Re: [PATCH v2 17/18] perf header: Fix various error path memory leaks
From: Namhyung Kim
Date: Mon Oct 09 2023 - 02:57:51 EST
On Thu, Oct 5, 2023 at 4:09 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> Memory leaks were detected by clang-tidy.
>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
> tools/perf/util/header.c | 63 ++++++++++++++++++++++++----------------
> 1 file changed, 38 insertions(+), 25 deletions(-)
>
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index d812e1e371a7..41b78e40b22b 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -2598,8 +2598,10 @@ static int process_cpu_topology(struct feat_fd *ff, void *data __maybe_unused)
> goto error;
>
> /* include a NULL character at the end */
> - if (strbuf_add(&sb, str, strlen(str) + 1) < 0)
> + if (strbuf_add(&sb, str, strlen(str) + 1) < 0) {
> + free(str);
> goto error;
> + }
> size += string_size(str);
> free(str);
> }
> @@ -2617,8 +2619,10 @@ static int process_cpu_topology(struct feat_fd *ff, void *data __maybe_unused)
> goto error;
>
> /* include a NULL character at the end */
> - if (strbuf_add(&sb, str, strlen(str) + 1) < 0)
> + if (strbuf_add(&sb, str, strlen(str) + 1) < 0) {
> + free(str);
> goto error;
> + }
> size += string_size(str);
> free(str);
> }
> @@ -2681,8 +2685,10 @@ static int process_cpu_topology(struct feat_fd *ff, void *data __maybe_unused)
> goto error;
>
> /* include a NULL character at the end */
> - if (strbuf_add(&sb, str, strlen(str) + 1) < 0)
> + if (strbuf_add(&sb, str, strlen(str) + 1) < 0) {
> + free(str);
> goto error;
> + }
> size += string_size(str);
> free(str);
> }
For these cases, it'd be simpler to free it in the error path.
> @@ -2736,10 +2742,9 @@ static int process_numa_topology(struct feat_fd *ff, void *data __maybe_unused)
> goto error;
>
> n->map = perf_cpu_map__new(str);
> + free(str);
> if (!n->map)
> goto error;
> -
> - free(str);
> }
> ff->ph->env.nr_numa_nodes = nr;
> ff->ph->env.numa_nodes = nodes;
> @@ -2913,10 +2918,10 @@ static int process_cache(struct feat_fd *ff, void *data __maybe_unused)
> return -1;
>
> for (i = 0; i < cnt; i++) {
> - struct cpu_cache_level c;
> + struct cpu_cache_level *c = &caches[i];
>
> #define _R(v) \
> - if (do_read_u32(ff, &c.v))\
> + if (do_read_u32(ff, &c->v)) \
> goto out_free_caches; \
>
> _R(level)
> @@ -2926,22 +2931,25 @@ static int process_cache(struct feat_fd *ff, void *data __maybe_unused)
> #undef _R
>
> #define _R(v) \
> - c.v = do_read_string(ff); \
> - if (!c.v) \
> - goto out_free_caches;
> + c->v = do_read_string(ff); \
> + if (!c->v) \
> + goto out_free_caches; \
>
> _R(type)
> _R(size)
> _R(map)
> #undef _R
> -
> - caches[i] = c;
> }
>
> ff->ph->env.caches = caches;
> ff->ph->env.caches_cnt = cnt;
> return 0;
> out_free_caches:
> + for (i = 0; i < cnt; i++) {
> + free(caches[i].type);
> + free(caches[i].size);
> + free(caches[i].map);
> + }
> free(caches);
> return -1;
> }
Looks ok.
> @@ -3585,18 +3593,16 @@ static int perf_header__adds_write(struct perf_header *header,
> struct feat_copier *fc)
> {
> int nr_sections;
> - struct feat_fd ff;
> + struct feat_fd ff = {
> + .fd = fd,
> + .ph = header,
> + };
I'm fine with this change.
> struct perf_file_section *feat_sec, *p;
> int sec_size;
> u64 sec_start;
> int feat;
> int err;
>
> - ff = (struct feat_fd){
> - .fd = fd,
> - .ph = header,
> - };
> -
> nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
> if (!nr_sections)
> return 0;
> @@ -3623,6 +3629,7 @@ static int perf_header__adds_write(struct perf_header *header,
> err = do_write(&ff, feat_sec, sec_size);
> if (err < 0)
> pr_debug("failed to write feature section\n");
> + free(ff.buf);
But it looks like false alarams. Since the feat_fd has fd
and no buf, it won't allocate the buffer in do_write() and
just use __do_write_fd(). So no need to free the buf.
Thanks,
Namhyung
> free(feat_sec);
> return err;
> }
> @@ -3630,11 +3637,11 @@ static int perf_header__adds_write(struct perf_header *header,
> int perf_header__write_pipe(int fd)
> {
> struct perf_pipe_file_header f_header;
> - struct feat_fd ff;
> + struct feat_fd ff = {
> + .fd = fd,
> + };
> int err;
>
> - ff = (struct feat_fd){ .fd = fd };
> -
> f_header = (struct perf_pipe_file_header){
> .magic = PERF_MAGIC,
> .size = sizeof(f_header),
> @@ -3645,7 +3652,7 @@ int perf_header__write_pipe(int fd)
> pr_debug("failed to write perf pipe header\n");
> return err;
> }
> -
> + free(ff.buf);
> return 0;
> }
>
> @@ -3658,11 +3665,12 @@ static int perf_session__do_write_header(struct perf_session *session,
> struct perf_file_attr f_attr;
> struct perf_header *header = &session->header;
> struct evsel *evsel;
> - struct feat_fd ff;
> + struct feat_fd ff = {
> + .fd = fd,
> + };
> u64 attr_offset;
> int err;
>
> - ff = (struct feat_fd){ .fd = fd};
> lseek(fd, sizeof(f_header), SEEK_SET);
>
> evlist__for_each_entry(session->evlist, evsel) {
> @@ -3670,6 +3678,7 @@ static int perf_session__do_write_header(struct perf_session *session,
> err = do_write(&ff, evsel->core.id, evsel->core.ids * sizeof(u64));
> if (err < 0) {
> pr_debug("failed to write perf header\n");
> + free(ff.buf);
> return err;
> }
> }
> @@ -3695,6 +3704,7 @@ static int perf_session__do_write_header(struct perf_session *session,
> err = do_write(&ff, &f_attr, sizeof(f_attr));
> if (err < 0) {
> pr_debug("failed to write perf header attribute\n");
> + free(ff.buf);
> return err;
> }
> }
> @@ -3705,8 +3715,10 @@ static int perf_session__do_write_header(struct perf_session *session,
>
> if (at_exit) {
> err = perf_header__adds_write(header, evlist, fd, fc);
> - if (err < 0)
> + if (err < 0) {
> + free(ff.buf);
> return err;
> + }
> }
>
> f_header = (struct perf_file_header){
> @@ -3728,6 +3740,7 @@ static int perf_session__do_write_header(struct perf_session *session,
>
> lseek(fd, 0, SEEK_SET);
> err = do_write(&ff, &f_header, sizeof(f_header));
> + free(ff.buf);
> if (err < 0) {
> pr_debug("failed to write perf header\n");
> return err;
> --
> 2.42.0.609.gbb76f46606-goog
>