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 <[email protected]>

---
 tools/perf/util/annotate.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

tools/perf/util/annotate.c +4 -4

index 28cd6a174..4a870181e 100644
@@ -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);
 	}

Signature · 1 line

2.11.0

Acked-by Jiri Olsa <[email protected]>

Quoted 1 line · On Sun, 14 Oct 2018 16:04:51 +0200 Jiri Olsa <[email protected]> wrote:

Acked-by Jiri Olsa <[email protected]>

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