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

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

[Ivan Krylov]

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>
---
 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

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

[Jiri Olsa]

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

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

[Ivan Krylov]

On Sun, 14 Oct 2018 16:04:51 +0200
Jiri Olsa <jolsa@redhat.com> wrote:

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

Is there anything I could do to improve the patch? Should I wrap the
path to objdump executable in a similar way?

-- 
Best regards,
Ivan

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

[Arnaldo Carvalho de Melo]

Em Sun, Dec 30, 2018 at 05:37:43PM +0300, Ivan Krylov escreveu:
> On Sun, 14 Oct 2018 16:04:51 +0200
> Jiri Olsa <jolsa@redhat.com> wrote:
> 
> > Acked-by: Jiri Olsa <jolsa@kernel.org>
> 
> Is there anything I could do to improve the patch? Should I wrap the
> path to objdump executable in a similar way?

Nope, just fell thru the holidays crack, processing it now.

- Arnaldo

[tip:perf/urgent] perf annotate: Pass filename to objdump via execl

[tip-bot for Ivan Krylov]

Commit-ID:  442b4eb3af44906fcbb526d98c314b27f8c9acf3
Gitweb:     https://git.kernel.org/tip/442b4eb3af44906fcbb526d98c314b27f8c9acf3
Author:     Ivan Krylov <krylov.r00t@gmail.com>
AuthorDate: Sun, 14 Oct 2018 11:18:03 +0300
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 4 Jan 2019 12:54:49 -0300

perf annotate: Pass filename to objdump via execl

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>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20181014111803.5d83b806@Tarkus
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 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 ac9805e0bc76..70de8f6b3aee 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1723,15 +1723,14 @@ 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");
@@ -1756,7 +1755,8 @@ 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);
 	}