From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: [PATCH 12/25] perf callchain: Fix segfault in thread__resolve_callchain_sample() Date: Tue, 19 Nov 2019 08:32:32 -0300 Message-ID: <20191119113245.19593-13-acme@kernel.org> References: <20191119113245.19593-1-acme@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20191119113245.19593-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Adrian Hunter , Arnaldo Carvalho de Melo , Jiri Olsa List-Id: linux-perf-users.vger.kernel.org From: Adrian Hunter 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 Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Link: http://lore.kernel.org/lkml/20191114142538.4097-1-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- 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 7d2e211e376c..71ee078d30f4 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -2385,7 +2385,7 @@ 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) -- 2.21.0