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authorTommi Rantala <tommi.t.rantala@nokia.com>2017-03-22 15:06:20 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-03-22 09:17:43 +0100
commitda1a974e27c7aea0b1859be3774ea7577f4ffd95 (patch)
tree62214a115726394e261a58632f617fdf9ad4f043 /tools
parent58f8d0c05a734ff4071db3f2cf444570ce69236f (diff)
perf buildid: Do not assume that readlink() returns a null terminated string
[ Upstream commit 5a2342111c68e623e27ee7ea3d0492d8dad6bda0 ] Valgrind was complaining: $ valgrind ./perf list >/dev/null ==11643== Memcheck, a memory error detector ==11643== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al. ==11643== Using Valgrind-3.12.0 and LibVEX; rerun with -h for copyright info ==11643== Command: ./perf list ==11643== ==11643== Conditional jump or move depends on uninitialised value(s) ==11643== at 0x4C30620: rindex (vg_replace_strmem.c:199) ==11643== by 0x49DAA9: build_id_cache__origname (build-id.c:198) ==11643== by 0x49E1C7: build_id_cache__valid_id (build-id.c:222) ==11643== by 0x49E1C7: build_id_cache__list_all (build-id.c:507) ==11643== by 0x4B9C8F: print_sdt_events (parse-events.c:2067) ==11643== by 0x4BB0B3: print_events (parse-events.c:2313) ==11643== by 0x439501: cmd_list (builtin-list.c:53) ==11643== by 0x497150: run_builtin (perf.c:359) ==11643== by 0x428CE0: handle_internal_command (perf.c:421) ==11643== by 0x428CE0: run_argv (perf.c:467) ==11643== by 0x428CE0: main (perf.c:614) [...] Additionally, a zero length result from readlink() is not very interesting. Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170322130624.21881-3-tommi.t.rantala@nokia.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/build-id.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index e528c40739cc..993ef2762508 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -182,13 +182,17 @@ char *build_id_cache__origname(const char *sbuild_id)
char buf[PATH_MAX];
char *ret = NULL, *p;
size_t offs = 5; /* == strlen("../..") */
+ ssize_t len;
linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
if (!linkname)
return NULL;
- if (readlink(linkname, buf, PATH_MAX) < 0)
+ len = readlink(linkname, buf, sizeof(buf) - 1);
+ if (len <= 0)
goto out;
+ buf[len] = '\0';
+
/* The link should be "../..<origpath>/<sbuild_id>" */
p = strrchr(buf, '/'); /* Cut off the "/<sbuild_id>" */
if (p && (p > buf + offs)) {