linux-kernel - [tip:perf/core] perf annotate: Fix a bug following symbolic link of a build-id file

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <tip-6ebd2547dd24daf95a21b2bc59931de8502afcc3@git.kernel.org>
Date:   Mon, 27 Mar 2017 22:55:22 -0700
From:   tip-bot for Taeung Song <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     treeze.taeung@...il.com, tglx@...utronix.de, wangnan0@...wei.com,
        acme@...hat.com, jolsa@...hat.com, mhiramat@...nel.org,
        peterz@...radead.org, mingo@...nel.org, namhyung@...nel.org,
        hpa@...or.com, linux-kernel@...r.kernel.org
Subject: [tip:perf/core] perf annotate: Fix a bug following symbolic link of
 a build-id file

Commit-ID:  6ebd2547dd24daf95a21b2bc59931de8502afcc3
Gitweb:     http://git.kernel.org/tip/6ebd2547dd24daf95a21b2bc59931de8502afcc3
Author:     Taeung Song <treeze.taeung@...il.com>
AuthorDate: Mon, 27 Mar 2017 16:10:36 +0900
Committer:  Arnaldo Carvalho de Melo <acme@...hat.com>
CommitDate: Mon, 27 Mar 2017 14:58:20 -0300

perf annotate: Fix a bug following symbolic link of a build-id file

It is wrong way to read link name from a build-id file.  Because a
build-id file is not anymore a symbolic link but build-id directory of
it is symbolic link, so fix it.

For example, if build-id file name gotten from
dso__build_id_filename() is as below,

  /root/.debug/.build-id/4f/75c7d197c951659d1c1b8b5fd49bcdf8f3f8b1/elf

To correctly read link name of build-id, use the build-id dir path that
is a symbolic link, instead of the above build-id file name like below.

  /root/.debug/.build-id/4f/75c7d197c951659d1c1b8b5fd49bcdf8f3f8b1

Signed-off-by: Taeung Song <treeze.taeung@...il.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Masami Hiramatsu <mhiramat@...nel.org>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Wang Nan <wangnan0@...wei.com>
Link: http://lkml.kernel.org/r/1490598638-13947-2-git-send-email-treeze.taeung@gmail.com
Fixes: 01412261d994 ("perf buildid-cache: Use path/to/bin/buildid/elf instead of path/to/bin/buildid")
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/util/annotate.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 3d0263e..6dc9148 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1307,6 +1307,7 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
 {
 	char linkname[PATH_MAX];
 	char *build_id_filename;
+	char *build_id_path = NULL;
 
 	if (dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
 	    !dso__is_kcore(dso))
@@ -1322,8 +1323,14 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
 		goto fallback;
 	}
 
+	build_id_path = strdup(filename);
+	if (!build_id_path)
+		return -1;
+
+	dirname(build_id_path);
+
 	if (dso__is_kcore(dso) ||
-	    readlink(filename, linkname, sizeof(linkname)) < 0 ||
+	    readlink(build_id_path, linkname, sizeof(linkname)) < 0 ||
 	    strstr(linkname, DSO__NAME_KALLSYMS) ||
 	    access(filename, R_OK)) {
 fallback:
@@ -1335,6 +1342,7 @@ fallback:
 		__symbol__join_symfs(filename, filename_size, dso->long_name);
 	}
 
+	free(build_id_path);
 	return 0;
 }