perf tools: Fixup mmap event consumption

The tail position of the event buffer should only be modified after
actually use that event.

If not the event buffer could be invalid before use, and segment fault
occurs when invoking perf top -G.

Signed-off-by: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
Cc: David Ahern <dsahern@gmail.com>
Cc: Zhouyi Zhou <yizhouzhou@ict.ac.cn>
Link: http://lkml.kernel.org/r/1382600613-32177-1-git-send-email-zhouzhouyi@gmail.com
[ Simplified the logic using exit gotos and renamed write_tail method to mmap_consume ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

8 files changed, 17 insertions, 6 deletions

diff --git a/tools/perf/tests/code-reading.c b/tools/perf/tests/code-reading.c
index 6fb781d..e3fedfa 100644
--- a/tools/perf/tests/code-reading.c
+++ b/tools/perf/tests/code-reading.c
@@ -290,6 +290,7 @@ static int process_events(struct machine *machine, struct perf_evlist *evlist,
 	for (i = 0; i < evlist->nr_mmaps; i++) {
 		while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
 			ret = process_event(machine, evlist, event, state);
+			perf_evlist__mmap_consume(evlist, i);
 			if (ret < 0)
 				return ret;
 		}
diff --git a/tools/perf/tests/keep-tracking.c b/tools/perf/tests/keep-tracking.c
index d444ea2..376c356 100644
--- a/tools/perf/tests/keep-tracking.c
+++ b/tools/perf/tests/keep-tracking.c
@@ -36,6 +36,7 @@ static int find_comm(struct perf_evlist *evlist, const char *comm)
 			    (pid_t)event->comm.tid == getpid() &&
 			    strcmp(event->comm.comm, comm) == 0)
 				found += 1;
+			perf_evlist__mmap_consume(evlist, i);
 		}
 	}
 	return found;
diff --git a/tools/perf/tests/mmap-basic.c b/tools/perf/tests/mmap-basic.c
index c4185b9..a7232c2 100644
--- a/tools/perf/tests/mmap-basic.c
+++ b/tools/perf/tests/mmap-basic.c
@@ -122,6 +122,7 @@ int test__basic_mmap(void)
 			goto out_munmap;
 		}
 		nr_events[evsel->idx]++;
+		perf_evlist__mmap_consume(evlist, 0);
 	}
 
 	err = 0;
diff --git a/tools/perf/tests/open-syscall-tp-fields.c b/tools/perf/tests/open-syscall-tp-fields.c
index fc5b9fc..524b221 100644
--- a/tools/perf/tests/open-syscall-tp-fields.c
+++ b/tools/perf/tests/open-syscall-tp-fields.c
@@ -77,8 +77,10 @@ int test__syscall_open_tp_fields(void)
 
 				++nr_events;
 
-				if (type != PERF_RECORD_SAMPLE)
+				if (type != PERF_RECORD_SAMPLE) {
+					perf_evlist__mmap_consume(evlist, i);
 					continue;
+				}
 
 				err = perf_evsel__parse_sample(evsel, event, &sample);
 				if (err) {
diff --git a/tools/perf/tests/perf-record.c b/tools/perf/tests/perf-record.c
index b8a7056..7923b06 100644
--- a/tools/perf/tests/perf-record.c
+++ b/tools/perf/tests/perf-record.c
@@ -263,6 +263,8 @@ int test__PERF_RECORD(void)
 						 type);
 					++errs;
 				}
+
+				perf_evlist__mmap_consume(evlist, i);
 			}
 		}
 
diff --git a/tools/perf/tests/perf-time-to-tsc.c b/tools/perf/tests/perf-time-to-tsc.c
index 0ab61b1..4ca1b93 100644
--- a/tools/perf/tests/perf-time-to-tsc.c
+++ b/tools/perf/tests/perf-time-to-tsc.c
@@ -122,7 +122,7 @@ int test__perf_time_to_tsc(void)
 			if (event->header.type != PERF_RECORD_COMM ||
 			    (pid_t)event->comm.pid != getpid() ||
 			    (pid_t)event->comm.tid != getpid())
-				continue;
+				goto next_event;
 
 			if (strcmp(event->comm.comm, comm1) == 0) {
 				CHECK__(perf_evsel__parse_sample(evsel, event,
@@ -134,6 +134,8 @@ int test__perf_time_to_tsc(void)
 								 &sample));
 				comm2_time = sample.time;
 			}
+next_event:
+			perf_evlist__mmap_consume(evlist, i);
 		}
 	}
 
diff --git a/tools/perf/tests/sw-clock.c b/tools/perf/tests/sw-clock.c
index 2e41e2d..6e2b44e 100644
--- a/tools/perf/tests/sw-clock.c
+++ b/tools/perf/tests/sw-clock.c
@@ -78,7 +78,7 @@ static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
 		struct perf_sample sample;
 
 		if (event->header.type != PERF_RECORD_SAMPLE)
-			continue;
+			goto next_event;
 
 		err = perf_evlist__parse_sample(evlist, event, &sample);
 		if (err < 0) {
@@ -88,6 +88,8 @@ static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
 
 		total_periods += sample.period;
 		nr_samples++;
+next_event:
+		perf_evlist__mmap_consume(evlist, 0);
 	}
 
 	if ((u64) nr_samples == total_periods) {
diff --git a/tools/perf/tests/task-exit.c b/tools/perf/tests/task-exit.c
index 28fe589..a3e6487 100644
--- a/tools/perf/tests/task-exit.c
+++ b/tools/perf/tests/task-exit.c
@@ -96,10 +96,10 @@ int test__task_exit(void)
 
 retry:
 	while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
-		if (event->header.type != PERF_RECORD_EXIT)
-			continue;
+		if (event->header.type == PERF_RECORD_EXIT)
+			nr_exit++;
 
-		nr_exit++;
+		perf_evlist__mmap_consume(evlist, 0);
 	}
 
 	if (!exited || !nr_exit) {