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| author | Stephane Eranian <eranian@google.com> | 2010-05-17 12:46:01 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2010-06-15 08:57:22 +0200 |
| commit | ea2d2a0d32a1f98d5c1be461b715009ca7774156 (patch) | |
| tree | 177373a170c7eb7ff98c6112ea5628fec8ef8e47 | |
| parent | 60bd9460ca408a58ea14eede44ff82c23647f517 (diff) | |
| download | lwn-ea2d2a0d32a1f98d5c1be461b715009ca7774156.tar.gz lwn-ea2d2a0d32a1f98d5c1be461b715009ca7774156.zip | |
perf: Fix errors path in perf_output_begin()
In case the sampling buffer has no "payload" pages,
nr_pages is 0. The problem is that the error path in
perf_output_begin() skips to a label which assumes
perf_output_lock() has been issued which is not the
case. That triggers a WARN_ON() in
perf_output_unlock().
This patch fixes the problem by skipping
perf_output_unlock() in case data->nr_pages is 0.
[ upstream commit: 00d1d0b095ba4e5c0958cb228b2a9c445d4a339d ]
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4bf13674.014fd80a.6c82.ffffb20c@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | kernel/perf_event.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 43c1dfb7b386..e353be2a38ee 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -2933,7 +2933,7 @@ int perf_output_begin(struct perf_output_handle *handle, handle->sample = sample; if (!data->nr_pages) - goto fail; + goto out; have_lost = atomic_read(&data->lost); if (have_lost) |