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

[Arnaldo Carvalho de Melo <acme@kernel.org>]

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 stable@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 <hulkci@huawei.com>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> ---
>  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(&parent->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