Re: [PATCH 3/3] perf disasm: Fix not cleaning up disasm_line in symbol__disassemble_raw()

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Oct 14, 2024 at 07:42:48PM +0800, Li Huafei wrote:
> In symbol__disassemble_raw(), the created disasm_line should be
> discarded before returning an error.

But other error paths don't need to free the disasm_line because they
failed before creating one.  I think the simpler fix is to break the
loop when it fails on disasm_line__new().

Thanks,
Namhyung

> 
> Fixes: 0b971e6bf1c3 ("perf annotate: Add support to capture and parse raw instruction in powerpc using dso__data_read_offset utility")
> Signed-off-by: Li Huafei <lihuafei1@huawei.com>
> ---
>  tools/perf/util/disasm.c | 26 ++++++++++++--------------
>  1 file changed, 12 insertions(+), 14 deletions(-)
> 
> diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
> index 40d99f4d5cc7..4e5becd5eca6 100644
> --- a/tools/perf/util/disasm.c
> +++ b/tools/perf/util/disasm.c
> @@ -1774,25 +1774,23 @@ static int symbol__disassemble_raw(char *filename, struct symbol *sym,
>  		offset += 4;
>  	}
>  
> -	/* It failed in the middle */
> -	if (offset != len) {
> -		struct list_head *list = &notes->src->source;
> -
> -		/* Discard all lines and fallback to objdump */
> -		while (!list_empty(list)) {
> -			dl = list_first_entry(list, struct disasm_line, al.node);
> -
> -			list_del_init(&dl->al.node);
> -			disasm_line__free(dl);
> -		}
> -		count = -1;
> -	}
> -
>  out:
>  	free(buf);
>  	return count < 0 ? count : 0;
>  
>  err:
> +	if (!list_empty(&notes->src->source)) {
> +		struct disasm_line *tmp;
> +
> +		/*
> +		 * It probably failed in the middle of the above loop.
> +		 * Release any resources it might add.
> +		 */
> +		list_for_each_entry_safe(dl, tmp, &notes->src->source, al.node) {
> +			list_del(&dl->al.node);
> +			disasm_line__free(dl);
> +		}
> +	}
>  	count = -1;
>  	goto out;
>  }
> -- 
> 2.25.1
>