mirror of
https://github.com/torvalds/linux.git
synced 2024-12-28 05:41:55 +00:00
b58d977432
Add functionality to serialize the output from dump_stack() to avoid mangling of the output when dump_stack is called simultaneously from multiple cpus. [akpm@linux-foundation.org: fix comment indenting, avoid inclusion of <asm/> files - use <linux/> where possiblem fix uniprocessor build (__dump_stack undefined), remove unneeded ifdef around smp.h inclusion] Signed-off-by: Alex Thorlton <athorlton@sgi.com> Reported-by: Russ Anderson <rja@sgi.com> Reviewed-by: Robin Holt <holt@sgi.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: David S. Miller <davem@davemloft.net> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
64 lines
1.1 KiB
C
64 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);
|
|
|
|
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
|
|
void dump_stack(void)
|
|
{
|
|
__dump_stack();
|
|
}
|
|
#endif
|
|
EXPORT_SYMBOL(dump_stack);
|