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authorAndi Kleen <ak@linux.intel.com>2019-10-20 10:51:54 -0700
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-11-06 15:43:05 -0300
commit796c01a4bfb4b35ec6d1bd1cd5d520515d078b51 (patch)
tree57081bb36da7d51bac16f9e8287db0535b6d26b9 /tools/perf/util/evsel.c
parent9d604aad4bb022e848dec80d6fe5f73fe87061a2 (diff)
perf evsel: Always preserve errno while cleaning up perf_event_open failures
In some cases when perf_event_open fails, it may do some closes to clean up. In special cases these closes can fail too, which overwrites the errno of the perf_event_open, which is then incorrectly reported. Save/restore errno around closes. Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lore.kernel.org/lkml/20191020175202.32456-2-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/evsel.c')
-rw-r--r--tools/perf/util/evsel.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index abc7fda4a0fe..d831038b55f2 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1574,7 +1574,7 @@ int evsel__open(struct evsel *evsel, struct perf_cpu_map *cpus,
{
int cpu, thread, nthreads;
unsigned long flags = PERF_FLAG_FD_CLOEXEC;
- int pid = -1, err;
+ int pid = -1, err, old_errno;
enum { NO_CHANGE, SET_TO_MAX, INCREASED_MAX } set_rlimit = NO_CHANGE;
if ((perf_missing_features.write_backward && evsel->core.attr.write_backward) ||
@@ -1727,8 +1727,8 @@ try_fallback:
*/
if (err == -EMFILE && set_rlimit < INCREASED_MAX) {
struct rlimit l;
- int old_errno = errno;
+ old_errno = errno;
if (getrlimit(RLIMIT_NOFILE, &l) == 0) {
if (set_rlimit == NO_CHANGE)
l.rlim_cur = l.rlim_max;
@@ -1812,6 +1812,7 @@ out_close:
if (err)
threads->err_thread = thread;
+ old_errno = errno;
do {
while (--thread >= 0) {
close(FD(evsel, cpu, thread));
@@ -1819,6 +1820,7 @@ out_close:
}
thread = nthreads;
} while (--cpu >= 0);
+ errno = old_errno;
return err;
}