/*
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* Stack trace management functions
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*
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* Copyright (C) 2009 Helge Deller <deller@gmx.de>
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* based on arch/x86/kernel/stacktrace.c by Ingo Molnar <mingo@redhat.com>
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* and parisc unwind functions by Randolph Chung <tausq@debian.org>
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*
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* TODO: Userspace stacktrace (CONFIG_USER_STACKTRACE_SUPPORT)
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*/
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#include <linux/module.h>
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#include <linux/stacktrace.h>
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#include <asm/unwind.h>
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static void dump_trace(struct task_struct *task, struct stack_trace *trace)
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{
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struct unwind_frame_info info;
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/* initialize unwind info */
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if (task == current) {
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unsigned long sp;
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struct pt_regs r;
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HERE:
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asm volatile ("copy %%r30, %0" : "=r"(sp));
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memset(&r, 0, sizeof(struct pt_regs));
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r.iaoq[0] = (unsigned long)&&HERE;
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r.gr[2] = (unsigned long)__builtin_return_address(0);
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r.gr[30] = sp;
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unwind_frame_init(&info, task, &r);
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} else {
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unwind_frame_init_from_blocked_task(&info, task);
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}
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/* unwind stack and save entries in stack_trace struct */
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trace->nr_entries = 0;
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while (trace->nr_entries < trace->max_entries) {
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if (unwind_once(&info) < 0 || info.ip == 0)
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break;
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if (__kernel_text_address(info.ip))
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trace->entries[trace->nr_entries++] = info.ip;
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}
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}
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/*
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* Save stack-backtrace addresses into a stack_trace buffer.
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*/
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void save_stack_trace(struct stack_trace *trace)
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{
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dump_trace(current, trace);
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = ULONG_MAX;
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}
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EXPORT_SYMBOL_GPL(save_stack_trace);
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void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
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{
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dump_trace(tsk, trace);
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = ULONG_MAX;
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}
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EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
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