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authorJoonsoo Kim <iamjoonsoo.kim@lge.com>2014-12-12 16:55:58 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-13 12:42:48 -0800
commit9a92a6ce6f842713ccd0025c5228fe8bea61234c (patch)
tree1377a03f1f21fa4dac44c46794cb56254ad29be2
parentdbc8358c72373daa4f37b7e233fecbc47105fe54 (diff)
downloadlinux-9a92a6ce6f842713ccd0025c5228fe8bea61234c.tar.bz2
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>
-rw-r--r--include/linux/stacktrace.h5
-rw-r--r--kernel/stacktrace.c32
2 files changed, 37 insertions, 0 deletions
diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h
index 115b570e3bff..669045ab73f3 100644
--- a/include/linux/stacktrace.h
+++ b/include/linux/stacktrace.h
@@ -1,6 +1,8 @@
#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
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index 00fe55cc5a82..b6e4c16377c7 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -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