1 files changed, 34 insertions, 9 deletions

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 3b8dfe603e50..a7f93f5a1ac8 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1151,9 +1151,20 @@ static void branch_stack__printf(struct perf_sample *sample, bool callstack)
 	struct branch_entry *entries = perf_sample__branch_entries(sample);
 	uint64_t i;
 
-	printf("%s: nr:%" PRIu64 "\n",
-		!callstack ? "... branch stack" : "... branch callstack",
-		sample->branch_stack->nr);
+	if (!callstack) {
+		printf("%s: nr:%" PRIu64 "\n", "... branch stack", sample->branch_stack->nr);
+	} else {
+		/* the reason of adding 1 to nr is because after expanding
+		 * branch stack it generates nr + 1 callstack records. e.g.,
+		 *         B()->C()
+		 *         A()->B()
+		 * the final callstack should be:
+		 *         C()
+		 *         B()
+		 *         A()
+		 */
+		printf("%s: nr:%" PRIu64 "\n", "... branch callstack", sample->branch_stack->nr+1);
+	}
 
 	for (i = 0; i < sample->branch_stack->nr; i++) {
 		struct branch_entry *e = &entries[i];
@@ -1169,8 +1180,13 @@ static void branch_stack__printf(struct perf_sample *sample, bool callstack)
 				(unsigned)e->flags.reserved,
 				e->flags.type ? branch_type_name(e->flags.type) : "");
 		} else {
-			printf("..... %2"PRIu64": %016" PRIx64 "\n",
-				i, i > 0 ? e->from : e->to);
+			if (i == 0) {
+				printf("..... %2"PRIu64": %016" PRIx64 "\n"
+				       "..... %2"PRIu64": %016" PRIx64 "\n",
+						i, e->to, i+1, e->from);
+			} else {
+				printf("..... %2"PRIu64": %016" PRIx64 "\n", i+1, e->from);
+			}
 		}
 	}
 }
@@ -2095,6 +2111,7 @@ prefetch_event(char *buf, u64 head, size_t mmap_size,
 	       bool needs_swap, union perf_event *error)
 {
 	union perf_event *event;
+	u16 event_size;
 
 	/*
 	 * Ensure we have enough space remaining to read
@@ -2107,15 +2124,23 @@ prefetch_event(char *buf, u64 head, size_t mmap_size,
 	if (needs_swap)
 		perf_event_header__bswap(&event->header);
 
-	if (head + event->header.size <= mmap_size)
+	event_size = event->header.size;
+	if (head + event_size <= mmap_size)
 		return event;
 
 	/* We're not fetching the event so swap back again */
 	if (needs_swap)
 		perf_event_header__bswap(&event->header);
 
-	pr_debug("%s: head=%#" PRIx64 " event->header_size=%#x, mmap_size=%#zx:"
-		 " fuzzed or compressed perf.data?\n",__func__, head, event->header.size, mmap_size);
+	/* Check if the event fits into the next mmapped buf. */
+	if (event_size <= mmap_size - head % page_size) {
+		/* Remap buf and fetch again. */
+		return NULL;
+	}
+
+	/* Invalid input. Event size should never exceed mmap_size. */
+	pr_debug("%s: head=%#" PRIx64 " event->header.size=%#x, mmap_size=%#zx:"
+		 " fuzzed or compressed perf.data?\n", __func__, head, event_size, mmap_size);
 
 	return error;
 }
@@ -2567,7 +2592,7 @@ int perf_session__process_events(struct perf_session *session)
 	if (perf_data__is_pipe(session->data))
 		return __perf_session__process_pipe_events(session);
 
-	if (perf_data__is_dir(session->data))
+	if (perf_data__is_dir(session->data) && session->data->dir.nr)
 		return __perf_session__process_dir_events(session);
 
 	return __perf_session__process_events(session);