Commit a2854124 authored by Frederic Weisbecker's avatar Frederic Weisbecker
Browse files

perf tools: Pre-check sample size before parsing



Check that the total size of the sample fields having a fixed
size do not exceed the one of the whole event. This robustifies
the sample parsing.
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
parent 74429964
......@@ -474,6 +474,7 @@ static int test__basic_mmap(void)
unsigned int nr_events[nsyscalls],
expected_nr_events[nsyscalls], i, j;
struct perf_evsel *evsels[nsyscalls], *evsel;
int sample_size = perf_sample_size(attr.sample_type);
for (i = 0; i < nsyscalls; ++i) {
char name[64];
......@@ -558,7 +559,8 @@ static int test__basic_mmap(void)
goto out_munmap;
}
perf_event__parse_sample(event, attr.sample_type, false, &sample);
perf_event__parse_sample(event, attr.sample_type, sample_size,
false, &sample);
evsel = perf_evlist__id2evsel(evlist, sample.id);
if (evsel == NULL) {
pr_debug("event with id %" PRIu64
......
......@@ -35,6 +35,22 @@ const char *perf_event__name(unsigned int id)
return perf_event__names[id];
}
int perf_sample_size(u64 sample_type)
{
u64 mask = sample_type & PERF_SAMPLE_MASK;
int size = 0;
int i;
for (i = 0; i < 64; i++) {
if ((mask << i) & 1)
size++;
}
size *= sizeof(u64);
return size;
}
static struct perf_sample synth_sample = {
.pid = -1,
.tid = -1,
......
......@@ -56,6 +56,13 @@ struct read_event {
u64 id;
};
#define PERF_SAMPLE_MASK \
(PERF_SAMPLE_IP | PERF_SAMPLE_TID | \
PERF_SAMPLE_TIME | PERF_SAMPLE_ADDR | \
PERF_SAMPLE_ID | PERF_SAMPLE_STREAM_ID | \
PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD)
struct sample_event {
struct perf_event_header header;
u64 array[];
......@@ -75,6 +82,8 @@ struct perf_sample {
struct ip_callchain *callchain;
};
int perf_sample_size(u64 sample_type);
#define BUILD_ID_SIZE 20
struct build_id_event {
......@@ -178,6 +187,7 @@ int perf_event__preprocess_sample(const union perf_event *self,
const char *perf_event__name(unsigned int id);
int perf_event__parse_sample(const union perf_event *event, u64 type,
bool sample_id_all, struct perf_sample *sample);
int sample_size, bool sample_id_all,
struct perf_sample *sample);
#endif /* __PERF_RECORD_H */
......@@ -304,7 +304,8 @@ static int perf_event__parse_id_sample(const union perf_event *event, u64 type,
}
int perf_event__parse_sample(const union perf_event *event, u64 type,
bool sample_id_all, struct perf_sample *data)
int sample_size, bool sample_id_all,
struct perf_sample *data)
{
const u64 *array;
......@@ -319,6 +320,9 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
array = event->sample.array;
if (sample_size + sizeof(event->header) > event->header.size)
return -EFAULT;
if (type & PERF_SAMPLE_IP) {
data->ip = event->ip.ip;
array++;
......
......@@ -690,8 +690,9 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
return PyErr_NoMemory();
first = list_entry(evlist->entries.next, struct perf_evsel, node);
perf_event__parse_sample(event, first->attr.sample_type, sample_id_all,
&pevent->sample);
perf_event__parse_sample(event, first->attr.sample_type,
perf_sample_size(first->attr.sample_type),
sample_id_all, &pevent->sample);
return pyevent;
}
......
......@@ -97,6 +97,7 @@ static void perf_session__id_header_size(struct perf_session *session)
void perf_session__update_sample_type(struct perf_session *self)
{
self->sample_type = perf_evlist__sample_type(self->evlist);
self->sample_size = perf_sample_size(self->sample_type);
self->sample_id_all = perf_evlist__sample_id_all(self->evlist);
perf_session__id_header_size(self);
}
......
......@@ -43,6 +43,7 @@ struct perf_session {
*/
struct hists hists;
u64 sample_type;
int sample_size;
int fd;
bool fd_pipe;
bool repipe;
......@@ -159,6 +160,7 @@ static inline int perf_session__parse_sample(struct perf_session *session,
struct perf_sample *sample)
{
return perf_event__parse_sample(event, session->sample_type,
session->sample_size,
session->sample_id_all, sample);
}
......
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