Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

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 <leo.yan@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.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/20190708143937.7722-4-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

authored by

Leo Yan and committed by
Arnaldo Carvalho de Melo
323fd749 1d481458

+5 -8
+5 -8
tools/perf/util/intel-pt.c
··· 3210 3210 goto err_delete_thread; 3211 3211 } 3212 3212 3213 - if (session->itrace_synth_opts && session->itrace_synth_opts->set) { 3213 + if (session->itrace_synth_opts->set) { 3214 3214 pt->synth_opts = *session->itrace_synth_opts; 3215 3215 } else { 3216 3216 itrace_synth_opts__set_default(&pt->synth_opts, ··· 3220 3220 pt->synth_opts.branches = false; 3221 3221 pt->synth_opts.callchain = true; 3222 3222 } 3223 - if (session->itrace_synth_opts) 3224 - pt->synth_opts.thread_stack = 3223 + pt->synth_opts.thread_stack = 3225 3224 session->itrace_synth_opts->thread_stack; 3226 3225 } 3227 3226 ··· 3240 3241 pt->cbr2khz = tsc_freq / pt->max_non_turbo_ratio / 1000; 3241 3242 } 3242 3243 3243 - if (session->itrace_synth_opts) { 3244 - err = intel_pt_setup_time_ranges(pt, session->itrace_synth_opts); 3245 - if (err) 3246 - goto err_delete_thread; 3247 - } 3244 + err = intel_pt_setup_time_ranges(pt, session->itrace_synth_opts); 3245 + if (err) 3246 + goto err_delete_thread; 3248 3247 3249 3248 if (pt->synth_opts.calls) 3250 3249 pt->branches_filter |= PERF_IP_FLAG_CALL | PERF_IP_FLAG_ASYNC |