From aceb98261ea7d9fe38f9c140c5531f0b13623832 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Thu, 14 Nov 2019 16:25:38 +0200 Subject: [PATCH] perf callchain: Fix segfault in thread__resolve_callchain_sample() 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)