags,
|
&opts[cnt]);
|
MEM_FAIL(topts[cnt].entry == NULL,
|
"Failed to create trace option: %s",
|
opts[cnt].name);
|
}
|
}
|
|
static struct dentry *
|
create_trace_option_core_file(struct trace_array *tr,
|
const char *option, long index)
|
{
|
struct dentry *t_options;
|
|
t_options = trace_options_init_dentry(tr);
|
if (!t_options)
|
return NULL;
|
|
return trace_create_file(option, 0644, t_options,
|
(void *)&tr->trace_flags_index[index],
|
&trace_options_core_fops);
|
}
|
|
static void create_trace_options_dir(struct trace_array *tr)
|
{
|
struct dentry *t_options;
|
bool top_level = tr == &global_trace;
|
int i;
|
|
t_options = trace_options_init_dentry(tr);
|
if (!t_options)
|
return;
|
|
for (i = 0; trace_options[i]; i++) {
|
if (top_level ||
|
!((1 << i) & TOP_LEVEL_TRACE_FLAGS))
|
create_trace_option_core_file(tr, trace_options[i], i);
|
}
|
}
|
|
static ssize_t
|
rb_simple_read(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct trace_array *tr = filp->private_data;
|
char buf[64];
|
int r;
|
|
r = tracer_tracing_is_on(tr);
|
r = sprintf(buf, "%d\n", r);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
}
|
|
static ssize_t
|
rb_simple_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct trace_array *tr = filp->private_data;
|
struct trace_buffer *buffer = tr->array_buffer.buffer;
|
unsigned long val;
|
int ret;
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
if (ret)
|
return ret;
|
|
if (buffer) {
|
mutex_lock(&trace_types_lock);
|
if (!!val == tracer_tracing_is_on(tr)) {
|
val = 0; /* do nothing */
|
} else if (val) {
|
tracer_tracing_on(tr);
|
if (tr->current_trace->start)
|
tr->current_trace->start(tr);
|
} else {
|
tracer_tracing_off(tr);
|
if (tr->current_trace->stop)
|
tr->current_trace->stop(tr);
|
}
|
mutex_unlock(&trace_types_lock);
|
}
|
|
(*ppos)++;
|
|
return cnt;
|
}
|
|
static const struct file_operations rb_simple_fops = {
|
.open = tracing_open_generic_tr,
|
.read = rb_simple_read,
|
.write = rb_simple_write,
|
.release = tracing_release_generic_tr,
|
.llseek = default_llseek,
|
};
|
|
static ssize_t
|
buffer_percent_read(struct file *filp, char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct trace_array *tr = filp->private_data;
|
char buf[64];
|
int r;
|
|
r = tr->buffer_percent;
|
r = sprintf(buf, "%d\n", r);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
}
|
|
static ssize_t
|
buffer_percent_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct trace_array *tr = filp->private_data;
|
unsigned long val;
|
int ret;
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
if (ret)
|
return ret;
|
|
if (val > 100)
|
return -EINVAL;
|
|
if (!val)
|
val = 1;
|
|
tr->buffer_percent = val;
|
|
(*ppos)++;
|
|
return cnt;
|
}
|
|
static const struct file_operations buffer_percent_fops = {
|
.open = tracing_open_generic_tr,
|
.read = buffer_percent_read,
|
.write = buffer_percent_write,
|
.release = tracing_release_generic_tr,
|
.llseek = default_llseek,
|
};
|
|
static struct dentry *trace_instance_dir;
|
|
static void
|
init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer);
|
|
static int
|
allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size)
|
{
|
enum ring_buffer_flags rb_flags;
|
|
rb_flags = tr->trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;
|
|
buf->tr = tr;
|
|
buf->buffer = ring_buffer_alloc(size, rb_flags);
|
if (!buf->buffer)
|
return -ENOMEM;
|
|
buf->data = alloc_percpu(struct trace_array_cpu);
|
if (!buf->data) {
|
ring_buffer_free(buf->buffer);
|
buf->buffer = NULL;
|
return -ENOMEM;
|
}
|
|
/* Allocate the first page for all buffers */
|
set_buffer_entries(&tr->array_buffer,
|
ring_buffer_size(tr->array_buffer.buffer, 0));
|
|
return 0;
|
}
|
|
static int allocate_trace_buffers(struct trace_array *tr, int size)
|
{
|
int ret;
|
|
ret = allocate_trace_buffer(tr, &tr->array_buffer, size);
|
if (ret)
|
return ret;
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
ret = allocate_trace_buffer(tr, &tr->max_buffer,
|
allocate_snapshot ? size : 1);
|
if (MEM_FAIL(ret, "Failed to allocate trace buffer\n")) {
|
ring_buffer_free(tr->array_buffer.buffer);
|
tr->array_buffer.buffer = NULL;
|
free_percpu(tr->array_buffer.data);
|
tr->array_buffer.data = NULL;
|
return -ENOMEM;
|
}
|
tr->allocated_snapshot = allocate_snapshot;
|
|
/*
|
* Only the top level trace array gets its snapshot allocated
|
* from the kernel command line.
|
*/
|
allocate_snapshot = false;
|
#endif
|
|
return 0;
|
}
|
|
static void free_trace_buffer(struct array_buffer *buf)
|
{
|
if (buf->buffer) {
|
ring_buffer_free(buf->buffer);
|
buf->buffer = NULL;
|
free_percpu(buf->data);
|
buf->data = NULL;
|
}
|
}
|
|
static void free_trace_buffers(struct trace_array *tr)
|
{
|
if (!tr)
|
return;
|
|
free_trace_buffer(&tr->array_buffer);
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
free_trace_buffer(&tr->max_buffer);
|
#endif
|
}
|
|
static void init_trace_flags_index(struct trace_array *tr)
|
{
|
int i;
|
|
/* Used by the trace options files */
|
for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++)
|
tr->trace_flags_index[i] = i;
|
}
|
|
static void __update_tracer_options(struct trace_array *tr)
|
{
|
struct tracer *t;
|
|
for (t = trace_types; t; t = t->next)
|
add_tracer_options(tr, t);
|
}
|
|
static void update_tracer_options(struct trace_array *tr)
|
{
|
mutex_lock(&trace_types_lock);
|
tracer_options_updated = true;
|
__update_tracer_options(tr);
|
mutex_unlock(&trace_types_lock);
|
}
|
|
/* Must have trace_types_lock held */
|
struct trace_array *trace_array_find(const char *instance)
|
{
|
struct trace_array *tr, *found = NULL;
|
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
|
if (tr->name && strcmp(tr->name, instance) == 0) {
|
found = tr;
|
break;
|
}
|
}
|
|
return found;
|
}
|
|
struct trace_array *trace_array_find_get(const char *instance)
|
{
|
struct trace_array *tr;
|
|
mutex_lock(&trace_types_lock);
|
tr = trace_array_find(instance);
|
if (tr)
|
tr->ref++;
|
mutex_unlock(&trace_types_lock);
|
|
return tr;
|
}
|
|
static int trace_array_create_dir(struct trace_array *tr)
|
{
|
int ret;
|
|
tr->dir = tracefs_create_dir(tr->name, trace_instance_dir);
|
if (!tr->dir)
|
return -EINVAL;
|
|
ret = event_trace_add_tracer(tr->dir, tr);
|
if (ret) {
|
tracefs_remove(tr->dir);
|
return ret;
|
}
|
|
init_tracer_tracefs(tr, tr->dir);
|
__update_tracer_options(tr);
|
|
return ret;
|
}
|
|
static struct trace_array *trace_array_create(const char *name)
|
{
|
struct trace_array *tr;
|
int ret;
|
|
ret = -ENOMEM;
|
tr = kzalloc(sizeof(*tr), GFP_KERNEL);
|
if (!tr)
|
return ERR_PTR(ret);
|
|
tr->name = kstrdup(name, GFP_KERNEL);
|
if (!tr->name)
|
goto out_free_tr;
|
|
if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL))
|
goto out_free_tr;
|
|
tr->trace_flags = global_trace.trace_flags & ~ZEROED_TRACE_FLAGS;
|
|
cpumask_copy(tr->tracing_cpumask, cpu_all_mask);
|
|
raw_spin_lock_init(&tr->start_lock);
|
|
tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
|
|
tr->current_trace = &nop_trace;
|
|
INIT_LIST_HEAD(&tr->systems);
|
INIT_LIST_HEAD(&tr->events);
|
INIT_LIST_HEAD(&tr->hist_vars);
|
INIT_LIST_HEAD(&tr->err_log);
|
|
if (allocate_trace_buffers(tr, trace_buf_size) < 0)
|
goto out_free_tr;
|
|
if (ftrace_allocate_ftrace_ops(tr) < 0)
|
goto out_free_tr;
|
|
ftrace_init_trace_array(tr);
|
|
init_trace_flags_index(tr);
|
|
if (trace_instance_dir) {
|
ret = trace_array_create_dir(tr);
|
if (ret)
|
goto out_free_tr;
|
} else
|
__trace_early_add_events(tr);
|
|
list_add(&tr->list, &ftrace_trace_arrays);
|
|
tr->ref++;
|
|
return tr;
|
|
out_free_tr:
|
ftrace_free_ftrace_ops(tr);
|
free_trace_buffers(tr);
|
free_cpumask_var(tr->tracing_cpumask);
|
kfree(tr->name);
|
kfree(tr);
|
|
return ERR_PTR(ret);
|
}
|
|
static int instance_mkdir(const char *name)
|
{
|
struct trace_array *tr;
|
int ret;
|
|
mutex_lock(&event_mutex);
|
mutex_lock(&trace_types_lock);
|
|
ret = -EEXIST;
|
if (trace_array_find(name))
|
goto out_unlock;
|
|
tr = trace_array_create(name);
|
|
ret = PTR_ERR_OR_ZERO(tr);
|
|
out_unlock:
|
mutex_unlock(&trace_types_lock);
|
mutex_unlock(&event_mutex);
|
return ret;
|
}
|
|
/**
|
* trace_array_get_by_name - Create/Lookup a trace array, given its name.
|
* @name: The name of the trace array to be looked up/created.
|
*
|
* Returns pointer to trace array with given name.
|
* NULL, if it cannot be created.
|
*
|
* NOTE: This function increments the reference counter associated with the
|
* trace array returned. This makes sure it cannot be freed while in use.
|
* Use trace_array_put() once the trace array is no longer needed.
|
* If the trace_array is to be freed, trace_array_destroy() needs to
|
* be called after the trace_array_put(), or simply let user space delete
|
* it from the tracefs instances directory. But until the
|
* trace_array_put() is called, user space can not delete it.
|
*
|
*/
|
struct trace_array *trace_array_get_by_name(const char *name)
|
{
|
struct trace_array *tr;
|
|
mutex_lock(&event_mutex);
|
mutex_lock(&trace_types_lock);
|
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
|
if (tr->name && strcmp(tr->name, name) == 0)
|
goto out_unlock;
|
}
|
|
tr = trace_array_create(name);
|
|
if (IS_ERR(tr))
|
tr = NULL;
|
out_unlock:
|
if (tr)
|
tr->ref++;
|
|
mutex_unlock(&trace_types_lock);
|
mutex_unlock(&event_mutex);
|
return tr;
|
}
|
EXPORT_SYMBOL_GPL(trace_array_get_by_name);
|
|
static int __remove_instance(struct trace_array *tr)
|
{
|
int i;
|
|
/* Reference counter for a newly created trace array = 1. */
|
if (tr->ref > 1 || (tr->current_trace && tr->trace_ref))
|
return -EBUSY;
|
|
list_del(&tr->list);
|
|
/* Disable all the flags that were enabled coming in */
|
for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) {
|
if ((1 << i) & ZEROED_TRACE_FLAGS)
|
set_tracer_flag(tr, 1 << i, 0);
|
}
|
|
tracing_set_nop(tr);
|
clear_ftrace_function_probes(tr);
|
event_trace_del_tracer(tr);
|
ftrace_clear_pids(tr);
|
ftrace_destroy_function_files(tr);
|
tracefs_remove(tr->dir);
|
free_trace_buffers(tr);
|
|
for (i = 0; i < tr->nr_topts; i++) {
|
kfree(tr->topts[i].topts);
|
}
|
kfree(tr->topts);
|
|
free_cpumask_var(tr->tracing_cpumask);
|
kfree(tr->name);
|
kfree(tr);
|
|
return 0;
|
}
|
|
int trace_array_destroy(struct trace_array *this_tr)
|
{
|
struct trace_array *tr;
|
int ret;
|
|
if (!this_tr)
|
return -EINVAL;
|
|
mutex_lock(&event_mutex);
|
mutex_lock(&trace_types_lock);
|
|
ret = -ENODEV;
|
|
/* Making sure trace array exists before destroying it. */
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
|
if (tr == this_tr) {
|
ret = __remove_instance(tr);
|
break;
|
}
|
}
|
|
mutex_unlock(&trace_types_lock);
|
mutex_unlock(&event_mutex);
|
|
return ret;
|
}
|
EXPORT_SYMBOL_GPL(trace_array_destroy);
|
|
static int instance_rmdir(const char *name)
|
{
|
struct trace_array *tr;
|
int ret;
|
|
mutex_lock(&event_mutex);
|
mutex_lock(&trace_types_lock);
|
|
ret = -ENODEV;
|
tr = trace_array_find(name);
|
if (tr)
|
ret = __remove_instance(tr);
|
|
mutex_unlock(&trace_types_lock);
|
mutex_unlock(&event_mutex);
|
|
return ret;
|
}
|
|
static __init void create_trace_instances(struct dentry *d_tracer)
|
{
|
struct trace_array *tr;
|
|
trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer,
|
instance_mkdir,
|
instance_rmdir);
|
if (MEM_FAIL(!trace_instance_dir, "Failed to create instances directory\n"))
|
return;
|
|
mutex_lock(&event_mutex);
|
mutex_lock(&trace_types_lock);
|
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
|
if (!tr->name)
|
continue;
|
if (MEM_FAIL(trace_array_create_dir(tr) < 0,
|
"Failed to create instance directory\n"))
|
break;
|
}
|
|
mutex_unlock(&trace_types_lock);
|
mutex_unlock(&event_mutex);
|
}
|
|
static void
|
init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
|
{
|
struct trace_event_file *file;
|
int cpu;
|
|
trace_create_file("available_tracers", 0444, d_tracer,
|
tr, &show_traces_fops);
|
|
trace_create_file("current_tracer", 0644, d_tracer,
|
tr, &set_tracer_fops);
|
|
trace_create_file("tracing_cpumask", 0644, d_tracer,
|
tr, &tracing_cpumask_fops);
|
|
trace_create_file("trace_options", 0644, d_tracer,
|
tr, &tracing_iter_fops);
|
|
trace_create_file("trace", 0644, d_tracer,
|
tr, &tracing_fops);
|
|
trace_create_file("trace_pipe", 0444, d_tracer,
|
tr, &tracing_pipe_fops);
|
|
trace_create_file("buffer_size_kb", 0644, d_tracer,
|
tr, &tracing_entries_fops);
|
|
trace_create_file("buffer_total_size_kb", 0444, d_tracer,
|
tr, &tracing_total_entries_fops);
|
|
trace_create_file("free_buffer", 0200, d_tracer,
|
tr, &tracing_free_buffer_fops);
|
|
trace_create_file("trace_marker", 0220, d_tracer,
|
tr, &tracing_mark_fops);
|
|
file = __find_event_file(tr, "ftrace", "print");
|
if (file && file->dir)
|
trace_create_file("trigger", 0644, file->dir, file,
|
&event_trigger_fops);
|
tr->trace_marker_file = file;
|
|
trace_create_file("trace_marker_raw", 0220, d_tracer,
|
tr, &tracing_mark_raw_fops);
|
|
trace_create_file("trace_clock", 0644, d_tracer, tr,
|
&trace_clock_fops);
|
|
trace_create_file("tracing_on", 0644, d_tracer,
|
tr, &rb_simple_fops);
|
|
trace_create_file("timestamp_mode", 0444, d_tracer, tr,
|
&trace_time_stamp_mode_fops);
|
|
tr->buffer_percent = 50;
|
|
trace_create_file("buffer_percent", 0444, d_tracer,
|
tr, &buffer_percent_fops);
|
|
create_trace_options_dir(tr);
|
|
#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
|
trace_create_maxlat_file(tr, d_tracer);
|
#endif
|
|
if (ftrace_create_function_files(tr, d_tracer))
|
MEM_FAIL(1, "Could not allocate function filter files");
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
trace_create_file("snapshot", 0644, d_tracer,
|
tr, &snapshot_fops);
|
#endif
|
|
trace_create_file("error_log", 0644, d_tracer,
|
tr, &tracing_err_log_fops);
|
|
for_each_tracing_cpu(cpu)
|
tracing_init_tracefs_percpu(tr, cpu);
|
|
ftrace_init_tracefs(tr, d_tracer);
|
}
|
|
#ifndef CONFIG_TRACEFS_DISABLE_AUTOMOUNT
|
static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore)
|
{
|
struct vfsmount *mnt;
|
struct file_system_type *type;
|
|
/*
|
* To maintain backward compatibility for tools that mount
|
* debugfs to get to the tracing facility, tracefs is automatically
|
* mounted to the debugfs/tracing directory.
|
*/
|
type = get_fs_type("tracefs");
|
if (!type)
|
return NULL;
|
mnt = vfs_submount(mntpt, type, "tracefs", NULL);
|
put_filesystem(type);
|
if (IS_ERR(mnt))
|
return NULL;
|
mntget(mnt);
|
|
return mnt;
|
}
|
#endif
|
|
/**
|
* tracing_init_dentry - initialize top level trace array
|
*
|
* This is called when creating files or directories in the tracing
|
* directory. It is called via fs_initcall() by any of the boot up code
|
* and expects to return the dentry of the top level tracing directory.
|
*/
|
int tracing_init_dentry(void)
|
{
|
struct trace_array *tr = &global_trace;
|
|
if (security_locked_down(LOCKDOWN_TRACEFS)) {
|
pr_warn("Tracing disabled due to lockdown\n");
|
return -EPERM;
|
}
|
|
/* The top level trace array uses NULL as parent */
|
if (tr->dir)
|
return 0;
|
|
if (WARN_ON(!tracefs_initialized()))
|
return -ENODEV;
|
|
#ifndef CONFIG_TRACEFS_DISABLE_AUTOMOUNT
|
/*
|
* As there may still be users that expect the tracing
|
* files to exist in debugfs/tracing, we must automount
|
* the tracefs file system there, so older tools still
|
* work with the newer kerenl.
|
*/
|
tr->dir = debugfs_create_automount("tracing", NULL,
|
trace_automount, NULL);
|
#else
|
tr->dir = ERR_PTR(-ENODEV);
|
#endif
|
|
return 0;
|
}
|
|
extern struct trace_eval_map *__start_ftrace_eval_maps[];
|
extern struct trace_eval_map *__stop_ftrace_eval_maps[];
|
|
static void __init trace_eval_init(void)
|
{
|
int len;
|
|
len = __stop_ftrace_eval_maps - __start_ftrace_eval_maps;
|
trace_insert_eval_map(NULL, __start_ftrace_eval_maps, len);
|
}
|
|
#ifdef CONFIG_MODULES
|
static void trace_module_add_evals(struct module *mod)
|
{
|
if (!mod->num_trace_evals)
|
return;
|
|
/*
|
* Modules with bad taint do not have events created, do
|
* not bother with enums either.
|
*/
|
if (trace_module_has_bad_taint(mod))
|
return;
|
|
trace_insert_eval_map(mod, mod->trace_evals, mod->num_trace_evals);
|
}
|
|
#ifdef CONFIG_TRACE_EVAL_MAP_FILE
|
static void trace_module_remove_evals(struct module *mod)
|
{
|
union trace_eval_map_item *map;
|
union trace_eval_map_item **last = &trace_eval_maps;
|
|
if (!mod->num_trace_evals)
|
return;
|
|
mutex_lock(&trace_eval_mutex);
|
|
map = trace_eval_maps;
|
|
while (map) {
|
if (map->head.mod == mod)
|
break;
|
map = trace_eval_jmp_to_tail(map);
|
last = &map->tail.next;
|
map = map->tail.next;
|
}
|
if (!map)
|
goto out;
|
|
*last = trace_eval_jmp_to_tail(map)->tail.next;
|
kfree(map);
|
out:
|
mutex_unlock(&trace_eval_mutex);
|
}
|
#else
|
static inline void trace_module_remove_evals(struct module *mod) { }
|
#endif /* CONFIG_TRACE_EVAL_MAP_FILE */
|
|
static int trace_module_notify(struct notifier_block *self,
|
unsigned long val, void *data)
|
{
|
struct module *mod = data;
|
|
switch (val) {
|
case MODULE_STATE_COMING:
|
trace_module_add_evals(mod);
|
break;
|
case MODULE_STATE_GOING:
|
trace_module_remove_evals(mod);
|
break;
|
}
|
|
return NOTIFY_OK;
|
}
|
|
static struct notifier_block trace_module_nb = {
|
.notifier_call = trace_module_notify,
|
.priority = 0,
|
};
|
#endif /* CONFIG_MODULES */
|
|
static __init int tracer_init_tracefs(void)
|
{
|
int ret;
|
|
trace_access_lock_init();
|
|
ret = tracing_init_dentry();
|
if (ret)
|
return 0;
|
|
event_trace_init();
|
|
init_tracer_tracefs(&global_trace, NULL);
|
ftrace_init_tracefs_toplevel(&global_trace, NULL);
|
|
trace_create_file("tracing_thresh", 0644, NULL,
|
&global_trace, &tracing_thresh_fops);
|
|
trace_create_file("README", 0444, NULL,
|
NULL, &tracing_readme_fops);
|
|
trace_create_file("saved_cmdlines", 0444, NULL,
|
NULL, &tracing_saved_cmdlines_fops);
|
|
trace_create_file("saved_cmdlines_size", 0644, NULL,
|
NULL, &tracing_saved_cmdlines_size_fops);
|
|
trace_create_file("saved_tgids", 0444, NULL,
|
NULL, &tracing_saved_tgids_fops);
|
|
trace_eval_init();
|
|
trace_create_eval_file(NULL);
|
|
#ifdef CONFIG_MODULES
|
register_module_notifier(&trace_module_nb);
|
#endif
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
trace_create_file("dyn_ftrace_total_info", 0444, NULL,
|
NULL, &tracing_dyn_info_fops);
|
#endif
|
|
create_trace_instances(NULL);
|
|
update_tracer_options(&global_trace);
|
|
return 0;
|
}
|
|
static int trace_panic_handler(struct notifier_block *this,
|
unsigned long event, void *unused)
|
{
|
bool ftrace_check = false;
|
|
trace_android_vh_ftrace_oops_enter(&ftrace_check);
|
|
if (ftrace_check)
|
return NOTIFY_OK;
|
|
if (ftrace_dump_on_oops)
|
ftrace_dump(ftrace_dump_on_oops);
|
|
trace_android_vh_ftrace_oops_exit(&ftrace_check);
|
return NOTIFY_OK;
|
}
|
|
static struct notifier_block trace_panic_notifier = {
|
.notifier_call = trace_panic_handler,
|
.next = NULL,
|
.priority = 150 /* priority: INT_MAX >= x >= 0 */
|
};
|
|
static int trace_die_handler(struct notifier_block *self,
|
unsigned long val,
|
void *data)
|
{
|
bool ftrace_check = false;
|
|
trace_android_vh_ftrace_oops_enter(&ftrace_check);
|
|
if (ftrace_check)
|
return NOTIFY_OK;
|
|
switch (val) {
|
case DIE_OOPS:
|
if (ftrace_dump_on_oops)
|
ftrace_dump(ftrace_dump_on_oops);
|
break;
|
default:
|
break;
|
}
|
|
trace_android_vh_ftrace_oops_exit(&ftrace_check);
|
return NOTIFY_OK;
|
}
|
|
static struct notifier_block trace_die_notifier = {
|
.notifier_call = trace_die_handler,
|
.priority = 200
|
};
|
|
/*
|
* printk is set to max of 1024, we really don't need it that big.
|
* Nothing should be printing 1000 characters anyway.
|
*/
|
#define TRACE_MAX_PRINT 1000
|
|
/*
|
* Define here KERN_TRACE so that we have one place to modify
|
* it if we decide to change what log level the ftrace dump
|
* should be at.
|
*/
|
#define KERN_TRACE KERN_EMERG
|
|
void
|
trace_printk_seq(struct trace_seq *s)
|
{
|
bool dump_printk = true;
|
|
/* Probably should print a warning here. */
|
if (s->seq.len >= TRACE_MAX_PRINT)
|
s->seq.len = TRACE_MAX_PRINT;
|
|
/*
|
* More paranoid code. Although the buffer size is set to
|
* PAGE_SIZE, and TRACE_MAX_PRINT is 1000, this is just
|
* an extra layer of protection.
|
*/
|
if (WARN_ON_ONCE(s->seq.len >= s->seq.size))
|
s->seq.len = s->seq.size - 1;
|
|
/* should be zero ended, but we are paranoid. */
|
s->buffer[s->seq.len] = 0;
|
|
trace_android_vh_ftrace_dump_buffer(s, &dump_printk);
|
if (dump_printk)
|
printk(KERN_TRACE "%s", s->buffer);
|
|
trace_seq_init(s);
|
}
|
|
void trace_init_global_iter(struct trace_iterator *iter)
|
{
|
iter->tr = &global_trace;
|
iter->trace = iter->tr->current_trace;
|
iter->cpu_file = RING_BUFFER_ALL_CPUS;
|
iter->array_buffer = &global_trace.array_buffer;
|
|
if (iter->trace && iter->trace->open)
|
iter->trace->open(iter);
|
|
/* Annotate start of buffers if we had overruns */
|
if (ring_buffer_overruns(iter->array_buffer->buffer))
|
iter->iter_flags |= TRACE_FILE_ANNOTATE;
|
|
/* Output in nanoseconds only if we are using a clock in nanoseconds. */
|
if (trace_clocks[iter->tr->clock_id].in_ns)
|
iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
|
}
|
|
void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
|
{
|
/* use static because iter can be a bit big for the stack */
|
static struct trace_iterator iter;
|
static atomic_t dump_running;
|
struct trace_array *tr = &global_trace;
|
unsigned int old_userobj;
|
unsigned long flags;
|
int cnt = 0, cpu;
|
bool ftrace_check = false;
|
unsigned long size;
|
|
/* Only allow one dump user at a time. */
|
if (atomic_inc_return(&dump_running) != 1) {
|
atomic_dec(&dump_running);
|
return;
|
}
|
|
/*
|
* Always turn off tracing when we dump.
|
* We don't need to show trace output of what happens
|
* between multiple crashes.
|
*
|
* If the user does a sysrq-z, then they can re-enable
|
* tracing with echo 1 > tracing_on.
|
*/
|
tracing_off();
|
|
local_irq_save(flags);
|
|
/* Simulate the iterator */
|
trace_init_global_iter(&iter);
|
/* Can not use kmalloc for iter.temp */
|
iter.temp = static_temp_buf;
|
iter.temp_size = STATIC_TEMP_BUF_SIZE;
|
|
for_each_tracing_cpu(cpu) {
|
atomic_inc(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
|
size = ring_buffer_size(iter.array_buffer->buffer, cpu);
|
trace_android_vh_ftrace_size_check(size, &ftrace_check);
|
}
|
|
old_userobj = tr->trace_flags & TRACE_ITER_SYM_USEROBJ;
|
|
/* don't look at user memory in panic mode */
|
tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
|
|
if (ftrace_check)
|
goto out_enable;
|
|
switch (oops_dump_mode) {
|
case DUMP_ALL:
|
iter.cpu_file = RING_BUFFER_ALL_CPUS;
|
break;
|
case DUMP_ORIG:
|
iter.cpu_file = raw_smp_processor_id();
|
break;
|
case DUMP_NONE:
|
goto out_enable;
|
default:
|
printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
|
iter.cpu_file = RING_BUFFER_ALL_CPUS;
|
}
|
|
printk(KERN_TRACE "Dumping ftrace buffer:\n");
|
|
/* Did function tracer already get disabled? */
|
if (ftrace_is_dead()) {
|
printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n");
|
printk("# MAY BE MISSING FUNCTION EVENTS\n");
|
}
|
|
/*
|
* We need to stop all tracing on all CPUS to read
|
* the next buffer. This is a bit expensive, but is
|
* not done often. We fill all what we can read,
|
* and then release the locks again.
|
*/
|
|
while (!trace_empty(&iter)) {
|
ftrace_check = true;
|
|
if (!cnt)
|
printk(KERN_TRACE "---------------------------------\n");
|
|
cnt++;
|
|
trace_iterator_reset(&iter);
|
trace_android_vh_ftrace_format_check(&ftrace_check);
|
if (ftrace_check)
|
iter.iter_flags |= TRACE_FILE_LAT_FMT;
|
|
if (trace_find_next_entry_inc(&iter) != NULL) {
|
int ret;
|
|
ret = print_trace_line(&iter);
|
if (ret != TRACE_TYPE_NO_CONSUME)
|
trace_consume(&iter);
|
}
|
touch_nmi_watchdog();
|
|
trace_printk_seq(&iter.seq);
|
}
|
|
if (!cnt)
|
printk(KERN_TRACE " (ftrace buffer empty)\n");
|
else
|
printk(KERN_TRACE "---------------------------------\n");
|
|
out_enable:
|
tr->trace_flags |= old_userobj;
|
|
for_each_tracing_cpu(cpu) {
|
atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
|
}
|
atomic_dec(&dump_running);
|
local_irq_restore(flags);
|
}
|
EXPORT_SYMBOL_GPL(ftrace_dump);
|
|
int trace_run_command(const char *buf, int (*createfn)(int, char **))
|
{
|
char **argv;
|
int argc, ret;
|
|
argc = 0;
|
ret = 0;
|
argv = argv_split(GFP_KERNEL, buf, &argc);
|
if (!argv)
|
return -ENOMEM;
|
|
if (argc)
|
ret = createfn(argc, argv);
|
|
argv_free(argv);
|
|
return ret;
|
}
|
|
#define WRITE_BUFSIZE 4096
|
|
ssize_t trace_parse_run_command(struct file *file, const char __user *buffer,
|
size_t count, loff_t *ppos,
|
int (*createfn)(int, char **))
|
{
|
char *kbuf, *buf, *tmp;
|
int ret = 0;
|
size_t done = 0;
|
size_t size;
|
|
kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
|
if (!kbuf)
|
return -ENOMEM;
|
|
while (done < count) {
|
size = count - done;
|
|
if (size >= WRITE_BUFSIZE)
|
size = WRITE_BUFSIZE - 1;
|
|
if (copy_from_user(kbuf, buffer + done, size)) {
|
ret = -EFAULT;
|
goto out;
|
}
|
kbuf[size] = '\0';
|
buf = kbuf;
|
do {
|
tmp = strchr(buf, '\n');
|
if (tmp) {
|
*tmp = '\0';
|
size = tmp - buf + 1;
|
} else {
|
size = strlen(buf);
|
if (done + size < count) {
|
if (buf != kbuf)
|
break;
|
/* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */
|
pr_warn("Line length is too long: Should be less than %d\n",
|
WRITE_BUFSIZE - 2);
|
ret = -EINVAL;
|
goto out;
|
}
|
}
|
done += size;
|
|
/* Remove comments */
|
tmp = strchr(buf, '#');
|
|
if (tmp)
|
*tmp = '\0';
|
|
ret = trace_run_command(buf, createfn);
|
if (ret)
|
goto out;
|
buf += size;
|
|
} while (done < count);
|
}
|
ret = done;
|
|
out:
|
kfree(kbuf);
|
|
return ret;
|
}
|
|
__init static int tracer_alloc_buffers(void)
|
{
|
int ring_buf_size;
|
int ret = -ENOMEM;
|
|
|
if (security_locked_down(LOCKDOWN_TRACEFS)) {
|
pr_warn("Tracing disabled due to lockdown\n");
|
return -EPERM;
|
}
|
|
/*
|
* Make sure we don't accidentally add more trace options
|
* than we have bits for.
|
*/
|
BUILD_BUG_ON(TRACE_ITER_LAST_BIT > TRACE_FLAGS_MAX_SIZE);
|
|
if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
|
goto out;
|
|
if (!alloc_cpumask_var(&global_trace.tracing_cpumask, GFP_KERNEL))
|
goto out_free_buffer_mask;
|
|
/* Only allocate trace_printk buffers if a trace_printk exists */
|
if (&__stop___trace_bprintk_fmt != &__start___trace_bprintk_fmt)
|
/* Must be called before global_trace.buffer is allocated */
|
trace_printk_init_buffers();
|
|
/* To save memory, keep the ring buffer size to its minimum */
|
if (ring_buffer_expanded)
|
ring_buf_size = trace_buf_size;
|
else
|
ring_buf_size = 1;
|
|
cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
|
cpumask_copy(global_trace.tracing_cpumask, cpu_all_mask);
|
|
raw_spin_lock_init(&global_trace.start_lock);
|
|
/*
|
* The prepare callbacks allocates some memory for the ring buffer. We
|
* don't free the buffer if the CPU goes down. If we were to free
|
* the buffer, then the user would lose any trace that was in the
|
* buffer. The memory will be removed once the "instance" is removed.
|
*/
|
ret = cpuhp_setup_state_multi(CPUHP_TRACE_RB_PREPARE,
|
"trace/RB:preapre", trace_rb_cpu_prepare,
|
NULL);
|
if (ret < 0)
|
goto out_free_cpumask;
|
/* Used for event triggers */
|
ret = -ENOMEM;
|
temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE);
|
if (!temp_buffer)
|
goto out_rm_hp_state;
|
|
if (trace_create_savedcmd() < 0)
|
goto out_free_temp_buffer;
|
|
/* TODO: make the number of buffers hot pluggable with CPUS */
|
if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {
|
MEM_FAIL(1, "tracer: failed to allocate ring buffer!\n");
|
goto out_free_savedcmd;
|
}
|
|
if (global_trace.buffer_disabled)
|
tracing_off();
|
|
if (trace_boot_clock) {
|
ret = tracing_set_clock(&global_trace, trace_boot_clock);
|
if (ret < 0)
|
pr_warn("Trace clock %s not defined, going back to default\n",
|
trace_boot_clock);
|
}
|
|
/*
|
* register_tracer() might reference current_trace, so it
|
* needs to be set before we register anything. This is
|
* just a bootstrap of current_trace anyway.
|
*/
|
global_trace.current_trace = &nop_trace;
|
|
global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
|
|
ftrace_init_global_array_ops(&global_trace);
|
|
init_trace_flags_index(&global_trace);
|
|
register_tracer(&nop_trace);
|
|
/* Function tracing may start here (via kernel command line) */
|
init_function_trace();
|
|
/* All seems OK, enable tracing */
|
tracing_disabled = 0;
|
|
atomic_notifier_chain_register(&panic_notifier_list,
|
&trace_panic_notifier);
|
|
register_die_notifier(&trace_die_notifier);
|
|
global_trace.flags = TRACE_ARRAY_FL_GLOBAL;
|
|
INIT_LIST_HEAD(&global_trace.systems);
|
INIT_LIST_HEAD(&global_trace.events);
|
INIT_LIST_HEAD(&global_trace.hist_vars);
|
INIT_LIST_HEAD(&global_trace.err_log);
|
list_add(&global_trace.list, &ftrace_trace_arrays);
|
|
apply_trace_boot_options();
|
|
register_snapshot_cmd();
|
|
return 0;
|
|
out_free_savedcmd:
|
free_saved_cmdlines_buffer(savedcmd);
|
out_free_temp_buffer:
|
ring_buffer_free(temp_buffer);
|
out_rm_hp_state:
|
cpuhp_remove_multi_state(CPUHP_TRACE_RB_PREPARE);
|
out_free_cpumask:
|
free_cpumask_var(global_trace.tracing_cpumask);
|
out_free_buffer_mask:
|
free_cpumask_var(tracing_buffer_mask);
|
out:
|
return ret;
|
}
|
|
void __init early_trace_init(void)
|
{
|
if (tracepoint_printk) {
|
tracepoint_print_iter =
|
kmalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL);
|
if (MEM_FAIL(!tracepoint_print_iter,
|
"Failed to allocate trace iterator\n"))
|
tracepoint_printk = 0;
|
else
|
static_key_enable(&tracepoint_printk_key.key);
|
}
|
tracer_alloc_buffers();
|
}
|
|
void __init trace_init(void)
|
{
|
trace_event_init();
|
}
|
|
__init static int clear_boot_tracer(void)
|
{
|
/*
|
* The default tracer at boot buffer is an init section.
|
* This function is called in lateinit. If we did not
|
* find the boot tracer, then clear it out, to prevent
|
* later registration from accessing the buffer that is
|
* about to be freed.
|
*/
|
if (!default_bootup_tracer)
|
return 0;
|
|
printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n",
|
default_bootup_tracer);
|
default_bootup_tracer = NULL;
|
|
return 0;
|
}
|
|
fs_initcall(tracer_init_tracefs);
|
late_initcall_sync(clear_boot_tracer);
|
|
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
|
__init static int tracing_set_default_clock(void)
|
{
|
/* sched_clock_stable() is determined in late_initcall */
|
if (!trace_boot_clock && !sched_clock_stable()) {
|
if (security_locked_down(LOCKDOWN_TRACEFS)) {
|
pr_warn("Can not set tracing clock due to lockdown\n");
|
return -EPERM;
|
}
|
|
printk(KERN_WARNING
|
"Unstable clock detected, switching default tracing clock to \"global\"\n"
|
"If you want to keep using the local clock, then add:\n"
|
" \"trace_clock=local\"\n"
|
"on the kernel command line\n");
|
tracing_set_clock(&global_trace, "global");
|
}
|
|
return 0;
|
}
|
late_initcall_sync(tracing_set_default_clock);
|
#endif
|
