Re: [PATCH] perf annotate: fix 's' on source line when disasm is empty

From: Arnaldo Carvalho de Melo
Date: Mon Jul 05 2021 - 13:52:58 EST


Em Mon, Jul 05, 2021 at 06:15:25PM +0200, Riccardo Mancini escreveu:
> 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: 6de249d66d2e

Next time please make the fixes be of this form:

Fixes: 6de249d66d2e7881 ("perf annotate: Allow 's' on source code lines")

⬢[acme@toolbox perf]$ git config core.abbrev 16
⬢[acme@toolbox perf]$ git config core.abbrev
16
⬢[acme@toolbox perf]$ head -2 ~/.gitconfig
[core]
abbrev = 16
⬢[acme@toolbox perf]$

Thanks, applied.

- Arnaldo

> Signed-off-by: Riccardo Mancini <rickyman7@xxxxxxxxx>
> ---
> tools/perf/ui/browsers/annotate.c | 4 ++--
> 1 file 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;
> }
> --
> 2.23.0
>

--

- Arnaldo