| 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 |
|
| 13 | static 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
|
| 25 | static atomic_t dump_lock = ATOMIC_INIT(-1);
|
| 26 |
|
| 27 | asmlinkage __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 |
|
| 38 | retry:
|
| 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
|
| 60 | asmlinkage __visible void dump_stack(void)
|
| 61 | {
|
| 62 | __dump_stack();
|
| 63 | }
|
| 64 | #endif
|
| 65 | EXPORT_SYMBOL(dump_stack);
|