diff options
| author | Wang Nan <wangnan0@huawei.com> | 2016-06-07 03:54:38 (GMT) |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-06-07 13:49:41 (GMT) |
| commit | c58c49ac630979a285d574b3f72a528209515fb3 (patch) | |
| tree | 67f46c71f137fd68759b815c9acf1d946e5eec29 | |
| parent | edb13ed47c1a196eca4b669b7c20d26b27260813 (diff) | |
| download | linux-c58c49ac630979a285d574b3f72a528209515fb3.tar.xz | |
perf tools: Fix crash in build_id_cache__kallsyms_path()
build_id_cache__kallsyms_path() accepts a string buffer but also allocs
a buffer using asnprintf. Unfortunately, the its only user passes it a
stack-allocated buffer. Freeing it causes crashes like this:
$ perf script
*** Error in `/home/wangnan/perf': free(): invalid pointer: 0x00007fffffff9630 ***
======= Backtrace: =========
lib64/libc.so.6(+0x6eeef)[0x7ffff5dbaeef]
lib64/libc.so.6(+0x78cae)[0x7ffff5dc4cae]
lib64/libc.so.6(+0x79987)[0x7ffff5dc5987]
/home/w00229757/perf(build_id_cache__kallsyms_path+0x6b)[0x49681b]
/home/w00229757/perf[0x4bdd40]
/home/w00229757/perf(dso__load+0xa3a)[0x4c048a]
/home/w00229757/perf(map__load+0x6f)[0x4d561f]
/home/w00229757/perf(thread__find_addr_map+0x235)[0x49e935]
/home/w00229757/perf(machine__resolve+0x7d)[0x49ec6d]
/home/w00229757/perf[0x4555a8]
/home/w00229757/perf[0x4d9507]
/home/w00229757/perf[0x4d9e80]
/home/w00229757/perf(ordered_events__flush+0x354)[0x4dd444]
/home/w00229757/perf(perf_session__process_events+0x3d0)[0x4dc140]
/home/w00229757/perf(cmd_script+0x12b0)[0x4592e0]
/home/w00229757/perf[0x4911f1]
/home/w00229757/perf(main+0x68f)[0x4352ef]
/lib64/libc.so.6(__libc_start_main+0xf5)[0x7ffff5d6dbd5]
/home/w00229757/perf[0x435415]
======= Memory map: ========
This patch simplifies build_id_cache__kallsyms_path(), not even
considering allocating a string buffer, so never frees anything. Its
caller should manage memory allocation.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Fixes: 01412261d994 ("perf buildid-cache: Use path/to/bin/buildid/elf instead of path/to/bin/buildid")
Link: http://lkml.kernel.org/r/1465271678-7392-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/build-id.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index 67f986c..20aef90 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -147,20 +147,17 @@ static int asnprintf(char **strp, size_t size, const char *fmt, ...) char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf, size_t size) { - bool is_alloc = !!bf; bool retry_old = true; - asnprintf(&bf, size, "%s/%s/%s/kallsyms", - buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); + snprintf(bf, size, "%s/%s/%s/kallsyms", + buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); retry: if (!access(bf, F_OK)) return bf; - if (is_alloc) - free(bf); if (retry_old) { /* Try old style kallsyms cache */ - asnprintf(&bf, size, "%s/%s/%s", - buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); + snprintf(bf, size, "%s/%s/%s", + buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); retry_old = false; goto retry; } |