[PATCH v3 45/57] perf: Simplify perf_event_parse_addr_filter()

[Kees Cook]

On Mon, Jun 12, 2023 at 11:07:58AM +0200, Peter Zijlstra wrote:
> XXX this code needs a cleanup

:)

> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz at infradead.org>
> ---
>  kernel/events/core.c |   56 ++++++++++++++++++++-------------------------------
>  1 file changed, 22 insertions(+), 34 deletions(-)
> 
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -10495,6 +10495,8 @@ static void free_filters_list(struct lis
>  	}
>  }
>  
> +DEFINE_FREE(filter_list, struct list_head *, if (_T) free_filters_list(_T))
> +
>  /*
>   * Free existing address filters and optionally install new ones
>   */
> @@ -10658,13 +10660,15 @@ perf_event_parse_addr_filter(struct perf
>  			     struct list_head *filters)
>  {
>  	struct perf_addr_filter *filter = NULL;
> -	char *start, *orig, *filename = NULL;
>  	substring_t args[MAX_OPT_ARGS];
>  	int state = IF_STATE_ACTION, token;
>  	unsigned int kernel = 0;
> -	int ret = -EINVAL;
> +	char *start;
> +	int ret;
>  
> -	orig = fstr = kstrdup(fstr, GFP_KERNEL);
> +	struct list_head *fguard __free(filter_list) = filters;
> +	char *filename __free(kfree) = NULL;
> +	char *orig __free(kfree) = fstr = kstrdup(fstr, GFP_KERNEL);

Ah! I see a kfree users. Sorry for the noise. :)

-- 
Kees Cook