perf evlist: Restore original errno after open failed
authorNamhyung Kim <namhyung.kim@lge.com>
Thu, 23 Feb 2012 03:13:36 +0000 (12:13 +0900)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Mon, 5 Mar 2012 13:15:49 +0000 (10:15 -0300)
commit41c21a68308f2f268a01ec1a7fa5f650e320a0f3
treea843f5fdfeff7eda29ef3b1ea4b7b9e0836e97a8
parent737f24bda723fdf89ecaacb99fa2bf5683c32799
perf evlist: Restore original errno after open failed

If perf_evsel__open() failed, the errno was set and returned properly.

However since the perf_evlist__open() called close() on fd's for all of
evsel x cpu x thread after the failure, the errno was overridden by
other code (EBADF). So the caller of the function ended up seeing
different error message and getting confused.

Fit it by restoring original return value. Because one of caller of the
function is in the python extension, and it uses system errno
internally, it'd be better restoring the original value rather than
using the return value of the function directly, IMHO (i.e. I'm not a
python expert :)

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1329966816-23175-1-git-send-email-namhyung.kim@lge.com
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/util/evlist.c