perf tools: Move dereference after NULL test
In each case, if the NULL test on thread is needed, then the
dereference should be after the NULL test.
A simplified version of the semantic match that detects this
problem is as follows (http://coccinelle.lip6.fr/):
// <smpl>
@match exists@
expression x, E;
identifier fld;
@@
* x->fld
... when != \(x = E\|&x\)
* x == NULL
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
LKML-Reference: <Pine.LNX.4.64.0910170842500.9213@ask.diku.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index ce8459a..4c129ff 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -80,14 +80,14 @@
(void *)(long)ip,
(long long)period);
- dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
-
if (thread == NULL) {
eprintf("problem processing %d event, skipping it.\n",
event->header.type);
return -1;
}
+ dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
+
if (sample_type & PERF_SAMPLE_RAW) {
struct {
u32 size;