perf probe: Fix coredump introduced by probe module option

perf will coredump if the user doesn't give the "-m" option in probe
command, this patch fixes it.

[root@localhost perf]# ./perf probe --add='PROBE'
Segmentation fault (core dumped)

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1311602888-2389-1-git-send-email-bookjovi@gmail.com
Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index b82d54fa2c56..1c7bfa5fe0a8 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1820,11 +1820,15 @@ static int convert_to_probe_trace_events(struct perf_probe_event *pev,
                 ret = -ENOMEM;
                 goto error;
         }
-        tev->point.module = strdup(module);
-        if (tev->point.module == NULL) {
-                ret = -ENOMEM;
-                goto error;
+
+        if (module) {
+                tev->point.module = strdup(module);
+                if (tev->point.module == NULL) {
+                        ret = -ENOMEM;
+                        goto error;
+                }
         }
+
         tev->point.offset = pev->point.offset;
         tev->point.retprobe = pev->point.retprobe;
         tev->nargs = pev->nargs;