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authorStephane Eranian <eranian@google.com>2019-03-07 10:52:33 -0800
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-03-11 11:56:02 -0300
commitd9c1bb2f6a2157b38e8eb63af437cb22701d31ee (patch)
tree12f3bf912bb2330eb859fe2779c9c088ade4aef0 /kernel
parentb339da480315505aa28a723a983217ebcff95c86 (diff)
perf/core: Restore mmap record type correctly
On mmap(), perf_events generates a RECORD_MMAP record and then checks which events are interested in this record. There are currently 2 versions of mmap records: RECORD_MMAP and RECORD_MMAP2. MMAP2 is larger. The event configuration controls which version the user level tool accepts. If the event->attr.mmap2=1 field then MMAP2 record is returned. The perf_event_mmap_output() takes care of this. It checks attr->mmap2 and corrects the record fields before putting it in the sampling buffer of the event. At the end the function restores the modified MMAP record fields. The problem is that the function restores the size but not the type. Thus, if a subsequent event only accepts MMAP type, then it would instead receive an MMAP2 record with a size of MMAP record. This patch fixes the problem by restoring the record type on exit. Signed-off-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Fixes: 13d7a2410fa6 ("perf: Add attr->mmap2 attribute to an event") Link: http://lkml.kernel.org/r/20190307185233.225521-1-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 6fb27b564730..514b8e014a2d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7189,6 +7189,7 @@ static void perf_event_mmap_output(struct perf_event *event,
struct perf_output_handle handle;
struct perf_sample_data sample;
int size = mmap_event->event_id.header.size;
+ u32 type = mmap_event->event_id.header.type;
int ret;
if (!perf_event_mmap_match(event, data))
@@ -7232,6 +7233,7 @@ static void perf_event_mmap_output(struct perf_event *event,
perf_output_end(&handle);
out:
mmap_event->event_id.header.size = size;
+ mmap_event->event_id.header.type = type;
}
static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)