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From: Riccardo Mancini <rickyman7@gmail.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>
Cc: Riccardo Mancini <rickyman7@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] perf: fix segfault when wrong option for --debug is provided
Date: Mon, 31 May 2021 23:28:28 +0200	[thread overview]
Message-ID: <20210531212828.240077-1-rickyman7@gmail.com> (raw)

The command `perf --debug record` causes a segfault instead of notifying
the user of the unrecognized option for --debug (the correct syntax would
be `perf --debug verbose=2 record`).

The bug is caused by a call to pr_err before debug_file (debug.c:34) is
set via perf_debug_setup(). It has been introduced in
commit 8abceacff87d ("perf debug: Add debug_set_file function").

This patch resolves the bug by calling perf_debug_setup earlier in the
main, so that debug_file is set to stderr before any call to a debug
printing function is made.

Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
---
 tools/perf/perf.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 20cb91ef06ffc..cffbab2d085a7 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -448,6 +448,7 @@ int main(int argc, const char **argv)
 	pager_init(PERF_PAGER_ENVIRONMENT);
 
 	libperf_init(libperf_print);
+	perf_debug_setup();
 
 	cmd = extract_argv0_path(argv[0]);
 	if (!cmd)
@@ -531,8 +532,6 @@ int main(int argc, const char **argv)
 	 */
 	pthread__block_sigwinch();
 
-	perf_debug_setup();
-
 	while (1) {
 		static int done_help;
 
-- 
2.23.0


             reply	other threads:[~2021-05-31 21:31 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-31 21:28 Riccardo Mancini [this message]
2021-06-01 13:37 ` Arnaldo Carvalho de Melo

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