perf build-id: Ensure struct build_id is empty before use

If a build ID is read then not all code paths may ensure it is empty
before use. Initialize the build_id to be zero-ed unless there is
clear initialization such as a call to build_id__init.

Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250724163302.596743-6-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

11 files changed, 20 insertions, 17 deletions

diff --git a/tools/perf/bench/inject-buildid.c b/tools/perf/bench/inject-buildid.c
index f55c07e4be94..aad572a78d7f 100644
--- a/tools/perf/bench/inject-buildid.c
+++ b/tools/perf/bench/inject-buildid.c
@@ -80,7 +80,7 @@ static int add_dso(const char *fpath, const struct stat *sb __maybe_unused,
 		   int typeflag, struct FTW *ftwbuf __maybe_unused)
 {
 	struct bench_dso *dso = &dsos[nr_dsos];
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 
 	if (typeflag == FTW_D || typeflag == FTW_SL)
 		return 0;
diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index 3f7739b21148..e936a34b7d37 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -175,7 +175,7 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
 static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
 {
 	char sbuild_id[SBUILD_ID_SIZE];
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	int err;
 	struct nscookie nsc;
 
@@ -198,7 +198,7 @@ static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
 static int build_id_cache__remove_file(const char *filename, struct nsinfo *nsi)
 {
 	char sbuild_id[SBUILD_ID_SIZE];
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	struct nscookie nsc;
 
 	int err;
@@ -275,7 +275,7 @@ static int build_id_cache__purge_all(void)
 static bool dso__missing_buildid_cache(struct dso *dso, int parm __maybe_unused)
 {
 	char filename[PATH_MAX];
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 
 	if (!dso__build_id_filename(dso, filename, sizeof(filename), false))
 		return true;
@@ -303,7 +303,7 @@ static int build_id_cache__fprintf_missing(struct perf_session *session, FILE *f
 static int build_id_cache__update_file(const char *filename, struct nsinfo *nsi)
 {
 	char sbuild_id[SBUILD_ID_SIZE];
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	struct nscookie nsc;
 
 	int err;
diff --git a/tools/perf/tests/pe-file-parsing.c b/tools/perf/tests/pe-file-parsing.c
index fff58b220c07..30c7da79e109 100644
--- a/tools/perf/tests/pe-file-parsing.c
+++ b/tools/perf/tests/pe-file-parsing.c
@@ -24,7 +24,7 @@ static int run_dir(const char *d)
 {
 	char filename[PATH_MAX];
 	char debugfile[PATH_MAX];
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	char debuglink[PATH_MAX];
 	char expect_build_id[] = {
 		0x5a, 0x0f, 0xd8, 0x82, 0xb5, 0x30, 0x84, 0x22,
diff --git a/tools/perf/tests/sdt.c b/tools/perf/tests/sdt.c
index 663c8f700069..93baee2eae42 100644
--- a/tools/perf/tests/sdt.c
+++ b/tools/perf/tests/sdt.c
@@ -28,7 +28,7 @@ static int target_function(void)
 static int build_id_cache__add_file(const char *filename)
 {
 	char sbuild_id[SBUILD_ID_SIZE];
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	int err;
 
 	err = filename__read_build_id(filename, &bid);
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 3386fa8e1e7e..1abd5a670665 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -95,7 +95,7 @@ int build_id__snprintf(const struct build_id *build_id, char *bf, size_t bf_size
 int sysfs__snprintf_build_id(const char *root_dir, char *sbuild_id, size_t sbuild_id_size)
 {
 	char notes[PATH_MAX];
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	int ret;
 
 	if (!root_dir)
@@ -112,7 +112,7 @@ int sysfs__snprintf_build_id(const char *root_dir, char *sbuild_id, size_t sbuil
 
 int filename__snprintf_build_id(const char *pathname, char *sbuild_id, size_t sbuild_id_size)
 {
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	int ret;
 
 	ret = filename__read_build_id(pathname, &bid);
@@ -849,7 +849,7 @@ static int filename__read_build_id_ns(const char *filename,
 
 static bool dso__build_id_mismatch(struct dso *dso, const char *name)
 {
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	bool ret = false;
 
 	mutex_lock(dso__lock(dso));
diff --git a/tools/perf/util/debuginfo.c b/tools/perf/util/debuginfo.c
index b5deea7cbdf2..a44c70f93156 100644
--- a/tools/perf/util/debuginfo.c
+++ b/tools/perf/util/debuginfo.c
@@ -103,7 +103,7 @@ struct debuginfo *debuginfo__new(const char *path)
 	char buf[PATH_MAX], nil = '\0';
 	struct dso *dso;
 	struct debuginfo *dinfo = NULL;
-	struct build_id bid;
+	struct build_id bid = { .size = 0};
 
 	/* Try to open distro debuginfo files */
 	dso = dso__new(path);
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index c10549fc451b..57ad150f8c43 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1063,7 +1063,6 @@ static int sprint_line_description(char *sbuf, size_t size, struct line_range *l
 static int __show_line_range(struct line_range *lr, const char *module,
 			     bool user)
 {
-	struct build_id bid;
 	int l = 1;
 	struct int_node *ln;
 	struct debuginfo *dinfo;
@@ -1088,6 +1087,8 @@ static int __show_line_range(struct line_range *lr, const char *module,
 			ret = -ENOENT;
 	}
 	if (dinfo->build_id) {
+		struct build_id bid;
+
 		build_id__init(&bid, dinfo->build_id, BUILD_ID_SIZE);
 		build_id__snprintf(&bid, sbuild_id, sizeof(sbuild_id));
 	}
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index b74f6fe24bb6..5ffd97ee4898 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -848,7 +848,6 @@ static int probe_point_lazy_walker(const char *fname, int lineno,
 /* Find probe points from lazy pattern  */
 static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 {
-	struct build_id bid;
 	char sbuild_id[SBUILD_ID_SIZE] = "";
 	int ret = 0;
 	char *fpath;
@@ -858,6 +857,8 @@ static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
 
 		comp_dir = cu_get_comp_dir(&pf->cu_die);
 		if (pf->dbg->build_id) {
+			struct build_id bid;
+
 			build_id__init(&bid, pf->dbg->build_id, BUILD_ID_SIZE);
 			build_id__snprintf(&bid, sbuild_id, sizeof(sbuild_id));
 		}
diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
index c73fe2e09fe9..7201494c5c20 100644
--- a/tools/perf/util/symbol-minimal.c
+++ b/tools/perf/util/symbol-minimal.c
@@ -317,7 +317,7 @@ int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
 		  struct symsrc *runtime_ss __maybe_unused,
 		  int kmodule __maybe_unused)
 {
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	int ret;
 
 	ret = fd__is_64_bit(ss->fd);
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 573c65da9fe0..e816e4220d33 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1813,7 +1813,6 @@ int dso__load(struct dso *dso, struct map *map)
 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
 	bool kmod;
 	bool perfmap;
-	struct build_id bid;
 	struct nscookie nsc;
 	char newmapname[PATH_MAX];
 	const char *map_path = dso__long_name(dso);
@@ -1874,6 +1873,8 @@ int dso__load(struct dso *dso, struct map *map)
 	 */
 	if (!dso__has_build_id(dso) &&
 	    is_regular_file(dso__long_name(dso))) {
+		struct build_id bid = { .size = 0, };
+
 		__symbol__join_symfs(name, PATH_MAX, dso__long_name(dso));
 		if (filename__read_build_id(name, &bid) > 0)
 			dso__set_build_id(dso, &bid);
@@ -2122,7 +2123,7 @@ static bool filename__readable(const char *file)
 
 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 {
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	char sbuild_id[SBUILD_ID_SIZE];
 	bool is_host = false;
 	char path[PATH_MAX];
diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index d3c454174602..d6f9a4548c92 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -368,7 +368,7 @@ static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event,
 					     struct machine *machine,
 					     bool is_kernel)
 {
-	struct build_id bid;
+	struct build_id bid = { .size = 0, };
 	struct nsinfo *nsi;
 	struct nscookie nc;
 	struct dso *dso = NULL;