Re: [PATCH] perf annotate: pass filename to objdump via execl

[Jiri Olsa <jolsa@redhat.com>]

On Sun, Oct 14, 2018 at 11:18:03AM +0300, Ivan Krylov wrote:
> The symbol__disassemble() function uses shell to launch objdump and filter
> its output via grep. Passing filenames by interpolating them into the
> command line via "%s" may lead to problems if said filenames contain
> special characters.
> 
> Instead, pass the filename as a command line argument where it is not
> subject to any kind of interpretation, then use quoted shell
> interpolation to build the strings we need safely.
> 
> Signed-off-by: Ivan Krylov <krylov.r00t@gmail.com>

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka

> ---
>  tools/perf/util/annotate.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index 28cd6a174..4a870181e 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -1696,15 +1696,14 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
>  	err = asprintf(&command,
>  		 "%s %s%s --start-address=0x%016" PRIx64
>  		 " --stop-address=0x%016" PRIx64
> -		 " -l -d %s %s -C \"%s\" 2>/dev/null|grep -v \"%s:\"|expand",
> +		 " -l -d %s %s -C \"$1\" 2>/dev/null|grep -v \"$1:\"|expand",
>  		 opts->objdump_path ?: "objdump",
>  		 opts->disassembler_style ? "-M " : "",
>  		 opts->disassembler_style ?: "",
>  		 map__rip_2objdump(map, sym->start),
>  		 map__rip_2objdump(map, sym->end),
>  		 opts->show_asm_raw ? "" : "--no-show-raw",
> -		 opts->annotate_src ? "-S" : "",
> -		 symfs_filename, symfs_filename);
> +		 opts->annotate_src ? "-S" : "");
>  
>  	if (err < 0) {
>  		pr_err("Failure allocating memory for the command to run\n");
> @@ -1729,7 +1728,8 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
>  		close(stdout_fd[0]);
>  		dup2(stdout_fd[1], 1);
>  		close(stdout_fd[1]);
> -		execl("/bin/sh", "sh", "-c", command, NULL);
> +		execl("/bin/sh", "sh", "-c", command, "--", symfs_filename,
> +		      NULL);
>  		perror(command);
>  		exit(-1);
>  	}
> -- 
> 2.11.0