4 files changed, 59 insertions, 24 deletions

diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 34c6fcb82d9..1f771ce3a95 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -69,6 +69,13 @@ struct build_id_event {
 	char			 filename[];
 };
 
+struct build_id_list {
+	struct build_id_event	event;
+	struct list_head	list;
+	const char		*dso_name;
+	int			len;
+};
+
 typedef union event_union {
 	struct perf_event_header	header;
 	struct ip_event			ip;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index a4d0bbef9a4..2f702c23f71 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -174,29 +174,18 @@ static void do_write(int fd, void *buf, size_t size)
 	}
 }
 
-static bool write_buildid_table(int fd)
+static void write_buildid_table(int fd, struct list_head *id_head)
 {
-	struct dso *pos;
-	bool have_buildid = false;
-
-	list_for_each_entry(pos, &dsos, node) {
-		struct build_id_event b;
-		size_t len;
-
-		if (filename__read_build_id(pos->long_name,
-					    &b.build_id,
-					    sizeof(b.build_id)) < 0)
-			continue;
-		have_buildid = true;
-		memset(&b.header, 0, sizeof(b.header));
-		len = strlen(pos->long_name) + 1;
-		len = ALIGN(len, 64);
-		b.header.size = sizeof(b) + len;
-		do_write(fd, &b, sizeof(b));
-		do_write(fd, pos->long_name, len);
-	}
+	struct build_id_list *iter, *next;
+
+	list_for_each_entry_safe(iter, next, id_head, list) {
+		struct build_id_event *b = &iter->event;
 
-	return have_buildid;
+		do_write(fd, b, sizeof(*b));
+		do_write(fd, (void *)iter->dso_name, iter->len);
+		list_del(&iter->list);
+		free(iter);
+	}
 }
 
 static void
@@ -226,10 +215,14 @@ perf_header__adds_write(struct perf_header *self, int fd, bool at_exit)
 	}
 
 	if (at_exit) {
-		lseek(fd, self->data_offset + self->data_size, SEEK_SET);
-		if (write_buildid_table(fd))
+		LIST_HEAD(id_list);
+
+		if (fetch_build_id_table(&id_list)) {
+			lseek(fd, self->data_offset + self->data_size, SEEK_SET);
 			perf_header__set_feat(self, HEADER_BUILD_ID);
-		lseek(fd, cur_offset, SEEK_SET);
+			write_buildid_table(fd, &id_list);
+			lseek(fd, cur_offset, SEEK_SET);
+		}
 	}
 };
 
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index a2e95ce1f22..9c286db6200 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -851,6 +851,40 @@ out_close:
 	return err;
 }
 
+bool fetch_build_id_table(struct list_head *head)
+{
+	bool have_buildid = false;
+	struct dso *pos;
+
+	list_for_each_entry(pos, &dsos, node) {
+		struct build_id_list *new;
+		struct build_id_event b;
+		size_t len;
+
+		if (filename__read_build_id(pos->long_name,
+					    &b.build_id,
+					    sizeof(b.build_id)) < 0)
+			continue;
+		have_buildid = true;
+		memset(&b.header, 0, sizeof(b.header));
+		len = strlen(pos->long_name) + 1;
+		len = ALIGN(len, 64);
+		b.header.size = sizeof(b) + len;
+
+		new = malloc(sizeof(*new));
+		if (!new)
+			die("No memory\n");
+
+		memcpy(&new->event, &b, sizeof(b));
+		new->dso_name = pos->long_name;
+		new->len = len;
+
+		list_add_tail(&new->list, head);
+	}
+
+	return have_buildid;
+}
+
 int filename__read_build_id(const char *filename, void *bf, size_t size)
 {
 	int fd, err = -1;
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index f8c1899af48..0a34a5493f1 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -86,6 +86,7 @@ char dso__symtab_origin(const struct dso *self);
 void dso__set_build_id(struct dso *self, void *build_id);
 
 int filename__read_build_id(const char *filename, void *bf, size_t size);
+bool fetch_build_id_table(struct list_head *head);
 int build_id__sprintf(u8 *self, int len, char *bf);
 
 int load_kernel(symbol_filter_t filter);