perf annotate: Fix 's' on source line when disasm is empty

If the disasm is empty, 's' should fail. Instead it seemingly works,
hiding the empty lines and causing an assertion error on the next time
annotate is called (from within perf report).

The problem is caused by a buffer overflow, caused by a wrong exit
condition in annotate_browser__find_next_asm_line, which checks
browser->b.top instead of browser->b.entries.

This patch fixes the issue, making annotate_browser__toggle_source
fail if the disasm is empty (nothing happens to the user).

Fixes: 6de249d66d2e7881 ("perf annotate: Allow 's' on source code lines")
Signed-off-by: Riccardo Mancini <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Martin Liška <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
index f5509a958e38..5812a2214cc1 100644
--- a/tools/perf/ui/browsers/annotate.c
+++ b/tools/perf/ui/browsers/annotate.c
@@ -350,14 +350,14 @@ static struct annotation_line *annotate_browser__find_next_asm_line(
 	struct annotation_line *it = al;
 
 	/* find next asm line */
-	list_for_each_entry_continue(it, browser->b.top, node) {
+	list_for_each_entry_continue(it, browser->b.entries, node) {
 		if (it->idx_asm >= 0)
 			return it;
 	}
 
 	/* no asm line found forwards, try backwards */
 	it = al;
-	list_for_each_entry_continue_reverse(it, browser->b.top, node) {
+	list_for_each_entry_continue_reverse(it, browser->b.entries, node) {
 		if (it->idx_asm >= 0)
 			return it;
 	}