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>
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index 00fe55c..b6e4c16 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -25,6 +25,38 @@
}
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