From 46755bddc8fe2cf220f105b06f347b116819af3f Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Mon, 17 May 2010 12:46:01 +0200 Subject: [PATCH] perf: Fix errors path in perf_output_begin() commit ea2d2a0d32a1f98d5c1be461b715009ca7774156 in tip. 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 Signed-off-by: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: <4bf13674.014fd80a.6c82.ffffb20c@mx.google.com> Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Signed-off-by: Paul Gortmaker --- 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 dd73870..0bb58a7 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -3014,7 +3014,7 @@ 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) -- 1.7.0.4