linux/lib/dump_stack.c
Andi Kleen b6c035d04e x86, asmlinkage: Make dump_stack visible
dump_stack is used from assembler code, so make it visible.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1375740170-7446-15-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-08-06 14:21:01 -07:00

63 lines
1.1 KiB
C

/*
* Provide a default dump_stack() function for architectures
* which don't implement their own.
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/atomic.h>
static void __dump_stack(void)
{
dump_stack_print_info(KERN_DEFAULT);
show_stack(NULL, NULL);
}
/**
* dump_stack - dump the current task information and its stack trace
*
* Architectures can override this implementation by implementing its own.
*/
#ifdef CONFIG_SMP
static atomic_t dump_lock = ATOMIC_INIT(-1);
asmlinkage void dump_stack(void)
{
int was_locked;
int old;
int cpu;
/*
* Permit this cpu to perform nested stack dumps while serialising
* against other CPUs
*/
preempt_disable();
retry:
cpu = smp_processor_id();
old = atomic_cmpxchg(&dump_lock, -1, cpu);
if (old == -1) {
was_locked = 0;
} else if (old == cpu) {
was_locked = 1;
} else {
cpu_relax();
goto retry;
}
__dump_stack();
if (!was_locked)
atomic_set(&dump_lock, -1);
preempt_enable();
}
#else
asmlinkage void dump_stack(void)
{
__dump_stack();
}
#endif
EXPORT_SYMBOL(dump_stack);