Re: [PATCH] perf expr: Fix memory leaks in metric bison

[Jiri Olsa]

On Tue, May 12, 2020 at 05:03:18PM -0700, Ian Rogers wrote:
> Add a destructor for strings to reclaim memory in the event of errors.
> Free the ID given for a lookup, it was previously strdup-ed in the lex
> code.
> 
> Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

thanks,
jirka

> ---
>  tools/perf/util/expr.y | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
> index 21e82a1e11a2..3b49b230b111 100644
> --- a/tools/perf/util/expr.y
> +++ b/tools/perf/util/expr.y
> @@ -27,6 +27,7 @@
>  %token EXPR_PARSE EXPR_OTHER EXPR_ERROR
>  %token <num> NUMBER
>  %token <str> ID
> +%destructor { free ($$); } <str>
>  %token MIN MAX IF ELSE SMT_ON
>  %left MIN MAX IF
>  %left '|'
> @@ -94,8 +95,10 @@ if_expr:
>  expr:	  NUMBER
>  	| ID			{ if (lookup_id(ctx, $1, &$$) < 0) {
>  					pr_debug("%s not found\n", $1);
> +					free($1);
>  					YYABORT;
>  				  }
> +				  free($1);
>  				}
>  	| expr '|' expr		{ $$ = (long)$1 | (long)$3; }
>  	| expr '&' expr		{ $$ = (long)$1 & (long)$3; }
> -- 
> 2.26.2.645.ge9eca65c58-goog
>