linux-stable/kernel/stacktrace.c
Joonsoo Kim 9a92a6ce6f 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: Joonsoo 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:48 -08:00

75 lines
1.7 KiB
C

/*
* kernel/stacktrace.c
*
* Stack trace management functions
*
* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/kallsyms.h>
#include <linux/stacktrace.h>
void print_stack_trace(struct stack_trace *trace, int spaces)
{
int i;
if (WARN_ON(!trace->entries))
return;
for (i = 0; i < trace->nr_entries; i++) {
printk("%*c", 1 + spaces, ' ');
print_ip_sym(trace->entries[i]);
}
}
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
* (whenever this facility is utilized - for example by procfs):
*/
__weak void
save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
}
__weak void
save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
{
WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
}