From: Stephane Eranian <eranian@google.com>
To: linux-kernel@vger.kernel.org
Cc: peterz@infradead.org, mingo@elte.hu, paulus@samba.org,
davem@davemloft.net, fweisbec@gmail.com, acme@infradead.org,
perfmon2-devel@lists.sf.net, eranian@gmail.com,
eranian@google.com, jkacur@redhat.com
Subject: [PATCH] perf_events: fix errors path in perf_output_begin() (take 3)
Date: Mon, 17 May 2010 12:46:01 +0200 [thread overview]
Message-ID: <4bf13674.014fd80a.6c82.ffffb20c@mx.google.com> (raw)
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.
Signed-off-by: Stephane Eranian <eranian@google.com>
--
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index a4fa381..4fdb919 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -3036,7 +3036,7 @@ 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)
next reply other threads:[~2010-05-17 12:28 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-17 10:46 Stephane Eranian [this message]
2010-05-18 17:16 ` [tip:perf/core] perf: Fix errors path in perf_output_begin() tip-bot for Stephane Eranian
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