From: Leo Yan Date: Mon, 8 Jul 2019 14:39:36 +0000 (+0800) Subject: perf intel-pt: Fix potential NULL pointer dereference found by the smatch tool X-Git-Tag: v5.3-rc1~10^2~6^2 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=323fd749821daab0f327ec86d707c4542963cdb0;p=linux-2.6-block.git perf intel-pt: Fix potential NULL pointer dereference found by the smatch tool Based on the following report from Smatch, fix the potential NULL pointer dereference check. tools/perf/util/intel-pt.c:3200 intel_pt_process_auxtrace_info() error: we previously assumed 'session->itrace_synth_opts' could be null (see line 3196) tools/perf/util/intel-pt.c:3206 intel_pt_process_auxtrace_info() warn: variable dereferenced before check 'session->itrace_synth_opts' (see line 3200) tools/perf/util/intel-pt.c 3196 if (session->itrace_synth_opts && session->itrace_synth_opts->set) { 3197 pt->synth_opts = *session->itrace_synth_opts; 3198 } else { 3199 itrace_synth_opts__set_default(&pt->synth_opts, 3200 session->itrace_synth_opts->default_no_sample); ^^^^^^^^^^^^^^^^^^^^^^^^^^ 3201 if (!session->itrace_synth_opts->default_no_sample && 3202 !session->itrace_synth_opts->inject) { 3203 pt->synth_opts.branches = false; 3204 pt->synth_opts.callchain = true; 3205 } 3206 if (session->itrace_synth_opts) ^^^^^^^^^^^^^^^^^^^^^^^^^^ 3207 pt->synth_opts.thread_stack = 3208 session->itrace_synth_opts->thread_stack; 3209 } 'session->itrace_synth_opts' is impossible to be a NULL pointer in intel_pt_process_auxtrace_info(), thus this patch removes the NULL test for 'session->itrace_synth_opts'. Signed-off-by: Leo Yan Acked-by: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jiri Olsa Cc: Mathieu Poirier Cc: Namhyung Kim Cc: Suzuki Poulouse Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20190708143937.7722-4-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c index c76a96f777fb..df061599fef4 100644 --- a/tools/perf/util/intel-pt.c +++ b/tools/perf/util/intel-pt.c @@ -3210,7 +3210,7 @@ int intel_pt_process_auxtrace_info(union perf_event *event, goto err_delete_thread; } - if (session->itrace_synth_opts && session->itrace_synth_opts->set) { + if (session->itrace_synth_opts->set) { pt->synth_opts = *session->itrace_synth_opts; } else { itrace_synth_opts__set_default(&pt->synth_opts, @@ -3220,8 +3220,7 @@ int intel_pt_process_auxtrace_info(union perf_event *event, pt->synth_opts.branches = false; pt->synth_opts.callchain = true; } - if (session->itrace_synth_opts) - pt->synth_opts.thread_stack = + pt->synth_opts.thread_stack = session->itrace_synth_opts->thread_stack; } @@ -3241,11 +3240,9 @@ int intel_pt_process_auxtrace_info(union perf_event *event, pt->cbr2khz = tsc_freq / pt->max_non_turbo_ratio / 1000; } - if (session->itrace_synth_opts) { - err = intel_pt_setup_time_ranges(pt, session->itrace_synth_opts); - if (err) - goto err_delete_thread; - } + err = intel_pt_setup_time_ranges(pt, session->itrace_synth_opts); + if (err) + goto err_delete_thread; if (pt->synth_opts.calls) pt->branches_filter |= PERF_IP_FLAG_CALL | PERF_IP_FLAG_ASYNC |