perf tools: Pass build_id object to dso__build_id_equal()

Passing build_id object to dso__build_id_equal(), so we can properly
check build id with different size than sha1.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20201013192441.1299447-7-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/dso.c

@@ -1332,9 +1332,10 @@ void dso__set_build_id(struct dso *dso, struct build_id *bid)
 	dso->has_build_id = 1;
 }
 
-bool dso__build_id_equal(const struct dso *dso, u8 *build_id)
+bool dso__build_id_equal(const struct dso *dso, struct build_id *bid)
 {
-	return memcmp(dso->bid.data, build_id, sizeof(dso->bid.data)) == 0;
+	return dso->bid.size == bid->size &&
+	       memcmp(dso->bid.data, bid->data, dso->bid.size) == 0;
 }
 
 void dso__read_running_kernel_build_id(struct dso *dso, struct machine *machine)

tools/perf/util/dso.h

@@ -261,7 +261,7 @@ void dso__set_sorted_by_name(struct dso *dso);
 void dso__sort_by_name(struct dso *dso);
 
 void dso__set_build_id(struct dso *dso, struct build_id *bid);
-bool dso__build_id_equal(const struct dso *dso, u8 *build_id);
+bool dso__build_id_equal(const struct dso *dso, struct build_id *bid);
 void dso__read_running_kernel_build_id(struct dso *dso,
 				       struct machine *machine);
 int dso__kernel_module_get_build_id(struct dso *dso, const char *root_dir);

tools/perf/util/symbol-elf.c

@@ -834,13 +834,17 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
 	/* Always reject images with a mismatched build-id: */
 	if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
 		u8 build_id[BUILD_ID_SIZE];
+		struct build_id bid;
+		int size;
 
-		if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
+		size = elf_read_build_id(elf, build_id, BUILD_ID_SIZE);
+		if (size <= 0) {
 			dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
 			goto out_elf_end;
 		}
 
-		if (!dso__build_id_equal(dso, build_id)) {
+		build_id__init(&bid, build_id, size);
+		if (!dso__build_id_equal(dso, &bid)) {
 			pr_debug("%s: build id mismatch for %s.\n", __func__, name);
 			dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
 			goto out_elf_end;

tools/perf/util/symbol.c

@@ -2136,7 +2136,7 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 	}
 
 	if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
-		is_host = dso__build_id_equal(dso, bid.data);
+		is_host = dso__build_id_equal(dso, &bid);
 
 	/* Try a fast path for /proc/kallsyms if possible */
 	if (is_host) {