Re: [PATCH 1/1] perf map: Fix error return code in maps__clone()

[Leizhen (ThunderTown)]

On 2021/4/15 20:42, Arnaldo Carvalho de Melo wrote:
> Em Thu, Apr 15, 2021 at 05:27:44PM +0800, Zhen Lei escreveu:
>> Although 'err' has been initialized to -ENOMEM, but it will be reassigned
>> by the "err = unwind__prepare_access(...)" statement in the for loop. So
>> that, the value of 'err' is unknown when map__clone() failed.
> 
> You forgot to research and add this:
> 
> Fixes: 6c502584438bda63 ("perf unwind: Call unwind__prepare_access for forked 
> thread")
> 
> So that the sta...@kernel.org guys can pick this up automagically and
> apply this fix to the stable kernels.
> 
> I've added it.

OK, thank you very much.

> 
> Thanks, applied.
> 
> - Arnaldo
>  
>> Reported-by: Hulk Robot 
>> Signed-off-by: Zhen Lei 
>> ---
>>  tools/perf/util/map.c | 7 +--
>>  1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
>> index fbc40a2c17d4dca..8af693d9678cefe 100644
>> --- a/tools/perf/util/map.c
>> +++ b/tools/perf/util/map.c
>> @@ -840,15 +840,18 @@ int maps__fixup_overlappings(struct maps *maps, struct 
>> map *map, FILE *fp)
>>  int maps__clone(struct thread *thread, struct maps *parent)
>>  {
>>  struct maps *maps = thread->maps;
>> -int err = -ENOMEM;
>> +int err;
>>  struct map *map;
>>  
>>  down_read(>lock);
>>  
>>  maps__for_each_entry(parent, map) {
>>  struct map *new = map__clone(map);
>> -if (new == NULL)
>> +
>> +if (new == NULL) {
>> +err = -ENOMEM;
>>  goto out_unlock;
>> +}
>>  
>>  err = unwind__prepare_access(maps, new, NULL);
>>  if (err)
>> -- 
>> 2.26.0.106.g9fadedd
>>
>>
> 

Re: [PATCH 1/1] perf map: Fix error return code in maps__clone()

[Arnaldo Carvalho de Melo]

Em Thu, Apr 15, 2021 at 05:27:44PM +0800, Zhen Lei escreveu:
> Although 'err' has been initialized to -ENOMEM, but it will be reassigned
> by the "err = unwind__prepare_access(...)" statement in the for loop. So
> that, the value of 'err' is unknown when map__clone() failed.

You forgot to research and add this:

Fixes: 6c502584438bda63 ("perf unwind: Call unwind__prepare_access for forked 
thread")

So that the sta...@kernel.org guys can pick this up automagically and
apply this fix to the stable kernels.

I've added it.

Thanks, applied.

- Arnaldo
 
> Reported-by: Hulk Robot 
> Signed-off-by: Zhen Lei 
> ---
>  tools/perf/util/map.c | 7 +--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index fbc40a2c17d4dca..8af693d9678cefe 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -840,15 +840,18 @@ int maps__fixup_overlappings(struct maps *maps, struct 
> map *map, FILE *fp)
>  int maps__clone(struct thread *thread, struct maps *parent)
>  {
>   struct maps *maps = thread->maps;
> - int err = -ENOMEM;
> + int err;
>   struct map *map;
>  
>   down_read(>lock);
>  
>   maps__for_each_entry(parent, map) {
>   struct map *new = map__clone(map);
> - if (new == NULL)
> +
> + if (new == NULL) {
> + err = -ENOMEM;
>   goto out_unlock;
> + }
>  
>   err = unwind__prepare_access(maps, new, NULL);
>   if (err)
> -- 
> 2.26.0.106.g9fadedd
> 
> 

-- 

- Arnaldo

Re: [PATCH 1/1] perf map: Fix error return code in maps__clone()

[Jiri Olsa]

On Thu, Apr 15, 2021 at 05:27:44PM +0800, Zhen Lei wrote:
> Although 'err' has been initialized to -ENOMEM, but it will be reassigned
> by the "err = unwind__prepare_access(...)" statement in the for loop. So
> that, the value of 'err' is unknown when map__clone() failed.
> 
> Reported-by: Hulk Robot 
> Signed-off-by: Zhen Lei 

Acked-by: Jiri Olsa 

thanks,
jirka

> ---
>  tools/perf/util/map.c | 7 +--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index fbc40a2c17d4dca..8af693d9678cefe 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -840,15 +840,18 @@ int maps__fixup_overlappings(struct maps *maps, struct 
> map *map, FILE *fp)
>  int maps__clone(struct thread *thread, struct maps *parent)
>  {
>   struct maps *maps = thread->maps;
> - int err = -ENOMEM;
> + int err;
>   struct map *map;
>  
>   down_read(>lock);
>  
>   maps__for_each_entry(parent, map) {
>   struct map *new = map__clone(map);
> - if (new == NULL)
> +
> + if (new == NULL) {
> + err = -ENOMEM;
>   goto out_unlock;
> + }
>  
>   err = unwind__prepare_access(maps, new, NULL);
>   if (err)
> -- 
> 2.26.0.106.g9fadedd
> 
>