From: James Clark <james.clark@linaro.org>
Date: Mon, 20 Apr 2026 11:52:17 +0000 (+0100)
Subject: perf annotate: Fix crashes on empty annotate windows
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=74802634e4a7e556429417963a8cbda27dd8b4b3;p=thirdparty%2Fkernel%2Flinux.git

perf annotate: Fix crashes on empty annotate windows

Annotate can open with an empty window if the disassembly tool fails.
After the linked change, the TUI started assuming there was a current
annotation line and could assert or segfault in the seek, refresh, and
source-toggle paths.

Handle empty annotate windows explicitly: set the asm entry count before
resetting the browser, return early when refreshing an empty list, and
ignore source line toggle when there is no current annotation line.

Fixes the following when opening an annotation:

  perf: ui/browser.c:125: ui_browser__list_head_seek: Assertion `pos != NULL' failed.
  Aborted

Fixes: e201757f7a0a901e ("perf annotate: Fix source code annotate with objdump")
Assisted-by: GitHub Copilot:GPT-5.4
Signed-off-by: James Clark <james.clark@linaro.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/ui/browser.c b/tools/perf/ui/browser.c
index dc88427b4ae5a..321187b204d38 100644
--- a/tools/perf/ui/browser.c
+++ b/tools/perf/ui/browser.c
@@ -513,6 +513,9 @@ unsigned int ui_browser__list_head_refresh(struct ui_browser *browser)
 	struct list_head *head = browser->entries;
 	int row = 0;
 
+	if (browser->nr_entries == 0)
+		return 0;
+
 	if (browser->top == NULL || browser->top == browser->entries)
                 browser->top = ui_browser__list_head_filter_entries(browser, head->next);
 
diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
index e220c4dfc8819..97ae4c86bebbe 100644
--- a/tools/perf/ui/browsers/annotate.c
+++ b/tools/perf/ui/browsers/annotate.c
@@ -449,6 +449,9 @@ static bool annotate_browser__toggle_source(struct annotate_browser *browser,
 	struct annotation_line *al;
 	off_t offset = browser->b.index - browser->b.top_idx;
 
+	if (browser->b.nr_entries == 0)
+		return false;
+
 	browser->b.seek(&browser->b, offset, SEEK_CUR);
 	al = list_entry(browser->b.top, struct annotation_line, node);
 
@@ -542,8 +545,8 @@ static void annotate_browser__show_full_location(struct ui_browser *browser)
 static void ui_browser__init_asm_mode(struct ui_browser *browser)
 {
 	struct annotation *notes = browser__annotation(browser);
-	ui_browser__reset_index(browser);
 	browser->nr_entries = notes->src->nr_asm_entries;
+	ui_browser__reset_index(browser);
 }
 
 static int sym_title(struct symbol *sym, struct map *map, char *title,