Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Provide a default dump_stack() function for architectures
3 * which don't implement their own.
4 */
5
6#include <linux/kernel.h>
7#include <linux/export.h>
8#include <linux/sched.h>
9#include <linux/sched/debug.h>
10#include <linux/smp.h>
11#include <linux/atomic.h>
12
13static void __dump_stack(void)
14{
15 dump_stack_print_info(KERN_DEFAULT);
16 show_stack(NULL, NULL);
17}
18
19/**
20 * dump_stack - dump the current task information and its stack trace
21 *
22 * Architectures can override this implementation by implementing its own.
23 */
24#ifdef CONFIG_SMP
25static atomic_t dump_lock = ATOMIC_INIT(-1);
26
27asmlinkage __visible void dump_stack(void)
28{
29 unsigned long flags;
30 int was_locked;
31 int old;
32 int cpu;
33
34 /*
35 * Permit this cpu to perform nested stack dumps while serialising
36 * against other CPUs
37 */
38retry:
39 local_irq_save(flags);
40 cpu = smp_processor_id();
41 old = atomic_cmpxchg(&dump_lock, -1, cpu);
42 if (old == -1) {
43 was_locked = 0;
44 } else if (old == cpu) {
45 was_locked = 1;
46 } else {
47 local_irq_restore(flags);
48 cpu_relax();
49 goto retry;
50 }
51
52 __dump_stack();
53
54 if (!was_locked)
55 atomic_set(&dump_lock, -1);
56
57 local_irq_restore(flags);
58}
59#else
60asmlinkage __visible void dump_stack(void)
61{
62 __dump_stack();
63}
64#endif
65EXPORT_SYMBOL(dump_stack);