perf tools: Pass build_id object to filename__read_build_id()

Pass a build_id object to filename__read_build_id function, so it can
populate the size of the build_id object.

Changing filename__read_build_id() code for both ELF/non-ELF code.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20201013192441.1299447-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

6 files changed, 38 insertions, 32 deletions

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 7da13ddb0d50..62b258aaa128 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -130,16 +130,14 @@ int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
 
 int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
 {
-	u8 build_id[BUILD_ID_SIZE];
+	struct build_id bid;
 	int ret;
 
-	ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
+	ret = filename__read_build_id(pathname, &bid);
 	if (ret < 0)
 		return ret;
-	else if (ret != sizeof(build_id))
-		return -EINVAL;
 
-	return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
+	return build_id__sprintf(bid.data, sizeof(bid.data), sbuild_id);
 }
 
 /* asnprintf consolidates asprintf and snprintf */
diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c
index e3af46e818f1..87161e431830 100644
--- a/tools/perf/util/dsos.c
+++ b/tools/perf/util/dsos.c
@@ -73,8 +73,7 @@ bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
 			continue;
 		}
 		nsinfo__mountns_enter(pos->nsinfo, &nsc);
-		if (filename__read_build_id(pos->long_name, pos->bid.data,
-					    sizeof(pos->bid.data)) > 0) {
+		if (filename__read_build_id(pos->long_name, &pos->bid) > 0) {
 			have_build_id	  = true;
 			pos->has_build_id = true;
 		}
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 94a156df22d5..61d7c444e6f5 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -534,8 +534,9 @@ out:
 
 #ifdef HAVE_LIBBFD_BUILDID_SUPPORT
 
-int filename__read_build_id(const char *filename, void *bf, size_t size)
+int filename__read_build_id(const char *filename, struct build_id *bid)
 {
+	size_t size = sizeof(bid->data);
 	int err = -1;
 	bfd *abfd;
 
@@ -551,9 +552,9 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
 	if (!abfd->build_id || abfd->build_id->size > size)
 		goto out_close;
 
-	memcpy(bf, abfd->build_id->data, abfd->build_id->size);
-	memset(bf + abfd->build_id->size, 0, size - abfd->build_id->size);
-	err = abfd->build_id->size;
+	memcpy(bid->data, abfd->build_id->data, abfd->build_id->size);
+	memset(bid->data + abfd->build_id->size, 0, size - abfd->build_id->size);
+	err = bid->size = abfd->build_id->size;
 
 out_close:
 	bfd_close(abfd);
@@ -562,8 +563,9 @@ out_close:
 
 #else // HAVE_LIBBFD_BUILDID_SUPPORT
 
-int filename__read_build_id(const char *filename, void *bf, size_t size)
+int filename__read_build_id(const char *filename, struct build_id *bid)
 {
+	size_t size = sizeof(bid->data);
 	int fd, err = -1;
 	Elf *elf;
 
@@ -580,7 +582,9 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
 		goto out_close;
 	}
 
-	err = elf_read_build_id(elf, bf, size);
+	err = elf_read_build_id(elf, bid->data, size);
+	if (err > 0)
+		bid->size = err;
 
 	elf_end(elf);
 out_close:
diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
index d6e99af263ec..5173331ee6e4 100644
--- a/tools/perf/util/symbol-minimal.c
+++ b/tools/perf/util/symbol-minimal.c
@@ -31,9 +31,10 @@ static bool check_need_swap(int file_endian)
 
 #define NT_GNU_BUILD_ID	3
 
-static int read_build_id(void *note_data, size_t note_len, void *bf,
-			 size_t size, bool need_swap)
+static int read_build_id(void *note_data, size_t note_len, struct build_id *bid,
+			 bool need_swap)
 {
+	size_t size = sizeof(bid->data);
 	struct {
 		u32 n_namesz;
 		u32 n_descsz;
@@ -63,8 +64,9 @@ static int read_build_id(void *note_data, size_t note_len, void *bf,
 		    nhdr->n_namesz == sizeof("GNU")) {
 			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
 				size_t sz = min(size, descsz);
-				memcpy(bf, ptr, sz);
-				memset(bf + sz, 0, size - sz);
+				memcpy(bid->data, ptr, sz);
+				memset(bid->data + sz, 0, size - sz);
+				bid->size = sz;
 				return 0;
 			}
 		}
@@ -84,7 +86,7 @@ int filename__read_debuglink(const char *filename __maybe_unused,
 /*
  * Just try PT_NOTE header otherwise fails
  */
-int filename__read_build_id(const char *filename, void *bf, size_t size)
+int filename__read_build_id(const char *filename, struct build_id *bid)
 {
 	FILE *fp;
 	int ret = -1;
@@ -156,9 +158,9 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
 			if (fread(buf, buf_size, 1, fp) != 1)
 				goto out_free;
 
-			ret = read_build_id(buf, buf_size, bf, size, need_swap);
+			ret = read_build_id(buf, buf_size, bid, need_swap);
 			if (ret == 0)
-				ret = size;
+				ret = bid->size;
 			break;
 		}
 	} else {
@@ -207,9 +209,9 @@ int filename__read_build_id(const char *filename, void *bf, size_t size)
 			if (fread(buf, buf_size, 1, fp) != 1)
 				goto out_free;
 
-			ret = read_build_id(buf, buf_size, bf, size, need_swap);
+			ret = read_build_id(buf, buf_size, bid, need_swap);
 			if (ret == 0)
-				ret = size;
+				ret = bid->size;
 			break;
 		}
 	}
@@ -220,8 +222,9 @@ out:
 	return ret;
 }
 
-int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
+int sysfs__read_build_id(const char *filename, void *build_id, size_t size __maybe_unused)
 {
+	struct build_id bid;
 	int fd;
 	int ret = -1;
 	struct stat stbuf;
@@ -243,7 +246,9 @@ int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
 	if (read(fd, buf, buf_size) != (ssize_t) buf_size)
 		goto out_free;
 
-	ret = read_build_id(buf, buf_size, build_id, size, false);
+	ret = read_build_id(buf, buf_size, &bid, false);
+	if (ret > 0)
+		memcpy(build_id, bid.data, bid.size);
 out_free:
 	free(buf);
 out:
@@ -339,16 +344,15 @@ int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
 		  struct symsrc *runtime_ss __maybe_unused,
 		  int kmodule __maybe_unused)
 {
-	unsigned char build_id[BUILD_ID_SIZE];
+	struct build_id bid;
 	int ret;
 
 	ret = fd__is_64_bit(ss->fd);
 	if (ret >= 0)
 		dso->is_64_bit = ret;
 
-	if (filename__read_build_id(ss->name, build_id, BUILD_ID_SIZE) > 0) {
-		dso__set_build_id(dso, build_id);
-	}
+	if (filename__read_build_id(ss->name, &bid) > 0)
+		dso__set_build_id(dso, bid.data);
 	return 0;
 }
 
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index c772c8c70db5..4c43bb959fee 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1755,7 +1755,7 @@ int dso__load(struct dso *dso, struct map *map)
 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
 	bool kmod;
 	bool perfmap;
-	unsigned char build_id[BUILD_ID_SIZE];
+	struct build_id bid;
 	struct nscookie nsc;
 	char newmapname[PATH_MAX];
 	const char *map_path = dso->long_name;
@@ -1817,8 +1817,8 @@ int dso__load(struct dso *dso, struct map *map)
 	if (!dso->has_build_id &&
 	    is_regular_file(dso->long_name)) {
 	    __symbol__join_symfs(name, PATH_MAX, dso->long_name);
-	    if (filename__read_build_id(name, build_id, BUILD_ID_SIZE) > 0)
-		dso__set_build_id(dso, build_id);
+		if (filename__read_build_id(name, &bid) > 0)
+			dso__set_build_id(dso, bid.data);
 	}
 
 	/*
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 11fe71f46d14..98908fa3f796 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -23,6 +23,7 @@ struct dso;
 struct map;
 struct maps;
 struct option;
+struct build_id;
 
 /*
  * libelf 0.8.x and earlier do not support ELF_C_READ_MMAP;
@@ -142,7 +143,7 @@ struct symbol *dso__next_symbol(struct symbol *sym);
 
 enum dso_type dso__type_fd(int fd);
 
-int filename__read_build_id(const char *filename, void *bf, size_t size);
+int filename__read_build_id(const char *filename, struct build_id *id);
 int sysfs__read_build_id(const char *filename, void *bf, size_t size);
 int modules__parse(const char *filename, void *arg,
 		   int (*process_module)(void *arg, const char *name,