diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-11-13 22:06:29 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-11-28 20:21:01 +0300 |
| commit | 4a2233b194c77ae1ea8304cb7c00b551de4313f0 (patch) | |
| tree | 4f9940561f9fea24c14c34ab3d410580b4d299ff /tools | |
| parent | 501e5bbec3c19498fa520fd3ffd68bd907f31bf7 (diff) | |
| download | linux-4a2233b194c77ae1ea8304cb7c00b551de4313f0.tar.xz | |
perf machine: Guard against NULL in machine__exit()
A recent fix for 'perf trace' introduced a bug where
machine__exit(trace->host) could be called while trace->host was still
NULL, so make this more robust by guarding against NULL, just like
free() does.
The problem happens, for instance, when !root users try to run 'perf
trace':
[acme@jouet linux]$ trace
Error: No permissions to read /sys/kernel/debug/tracing/events/raw_syscalls/sys_(enter|exit)
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
perf: Segmentation fault
Obtained 7 stack frames.
[0x4f1b2e]
/lib64/libc.so.6(+0x3671f) [0x7f43a1dd971f]
[0x4f3fec]
[0x47468b]
[0x42a2db]
/lib64/libc.so.6(__libc_start_main+0xe9) [0x7f43a1dc3509]
[0x42a6c9]
Segmentation fault (core dumped)
[acme@jouet linux]$
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrei Vagin <avagin@openvz.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 33974a414ce2 ("perf trace: Call machine__exit() at exit")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/machine.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 6a8d03c3d9b7..270f3223c6df 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -172,6 +172,9 @@ void machine__exit(struct machine *machine) { int i; + if (machine == NULL) + return; + machine__destroy_kernel_maps(machine); map_groups__exit(&machine->kmaps); dsos__exit(&machine->dsos); |