Git Repo - linux.git/blame_incremental

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Commit	Line	Data
	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/smp.h>
	10	#include <linux/atomic.h>
	11
	12	static void __dump_stack(void)
	13	{
	14	dump_stack_print_info(KERN_DEFAULT);
	15	show_stack(NULL, NULL);
	16	}
	17
	18	/**
	19	* dump_stack - dump the current task information and its stack trace
	20	*
	21	* Architectures can override this implementation by implementing its own.
	22	*/
	23	#ifdef CONFIG_SMP
	24	static atomic_t dump_lock = ATOMIC_INIT(-1);
	25
	26	asmlinkage void dump_stack(void)
	27	{
	28	int was_locked;
	29	int old;
	30	int cpu;
	31
	32	/*
	33	* Permit this cpu to perform nested stack dumps while serialising
	34	* against other CPUs
	35	*/
	36	preempt_disable();
	37
	38	retry:
	39	cpu = smp_processor_id();
	40	old = atomic_cmpxchg(&dump_lock, -1, cpu);
	41	if (old == -1) {
	42	was_locked = 0;
	43	} else if (old == cpu) {
	44	was_locked = 1;
	45	} else {
	46	cpu_relax();
	47	goto retry;
	48	}
	49
	50	__dump_stack();
	51
	52	if (!was_locked)
	53	atomic_set(&dump_lock, -1);
	54
	55	preempt_enable();
	56	}
	57	#else
	58	asmlinkage void dump_stack(void)
	59	{
	60	__dump_stack();
	61	}
	62	#endif
	63	EXPORT_SYMBOL(dump_stack);