2012-08-23 15:10:43

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: [PATCH 11/12] tools lib traceevent: Fix strerror_r() use in pevent_strerror

From: Namhyung Kim <[email protected]>

glibc-2.16 starts to mark the function with attribute warn_unused_result
so that it can cause a build warning.

Since GNU version of strerror_r() can return a pointer to a string
without setting @buf, check the return value and copy/truncate it to our
buffer if needed.

Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/lib/traceevent/event-parse.c | 7 ++++++-
tools/lib/traceevent/event-utils.h | 6 ++++++
2 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 1373e4c..f978c59 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -4809,7 +4809,12 @@ int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum,
const char *msg;

if (errnum >= 0) {
- strerror_r(errnum, buf, buflen);
+ msg = strerror_r(errnum, buf, buflen);
+ if (msg != buf) {
+ size_t len = strlen(msg);
+ char *c = mempcpy(buf, msg, min(buflen-1, len));
+ *c = '\0';
+ }
return 0;
}

diff --git a/tools/lib/traceevent/event-utils.h b/tools/lib/traceevent/event-utils.h
index 0829638..bc07500 100644
--- a/tools/lib/traceevent/event-utils.h
+++ b/tools/lib/traceevent/event-utils.h
@@ -39,6 +39,12 @@ void __vdie(const char *fmt, ...);
void __vwarning(const char *fmt, ...);
void __vpr_stat(const char *fmt, ...);

+#define min(x, y) ({ \
+ typeof(x) _min1 = (x); \
+ typeof(y) _min2 = (y); \
+ (void) (&_min1 == &_min2); \
+ _min1 < _min2 ? _min1 : _min2; })
+
static inline char *strim(char *string)
{
char *ret;
--
1.7.1