Based on the following report from Smatch, fix the potential
NULL pointer dereference check.
tools/perf/ui/browsers/hists.c:641
hist_browser__run() error: we previously assumed 'hbt' could be
null (see line 625)
tools/perf/ui/browsers/hists.c:3088
perf_evsel__hists_browse() error: we previously assumed
'browser->he_selection' could be null (see line 2902)
tools/perf/ui/browsers/hists.c:3272
perf_evsel_menu__run() error: we previously assumed 'hbt' could be
null (see line 3260)
This patch firstly validating the pointers before access them, so can
fix potential NULL pointer dereference.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190708143937.7722-2-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
ceb75476db