Thread (1 message) 1 message, 1 author, 2019-05-03
STALE2683d REVIEWED: 3 (3M)

1 review trailer (1 from subsystem maintainers).

[PATCH 01/11] perf bpf: Return value with unlocking in perf_env__find_btf()

From: Arnaldo Carvalho de Melo <acme@kernel.org>
Date: 2019-05-03 00:25:52
Also in: bpf, linux-perf-users, lkml
Subsystem: performance events subsystem, the rest · Maintainers: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds

From: Bo YU <redacted>

In perf_env__find_btf(), we're returning without unlocking
"env->bpf_progs.lock". There may be cause lockdep issue.

Detected by CoversityScan, CID# 1444762:(program hangs(LOCK))

Signed-off-by: Bo YU <redacted>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <redacted>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <redacted>
Cc: Yonghong Song <redacted>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Fixes: 2db7b1e0bd49d: (perf bpf: Return NULL when RB tree lookup fails in perf_env__find_btf())
Link: http://lkml.kernel.org/r/20190422080138.10088-1-tsu.yubo@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <redacted>
---
 tools/perf/util/env.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 9494f9dc61ec..6a3eaf7d9353 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -115,8 +115,8 @@ struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id)
 	}
 	node = NULL;
 
-	up_read(&env->bpf_progs.lock);
 out:
+	up_read(&env->bpf_progs.lock);
 	return node;
 }
 
-- 
2.20.1
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