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Commit 9a92a6ce authored by Joonsoo Kim's avatar Joonsoo Kim Committed by Linus Torvalds
Browse files

stacktrace: introduce snprint_stack_trace for buffer output 



Current stacktrace only have the function for console output.  page_owner
that will be introduced in following patch needs to print the output of
stacktrace into the buffer for our own output format so so new function,
snprint_stack_trace(), is needed.

Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent dbc8358c

include/linux/stacktrace.h

+5 −0
Original line number Diff line number Diff line 
#ifndef __LINUX_STACKTRACE_H

#define __LINUX_STACKTRACE_H



#include <linux/types.h>



struct task_struct;

struct pt_regs;
@@ -20,6 +22,8 @@ extern void save_stack_trace_tsk(struct task_struct *tsk, 
				struct stack_trace *trace);



extern void print_stack_trace(struct stack_trace *trace, int spaces);

extern int snprint_stack_trace(char *buf, size_t size,

			struct stack_trace *trace, int spaces);



#ifdef CONFIG_USER_STACKTRACE_SUPPORT

extern void save_stack_trace_user(struct stack_trace *trace);
@@ -32,6 +36,7 @@ extern void save_stack_trace_user(struct stack_trace *trace); 
# define save_stack_trace_tsk(tsk, trace)		do { } while (0)

# define save_stack_trace_user(trace)			do { } while (0)

# define print_stack_trace(trace, spaces)		do { } while (0)

# define snprint_stack_trace(buf, size, trace, spaces)	do { } while (0)

#endif



#endif

kernel/stacktrace.c

+32 −0
Original line number Diff line number Diff line
@@ -25,6 +25,38 @@ void print_stack_trace(struct stack_trace *trace, int spaces) 
}

EXPORT_SYMBOL_GPL(print_stack_trace);



int snprint_stack_trace(char *buf, size_t size,

			struct stack_trace *trace, int spaces)

{

	int i;

	unsigned long ip;

	int generated;

	int total = 0;



	if (WARN_ON(!trace->entries))

		return 0;



	for (i = 0; i < trace->nr_entries; i++) {

		ip = trace->entries[i];

		generated = snprintf(buf, size, "%*c[<%p>] %pS\n",

				1 + spaces, ' ', (void *) ip, (void *) ip);



		total += generated;



		/* Assume that generated isn't a negative number */

		if (generated >= size) {

			buf += size;

			size = 0;

		} else {

			buf += generated;

			size -= generated;

		}

	}



	return total;

}

EXPORT_SYMBOL_GPL(snprint_stack_trace);



/*

 * Architectures that do not implement save_stack_trace_tsk or

 * save_stack_trace_regs get this weak alias and a once-per-bootup warning