Re: [PATCH v4 1/2] perf tools annotate: fix a crash when annotate the same symbol with 's' and 'T'

[James Clark <james.clark@linaro.org>]

On 20/10/2025 8:30 am, Tianyou Li wrote:
> When perf report with annotation for a symbol, press 's' and 'T', then exit
> the annotate browser. Once annotate the same symbol, the annotate browser
> will crash.
> 
> The browser.arch was required to be correctly updated when data type
> feature was enabled by 'T'. Usually it was initialized by symbol__annotate2
> function. If a symbol has already been correctly annotated at the first
> time, it should not call the symbol__annotate2 function again, thus the
> browser.arch will not get initialized. Then at the second time to show the
> annotate browser, the data type needs to be displayed but the browser.arch
> is empty.
> 
> Stack trace as below:
> 
> Perf: Segmentation fault
> -------- backtrace --------
>      #0 0x55d365 in ui__signal_backtrace setup.c:0
>      #1 0x7f5ff1a3e930 in __restore_rt libc.so.6[3e930]
>      #2 0x570f08 in arch__is perf[570f08]
>      #3 0x562186 in annotate_get_insn_location perf[562186]
>      #4 0x562626 in __hist_entry__get_data_type annotate.c:0
>      #5 0x56476d in annotation_line__write perf[56476d]
>      #6 0x54e2db in annotate_browser__write annotate.c:0
>      #7 0x54d061 in ui_browser__list_head_refresh perf[54d061]
>      #8 0x54dc9e in annotate_browser__refresh annotate.c:0
>      #9 0x54c03d in __ui_browser__refresh browser.c:0
>      #10 0x54ccf8 in ui_browser__run perf[54ccf8]
>      #11 0x54eb92 in __hist_entry__tui_annotate perf[54eb92]
>      #12 0x552293 in do_annotate hists.c:0
>      #13 0x55941c in evsel__hists_browse hists.c:0
>      #14 0x55b00f in evlist__tui_browse_hists perf[55b00f]
>      #15 0x42ff02 in cmd_report perf[42ff02]
>      #16 0x494008 in run_builtin perf.c:0
>      #17 0x494305 in handle_internal_command perf.c:0
>      #18 0x410547 in main perf[410547]
>      #19 0x7f5ff1a295d0 in __libc_start_call_main libc.so.6[295d0]
>      #20 0x7f5ff1a29680 in __libc_start_main@@GLIBC_2.34 libc.so.6[29680]
>      #21 0x410b75 in _start perf[410b75]
> 
> Fixes: 1d4374afd000 ("perf annotate: Add 'T' hot key to toggle data type display")
> Reviewed-by: James Clark <james.clark@linaro.org>
> Tested-by: Namhyung Kim <namhyung@kernel.org>
> Signed-off-by: Tianyou Li <tianyou.li@intel.com>
> ---
>   tools/perf/ui/browsers/annotate.c | 23 +++++++++++++++++++----
>   tools/perf/util/annotate.c        |  2 +-
>   tools/perf/util/annotate.h        |  2 ++
>   3 files changed, 22 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
> index 112fe6ad112e..3a81912279ad 100644
> --- a/tools/perf/ui/browsers/annotate.c
> +++ b/tools/perf/ui/browsers/annotate.c
> @@ -862,6 +862,18 @@ static s64 annotate_browser__curr_hot_offset(struct annotate_browser *browser)
>   	return al ? al->offset : 0;
>   }
>   
> +static void annotate_browser__symbol_annotate_error(struct annotate_browser *browser, int err)
> +{
> +	struct map_symbol *ms = browser->b.priv;
> +	struct symbol *sym = ms->sym;
> +	struct dso *dso = map__dso(ms->map);
> +	char msg[BUFSIZ];
> +
> +	dso__set_annotate_warned(dso);
> +	symbol__strerror_disassemble(ms, err, msg, sizeof(msg));
> +	ui__error("Couldn't annotate %s:\n%s", sym->name, msg);
> +}
> +
>   static int annotate_browser__run(struct annotate_browser *browser,
>   				 struct evsel *evsel,
>   				 struct hist_browser_timer *hbt)
> @@ -1175,10 +1187,7 @@ int __hist_entry__tui_annotate(struct hist_entry *he, struct map_symbol *ms,
>   	if (not_annotated || !sym->annotate2) {
>   		err = symbol__annotate2(ms, evsel, &browser.arch);
>   		if (err) {
> -			char msg[BUFSIZ];
> -			dso__set_annotate_warned(dso);
> -			symbol__strerror_disassemble(ms, err, msg, sizeof(msg));
> -			ui__error("Couldn't annotate %s:\n%s", sym->name, msg);
> +			annotate_browser__symbol_annotate_error(&browser, err);
>   			return -1;
>   		}
>   
> @@ -1187,6 +1196,12 @@ int __hist_entry__tui_annotate(struct hist_entry *he, struct map_symbol *ms,
>   			if (!annotation__has_source(notes))
>   				ui__warning("Annotation has no source code.");
>   		}
> +	} else {
> +		err = evsel__get_arch(evsel, &browser.arch);
> +		if (err) {
> +			annotate_browser__symbol_annotate_error(&browser, err);
> +			return -1;
> +		}
>   	}
>   
>   	/* Copy necessary information when it's called from perf top */
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index a2e34f149a07..39d6594850f1 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -980,7 +980,7 @@ void symbol__calc_percent(struct symbol *sym, struct evsel *evsel)
>   	annotation__calc_percent(notes, evsel, symbol__size(sym));
>   }
>   
> -static int evsel__get_arch(struct evsel *evsel, struct arch **parch)
> +int evsel__get_arch(struct evsel *evsel, struct arch **parch)
>   {
>   	struct perf_env *env = evsel__env(evsel);
>   	const char *arch_name = perf_env__arch(env);
> diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
> index eaf6c8aa7f47..d4990bff29a7 100644
> --- a/tools/perf/util/annotate.h
> +++ b/tools/perf/util/annotate.h
> @@ -585,4 +585,6 @@ void debuginfo_cache__delete(void);
>   int annotation_br_cntr_entry(char **str, int br_cntr_nr, u64 *br_cntr,
>   			     int num_aggr, struct evsel *evsel);
>   int annotation_br_cntr_abbr_list(char **str, struct evsel *evsel, bool header);
> +
> +int evsel__get_arch(struct evsel *evsel, struct arch **parch);
>   #endif	/* __PERF_ANNOTATE_H */

Reviewed-by: James Clark <james.clark@linaro.org>