// SPDX-License-Identifier: GPL-2.0
|
/*
|
* event tracer
|
*
|
* Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
|
*
|
* - Added format output of fields of the trace point.
|
* This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
|
*
|
*/
|
|
#define pr_fmt(fmt) fmt
|
|
#include <linux/workqueue.h>
|
#include <linux/security.h>
|
#include <linux/spinlock.h>
|
#include <linux/kthread.h>
|
#include <linux/tracefs.h>
|
#include <linux/uaccess.h>
|
#include <linux/module.h>
|
#include <linux/ctype.h>
|
#include <linux/sort.h>
|
#include <linux/slab.h>
|
#include <linux/delay.h>
|
|
#include <trace/events/sched.h>
|
#include <trace/syscall.h>
|
|
#include <asm/setup.h>
|
|
#include "trace_output.h"
|
|
#undef TRACE_SYSTEM
|
#define TRACE_SYSTEM "TRACE_SYSTEM"
|
|
DEFINE_MUTEX(event_mutex);
|
|
LIST_HEAD(ftrace_events);
|
static LIST_HEAD(ftrace_generic_fields);
|
static LIST_HEAD(ftrace_common_fields);
|
static bool eventdir_initialized;
|
|
#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
|
|
static struct kmem_cache *field_cachep;
|
static struct kmem_cache *file_cachep;
|
|
static inline int system_refcount(struct event_subsystem *system)
|
{
|
return system->ref_count;
|
}
|
|
static int system_refcount_inc(struct event_subsystem *system)
|
{
|
return system->ref_count++;
|
}
|
|
static int system_refcount_dec(struct event_subsystem *system)
|
{
|
return --system->ref_count;
|
}
|
|
/* Double loops, do not use break, only goto's work */
|
#define do_for_each_event_file(tr, file) \
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
|
list_for_each_entry(file, &tr->events, list)
|
|
#define do_for_each_event_file_safe(tr, file) \
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
|
struct trace_event_file *___n; \
|
list_for_each_entry_safe(file, ___n, &tr->events, list)
|
|
#define while_for_each_event_file() \
|
}
|
|
static struct ftrace_event_field *
|
__find_event_field(struct list_head *head, char *name)
|
{
|
struct ftrace_event_field *field;
|
|
list_for_each_entry(field, head, link) {
|
if (!strcmp(field->name, name))
|
return field;
|
}
|
|
return NULL;
|
}
|
|
struct ftrace_event_field *
|
trace_find_event_field(struct trace_event_call *call, char *name)
|
{
|
struct ftrace_event_field *field;
|
struct list_head *head;
|
|
head = trace_get_fields(call);
|
field = __find_event_field(head, name);
|
if (field)
|
return field;
|
|
field = __find_event_field(&ftrace_generic_fields, name);
|
if (field)
|
return field;
|
|
return __find_event_field(&ftrace_common_fields, name);
|
}
|
|
static int __trace_define_field(struct list_head *head, const char *type,
|
const char *name, int offset, int size,
|
int is_signed, int filter_type)
|
{
|
struct ftrace_event_field *field;
|
|
field = kmem_cache_alloc(field_cachep, GFP_TRACE);
|
if (!field)
|
return -ENOMEM;
|
|
field->name = name;
|
field->type = type;
|
|
if (filter_type == FILTER_OTHER)
|
field->filter_type = filter_assign_type(type);
|
else
|
field->filter_type = filter_type;
|
|
field->offset = offset;
|
field->size = size;
|
field->is_signed = is_signed;
|
|
list_add(&field->link, head);
|
|
return 0;
|
}
|
|
int trace_define_field(struct trace_event_call *call, const char *type,
|
const char *name, int offset, int size, int is_signed,
|
int filter_type)
|
{
|
struct list_head *head;
|
|
if (WARN_ON(!call->class))
|
return 0;
|
|
head = trace_get_fields(call);
|
return __trace_define_field(head, type, name, offset, size,
|
is_signed, filter_type);
|
}
|
EXPORT_SYMBOL_GPL(trace_define_field);
|
|
#define __generic_field(type, item, filter_type) \
|
ret = __trace_define_field(&ftrace_generic_fields, #type, \
|
#item, 0, 0, is_signed_type(type), \
|
filter_type); \
|
if (ret) \
|
return ret;
|
|
#define __common_field(type, item) \
|
ret = __trace_define_field(&ftrace_common_fields, #type, \
|
"common_" #item, \
|
offsetof(typeof(ent), item), \
|
sizeof(ent.item), \
|
is_signed_type(type), FILTER_OTHER); \
|
if (ret) \
|
return ret;
|
|
static int trace_define_generic_fields(void)
|
{
|
int ret;
|
|
__generic_field(int, CPU, FILTER_CPU);
|
__generic_field(int, cpu, FILTER_CPU);
|
__generic_field(int, common_cpu, FILTER_CPU);
|
__generic_field(char *, COMM, FILTER_COMM);
|
__generic_field(char *, comm, FILTER_COMM);
|
|
return ret;
|
}
|
|
static int trace_define_common_fields(void)
|
{
|
int ret;
|
struct trace_entry ent;
|
|
__common_field(unsigned short, type);
|
__common_field(unsigned char, flags);
|
__common_field(unsigned char, preempt_count);
|
__common_field(int, pid);
|
__common_field(unsigned char, migrate_disable);
|
__common_field(unsigned char, preempt_lazy_count);
|
|
return ret;
|
}
|
|
static void trace_destroy_fields(struct trace_event_call *call)
|
{
|
struct ftrace_event_field *field, *next;
|
struct list_head *head;
|
|
head = trace_get_fields(call);
|
list_for_each_entry_safe(field, next, head, link) {
|
list_del(&field->link);
|
kmem_cache_free(field_cachep, field);
|
}
|
}
|
|
/*
|
* run-time version of trace_event_get_offsets_<call>() that returns the last
|
* accessible offset of trace fields excluding __dynamic_array bytes
|
*/
|
int trace_event_get_offsets(struct trace_event_call *call)
|
{
|
struct ftrace_event_field *tail;
|
struct list_head *head;
|
|
head = trace_get_fields(call);
|
/*
|
* head->next points to the last field with the largest offset,
|
* since it was added last by trace_define_field()
|
*/
|
tail = list_first_entry(head, struct ftrace_event_field, link);
|
return tail->offset + tail->size;
|
}
|
|
int trace_event_raw_init(struct trace_event_call *call)
|
{
|
int id;
|
|
id = register_trace_event(&call->event);
|
if (!id)
|
return -ENODEV;
|
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(trace_event_raw_init);
|
|
bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
|
{
|
struct trace_array *tr = trace_file->tr;
|
struct trace_array_cpu *data;
|
struct trace_pid_list *no_pid_list;
|
struct trace_pid_list *pid_list;
|
|
pid_list = rcu_dereference_raw(tr->filtered_pids);
|
no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
|
|
if (!pid_list && !no_pid_list)
|
return false;
|
|
data = this_cpu_ptr(tr->array_buffer.data);
|
|
return data->ignore_pid;
|
}
|
EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
|
|
void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
|
struct trace_event_file *trace_file,
|
unsigned long len)
|
{
|
struct trace_event_call *event_call = trace_file->event_call;
|
|
if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
|
trace_event_ignore_this_pid(trace_file))
|
return NULL;
|
|
/*
|
* If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
|
* preemption (adding one to the preempt_count). Since we are
|
* interested in the preempt_count at the time the tracepoint was
|
* hit, we need to subtract one to offset the increment.
|
*/
|
fbuffer->trace_ctx = tracing_gen_ctx_dec();
|
fbuffer->trace_file = trace_file;
|
|
fbuffer->event =
|
trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
|
event_call->event.type, len,
|
fbuffer->trace_ctx);
|
if (!fbuffer->event)
|
return NULL;
|
|
fbuffer->regs = NULL;
|
fbuffer->entry = ring_buffer_event_data(fbuffer->event);
|
return fbuffer->entry;
|
}
|
EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
|
|
int trace_event_reg(struct trace_event_call *call,
|
enum trace_reg type, void *data)
|
{
|
struct trace_event_file *file = data;
|
|
WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
|
switch (type) {
|
case TRACE_REG_REGISTER:
|
return tracepoint_probe_register(call->tp,
|
call->class->probe,
|
file);
|
case TRACE_REG_UNREGISTER:
|
tracepoint_probe_unregister(call->tp,
|
call->class->probe,
|
file);
|
return 0;
|
|
#ifdef CONFIG_PERF_EVENTS
|
case TRACE_REG_PERF_REGISTER:
|
return tracepoint_probe_register(call->tp,
|
call->class->perf_probe,
|
call);
|
case TRACE_REG_PERF_UNREGISTER:
|
tracepoint_probe_unregister(call->tp,
|
call->class->perf_probe,
|
call);
|
return 0;
|
case TRACE_REG_PERF_OPEN:
|
case TRACE_REG_PERF_CLOSE:
|
case TRACE_REG_PERF_ADD:
|
case TRACE_REG_PERF_DEL:
|
return 0;
|
#endif
|
}
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(trace_event_reg);
|
|
void trace_event_enable_cmd_record(bool enable)
|
{
|
struct trace_event_file *file;
|
struct trace_array *tr;
|
|
lockdep_assert_held(&event_mutex);
|
|
do_for_each_event_file(tr, file) {
|
|
if (!(file->flags & EVENT_FILE_FL_ENABLED))
|
continue;
|
|
if (enable) {
|
tracing_start_cmdline_record();
|
set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
|
} else {
|
tracing_stop_cmdline_record();
|
clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
|
}
|
} while_for_each_event_file();
|
}
|
|
void trace_event_enable_tgid_record(bool enable)
|
{
|
struct trace_event_file *file;
|
struct trace_array *tr;
|
|
lockdep_assert_held(&event_mutex);
|
|
do_for_each_event_file(tr, file) {
|
if (!(file->flags & EVENT_FILE_FL_ENABLED))
|
continue;
|
|
if (enable) {
|
tracing_start_tgid_record();
|
set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
|
} else {
|
tracing_stop_tgid_record();
|
clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
|
&file->flags);
|
}
|
} while_for_each_event_file();
|
}
|
|
static int __ftrace_event_enable_disable(struct trace_event_file *file,
|
int enable, int soft_disable)
|
{
|
struct trace_event_call *call = file->event_call;
|
struct trace_array *tr = file->tr;
|
unsigned long file_flags = file->flags;
|
int ret = 0;
|
int disable;
|
|
switch (enable) {
|
case 0:
|
/*
|
* When soft_disable is set and enable is cleared, the sm_ref
|
* reference counter is decremented. If it reaches 0, we want
|
* to clear the SOFT_DISABLED flag but leave the event in the
|
* state that it was. That is, if the event was enabled and
|
* SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
|
* is set we do not want the event to be enabled before we
|
* clear the bit.
|
*
|
* When soft_disable is not set but the SOFT_MODE flag is,
|
* we do nothing. Do not disable the tracepoint, otherwise
|
* "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
|
*/
|
if (soft_disable) {
|
if (atomic_dec_return(&file->sm_ref) > 0)
|
break;
|
disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
|
clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
|
} else
|
disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
|
|
if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
|
clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
|
if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
|
tracing_stop_cmdline_record();
|
clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
|
}
|
|
if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
|
tracing_stop_tgid_record();
|
clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
|
}
|
|
call->class->reg(call, TRACE_REG_UNREGISTER, file);
|
}
|
/* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
|
if (file->flags & EVENT_FILE_FL_SOFT_MODE)
|
set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
|
else
|
clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
|
break;
|
case 1:
|
/*
|
* When soft_disable is set and enable is set, we want to
|
* register the tracepoint for the event, but leave the event
|
* as is. That means, if the event was already enabled, we do
|
* nothing (but set SOFT_MODE). If the event is disabled, we
|
* set SOFT_DISABLED before enabling the event tracepoint, so
|
* it still seems to be disabled.
|
*/
|
if (!soft_disable)
|
clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
|
else {
|
if (atomic_inc_return(&file->sm_ref) > 1)
|
break;
|
set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
|
}
|
|
if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
|
bool cmd = false, tgid = false;
|
|
/* Keep the event disabled, when going to SOFT_MODE. */
|
if (soft_disable)
|
set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
|
|
if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
|
cmd = true;
|
tracing_start_cmdline_record();
|
set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
|
}
|
|
if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
|
tgid = true;
|
tracing_start_tgid_record();
|
set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
|
}
|
|
ret = call->class->reg(call, TRACE_REG_REGISTER, file);
|
if (ret) {
|
if (cmd)
|
tracing_stop_cmdline_record();
|
if (tgid)
|
tracing_stop_tgid_record();
|
pr_info("event trace: Could not enable event "
|
"%s\n", trace_event_name(call));
|
break;
|
}
|
set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
|
|
/* WAS_ENABLED gets set but never cleared. */
|
set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
|
}
|
break;
|
}
|
|
/* Enable or disable use of trace_buffered_event */
|
if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
|
(file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
|
if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
|
trace_buffered_event_enable();
|
else
|
trace_buffered_event_disable();
|
}
|
|
return ret;
|
}
|
|
int trace_event_enable_disable(struct trace_event_file *file,
|
int enable, int soft_disable)
|
{
|
return __ftrace_event_enable_disable(file, enable, soft_disable);
|
}
|
|
static int ftrace_event_enable_disable(struct trace_event_file *file,
|
int enable)
|
{
|
return __ftrace_event_enable_disable(file, enable, 0);
|
}
|
|
static void ftrace_clear_events(struct trace_array *tr)
|
{
|
struct trace_event_file *file;
|
|
mutex_lock(&event_mutex);
|
list_for_each_entry(file, &tr->events, list) {
|
ftrace_event_enable_disable(file, 0);
|
}
|
mutex_unlock(&event_mutex);
|
}
|
|
static void
|
event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
|
{
|
struct trace_pid_list *pid_list;
|
struct trace_array *tr = data;
|
|
pid_list = rcu_dereference_raw(tr->filtered_pids);
|
trace_filter_add_remove_task(pid_list, NULL, task);
|
|
pid_list = rcu_dereference_raw(tr->filtered_no_pids);
|
trace_filter_add_remove_task(pid_list, NULL, task);
|
}
|
|
static void
|
event_filter_pid_sched_process_fork(void *data,
|
struct task_struct *self,
|
struct task_struct *task)
|
{
|
struct trace_pid_list *pid_list;
|
struct trace_array *tr = data;
|
|
pid_list = rcu_dereference_sched(tr->filtered_pids);
|
trace_filter_add_remove_task(pid_list, self, task);
|
|
pid_list = rcu_dereference_sched(tr->filtered_no_pids);
|
trace_filter_add_remove_task(pid_list, self, task);
|
}
|
|
void trace_event_follow_fork(struct trace_array *tr, bool enable)
|
{
|
if (enable) {
|
register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
|
tr, INT_MIN);
|
register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit,
|
tr, INT_MAX);
|
} else {
|
unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
|
tr);
|
unregister_trace_sched_process_free(event_filter_pid_sched_process_exit,
|
tr);
|
}
|
}
|
|
static void
|
event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
|
struct task_struct *prev, struct task_struct *next)
|
{
|
struct trace_array *tr = data;
|
struct trace_pid_list *no_pid_list;
|
struct trace_pid_list *pid_list;
|
bool ret;
|
|
pid_list = rcu_dereference_sched(tr->filtered_pids);
|
no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
|
|
/*
|
* Sched switch is funny, as we only want to ignore it
|
* in the notrace case if both prev and next should be ignored.
|
*/
|
ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
|
trace_ignore_this_task(NULL, no_pid_list, next);
|
|
this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
|
(trace_ignore_this_task(pid_list, NULL, prev) &&
|
trace_ignore_this_task(pid_list, NULL, next)));
|
}
|
|
static void
|
event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
|
struct task_struct *prev, struct task_struct *next)
|
{
|
struct trace_array *tr = data;
|
struct trace_pid_list *no_pid_list;
|
struct trace_pid_list *pid_list;
|
|
pid_list = rcu_dereference_sched(tr->filtered_pids);
|
no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
|
|
this_cpu_write(tr->array_buffer.data->ignore_pid,
|
trace_ignore_this_task(pid_list, no_pid_list, next));
|
}
|
|
static void
|
event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
|
{
|
struct trace_array *tr = data;
|
struct trace_pid_list *no_pid_list;
|
struct trace_pid_list *pid_list;
|
|
/* Nothing to do if we are already tracing */
|
if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
|
return;
|
|
pid_list = rcu_dereference_sched(tr->filtered_pids);
|
no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
|
|
this_cpu_write(tr->array_buffer.data->ignore_pid,
|
trace_ignore_this_task(pid_list, no_pid_list, task));
|
}
|
|
static void
|
event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
|
{
|
struct trace_array *tr = data;
|
struct trace_pid_list *no_pid_list;
|
struct trace_pid_list *pid_list;
|
|
/* Nothing to do if we are not tracing */
|
if (this_cpu_read(tr->array_buffer.data->ignore_pid))
|
return;
|
|
pid_list = rcu_dereference_sched(tr->filtered_pids);
|
no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
|
|
/* Set tracing if current is enabled */
|
this_cpu_write(tr->array_buffer.data->ignore_pid,
|
trace_ignore_this_task(pid_list, no_pid_list, current));
|
}
|
|
static void unregister_pid_events(struct trace_array *tr)
|
{
|
unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
|
unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
|
|
unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
|
unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
|
|
unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
|
unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
|
|
unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
|
unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
|
}
|
|
static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
|
{
|
struct trace_pid_list *pid_list;
|
struct trace_pid_list *no_pid_list;
|
struct trace_event_file *file;
|
int cpu;
|
|
pid_list = rcu_dereference_protected(tr->filtered_pids,
|
lockdep_is_held(&event_mutex));
|
no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
|
lockdep_is_held(&event_mutex));
|
|
/* Make sure there's something to do */
|
if (!pid_type_enabled(type, pid_list, no_pid_list))
|
return;
|
|
if (!still_need_pid_events(type, pid_list, no_pid_list)) {
|
unregister_pid_events(tr);
|
|
list_for_each_entry(file, &tr->events, list) {
|
clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
|
}
|
|
for_each_possible_cpu(cpu)
|
per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
|
}
|
|
if (type & TRACE_PIDS)
|
rcu_assign_pointer(tr->filtered_pids, NULL);
|
|
if (type & TRACE_NO_PIDS)
|
rcu_assign_pointer(tr->filtered_no_pids, NULL);
|
|
/* Wait till all users are no longer using pid filtering */
|
tracepoint_synchronize_unregister();
|
|
if ((type & TRACE_PIDS) && pid_list)
|
trace_free_pid_list(pid_list);
|
|
if ((type & TRACE_NO_PIDS) && no_pid_list)
|
trace_free_pid_list(no_pid_list);
|
}
|
|
static void ftrace_clear_event_pids(struct trace_array *tr, int type)
|
{
|
mutex_lock(&event_mutex);
|
__ftrace_clear_event_pids(tr, type);
|
mutex_unlock(&event_mutex);
|
}
|
|
static void __put_system(struct event_subsystem *system)
|
{
|
struct event_filter *filter = system->filter;
|
|
WARN_ON_ONCE(system_refcount(system) == 0);
|
if (system_refcount_dec(system))
|
return;
|
|
list_del(&system->list);
|
|
if (filter) {
|
kfree(filter->filter_string);
|
kfree(filter);
|
}
|
kfree_const(system->name);
|
kfree(system);
|
}
|
|
static void __get_system(struct event_subsystem *system)
|
{
|
WARN_ON_ONCE(system_refcount(system) == 0);
|
system_refcount_inc(system);
|
}
|
|
static void __get_system_dir(struct trace_subsystem_dir *dir)
|
{
|
WARN_ON_ONCE(dir->ref_count == 0);
|
dir->ref_count++;
|
__get_system(dir->subsystem);
|
}
|
|
static void __put_system_dir(struct trace_subsystem_dir *dir)
|
{
|
WARN_ON_ONCE(dir->ref_count == 0);
|
/* If the subsystem is about to be freed, the dir must be too */
|
WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
|
|
__put_system(dir->subsystem);
|
if (!--dir->ref_count)
|
kfree(dir);
|
}
|
|
static void put_system(struct trace_subsystem_dir *dir)
|
{
|
mutex_lock(&event_mutex);
|
__put_system_dir(dir);
|
mutex_unlock(&event_mutex);
|
}
|
|
static void remove_subsystem(struct trace_subsystem_dir *dir)
|
{
|
if (!dir)
|
return;
|
|
if (!--dir->nr_events) {
|
tracefs_remove(dir->entry);
|
list_del(&dir->list);
|
__put_system_dir(dir);
|
}
|
}
|
|
static void remove_event_file_dir(struct trace_event_file *file)
|
{
|
struct dentry *dir = file->dir;
|
struct dentry *child;
|
|
if (dir) {
|
spin_lock(&dir->d_lock); /* probably unneeded */
|
list_for_each_entry(child, &dir->d_subdirs, d_child) {
|
if (d_really_is_positive(child)) /* probably unneeded */
|
d_inode(child)->i_private = NULL;
|
}
|
spin_unlock(&dir->d_lock);
|
|
tracefs_remove(dir);
|
}
|
|
list_del(&file->list);
|
remove_subsystem(file->system);
|
free_event_filter(file->filter);
|
kmem_cache_free(file_cachep, file);
|
}
|
|
/*
|
* __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
|
*/
|
static int
|
__ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
|
const char *sub, const char *event, int set)
|
{
|
struct trace_event_file *file;
|
struct trace_event_call *call;
|
const char *name;
|
int ret = -EINVAL;
|
int eret = 0;
|
|
list_for_each_entry(file, &tr->events, list) {
|
|
call = file->event_call;
|
name = trace_event_name(call);
|
|
if (!name || !call->class || !call->class->reg)
|
continue;
|
|
if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
|
continue;
|
|
if (match &&
|
strcmp(match, name) != 0 &&
|
strcmp(match, call->class->system) != 0)
|
continue;
|
|
if (sub && strcmp(sub, call->class->system) != 0)
|
continue;
|
|
if (event && strcmp(event, name) != 0)
|
continue;
|
|
ret = ftrace_event_enable_disable(file, set);
|
|
/*
|
* Save the first error and return that. Some events
|
* may still have been enabled, but let the user
|
* know that something went wrong.
|
*/
|
if (ret && !eret)
|
eret = ret;
|
|
ret = eret;
|
}
|
|
return ret;
|
}
|
|
static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
|
const char *sub, const char *event, int set)
|
{
|
int ret;
|
|
mutex_lock(&event_mutex);
|
ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
|
mutex_unlock(&event_mutex);
|
|
return ret;
|
}
|
|
int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
|
{
|
char *event = NULL, *sub = NULL, *match;
|
int ret;
|
|
if (!tr)
|
return -ENOENT;
|
/*
|
* The buf format can be <subsystem>:<event-name>
|
* *:<event-name> means any event by that name.
|
* :<event-name> is the same.
|
*
|
* <subsystem>:* means all events in that subsystem
|
* <subsystem>: means the same.
|
*
|
* <name> (no ':') means all events in a subsystem with
|
* the name <name> or any event that matches <name>
|
*/
|
|
match = strsep(&buf, ":");
|
if (buf) {
|
sub = match;
|
event = buf;
|
match = NULL;
|
|
if (!strlen(sub) || strcmp(sub, "*") == 0)
|
sub = NULL;
|
if (!strlen(event) || strcmp(event, "*") == 0)
|
event = NULL;
|
}
|
|
ret = __ftrace_set_clr_event(tr, match, sub, event, set);
|
|
/* Put back the colon to allow this to be called again */
|
if (buf)
|
*(buf - 1) = ':';
|
|
return ret;
|
}
|
|
/**
|
* trace_set_clr_event - enable or disable an event
|
* @system: system name to match (NULL for any system)
|
* @event: event name to match (NULL for all events, within system)
|
* @set: 1 to enable, 0 to disable
|
*
|
* This is a way for other parts of the kernel to enable or disable
|
* event recording.
|
*
|
* Returns 0 on success, -EINVAL if the parameters do not match any
|
* registered events.
|
*/
|
int trace_set_clr_event(const char *system, const char *event, int set)
|
{
|
struct trace_array *tr = top_trace_array();
|
|
if (!tr)
|
return -ENODEV;
|
|
return __ftrace_set_clr_event(tr, NULL, system, event, set);
|
}
|
EXPORT_SYMBOL_GPL(trace_set_clr_event);
|
|
/**
|
* trace_array_set_clr_event - enable or disable an event for a trace array.
|
* @tr: concerned trace array.
|
* @system: system name to match (NULL for any system)
|
* @event: event name to match (NULL for all events, within system)
|
* @enable: true to enable, false to disable
|
*
|
* This is a way for other parts of the kernel to enable or disable
|
* event recording.
|
*
|
* Returns 0 on success, -EINVAL if the parameters do not match any
|
* registered events.
|
*/
|
int trace_array_set_clr_event(struct trace_array *tr, const char *system,
|
const char *event, bool enable)
|
{
|
int set;
|
|
if (!tr)
|
return -ENOENT;
|
|
set = (enable == true) ? 1 : 0;
|
return __ftrace_set_clr_event(tr, NULL, system, event, set);
|
}
|
EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
|
|
/* 128 should be much more than enough */
|
#define EVENT_BUF_SIZE 127
|
|
static ssize_t
|
ftrace_event_write(struct file *file, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
struct trace_parser parser;
|
struct seq_file *m = file->private_data;
|
struct trace_array *tr = m->private;
|
ssize_t read, ret;
|
|
if (!cnt)
|
return 0;
|
|
ret = tracing_update_buffers();
|
if (ret < 0)
|
return ret;
|
|
if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
|
return -ENOMEM;
|
|
read = trace_get_user(&parser, ubuf, cnt, ppos);
|
|
if (read >= 0 && trace_parser_loaded((&parser))) {
|
int set = 1;
|
|
if (*parser.buffer == '!')
|
set = 0;
|
|
ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
|
if (ret)
|
goto out_put;
|
}
|
|
ret = read;
|
|
out_put:
|
trace_parser_put(&parser);
|
|
return ret;
|
}
|
|
static void *
|
t_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
struct trace_event_file *file = v;
|
struct trace_event_call *call;
|
struct trace_array *tr = m->private;
|
|
(*pos)++;
|
|
list_for_each_entry_continue(file, &tr->events, list) {
|
call = file->event_call;
|
/*
|
* The ftrace subsystem is for showing formats only.
|
* They can not be enabled or disabled via the event files.
|
*/
|
if (call->class && call->class->reg &&
|
!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
|
return file;
|
}
|
|
return NULL;
|
}
|
|
static void *t_start(struct seq_file *m, loff_t *pos)
|
{
|
struct trace_event_file *file;
|
struct trace_array *tr = m->private;
|
loff_t l;
|
|
mutex_lock(&event_mutex);
|
|
file = list_entry(&tr->events, struct trace_event_file, list);
|
for (l = 0; l <= *pos; ) {
|
file = t_next(m, file, &l);
|
if (!file)
|
break;
|
}
|
return file;
|
}
|
|
static void *
|
s_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
struct trace_event_file *file = v;
|
struct trace_array *tr = m->private;
|
|
(*pos)++;
|
|
list_for_each_entry_continue(file, &tr->events, list) {
|
if (file->flags & EVENT_FILE_FL_ENABLED)
|
return file;
|
}
|
|
return NULL;
|
}
|
|
static void *s_start(struct seq_file *m, loff_t *pos)
|
{
|
struct trace_event_file *file;
|
struct trace_array *tr = m->private;
|
loff_t l;
|
|
mutex_lock(&event_mutex);
|
|
file = list_entry(&tr->events, struct trace_event_file, list);
|
for (l = 0; l <= *pos; ) {
|
file = s_next(m, file, &l);
|
if (!file)
|
break;
|
}
|
return file;
|
}
|
|
static int t_show(struct seq_file *m, void *v)
|
{
|
struct trace_event_file *file = v;
|
struct trace_event_call *call = file->event_call;
|
|
if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
|
seq_printf(m, "%s:", call->class->system);
|
seq_printf(m, "%s\n", trace_event_name(call));
|
|
return 0;
|
}
|
|
static void t_stop(struct seq_file *m, void *p)
|
{
|
mutex_unlock(&event_mutex);
|
}
|
|
static void *
|
__next(struct seq_file *m, void *v, loff_t *pos, int type)
|
{
|
struct trace_array *tr = m->private;
|
struct trace_pid_list *pid_list;
|
|
if (type == TRACE_PIDS)
|
pid_list = rcu_dereference_sched(tr->filtered_pids);
|
else
|
pid_list = rcu_dereference_sched(tr->filtered_no_pids);
|
|
return trace_pid_next(pid_list, v, pos);
|
}
|
|
static void *
|
p_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
return __next(m, v, pos, TRACE_PIDS);
|
}
|
|
static void *
|
np_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
return __next(m, v, pos, TRACE_NO_PIDS);
|
}
|
|
static void *__start(struct seq_file *m, loff_t *pos, int type)
|
__acquires(RCU)
|
{
|
struct trace_pid_list *pid_list;
|
struct trace_array *tr = m->private;
|
|
/*
|
* Grab the mutex, to keep calls to p_next() having the same
|
* tr->filtered_pids as p_start() has.
|
* If we just passed the tr->filtered_pids around, then RCU would
|
* have been enough, but doing that makes things more complex.
|
*/
|
mutex_lock(&event_mutex);
|
rcu_read_lock_sched();
|
|
if (type == TRACE_PIDS)
|
pid_list = rcu_dereference_sched(tr->filtered_pids);
|
else
|
pid_list = rcu_dereference_sched(tr->filtered_no_pids);
|
|
if (!pid_list)
|
return NULL;
|
|
return trace_pid_start(pid_list, pos);
|
}
|
|
static void *p_start(struct seq_file *m, loff_t *pos)
|
__acquires(RCU)
|
{
|
return __start(m, pos, TRACE_PIDS);
|
}
|
|
static void *np_start(struct seq_file *m, loff_t *pos)
|
__acquires(RCU)
|
{
|
return __start(m, pos, TRACE_NO_PIDS);
|
}
|
|
static void p_stop(struct seq_file *m, void *p)
|
__releases(RCU)
|
{
|
rcu_read_unlock_sched();
|
mutex_unlock(&event_mutex);
|
}
|
|
static ssize_t
|
event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
struct trace_event_file *file;
|
unsigned long flags;
|
char buf[4] = "0";
|
|
mutex_lock(&event_mutex);
|
file = event_file_data(filp);
|
if (likely(file))
|
flags = file->flags;
|
mutex_unlock(&event_mutex);
|
|
if (!file)
|
return -ENODEV;
|
|
if (flags & EVENT_FILE_FL_ENABLED &&
|
!(flags & EVENT_FILE_FL_SOFT_DISABLED))
|
strcpy(buf, "1");
|
|
if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
|
flags & EVENT_FILE_FL_SOFT_MODE)
|
strcat(buf, "*");
|
|
strcat(buf, "\n");
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
|
}
|
|
static ssize_t
|
event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
struct trace_event_file *file;
|
unsigned long val;
|
int ret;
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
if (ret)
|
return ret;
|
|
ret = tracing_update_buffers();
|
if (ret < 0)
|
return ret;
|
|
switch (val) {
|
case 0:
|
case 1:
|
ret = -ENODEV;
|
mutex_lock(&event_mutex);
|
file = event_file_data(filp);
|
if (likely(file))
|
ret = ftrace_event_enable_disable(file, val);
|
mutex_unlock(&event_mutex);
|
break;
|
|
default:
|
return -EINVAL;
|
}
|
|
*ppos += cnt;
|
|
return ret ? ret : cnt;
|
}
|
|
static ssize_t
|
system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
const char set_to_char[4] = { '?', '0', '1', 'X' };
|
struct trace_subsystem_dir *dir = filp->private_data;
|
struct event_subsystem *system = dir->subsystem;
|
struct trace_event_call *call;
|
struct trace_event_file *file;
|
struct trace_array *tr = dir->tr;
|
char buf[2];
|
int set = 0;
|
int ret;
|
|
mutex_lock(&event_mutex);
|
list_for_each_entry(file, &tr->events, list) {
|
call = file->event_call;
|
if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
|
!trace_event_name(call) || !call->class || !call->class->reg)
|
continue;
|
|
if (system && strcmp(call->class->system, system->name) != 0)
|
continue;
|
|
/*
|
* We need to find out if all the events are set
|
* or if all events or cleared, or if we have
|
* a mixture.
|
*/
|
set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
|
|
/*
|
* If we have a mixture, no need to look further.
|
*/
|
if (set == 3)
|
break;
|
}
|
mutex_unlock(&event_mutex);
|
|
buf[0] = set_to_char[set];
|
buf[1] = '\n';
|
|
ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
|
|
return ret;
|
}
|
|
static ssize_t
|
system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
struct trace_subsystem_dir *dir = filp->private_data;
|
struct event_subsystem *system = dir->subsystem;
|
const char *name = NULL;
|
unsigned long val;
|
ssize_t ret;
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
if (ret)
|
return ret;
|
|
ret = tracing_update_buffers();
|
if (ret < 0)
|
return ret;
|
|
if (val != 0 && val != 1)
|
return -EINVAL;
|
|
/*
|
* Opening of "enable" adds a ref count to system,
|
* so the name is safe to use.
|
*/
|
if (system)
|
name = system->name;
|
|
ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
|
if (ret)
|
goto out;
|
|
ret = cnt;
|
|
out:
|
*ppos += cnt;
|
|
return ret;
|
}
|
|
enum {
|
FORMAT_HEADER = 1,
|
FORMAT_FIELD_SEPERATOR = 2,
|
FORMAT_PRINTFMT = 3,
|
};
|
|
static void *f_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
struct trace_event_call *call = event_file_data(m->private);
|
struct list_head *common_head = &ftrace_common_fields;
|
struct list_head *head = trace_get_fields(call);
|
struct list_head *node = v;
|
|
(*pos)++;
|
|
switch ((unsigned long)v) {
|
case FORMAT_HEADER:
|
node = common_head;
|
break;
|
|
case FORMAT_FIELD_SEPERATOR:
|
node = head;
|
break;
|
|
case FORMAT_PRINTFMT:
|
/* all done */
|
return NULL;
|
}
|
|
node = node->prev;
|
if (node == common_head)
|
return (void *)FORMAT_FIELD_SEPERATOR;
|
else if (node == head)
|
return (void *)FORMAT_PRINTFMT;
|
else
|
return node;
|
}
|
|
static int f_show(struct seq_file *m, void *v)
|
{
|
struct trace_event_call *call = event_file_data(m->private);
|
struct ftrace_event_field *field;
|
const char *array_descriptor;
|
|
switch ((unsigned long)v) {
|
case FORMAT_HEADER:
|
seq_printf(m, "name: %s\n", trace_event_name(call));
|
seq_printf(m, "ID: %d\n", call->event.type);
|
seq_puts(m, "format:\n");
|
return 0;
|
|
case FORMAT_FIELD_SEPERATOR:
|
seq_putc(m, '\n');
|
return 0;
|
|
case FORMAT_PRINTFMT:
|
seq_printf(m, "\nprint fmt: %s\n",
|
call->print_fmt);
|
return 0;
|
}
|
|
field = list_entry(v, struct ftrace_event_field, link);
|
/*
|
* Smartly shows the array type(except dynamic array).
|
* Normal:
|
* field:TYPE VAR
|
* If TYPE := TYPE[LEN], it is shown:
|
* field:TYPE VAR[LEN]
|
*/
|
array_descriptor = strchr(field->type, '[');
|
|
if (str_has_prefix(field->type, "__data_loc"))
|
array_descriptor = NULL;
|
|
if (!array_descriptor)
|
seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
|
field->type, field->name, field->offset,
|
field->size, !!field->is_signed);
|
else
|
seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
|
(int)(array_descriptor - field->type),
|
field->type, field->name,
|
array_descriptor, field->offset,
|
field->size, !!field->is_signed);
|
|
return 0;
|
}
|
|
static void *f_start(struct seq_file *m, loff_t *pos)
|
{
|
void *p = (void *)FORMAT_HEADER;
|
loff_t l = 0;
|
|
/* ->stop() is called even if ->start() fails */
|
mutex_lock(&event_mutex);
|
if (!event_file_data(m->private))
|
return ERR_PTR(-ENODEV);
|
|
while (l < *pos && p)
|
p = f_next(m, p, &l);
|
|
return p;
|
}
|
|
static void f_stop(struct seq_file *m, void *p)
|
{
|
mutex_unlock(&event_mutex);
|
}
|
|
static const struct seq_operations trace_format_seq_ops = {
|
.start = f_start,
|
.next = f_next,
|
.stop = f_stop,
|
.show = f_show,
|
};
|
|
static int trace_format_open(struct inode *inode, struct file *file)
|
{
|
struct seq_file *m;
|
int ret;
|
|
/* Do we want to hide event format files on tracefs lockdown? */
|
|
ret = seq_open(file, &trace_format_seq_ops);
|
if (ret < 0)
|
return ret;
|
|
m = file->private_data;
|
m->private = file;
|
|
return 0;
|
}
|
|
static ssize_t
|
event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
|
{
|
int id = (long)event_file_data(filp);
|
char buf[32];
|
int len;
|
|
if (unlikely(!id))
|
return -ENODEV;
|
|
len = sprintf(buf, "%d\n", id);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
|
}
|
|
static ssize_t
|
event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
struct trace_event_file *file;
|
struct trace_seq *s;
|
int r = -ENODEV;
|
|
if (*ppos)
|
return 0;
|
|
s = kmalloc(sizeof(*s), GFP_KERNEL);
|
|
if (!s)
|
return -ENOMEM;
|
|
trace_seq_init(s);
|
|
mutex_lock(&event_mutex);
|
file = event_file_data(filp);
|
if (file)
|
print_event_filter(file, s);
|
mutex_unlock(&event_mutex);
|
|
if (file)
|
r = simple_read_from_buffer(ubuf, cnt, ppos,
|
s->buffer, trace_seq_used(s));
|
|
kfree(s);
|
|
return r;
|
}
|
|
static ssize_t
|
event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
struct trace_event_file *file;
|
char *buf;
|
int err = -ENODEV;
|
|
if (cnt >= PAGE_SIZE)
|
return -EINVAL;
|
|
buf = memdup_user_nul(ubuf, cnt);
|
if (IS_ERR(buf))
|
return PTR_ERR(buf);
|
|
mutex_lock(&event_mutex);
|
file = event_file_data(filp);
|
if (file)
|
err = apply_event_filter(file, buf);
|
mutex_unlock(&event_mutex);
|
|
kfree(buf);
|
if (err < 0)
|
return err;
|
|
*ppos += cnt;
|
|
return cnt;
|
}
|
|
static LIST_HEAD(event_subsystems);
|
|
static int subsystem_open(struct inode *inode, struct file *filp)
|
{
|
struct event_subsystem *system = NULL;
|
struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
|
struct trace_array *tr;
|
int ret;
|
|
if (tracing_is_disabled())
|
return -ENODEV;
|
|
/* Make sure the system still exists */
|
mutex_lock(&event_mutex);
|
mutex_lock(&trace_types_lock);
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
|
list_for_each_entry(dir, &tr->systems, list) {
|
if (dir == inode->i_private) {
|
/* Don't open systems with no events */
|
if (dir->nr_events) {
|
__get_system_dir(dir);
|
system = dir->subsystem;
|
}
|
goto exit_loop;
|
}
|
}
|
}
|
exit_loop:
|
mutex_unlock(&trace_types_lock);
|
mutex_unlock(&event_mutex);
|
|
if (!system)
|
return -ENODEV;
|
|
/* Some versions of gcc think dir can be uninitialized here */
|
WARN_ON(!dir);
|
|
/* Still need to increment the ref count of the system */
|
if (trace_array_get(tr) < 0) {
|
put_system(dir);
|
return -ENODEV;
|
}
|
|
ret = tracing_open_generic(inode, filp);
|
if (ret < 0) {
|
trace_array_put(tr);
|
put_system(dir);
|
}
|
|
return ret;
|
}
|
|
static int system_tr_open(struct inode *inode, struct file *filp)
|
{
|
struct trace_subsystem_dir *dir;
|
struct trace_array *tr = inode->i_private;
|
int ret;
|
|
/* Make a temporary dir that has no system but points to tr */
|
dir = kzalloc(sizeof(*dir), GFP_KERNEL);
|
if (!dir)
|
return -ENOMEM;
|
|
ret = tracing_open_generic_tr(inode, filp);
|
if (ret < 0) {
|
kfree(dir);
|
return ret;
|
}
|
dir->tr = tr;
|
filp->private_data = dir;
|
|
return 0;
|
}
|
|
static int subsystem_release(struct inode *inode, struct file *file)
|
{
|
struct trace_subsystem_dir *dir = file->private_data;
|
|
trace_array_put(dir->tr);
|
|
/*
|
* If dir->subsystem is NULL, then this is a temporary
|
* descriptor that was made for a trace_array to enable
|
* all subsystems.
|
*/
|
if (dir->subsystem)
|
put_system(dir);
|
else
|
kfree(dir);
|
|
return 0;
|
}
|
|
static ssize_t
|
subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
struct trace_subsystem_dir *dir = filp->private_data;
|
struct event_subsystem *system = dir->subsystem;
|
struct trace_seq *s;
|
int r;
|
|
if (*ppos)
|
return 0;
|
|
s = kmalloc(sizeof(*s), GFP_KERNEL);
|
if (!s)
|
return -ENOMEM;
|
|
trace_seq_init(s);
|
|
print_subsystem_event_filter(system, s);
|
r = simple_read_from_buffer(ubuf, cnt, ppos,
|
s->buffer, trace_seq_used(s));
|
|
kfree(s);
|
|
return r;
|
}
|
|
static ssize_t
|
subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
loff_t *ppos)
|
{
|
struct trace_subsystem_dir *dir = filp->private_data;
|
char *buf;
|
int err;
|
|
if (cnt >= PAGE_SIZE)
|
return -EINVAL;
|
|
buf = memdup_user_nul(ubuf, cnt);
|
if (IS_ERR(buf))
|
return PTR_ERR(buf);
|
|
err = apply_subsystem_event_filter(dir, buf);
|
kfree(buf);
|
if (err < 0)
|
return err;
|
|
*ppos += cnt;
|
|
return cnt;
|
}
|
|
static ssize_t
|
show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
|
{
|
int (*func)(struct trace_seq *s) = filp->private_data;
|
struct trace_seq *s;
|
int r;
|
|
if (*ppos)
|
return 0;
|
|
s = kmalloc(sizeof(*s), GFP_KERNEL);
|
if (!s)
|
return -ENOMEM;
|
|
trace_seq_init(s);
|
|
func(s);
|
r = simple_read_from_buffer(ubuf, cnt, ppos,
|
s->buffer, trace_seq_used(s));
|
|
kfree(s);
|
|
return r;
|
}
|
|
static void ignore_task_cpu(void *data)
|
{
|
struct trace_array *tr = data;
|
struct trace_pid_list *pid_list;
|
struct trace_pid_list *no_pid_list;
|
|
/*
|
* This function is called by on_each_cpu() while the
|
* event_mutex is held.
|
*/
|
pid_list = rcu_dereference_protected(tr->filtered_pids,
|
mutex_is_locked(&event_mutex));
|
no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
|
mutex_is_locked(&event_mutex));
|
|
this_cpu_write(tr->array_buffer.data->ignore_pid,
|
trace_ignore_this_task(pid_list, no_pid_list, current));
|
}
|
|
static void register_pid_events(struct trace_array *tr)
|
{
|
/*
|
* Register a probe that is called before all other probes
|
* to set ignore_pid if next or prev do not match.
|
* Register a probe this is called after all other probes
|
* to only keep ignore_pid set if next pid matches.
|
*/
|
register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
|
tr, INT_MAX);
|
register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
|
tr, 0);
|
|
register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
|
tr, INT_MAX);
|
register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
|
tr, 0);
|
|
register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
|
tr, INT_MAX);
|
register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
|
tr, 0);
|
|
register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
|
tr, INT_MAX);
|
register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
|
tr, 0);
|
}
|
|
static ssize_t
|
event_pid_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos, int type)
|
{
|
struct seq_file *m = filp->private_data;
|
struct trace_array *tr = m->private;
|
struct trace_pid_list *filtered_pids = NULL;
|
struct trace_pid_list *other_pids = NULL;
|
struct trace_pid_list *pid_list;
|
struct trace_event_file *file;
|
ssize_t ret;
|
|
if (!cnt)
|
return 0;
|
|
ret = tracing_update_buffers();
|
if (ret < 0)
|
return ret;
|
|
mutex_lock(&event_mutex);
|
|
if (type == TRACE_PIDS) {
|
filtered_pids = rcu_dereference_protected(tr->filtered_pids,
|
lockdep_is_held(&event_mutex));
|
other_pids = rcu_dereference_protected(tr->filtered_no_pids,
|
lockdep_is_held(&event_mutex));
|
} else {
|
filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
|
lockdep_is_held(&event_mutex));
|
other_pids = rcu_dereference_protected(tr->filtered_pids,
|
lockdep_is_held(&event_mutex));
|
}
|
|
ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
|
if (ret < 0)
|
goto out;
|
|
if (type == TRACE_PIDS)
|
rcu_assign_pointer(tr->filtered_pids, pid_list);
|
else
|
rcu_assign_pointer(tr->filtered_no_pids, pid_list);
|
|
list_for_each_entry(file, &tr->events, list) {
|
set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
|
}
|
|
if (filtered_pids) {
|
tracepoint_synchronize_unregister();
|
trace_free_pid_list(filtered_pids);
|
} else if (pid_list && !other_pids) {
|
register_pid_events(tr);
|
}
|
|
/*
|
* Ignoring of pids is done at task switch. But we have to
|
* check for those tasks that are currently running.
|
* Always do this in case a pid was appended or removed.
|
*/
|
on_each_cpu(ignore_task_cpu, tr, 1);
|
|
out:
|
mutex_unlock(&event_mutex);
|
|
if (ret > 0)
|
*ppos += ret;
|
|
return ret;
|
}
|
|
static ssize_t
|
ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
|
}
|
|
static ssize_t
|
ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
|
size_t cnt, loff_t *ppos)
|
{
|
return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
|
}
|
|
static int ftrace_event_avail_open(struct inode *inode, struct file *file);
|
static int ftrace_event_set_open(struct inode *inode, struct file *file);
|
static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
|
static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
|
static int ftrace_event_release(struct inode *inode, struct file *file);
|
|
static const struct seq_operations show_event_seq_ops = {
|
.start = t_start,
|
.next = t_next,
|
.show = t_show,
|
.stop = t_stop,
|
};
|
|
static const struct seq_operations show_set_event_seq_ops = {
|
.start = s_start,
|
.next = s_next,
|
.show = t_show,
|
.stop = t_stop,
|
};
|
|
static const struct seq_operations show_set_pid_seq_ops = {
|
.start = p_start,
|
.next = p_next,
|
.show = trace_pid_show,
|
.stop = p_stop,
|
};
|
|
static const struct seq_operations show_set_no_pid_seq_ops = {
|
.start = np_start,
|
.next = np_next,
|
.show = trace_pid_show,
|
.stop = p_stop,
|
};
|
|
static const struct file_operations ftrace_avail_fops = {
|
.open = ftrace_event_avail_open,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = seq_release,
|
};
|
|
static const struct file_operations ftrace_set_event_fops = {
|
.open = ftrace_event_set_open,
|
.read = seq_read,
|
.write = ftrace_event_write,
|
.llseek = seq_lseek,
|
.release = ftrace_event_release,
|
};
|
|
static const struct file_operations ftrace_set_event_pid_fops = {
|
.open = ftrace_event_set_pid_open,
|
.read = seq_read,
|
.write = ftrace_event_pid_write,
|
.llseek = seq_lseek,
|
.release = ftrace_event_release,
|
};
|
|
static const struct file_operations ftrace_set_event_notrace_pid_fops = {
|
.open = ftrace_event_set_npid_open,
|
.read = seq_read,
|
.write = ftrace_event_npid_write,
|
.llseek = seq_lseek,
|
.release = ftrace_event_release,
|
};
|
|
static const struct file_operations ftrace_enable_fops = {
|
.open = tracing_open_generic,
|
.read = event_enable_read,
|
.write = event_enable_write,
|
.llseek = default_llseek,
|
};
|
|
static const struct file_operations ftrace_event_format_fops = {
|
.open = trace_format_open,
|
.read = seq_read,
|
.llseek = seq_lseek,
|
.release = seq_release,
|
};
|
|
static const struct file_operations ftrace_event_id_fops = {
|
.read = event_id_read,
|
.llseek = default_llseek,
|
};
|
|
static const struct file_operations ftrace_event_filter_fops = {
|
.open = tracing_open_generic,
|
.read = event_filter_read,
|
.write = event_filter_write,
|
.llseek = default_llseek,
|
};
|
|
static const struct file_operations ftrace_subsystem_filter_fops = {
|
.open = subsystem_open,
|
.read = subsystem_filter_read,
|
.write = subsystem_filter_write,
|
.llseek = default_llseek,
|
.release = subsystem_release,
|
};
|
|
static const struct file_operations ftrace_system_enable_fops = {
|
.open = subsystem_open,
|
.read = system_enable_read,
|
.write = system_enable_write,
|
.llseek = default_llseek,
|
.release = subsystem_release,
|
};
|
|
static const struct file_operations ftrace_tr_enable_fops = {
|
.open = system_tr_open,
|
.read = system_enable_read,
|
.write = system_enable_write,
|
.llseek = default_llseek,
|
.release = subsystem_release,
|
};
|
|
static const struct file_operations ftrace_show_header_fops = {
|
.open = tracing_open_generic,
|
.read = show_header,
|
.llseek = default_llseek,
|
};
|
|
static int
|
ftrace_event_open(struct inode *inode, struct file *file,
|
const struct seq_operations *seq_ops)
|
{
|
struct seq_file *m;
|
int ret;
|
|
ret = security_locked_down(LOCKDOWN_TRACEFS);
|
if (ret)
|
return ret;
|
|
ret = seq_open(file, seq_ops);
|
if (ret < 0)
|
return ret;
|
m = file->private_data;
|
/* copy tr over to seq ops */
|
m->private = inode->i_private;
|
|
return ret;
|
}
|
|
static int ftrace_event_release(struct inode *inode, struct file *file)
|
{
|
struct trace_array *tr = inode->i_private;
|
|
trace_array_put(tr);
|
|
return seq_release(inode, file);
|
}
|
|
static int
|
ftrace_event_avail_open(struct inode *inode, struct file *file)
|
{
|
const struct seq_operations *seq_ops = &show_event_seq_ops;
|
|
/* Checks for tracefs lockdown */
|
return ftrace_event_open(inode, file, seq_ops);
|
}
|
|
static int
|
ftrace_event_set_open(struct inode *inode, struct file *file)
|
{
|
const struct seq_operations *seq_ops = &show_set_event_seq_ops;
|
struct trace_array *tr = inode->i_private;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
(file->f_flags & O_TRUNC))
|
ftrace_clear_events(tr);
|
|
ret = ftrace_event_open(inode, file, seq_ops);
|
if (ret < 0)
|
trace_array_put(tr);
|
return ret;
|
}
|
|
static int
|
ftrace_event_set_pid_open(struct inode *inode, struct file *file)
|
{
|
const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
|
struct trace_array *tr = inode->i_private;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
(file->f_flags & O_TRUNC))
|
ftrace_clear_event_pids(tr, TRACE_PIDS);
|
|
ret = ftrace_event_open(inode, file, seq_ops);
|
if (ret < 0)
|
trace_array_put(tr);
|
return ret;
|
}
|
|
static int
|
ftrace_event_set_npid_open(struct inode *inode, struct file *file)
|
{
|
const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
|
struct trace_array *tr = inode->i_private;
|
int ret;
|
|
ret = tracing_check_open_get_tr(tr);
|
if (ret)
|
return ret;
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
(file->f_flags & O_TRUNC))
|
ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
|
|
ret = ftrace_event_open(inode, file, seq_ops);
|
if (ret < 0)
|
trace_array_put(tr);
|
return ret;
|
}
|
|
static struct event_subsystem *
|
create_new_subsystem(const char *name)
|
{
|
struct event_subsystem *system;
|
|
/* need to create new entry */
|
system = kmalloc(sizeof(*system), GFP_KERNEL);
|
if (!system)
|
return NULL;
|
|
system->ref_count = 1;
|
|
/* Only allocate if dynamic (kprobes and modules) */
|
system->name = kstrdup_const(name, GFP_KERNEL);
|
if (!system->name)
|
goto out_free;
|
|
system->filter = NULL;
|
|
system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
|
if (!system->filter)
|
goto out_free;
|
|
list_add(&system->list, &event_subsystems);
|
|
return system;
|
|
out_free:
|
kfree_const(system->name);
|
kfree(system);
|
return NULL;
|
}
|
|
static struct dentry *
|
event_subsystem_dir(struct trace_array *tr, const char *name,
|
struct trace_event_file *file, struct dentry *parent)
|
{
|
struct trace_subsystem_dir *dir;
|
struct event_subsystem *system;
|
struct dentry *entry;
|
|
/* First see if we did not already create this dir */
|
list_for_each_entry(dir, &tr->systems, list) {
|
system = dir->subsystem;
|
if (strcmp(system->name, name) == 0) {
|
dir->nr_events++;
|
file->system = dir;
|
return dir->entry;
|
}
|
}
|
|
/* Now see if the system itself exists. */
|
list_for_each_entry(system, &event_subsystems, list) {
|
if (strcmp(system->name, name) == 0)
|
break;
|
}
|
/* Reset system variable when not found */
|
if (&system->list == &event_subsystems)
|
system = NULL;
|
|
dir = kmalloc(sizeof(*dir), GFP_KERNEL);
|
if (!dir)
|
goto out_fail;
|
|
if (!system) {
|
system = create_new_subsystem(name);
|
if (!system)
|
goto out_free;
|
} else
|
__get_system(system);
|
|
dir->entry = tracefs_create_dir(name, parent);
|
if (!dir->entry) {
|
pr_warn("Failed to create system directory %s\n", name);
|
__put_system(system);
|
goto out_free;
|
}
|
|
dir->tr = tr;
|
dir->ref_count = 1;
|
dir->nr_events = 1;
|
dir->subsystem = system;
|
file->system = dir;
|
|
entry = tracefs_create_file("filter", 0644, dir->entry, dir,
|
&ftrace_subsystem_filter_fops);
|
if (!entry) {
|
kfree(system->filter);
|
system->filter = NULL;
|
pr_warn("Could not create tracefs '%s/filter' entry\n", name);
|
}
|
|
trace_create_file("enable", 0644, dir->entry, dir,
|
&ftrace_system_enable_fops);
|
|
list_add(&dir->list, &tr->systems);
|
|
return dir->entry;
|
|
out_free:
|
kfree(dir);
|
out_fail:
|
/* Only print this message if failed on memory allocation */
|
if (!dir || !system)
|
pr_warn("No memory to create event subsystem %s\n", name);
|
return NULL;
|
}
|
|
static int
|
event_define_fields(struct trace_event_call *call)
|
{
|
struct list_head *head;
|
int ret = 0;
|
|
/*
|
* Other events may have the same class. Only update
|
* the fields if they are not already defined.
|
*/
|
head = trace_get_fields(call);
|
if (list_empty(head)) {
|
struct trace_event_fields *field = call->class->fields_array;
|
unsigned int offset = sizeof(struct trace_entry);
|
|
for (; field->type; field++) {
|
if (field->type == TRACE_FUNCTION_TYPE) {
|
field->define_fields(call);
|
break;
|
}
|
|
offset = ALIGN(offset, field->align);
|
ret = trace_define_field(call, field->type, field->name,
|
offset, field->size,
|
field->is_signed, field->filter_type);
|
if (WARN_ON_ONCE(ret)) {
|
pr_err("error code is %d\n", ret);
|
break;
|
}
|
|
offset += field->size;
|
}
|
}
|
|
return ret;
|
}
|
|
static int
|
event_create_dir(struct dentry *parent, struct trace_event_file *file)
|
{
|
struct trace_event_call *call = file->event_call;
|
struct trace_array *tr = file->tr;
|
struct dentry *d_events;
|
const char *name;
|
int ret;
|
|
/*
|
* If the trace point header did not define TRACE_SYSTEM
|
* then the system would be called "TRACE_SYSTEM".
|
*/
|
if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
|
d_events = event_subsystem_dir(tr, call->class->system, file, parent);
|
if (!d_events)
|
return -ENOMEM;
|
} else
|
d_events = parent;
|
|
name = trace_event_name(call);
|
file->dir = tracefs_create_dir(name, d_events);
|
if (!file->dir) {
|
pr_warn("Could not create tracefs '%s' directory\n", name);
|
return -1;
|
}
|
|
if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
|
trace_create_file("enable", 0644, file->dir, file,
|
&ftrace_enable_fops);
|
|
#ifdef CONFIG_PERF_EVENTS
|
if (call->event.type && call->class->reg)
|
trace_create_file("id", 0444, file->dir,
|
(void *)(long)call->event.type,
|
&ftrace_event_id_fops);
|
#endif
|
|
ret = event_define_fields(call);
|
if (ret < 0) {
|
pr_warn("Could not initialize trace point events/%s\n", name);
|
return ret;
|
}
|
|
/*
|
* Only event directories that can be enabled should have
|
* triggers or filters.
|
*/
|
if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
|
trace_create_file("filter", 0644, file->dir, file,
|
&ftrace_event_filter_fops);
|
|
trace_create_file("trigger", 0644, file->dir, file,
|
&event_trigger_fops);
|
}
|
|
#ifdef CONFIG_HIST_TRIGGERS
|
trace_create_file("hist", 0444, file->dir, file,
|
&event_hist_fops);
|
#endif
|
#ifdef CONFIG_HIST_TRIGGERS_DEBUG
|
trace_create_file("hist_debug", 0444, file->dir, file,
|
&event_hist_debug_fops);
|
#endif
|
trace_create_file("format", 0444, file->dir, call,
|
&ftrace_event_format_fops);
|
|
#ifdef CONFIG_TRACE_EVENT_INJECT
|
if (call->event.type && call->class->reg)
|
trace_create_file("inject", 0200, file->dir, file,
|
&event_inject_fops);
|
#endif
|
|
return 0;
|
}
|
|
static void remove_event_from_tracers(struct trace_event_call *call)
|
{
|
struct trace_event_file *file;
|
struct trace_array *tr;
|
|
do_for_each_event_file_safe(tr, file) {
|
if (file->event_call != call)
|
continue;
|
|
remove_event_file_dir(file);
|
/*
|
* The do_for_each_event_file_safe() is
|
* a double loop. After finding the call for this
|
* trace_array, we use break to jump to the next
|
* trace_array.
|
*/
|
break;
|
} while_for_each_event_file();
|
}
|
|
static void event_remove(struct trace_event_call *call)
|
{
|
struct trace_array *tr;
|
struct trace_event_file *file;
|
|
do_for_each_event_file(tr, file) {
|
if (file->event_call != call)
|
continue;
|
|
if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
|
tr->clear_trace = true;
|
|
ftrace_event_enable_disable(file, 0);
|
/*
|
* The do_for_each_event_file() is
|
* a double loop. After finding the call for this
|
* trace_array, we use break to jump to the next
|
* trace_array.
|
*/
|
break;
|
} while_for_each_event_file();
|
|
if (call->event.funcs)
|
__unregister_trace_event(&call->event);
|
remove_event_from_tracers(call);
|
list_del(&call->list);
|
}
|
|
static int event_init(struct trace_event_call *call)
|
{
|
int ret = 0;
|
const char *name;
|
|
name = trace_event_name(call);
|
if (WARN_ON(!name))
|
return -EINVAL;
|
|
if (call->class->raw_init) {
|
ret = call->class->raw_init(call);
|
if (ret < 0 && ret != -ENOSYS)
|
pr_warn("Could not initialize trace events/%s\n", name);
|
}
|
|
return ret;
|
}
|
|
static int
|
__register_event(struct trace_event_call *call, struct module *mod)
|
{
|
int ret;
|
|
ret = event_init(call);
|
if (ret < 0)
|
return ret;
|
|
list_add(&call->list, &ftrace_events);
|
call->mod = mod;
|
|
return 0;
|
}
|
|
static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
|
{
|
int rlen;
|
int elen;
|
|
/* Find the length of the eval value as a string */
|
elen = snprintf(ptr, 0, "%ld", map->eval_value);
|
/* Make sure there's enough room to replace the string with the value */
|
if (len < elen)
|
return NULL;
|
|
snprintf(ptr, elen + 1, "%ld", map->eval_value);
|
|
/* Get the rest of the string of ptr */
|
rlen = strlen(ptr + len);
|
memmove(ptr + elen, ptr + len, rlen);
|
/* Make sure we end the new string */
|
ptr[elen + rlen] = 0;
|
|
return ptr + elen;
|
}
|
|
static void update_event_printk(struct trace_event_call *call,
|
struct trace_eval_map *map)
|
{
|
char *ptr;
|
int quote = 0;
|
int len = strlen(map->eval_string);
|
|
for (ptr = call->print_fmt; *ptr; ptr++) {
|
if (*ptr == '\\') {
|
ptr++;
|
/* paranoid */
|
if (!*ptr)
|
break;
|
continue;
|
}
|
if (*ptr == '"') {
|
quote ^= 1;
|
continue;
|
}
|
if (quote)
|
continue;
|
if (isdigit(*ptr)) {
|
/* skip numbers */
|
do {
|
ptr++;
|
/* Check for alpha chars like ULL */
|
} while (isalnum(*ptr));
|
if (!*ptr)
|
break;
|
/*
|
* A number must have some kind of delimiter after
|
* it, and we can ignore that too.
|
*/
|
continue;
|
}
|
if (isalpha(*ptr) || *ptr == '_') {
|
if (strncmp(map->eval_string, ptr, len) == 0 &&
|
!isalnum(ptr[len]) && ptr[len] != '_') {
|
ptr = eval_replace(ptr, map, len);
|
/* enum/sizeof string smaller than value */
|
if (WARN_ON_ONCE(!ptr))
|
return;
|
/*
|
* No need to decrement here, as eval_replace()
|
* returns the pointer to the character passed
|
* the eval, and two evals can not be placed
|
* back to back without something in between.
|
* We can skip that something in between.
|
*/
|
continue;
|
}
|
skip_more:
|
do {
|
ptr++;
|
} while (isalnum(*ptr) || *ptr == '_');
|
if (!*ptr)
|
break;
|
/*
|
* If what comes after this variable is a '.' or
|
* '->' then we can continue to ignore that string.
|
*/
|
if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
|
ptr += *ptr == '.' ? 1 : 2;
|
if (!*ptr)
|
break;
|
goto skip_more;
|
}
|
/*
|
* Once again, we can skip the delimiter that came
|
* after the string.
|
*/
|
continue;
|
}
|
}
|
}
|
|
void trace_event_eval_update(struct trace_eval_map **map, int len)
|
{
|
struct trace_event_call *call, *p;
|
const char *last_system = NULL;
|
bool first = false;
|
int last_i;
|
int i;
|
|
down_write(&trace_event_sem);
|
list_for_each_entry_safe(call, p, &ftrace_events, list) {
|
/* events are usually grouped together with systems */
|
if (!last_system || call->class->system != last_system) {
|
first = true;
|
last_i = 0;
|
last_system = call->class->system;
|
}
|
|
/*
|
* Since calls are grouped by systems, the likelyhood that the
|
* next call in the iteration belongs to the same system as the
|
* previous call is high. As an optimization, we skip seaching
|
* for a map[] that matches the call's system if the last call
|
* was from the same system. That's what last_i is for. If the
|
* call has the same system as the previous call, then last_i
|
* will be the index of the first map[] that has a matching
|
* system.
|
*/
|
for (i = last_i; i < len; i++) {
|
if (call->class->system == map[i]->system) {
|
/* Save the first system if need be */
|
if (first) {
|
last_i = i;
|
first = false;
|
}
|
update_event_printk(call, map[i]);
|
}
|
}
|
}
|
up_write(&trace_event_sem);
|
}
|
|
static struct trace_event_file *
|
trace_create_new_event(struct trace_event_call *call,
|
struct trace_array *tr)
|
{
|
struct trace_pid_list *no_pid_list;
|
struct trace_pid_list *pid_list;
|
struct trace_event_file *file;
|
|
file = kmem_cache_alloc(file_cachep, GFP_TRACE);
|
if (!file)
|
return NULL;
|
|
pid_list = rcu_dereference_protected(tr->filtered_pids,
|
lockdep_is_held(&event_mutex));
|
no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
|
lockdep_is_held(&event_mutex));
|
|
if (pid_list || no_pid_list)
|
file->flags |= EVENT_FILE_FL_PID_FILTER;
|
|
file->event_call = call;
|
file->tr = tr;
|
atomic_set(&file->sm_ref, 0);
|
atomic_set(&file->tm_ref, 0);
|
INIT_LIST_HEAD(&file->triggers);
|
list_add(&file->list, &tr->events);
|
|
return file;
|
}
|
|
/* Add an event to a trace directory */
|
static int
|
__trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
|
{
|
struct trace_event_file *file;
|
|
file = trace_create_new_event(call, tr);
|
if (!file)
|
return -ENOMEM;
|
|
if (eventdir_initialized)
|
return event_create_dir(tr->event_dir, file);
|
else
|
return event_define_fields(call);
|
}
|
|
/*
|
* Just create a decriptor for early init. A descriptor is required
|
* for enabling events at boot. We want to enable events before
|
* the filesystem is initialized.
|
*/
|
static int
|
__trace_early_add_new_event(struct trace_event_call *call,
|
struct trace_array *tr)
|
{
|
struct trace_event_file *file;
|
|
file = trace_create_new_event(call, tr);
|
if (!file)
|
return -ENOMEM;
|
|
return event_define_fields(call);
|
}
|
|
struct ftrace_module_file_ops;
|
static void __add_event_to_tracers(struct trace_event_call *call);
|
|
/* Add an additional event_call dynamically */
|
int trace_add_event_call(struct trace_event_call *call)
|
{
|
int ret;
|
lockdep_assert_held(&event_mutex);
|
|
mutex_lock(&trace_types_lock);
|
|
ret = __register_event(call, NULL);
|
if (ret >= 0)
|
__add_event_to_tracers(call);
|
|
mutex_unlock(&trace_types_lock);
|
return ret;
|
}
|
|
/*
|
* Must be called under locking of trace_types_lock, event_mutex and
|
* trace_event_sem.
|
*/
|
static void __trace_remove_event_call(struct trace_event_call *call)
|
{
|
event_remove(call);
|
trace_destroy_fields(call);
|
free_event_filter(call->filter);
|
call->filter = NULL;
|
}
|
|
static int probe_remove_event_call(struct trace_event_call *call)
|
{
|
struct trace_array *tr;
|
struct trace_event_file *file;
|
|
#ifdef CONFIG_PERF_EVENTS
|
if (call->perf_refcount)
|
return -EBUSY;
|
#endif
|
do_for_each_event_file(tr, file) {
|
if (file->event_call != call)
|
continue;
|
/*
|
* We can't rely on ftrace_event_enable_disable(enable => 0)
|
* we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
|
* TRACE_REG_UNREGISTER.
|
*/
|
if (file->flags & EVENT_FILE_FL_ENABLED)
|
goto busy;
|
|
if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
|
tr->clear_trace = true;
|
/*
|
* The do_for_each_event_file_safe() is
|
* a double loop. After finding the call for this
|
* trace_array, we use break to jump to the next
|
* trace_array.
|
*/
|
break;
|
} while_for_each_event_file();
|
|
__trace_remove_event_call(call);
|
|
return 0;
|
busy:
|
/* No need to clear the trace now */
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
|
tr->clear_trace = false;
|
}
|
return -EBUSY;
|
}
|
|
/* Remove an event_call */
|
int trace_remove_event_call(struct trace_event_call *call)
|
{
|
int ret;
|
|
lockdep_assert_held(&event_mutex);
|
|
mutex_lock(&trace_types_lock);
|
down_write(&trace_event_sem);
|
ret = probe_remove_event_call(call);
|
up_write(&trace_event_sem);
|
mutex_unlock(&trace_types_lock);
|
|
return ret;
|
}
|
|
#define for_each_event(event, start, end) \
|
for (event = start; \
|
(unsigned long)event < (unsigned long)end; \
|
event++)
|
|
#ifdef CONFIG_MODULES
|
|
static void trace_module_add_events(struct module *mod)
|
{
|
struct trace_event_call **call, **start, **end;
|
|
if (!mod->num_trace_events)
|
return;
|
|
/* Don't add infrastructure for mods without tracepoints */
|
if (trace_module_has_bad_taint(mod)) {
|
pr_err("%s: module has bad taint, not creating trace events\n",
|
mod->name);
|
return;
|
}
|
|
start = mod->trace_events;
|
end = mod->trace_events + mod->num_trace_events;
|
|
for_each_event(call, start, end) {
|
__register_event(*call, mod);
|
__add_event_to_tracers(*call);
|
}
|
}
|
|
static void trace_module_remove_events(struct module *mod)
|
{
|
struct trace_event_call *call, *p;
|
|
down_write(&trace_event_sem);
|
list_for_each_entry_safe(call, p, &ftrace_events, list) {
|
if (call->mod == mod)
|
__trace_remove_event_call(call);
|
}
|
up_write(&trace_event_sem);
|
|
/*
|
* It is safest to reset the ring buffer if the module being unloaded
|
* registered any events that were used. The only worry is if
|
* a new module gets loaded, and takes on the same id as the events
|
* of this module. When printing out the buffer, traced events left
|
* over from this module may be passed to the new module events and
|
* unexpected results may occur.
|
*/
|
tracing_reset_all_online_cpus();
|
}
|
|
static int trace_module_notify(struct notifier_block *self,
|
unsigned long val, void *data)
|
{
|
struct module *mod = data;
|
|
mutex_lock(&event_mutex);
|
mutex_lock(&trace_types_lock);
|
switch (val) {
|
case MODULE_STATE_COMING:
|
trace_module_add_events(mod);
|
break;
|
case MODULE_STATE_GOING:
|
trace_module_remove_events(mod);
|
break;
|
}
|
mutex_unlock(&trace_types_lock);
|
mutex_unlock(&event_mutex);
|
|
return NOTIFY_OK;
|
}
|
|
static struct notifier_block trace_module_nb = {
|
.notifier_call = trace_module_notify,
|
.priority = 1, /* higher than trace.c module notify */
|
};
|
#endif /* CONFIG_MODULES */
|
|
/* Create a new event directory structure for a trace directory. */
|
static void
|
__trace_add_event_dirs(struct trace_array *tr)
|
{
|
struct trace_event_call *call;
|
int ret;
|
|
list_for_each_entry(call, &ftrace_events, list) {
|
ret = __trace_add_new_event(call, tr);
|
if (ret < 0)
|
pr_warn("Could not create directory for event %s\n",
|
trace_event_name(call));
|
}
|
}
|
|
/* Returns any file that matches the system and event */
|
struct trace_event_file *
|
__find_event_file(struct trace_array *tr, const char *system, const char *event)
|
{
|
struct trace_event_file *file;
|
struct trace_event_call *call;
|
const char *name;
|
|
list_for_each_entry(file, &tr->events, list) {
|
|
call = file->event_call;
|
name = trace_event_name(call);
|
|
if (!name || !call->class)
|
continue;
|
|
if (strcmp(event, name) == 0 &&
|
strcmp(system, call->class->system) == 0)
|
return file;
|
}
|
return NULL;
|
}
|
|
/* Returns valid trace event files that match system and event */
|
struct trace_event_file *
|
find_event_file(struct trace_array *tr, const char *system, const char *event)
|
{
|
struct trace_event_file *file;
|
|
file = __find_event_file(tr, system, event);
|
if (!file || !file->event_call->class->reg ||
|
file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
|
return NULL;
|
|
return file;
|
}
|
|
/**
|
* trace_get_event_file - Find and return a trace event file
|
* @instance: The name of the trace instance containing the event
|
* @system: The name of the system containing the event
|
* @event: The name of the event
|
*
|
* Return a trace event file given the trace instance name, trace
|
* system, and trace event name. If the instance name is NULL, it
|
* refers to the top-level trace array.
|
*
|
* This function will look it up and return it if found, after calling
|
* trace_array_get() to prevent the instance from going away, and
|
* increment the event's module refcount to prevent it from being
|
* removed.
|
*
|
* To release the file, call trace_put_event_file(), which will call
|
* trace_array_put() and decrement the event's module refcount.
|
*
|
* Return: The trace event on success, ERR_PTR otherwise.
|
*/
|
struct trace_event_file *trace_get_event_file(const char *instance,
|
const char *system,
|
const char *event)
|
{
|
struct trace_array *tr = top_trace_array();
|
struct trace_event_file *file = NULL;
|
int ret = -EINVAL;
|
|
if (instance) {
|
tr = trace_array_find_get(instance);
|
if (!tr)
|
return ERR_PTR(-ENOENT);
|
} else {
|
ret = trace_array_get(tr);
|
if (ret)
|
return ERR_PTR(ret);
|
}
|
|
mutex_lock(&event_mutex);
|
|
file = find_event_file(tr, system, event);
|
if (!file) {
|
trace_array_put(tr);
|
ret = -EINVAL;
|
goto out;
|
}
|
|
/* Don't let event modules unload while in use */
|
ret = try_module_get(file->event_call->mod);
|
if (!ret) {
|
trace_array_put(tr);
|
ret = -EBUSY;
|
goto out;
|
}
|
|
ret = 0;
|
out:
|
mutex_unlock(&event_mutex);
|
|
if (ret)
|
file = ERR_PTR(ret);
|
|
return file;
|
}
|
EXPORT_SYMBOL_GPL(trace_get_event_file);
|
|
/**
|
* trace_put_event_file - Release a file from trace_get_event_file()
|
* @file: The trace event file
|
*
|
* If a file was retrieved using trace_get_event_file(), this should
|
* be called when it's no longer needed. It will cancel the previous
|
* trace_array_get() called by that function, and decrement the
|
* event's module refcount.
|
*/
|
void trace_put_event_file(struct trace_event_file *file)
|
{
|
mutex_lock(&event_mutex);
|
module_put(file->event_call->mod);
|
mutex_unlock(&event_mutex);
|
|
trace_array_put(file->tr);
|
}
|
EXPORT_SYMBOL_GPL(trace_put_event_file);
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
/* Avoid typos */
|
#define ENABLE_EVENT_STR "enable_event"
|
#define DISABLE_EVENT_STR "disable_event"
|
|
struct event_probe_data {
|
struct trace_event_file *file;
|
unsigned long count;
|
int ref;
|
bool enable;
|
};
|
|
static void update_event_probe(struct event_probe_data *data)
|
{
|
if (data->enable)
|
clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
|
else
|
set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
|
}
|
|
static void
|
event_enable_probe(unsigned long ip, unsigned long parent_ip,
|
struct trace_array *tr, struct ftrace_probe_ops *ops,
|
void *data)
|
{
|
struct ftrace_func_mapper *mapper = data;
|
struct event_probe_data *edata;
|
void **pdata;
|
|
pdata = ftrace_func_mapper_find_ip(mapper, ip);
|
if (!pdata || !*pdata)
|
return;
|
|
edata = *pdata;
|
update_event_probe(edata);
|
}
|
|
static void
|
event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
|
struct trace_array *tr, struct ftrace_probe_ops *ops,
|
void *data)
|
{
|
struct ftrace_func_mapper *mapper = data;
|
struct event_probe_data *edata;
|
void **pdata;
|
|
pdata = ftrace_func_mapper_find_ip(mapper, ip);
|
if (!pdata || !*pdata)
|
return;
|
|
edata = *pdata;
|
|
if (!edata->count)
|
return;
|
|
/* Skip if the event is in a state we want to switch to */
|
if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
|
return;
|
|
if (edata->count != -1)
|
(edata->count)--;
|
|
update_event_probe(edata);
|
}
|
|
static int
|
event_enable_print(struct seq_file *m, unsigned long ip,
|
struct ftrace_probe_ops *ops, void *data)
|
{
|
struct ftrace_func_mapper *mapper = data;
|
struct event_probe_data *edata;
|
void **pdata;
|
|
pdata = ftrace_func_mapper_find_ip(mapper, ip);
|
|
if (WARN_ON_ONCE(!pdata || !*pdata))
|
return 0;
|
|
edata = *pdata;
|
|
seq_printf(m, "%ps:", (void *)ip);
|
|
seq_printf(m, "%s:%s:%s",
|
edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
|
edata->file->event_call->class->system,
|
trace_event_name(edata->file->event_call));
|
|
if (edata->count == -1)
|
seq_puts(m, ":unlimited\n");
|
else
|
seq_printf(m, ":count=%ld\n", edata->count);
|
|
return 0;
|
}
|
|
static int
|
event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
|
unsigned long ip, void *init_data, void **data)
|
{
|
struct ftrace_func_mapper *mapper = *data;
|
struct event_probe_data *edata = init_data;
|
int ret;
|
|
if (!mapper) {
|
mapper = allocate_ftrace_func_mapper();
|
if (!mapper)
|
return -ENODEV;
|
*data = mapper;
|
}
|
|
ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
|
if (ret < 0)
|
return ret;
|
|
edata->ref++;
|
|
return 0;
|
}
|
|
static int free_probe_data(void *data)
|
{
|
struct event_probe_data *edata = data;
|
|
edata->ref--;
|
if (!edata->ref) {
|
/* Remove the SOFT_MODE flag */
|
__ftrace_event_enable_disable(edata->file, 0, 1);
|
module_put(edata->file->event_call->mod);
|
kfree(edata);
|
}
|
return 0;
|
}
|
|
static void
|
event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
|
unsigned long ip, void *data)
|
{
|
struct ftrace_func_mapper *mapper = data;
|
struct event_probe_data *edata;
|
|
if (!ip) {
|
if (!mapper)
|
return;
|
free_ftrace_func_mapper(mapper, free_probe_data);
|
return;
|
}
|
|
edata = ftrace_func_mapper_remove_ip(mapper, ip);
|
|
if (WARN_ON_ONCE(!edata))
|
return;
|
|
if (WARN_ON_ONCE(edata->ref <= 0))
|
return;
|
|
free_probe_data(edata);
|
}
|
|
static struct ftrace_probe_ops event_enable_probe_ops = {
|
.func = event_enable_probe,
|
.print = event_enable_print,
|
.init = event_enable_init,
|
.free = event_enable_free,
|
};
|
|
static struct ftrace_probe_ops event_enable_count_probe_ops = {
|
.func = event_enable_count_probe,
|
.print = event_enable_print,
|
.init = event_enable_init,
|
.free = event_enable_free,
|
};
|
|
static struct ftrace_probe_ops event_disable_probe_ops = {
|
.func = event_enable_probe,
|
.print = event_enable_print,
|
.init = event_enable_init,
|
.free = event_enable_free,
|
};
|
|
static struct ftrace_probe_ops event_disable_count_probe_ops = {
|
.func = event_enable_count_probe,
|
.print = event_enable_print,
|
.init = event_enable_init,
|
.free = event_enable_free,
|
};
|
|
static int
|
event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
|
char *glob, char *cmd, char *param, int enabled)
|
{
|
struct trace_event_file *file;
|
struct ftrace_probe_ops *ops;
|
struct event_probe_data *data;
|
const char *system;
|
const char *event;
|
char *number;
|
bool enable;
|
int ret;
|
|
if (!tr)
|
return -ENODEV;
|
|
/* hash funcs only work with set_ftrace_filter */
|
if (!enabled || !param)
|
return -EINVAL;
|
|
system = strsep(¶m, ":");
|
if (!param)
|
return -EINVAL;
|
|
event = strsep(¶m, ":");
|
|
mutex_lock(&event_mutex);
|
|
ret = -EINVAL;
|
file = find_event_file(tr, system, event);
|
if (!file)
|
goto out;
|
|
enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
|
|
if (enable)
|
ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
|
else
|
ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
|
|
if (glob[0] == '!') {
|
ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
|
goto out;
|
}
|
|
ret = -ENOMEM;
|
|
data = kzalloc(sizeof(*data), GFP_KERNEL);
|
if (!data)
|
goto out;
|
|
data->enable = enable;
|
data->count = -1;
|
data->file = file;
|
|
if (!param)
|
goto out_reg;
|
|
number = strsep(¶m, ":");
|
|
ret = -EINVAL;
|
if (!strlen(number))
|
goto out_free;
|
|
/*
|
* We use the callback data field (which is a pointer)
|
* as our counter.
|
*/
|
ret = kstrtoul(number, 0, &data->count);
|
if (ret)
|
goto out_free;
|
|
out_reg:
|
/* Don't let event modules unload while probe registered */
|
ret = try_module_get(file->event_call->mod);
|
if (!ret) {
|
ret = -EBUSY;
|
goto out_free;
|
}
|
|
ret = __ftrace_event_enable_disable(file, 1, 1);
|
if (ret < 0)
|
goto out_put;
|
|
ret = register_ftrace_function_probe(glob, tr, ops, data);
|
/*
|
* The above returns on success the # of functions enabled,
|
* but if it didn't find any functions it returns zero.
|
* Consider no functions a failure too.
|
*/
|
if (!ret) {
|
ret = -ENOENT;
|
goto out_disable;
|
} else if (ret < 0)
|
goto out_disable;
|
/* Just return zero, not the number of enabled functions */
|
ret = 0;
|
out:
|
mutex_unlock(&event_mutex);
|
return ret;
|
|
out_disable:
|
__ftrace_event_enable_disable(file, 0, 1);
|
out_put:
|
module_put(file->event_call->mod);
|
out_free:
|
kfree(data);
|
goto out;
|
}
|
|
static struct ftrace_func_command event_enable_cmd = {
|
.name = ENABLE_EVENT_STR,
|
.func = event_enable_func,
|
};
|
|
static struct ftrace_func_command event_disable_cmd = {
|
.name = DISABLE_EVENT_STR,
|
.func = event_enable_func,
|
};
|
|
static __init int register_event_cmds(void)
|
{
|
int ret;
|
|
ret = register_ftrace_command(&event_enable_cmd);
|
if (WARN_ON(ret < 0))
|
return ret;
|
ret = register_ftrace_command(&event_disable_cmd);
|
if (WARN_ON(ret < 0))
|
unregister_ftrace_command(&event_enable_cmd);
|
return ret;
|
}
|
#else
|
static inline int register_event_cmds(void) { return 0; }
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
/*
|
* The top level array and trace arrays created by boot-time tracing
|
* have already had its trace_event_file descriptors created in order
|
* to allow for early events to be recorded.
|
* This function is called after the tracefs has been initialized,
|
* and we now have to create the files associated to the events.
|
*/
|
static void __trace_early_add_event_dirs(struct trace_array *tr)
|
{
|
struct trace_event_file *file;
|
int ret;
|
|
|
list_for_each_entry(file, &tr->events, list) {
|
ret = event_create_dir(tr->event_dir, file);
|
if (ret < 0)
|
pr_warn("Could not create directory for event %s\n",
|
trace_event_name(file->event_call));
|
}
|
}
|
|
/*
|
* For early boot up, the top trace array and the trace arrays created
|
* by boot-time tracing require to have a list of events that can be
|
* enabled. This must be done before the filesystem is set up in order
|
* to allow events to be traced early.
|
*/
|
void __trace_early_add_events(struct trace_array *tr)
|
{
|
struct trace_event_call *call;
|
int ret;
|
|
list_for_each_entry(call, &ftrace_events, list) {
|
/* Early boot up should not have any modules loaded */
|
if (WARN_ON_ONCE(call->mod))
|
continue;
|
|
ret = __trace_early_add_new_event(call, tr);
|
if (ret < 0)
|
pr_warn("Could not create early event %s\n",
|
trace_event_name(call));
|
}
|
}
|
|
/* Remove the event directory structure for a trace directory. */
|
static void
|
__trace_remove_event_dirs(struct trace_array *tr)
|
{
|
struct trace_event_file *file, *next;
|
|
list_for_each_entry_safe(file, next, &tr->events, list)
|
remove_event_file_dir(file);
|
}
|
|
static void __add_event_to_tracers(struct trace_event_call *call)
|
{
|
struct trace_array *tr;
|
|
list_for_each_entry(tr, &ftrace_trace_arrays, list)
|
__trace_add_new_event(call, tr);
|
}
|
|
extern struct trace_event_call *__start_ftrace_events[];
|
extern struct trace_event_call *__stop_ftrace_events[];
|
|
static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
|
|
static __init int setup_trace_event(char *str)
|
{
|
strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
|
ring_buffer_expanded = true;
|
disable_tracing_selftest("running event tracing");
|
|
return 1;
|
}
|
__setup("trace_event=", setup_trace_event);
|
|
/* Expects to have event_mutex held when called */
|
static int
|
create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
|
{
|
struct dentry *d_events;
|
struct dentry *entry;
|
|
entry = tracefs_create_file("set_event", 0644, parent,
|
tr, &ftrace_set_event_fops);
|
if (!entry) {
|
pr_warn("Could not create tracefs 'set_event' entry\n");
|
return -ENOMEM;
|
}
|
|
d_events = tracefs_create_dir("events", parent);
|
if (!d_events) {
|
pr_warn("Could not create tracefs 'events' directory\n");
|
return -ENOMEM;
|
}
|
|
entry = trace_create_file("enable", 0644, d_events,
|
tr, &ftrace_tr_enable_fops);
|
if (!entry) {
|
pr_warn("Could not create tracefs 'enable' entry\n");
|
return -ENOMEM;
|
}
|
|
/* There are not as crucial, just warn if they are not created */
|
|
entry = tracefs_create_file("set_event_pid", 0644, parent,
|
tr, &ftrace_set_event_pid_fops);
|
if (!entry)
|
pr_warn("Could not create tracefs 'set_event_pid' entry\n");
|
|
entry = tracefs_create_file("set_event_notrace_pid", 0644, parent,
|
tr, &ftrace_set_event_notrace_pid_fops);
|
if (!entry)
|
pr_warn("Could not create tracefs 'set_event_notrace_pid' entry\n");
|
|
/* ring buffer internal formats */
|
entry = trace_create_file("header_page", 0444, d_events,
|
ring_buffer_print_page_header,
|
&ftrace_show_header_fops);
|
if (!entry)
|
pr_warn("Could not create tracefs 'header_page' entry\n");
|
|
entry = trace_create_file("header_event", 0444, d_events,
|
ring_buffer_print_entry_header,
|
&ftrace_show_header_fops);
|
if (!entry)
|
pr_warn("Could not create tracefs 'header_event' entry\n");
|
|
tr->event_dir = d_events;
|
|
return 0;
|
}
|
|
/**
|
* event_trace_add_tracer - add a instance of a trace_array to events
|
* @parent: The parent dentry to place the files/directories for events in
|
* @tr: The trace array associated with these events
|
*
|
* When a new instance is created, it needs to set up its events
|
* directory, as well as other files associated with events. It also
|
* creates the event hierachry in the @parent/events directory.
|
*
|
* Returns 0 on success.
|
*
|
* Must be called with event_mutex held.
|
*/
|
int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
|
{
|
int ret;
|
|
lockdep_assert_held(&event_mutex);
|
|
ret = create_event_toplevel_files(parent, tr);
|
if (ret)
|
goto out;
|
|
down_write(&trace_event_sem);
|
/* If tr already has the event list, it is initialized in early boot. */
|
if (unlikely(!list_empty(&tr->events)))
|
__trace_early_add_event_dirs(tr);
|
else
|
__trace_add_event_dirs(tr);
|
up_write(&trace_event_sem);
|
|
out:
|
return ret;
|
}
|
|
/*
|
* The top trace array already had its file descriptors created.
|
* Now the files themselves need to be created.
|
*/
|
static __init int
|
early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
|
{
|
int ret;
|
|
mutex_lock(&event_mutex);
|
|
ret = create_event_toplevel_files(parent, tr);
|
if (ret)
|
goto out_unlock;
|
|
down_write(&trace_event_sem);
|
__trace_early_add_event_dirs(tr);
|
up_write(&trace_event_sem);
|
|
out_unlock:
|
mutex_unlock(&event_mutex);
|
|
return ret;
|
}
|
|
/* Must be called with event_mutex held */
|
int event_trace_del_tracer(struct trace_array *tr)
|
{
|
lockdep_assert_held(&event_mutex);
|
|
/* Disable any event triggers and associated soft-disabled events */
|
clear_event_triggers(tr);
|
|
/* Clear the pid list */
|
__ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
|
|
/* Disable any running events */
|
__ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
|
|
/* Make sure no more events are being executed */
|
tracepoint_synchronize_unregister();
|
|
down_write(&trace_event_sem);
|
__trace_remove_event_dirs(tr);
|
tracefs_remove(tr->event_dir);
|
up_write(&trace_event_sem);
|
|
tr->event_dir = NULL;
|
|
return 0;
|
}
|
|
static __init int event_trace_memsetup(void)
|
{
|
field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
|
file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
|
return 0;
|
}
|
|
static __init void
|
early_enable_events(struct trace_array *tr, bool disable_first)
|
{
|
char *buf = bootup_event_buf;
|
char *token;
|
int ret;
|
|
while (true) {
|
token = strsep(&buf, ",");
|
|
if (!token)
|
break;
|
|
if (*token) {
|
/* Restarting syscalls requires that we stop them first */
|
if (disable_first)
|
ftrace_set_clr_event(tr, token, 0);
|
|
ret = ftrace_set_clr_event(tr, token, 1);
|
if (ret)
|
pr_warn("Failed to enable trace event: %s\n", token);
|
}
|
|
/* Put back the comma to allow this to be called again */
|
if (buf)
|
*(buf - 1) = ',';
|
}
|
}
|
|
static __init int event_trace_enable(void)
|
{
|
struct trace_array *tr = top_trace_array();
|
struct trace_event_call **iter, *call;
|
int ret;
|
|
if (!tr)
|
return -ENODEV;
|
|
for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
|
|
call = *iter;
|
ret = event_init(call);
|
if (!ret)
|
list_add(&call->list, &ftrace_events);
|
}
|
|
/*
|
* We need the top trace array to have a working set of trace
|
* points at early init, before the debug files and directories
|
* are created. Create the file entries now, and attach them
|
* to the actual file dentries later.
|
*/
|
__trace_early_add_events(tr);
|
|
early_enable_events(tr, false);
|
|
trace_printk_start_comm();
|
|
register_event_cmds();
|
|
register_trigger_cmds();
|
|
return 0;
|
}
|
|
/*
|
* event_trace_enable() is called from trace_event_init() first to
|
* initialize events and perhaps start any events that are on the
|
* command line. Unfortunately, there are some events that will not
|
* start this early, like the system call tracepoints that need
|
* to set the TIF_SYSCALL_TRACEPOINT flag of pid 1. But event_trace_enable()
|
* is called before pid 1 starts, and this flag is never set, making
|
* the syscall tracepoint never get reached, but the event is enabled
|
* regardless (and not doing anything).
|
*/
|
static __init int event_trace_enable_again(void)
|
{
|
struct trace_array *tr;
|
|
tr = top_trace_array();
|
if (!tr)
|
return -ENODEV;
|
|
early_enable_events(tr, true);
|
|
return 0;
|
}
|
|
early_initcall(event_trace_enable_again);
|
|
/* Init fields which doesn't related to the tracefs */
|
static __init int event_trace_init_fields(void)
|
{
|
if (trace_define_generic_fields())
|
pr_warn("tracing: Failed to allocated generic fields");
|
|
if (trace_define_common_fields())
|
pr_warn("tracing: Failed to allocate common fields");
|
|
return 0;
|
}
|
|
__init int event_trace_init(void)
|
{
|
struct trace_array *tr;
|
struct dentry *entry;
|
int ret;
|
|
tr = top_trace_array();
|
if (!tr)
|
return -ENODEV;
|
|
entry = tracefs_create_file("available_events", 0444, NULL,
|
tr, &ftrace_avail_fops);
|
if (!entry)
|
pr_warn("Could not create tracefs 'available_events' entry\n");
|
|
ret = early_event_add_tracer(NULL, tr);
|
if (ret)
|
return ret;
|
|
#ifdef CONFIG_MODULES
|
ret = register_module_notifier(&trace_module_nb);
|
if (ret)
|
pr_warn("Failed to register trace events module notifier\n");
|
#endif
|
|
eventdir_initialized = true;
|
|
return 0;
|
}
|
|
void __init trace_event_init(void)
|
{
|
event_trace_memsetup();
|
init_ftrace_syscalls();
|
event_trace_enable();
|
event_trace_init_fields();
|
}
|
|
#ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
|
|
static DEFINE_SPINLOCK(test_spinlock);
|
static DEFINE_SPINLOCK(test_spinlock_irq);
|
static DEFINE_MUTEX(test_mutex);
|
|
static __init void test_work(struct work_struct *dummy)
|
{
|
spin_lock(&test_spinlock);
|
spin_lock_irq(&test_spinlock_irq);
|
udelay(1);
|
spin_unlock_irq(&test_spinlock_irq);
|
spin_unlock(&test_spinlock);
|
|
mutex_lock(&test_mutex);
|
msleep(1);
|
mutex_unlock(&test_mutex);
|
}
|
|
static __init int event_test_thread(void *unused)
|
{
|
void *test_malloc;
|
|
test_malloc = kmalloc(1234, GFP_KERNEL);
|
if (!test_malloc)
|
pr_info("failed to kmalloc\n");
|
|
schedule_on_each_cpu(test_work);
|
|
kfree(test_malloc);
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
while (!kthread_should_stop()) {
|
schedule();
|
set_current_state(TASK_INTERRUPTIBLE);
|
}
|
__set_current_state(TASK_RUNNING);
|
|
return 0;
|
}
|
|
/*
|
* Do various things that may trigger events.
|
*/
|
static __init void event_test_stuff(void)
|
{
|
struct task_struct *test_thread;
|
|
test_thread = kthread_run(event_test_thread, NULL, "test-events");
|
msleep(1);
|
kthread_stop(test_thread);
|
}
|
|
/*
|
* For every trace event defined, we will test each trace point separately,
|
* and then by groups, and finally all trace points.
|
*/
|
static __init void event_trace_self_tests(void)
|
{
|
struct trace_subsystem_dir *dir;
|
struct trace_event_file *file;
|
struct trace_event_call *call;
|
struct event_subsystem *system;
|
struct trace_array *tr;
|
int ret;
|
|
tr = top_trace_array();
|
if (!tr)
|
return;
|
|
pr_info("Running tests on trace events:\n");
|
|
list_for_each_entry(file, &tr->events, list) {
|
|
call = file->event_call;
|
|
/* Only test those that have a probe */
|
if (!call->class || !call->class->probe)
|
continue;
|
|
/*
|
* Testing syscall events here is pretty useless, but
|
* we still do it if configured. But this is time consuming.
|
* What we really need is a user thread to perform the
|
* syscalls as we test.
|
*/
|
#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
|
if (call->class->system &&
|
strcmp(call->class->system, "syscalls") == 0)
|
continue;
|
#endif
|
|
pr_info("Testing event %s: ", trace_event_name(call));
|
|
/*
|
* If an event is already enabled, someone is using
|
* it and the self test should not be on.
|
*/
|
if (file->flags & EVENT_FILE_FL_ENABLED) {
|
pr_warn("Enabled event during self test!\n");
|
WARN_ON_ONCE(1);
|
continue;
|
}
|
|
ftrace_event_enable_disable(file, 1);
|
event_test_stuff();
|
ftrace_event_enable_disable(file, 0);
|
|
pr_cont("OK\n");
|
}
|
|
/* Now test at the sub system level */
|
|
pr_info("Running tests on trace event systems:\n");
|
|
list_for_each_entry(dir, &tr->systems, list) {
|
|
system = dir->subsystem;
|
|
/* the ftrace system is special, skip it */
|
if (strcmp(system->name, "ftrace") == 0)
|
continue;
|
|
pr_info("Testing event system %s: ", system->name);
|
|
ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
|
if (WARN_ON_ONCE(ret)) {
|
pr_warn("error enabling system %s\n",
|
system->name);
|
continue;
|
}
|
|
event_test_stuff();
|
|
ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
|
if (WARN_ON_ONCE(ret)) {
|
pr_warn("error disabling system %s\n",
|
system->name);
|
continue;
|
}
|
|
pr_cont("OK\n");
|
}
|
|
/* Test with all events enabled */
|
|
pr_info("Running tests on all trace events:\n");
|
pr_info("Testing all events: ");
|
|
ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
|
if (WARN_ON_ONCE(ret)) {
|
pr_warn("error enabling all events\n");
|
return;
|
}
|
|
event_test_stuff();
|
|
/* reset sysname */
|
ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
|
if (WARN_ON_ONCE(ret)) {
|
pr_warn("error disabling all events\n");
|
return;
|
}
|
|
pr_cont("OK\n");
|
}
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
|
|
static struct trace_event_file event_trace_file __initdata;
|
|
static void __init
|
function_test_events_call(unsigned long ip, unsigned long parent_ip,
|
struct ftrace_ops *op, struct pt_regs *pt_regs)
|
{
|
struct trace_buffer *buffer;
|
struct ring_buffer_event *event;
|
struct ftrace_entry *entry;
|
unsigned int trace_ctx;
|
long disabled;
|
int cpu;
|
|
trace_ctx = tracing_gen_ctx();
|
preempt_disable_notrace();
|
cpu = raw_smp_processor_id();
|
disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
|
|
if (disabled != 1)
|
goto out;
|
|
event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
|
TRACE_FN, sizeof(*entry),
|
trace_ctx);
|
if (!event)
|
goto out;
|
entry = ring_buffer_event_data(event);
|
entry->ip = ip;
|
entry->parent_ip = parent_ip;
|
|
event_trigger_unlock_commit(&event_trace_file, buffer, event,
|
entry, trace_ctx);
|
out:
|
atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
|
preempt_enable_notrace();
|
}
|
|
static struct ftrace_ops trace_ops __initdata =
|
{
|
.func = function_test_events_call,
|
.flags = FTRACE_OPS_FL_RECURSION_SAFE,
|
};
|
|
static __init void event_trace_self_test_with_function(void)
|
{
|
int ret;
|
|
event_trace_file.tr = top_trace_array();
|
if (WARN_ON(!event_trace_file.tr))
|
return;
|
|
ret = register_ftrace_function(&trace_ops);
|
if (WARN_ON(ret < 0)) {
|
pr_info("Failed to enable function tracer for event tests\n");
|
return;
|
}
|
pr_info("Running tests again, along with the function tracer\n");
|
event_trace_self_tests();
|
unregister_ftrace_function(&trace_ops);
|
}
|
#else
|
static __init void event_trace_self_test_with_function(void)
|
{
|
}
|
#endif
|
|
static __init int event_trace_self_tests_init(void)
|
{
|
if (!tracing_selftest_disabled) {
|
event_trace_self_tests();
|
event_trace_self_test_with_function();
|
}
|
|
return 0;
|
}
|
|
late_initcall(event_trace_self_tests_init);
|
|
#endif
|
