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From: Adrian Hunter <adrian.hunter@intel.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>, linux-kernel@vger.kernel.org
Subject: [PATCH] perf callchain: Fix segfault in thread__resolve_callchain_sample()
Date: Thu, 14 Nov 2019 16:25:38 +0200	[thread overview]
Message-ID: <20191114142538.4097-1-adrian.hunter@intel.com> (raw)

Do not dereference 'chain' when it is NULL.

  $ perf record -e intel_pt//u -e branch-misses:u uname
  $ perf report --itrace=l --branch-history
  perf: Segmentation fault

Fixes: e9024d519d89 ("perf callchain: Honour the ordering of PERF_CONTEXT_{USER,KERNEL,etc}")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 tools/perf/util/machine.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 6a0f5c25ce3e..0a21ab69a247 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2414,7 +2414,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
 	}
 
 check_calls:
-	if (callchain_param.order != ORDER_CALLEE) {
+	if (chain && callchain_param.order != ORDER_CALLEE) {
 		err = find_prev_cpumode(chain, thread, cursor, parent, root_al,
 					&cpumode, chain->nr - first_call);
 		if (err)
-- 
2.17.1


             reply	other threads:[~2019-11-14 14:26 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-14 14:25 Adrian Hunter [this message]
2019-11-14 19:13 ` [PATCH] perf callchain: Fix segfault in thread__resolve_callchain_sample() Arnaldo Carvalho de Melo
2019-11-19 16:56 ` [tip: perf/core] " tip-bot2 for Adrian Hunter

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