| Message ID | 20190702103420.27540-6-leo.yan@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | perf: Fix errors detected by Smatch | expand |
Em Tue, Jul 02, 2019 at 06:34:14PM +0800, Leo Yan escreveu: > Based on the following report from Smatch, fix the potential > NULL pointer dereference check. > > tools/perf/builtin-trace.c:1044 > thread_trace__new() error: we previously assumed 'ttrace' could be > null (see line 1041). > > tools/perf/builtin-trace.c > 1037 static struct thread_trace *thread_trace__new(void) > 1038 { > 1039 struct thread_trace *ttrace = zalloc(sizeof(struct thread_trace)); > 1040 > 1041 if (ttrace) > 1042 ttrace->files.max = -1; > 1043 > 1044 ttrace->syscall_stats = intlist__new(NULL); > ^^^^^^^^ > 1045 > 1046 return ttrace; > 1047 } > > This patch directly returns NULL when fail to allocate memory for > ttrace; this can avoid potential NULL pointer dereference. I did it slightly different, to avoid having two return lines, and that is what most other constructors (foo__new()) do in tools/perf/, kept your changeset comment and patch authorship, thanks. diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index d0eb7224dd36..e3fc9062f136 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1038,10 +1038,10 @@ static struct thread_trace *thread_trace__new(void) { struct thread_trace *ttrace = zalloc(sizeof(struct thread_trace)); - if (ttrace) + if (ttrace) { ttrace->files.max = -1; - - ttrace->syscall_stats = intlist__new(NULL); + ttrace->syscall_stats = intlist__new(NULL); + } return ttrace; }
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index f3532b081b31..874d78890c60 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1038,9 +1038,10 @@ static struct thread_trace *thread_trace__new(void) { struct thread_trace *ttrace = zalloc(sizeof(struct thread_trace)); - if (ttrace) - ttrace->files.max = -1; + if (ttrace == NULL) + return NULL; + ttrace->files.max = -1; ttrace->syscall_stats = intlist__new(NULL); return ttrace;
Based on the following report from Smatch, fix the potential NULL pointer dereference check. tools/perf/builtin-trace.c:1044 thread_trace__new() error: we previously assumed 'ttrace' could be null (see line 1041). tools/perf/builtin-trace.c 1037 static struct thread_trace *thread_trace__new(void) 1038 { 1039 struct thread_trace *ttrace = zalloc(sizeof(struct thread_trace)); 1040 1041 if (ttrace) 1042 ttrace->files.max = -1; 1043 1044 ttrace->syscall_stats = intlist__new(NULL); ^^^^^^^^ 1045 1046 return ttrace; 1047 } This patch directly returns NULL when fail to allocate memory for ttrace; this can avoid potential NULL pointer dereference. Signed-off-by: Leo Yan <leo.yan@linaro.org> --- tools/perf/builtin-trace.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)