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| author | Taeung Song <treeze.taeung@gmail.com> | 2016-02-26 00:12:59 +0900 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-02-25 12:54:20 -0300 |
| commit | 8579aca3f9a8f890d6d94ccaed7cf5fd54a0c3bd (patch) | |
| tree | f97e340ce9396e4281b2afd7396b88e970e414e9 /tools | |
| parent | bb109acc4adeae425147ca87b84d312ea40f24f1 (diff) | |
| download | linux-8579aca3f9a8f890d6d94ccaed7cf5fd54a0c3bd.tar.gz linux-8579aca3f9a8f890d6d94ccaed7cf5fd54a0c3bd.tar.bz2 linux-8579aca3f9a8f890d6d94ccaed7cf5fd54a0c3bd.zip | |
perf script: Exception handling when the print fmt is empty
After collecting samples for events 'syscalls:', perf-script with python
script doesn't occasionally work generating a segmentation fault.
The reason is that the print fmt is empty and a value of
event->print_fmt.args is NULL, so dereferencing the null pointer results
in a segmentation fault i.e.:
# perf record -e syscalls:*
# perf script -g python
# perf script -s perf-script.py
in trace_begin
syscalls__sys_enter_brk 3 79841.832099154 3777 test.sh syscall_nr=12, brk=0
... (omitted) ...
Segmentation fault (core dumped)
For example, a format of sys_enter_getuid() hasn't
print fmt as below.
# cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_getuid/format
name: sys_enter_getuid
ID: 188
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:int syscall_nr; offset:8; size:4; signed:1;
print fmt: ""
So add exception handling to avoid this problem.
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1456413179-12331-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/scripting-engines/trace-event-perl.c | 3 | ||||
| -rw-r--r-- | tools/perf/util/scripting-engines/trace-event-python.c | 3 |
2 files changed, 6 insertions, 0 deletions
diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c index 544509c159ce..b3aabc0d4eb0 100644 --- a/tools/perf/util/scripting-engines/trace-event-perl.c +++ b/tools/perf/util/scripting-engines/trace-event-perl.c @@ -187,6 +187,9 @@ static void define_event_symbols(struct event_format *event, const char *ev_name, struct print_arg *args) { + if (args == NULL) + return; + switch (args->type) { case PRINT_NULL: break; diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c index d72fafc1c800..309d90fa7698 100644 --- a/tools/perf/util/scripting-engines/trace-event-python.c +++ b/tools/perf/util/scripting-engines/trace-event-python.c @@ -205,6 +205,9 @@ static void define_event_symbols(struct event_format *event, const char *ev_name, struct print_arg *args) { + if (args == NULL) + return; + switch (args->type) { case PRINT_NULL: break; |