perf annotate: Fix crashes on empty annotate windows

[PATCH] perf annotate: Fix crashes on empty annotate windows

Posted by James Clark 1 month, 3 weeks ago

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: e201757f7a0a ("perf annotate: Fix source code annotate with objdump")
Assisted-by: GitHub Copilot:GPT-5.4
Signed-off-by: James Clark <james.clark@linaro.org>
---
 tools/perf/ui/browser.c           | 3 +++
 tools/perf/ui/browsers/annotate.c | 5 ++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/perf/ui/browser.c b/tools/perf/ui/browser.c
index dc88427b4ae5..321187b204d3 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 ea17e6d29a7e..0261cd922183 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,

---
base-commit: 841dbf4871c57ce2da18c4ea7ffac5487d0eda16
change-id: 20260417-james-perf-annotate-assert-20f520eeb35b

Best regards,
-- 
James Clark <james.clark@linaro.org>

Re: [PATCH] perf annotate: Fix crashes on empty annotate windows

Posted by Namhyung Kim 1 month, 3 weeks ago

On Mon, Apr 20, 2026 at 12:52:17PM +0100, James Clark wrote:
> 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: e201757f7a0a ("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>

Thanks,
Namhyung

> ---
>  tools/perf/ui/browser.c           | 3 +++
>  tools/perf/ui/browsers/annotate.c | 5 ++++-
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/ui/browser.c b/tools/perf/ui/browser.c
> index dc88427b4ae5..321187b204d3 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 ea17e6d29a7e..0261cd922183 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,
> 
> ---
> base-commit: 841dbf4871c57ce2da18c4ea7ffac5487d0eda16
> change-id: 20260417-james-perf-annotate-assert-20f520eeb35b
> 
> Best regards,
> -- 
> James Clark <james.clark@linaro.org>
>

Re: [PATCH] perf annotate: Fix crashes on empty annotate windows

Posted by Arnaldo Carvalho de Melo 1 week, 4 days ago

On Tue, Apr 21, 2026 at 07:15:45PM -0700, Namhyung Kim wrote:
> On Mon, Apr 20, 2026 at 12:52:17PM +0100, James Clark wrote:
> > 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: e201757f7a0a ("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>

Thanks, applied to perf-tools-next, for v7.2.

- Arnaldo

Re: [PATCH] perf annotate: Fix crashes on empty annotate windows

Posted by James Clark 2 weeks, 4 days ago


On 22/04/2026 3:15 am, Namhyung Kim wrote:
> On Mon, Apr 20, 2026 at 12:52:17PM +0100, James Clark wrote:
>> 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: e201757f7a0a ("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>
> 
> Thanks,
> Namhyung
> 

Ping, I think this one might have been missed.

Thanks
James

>> ---
>>   tools/perf/ui/browser.c           | 3 +++
>>   tools/perf/ui/browsers/annotate.c | 5 ++++-
>>   2 files changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/perf/ui/browser.c b/tools/perf/ui/browser.c
>> index dc88427b4ae5..321187b204d3 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 ea17e6d29a7e..0261cd922183 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,
>>
>> ---
>> base-commit: 841dbf4871c57ce2da18c4ea7ffac5487d0eda16
>> change-id: 20260417-james-perf-annotate-assert-20f520eeb35b
>>
>> Best regards,
>> -- 
>> James Clark <james.clark@linaro.org>
>>