diff options
| -rw-r--r-- | kernel/perf_event.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 3f2cc313ee25..7a932526946f 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -4920,6 +4920,13 @@ static int perf_event_set_output(struct perf_event *event, int output_fd) int fput_needed = 0; int ret = -EINVAL; + /* + * Don't allow output of inherited per-task events. This would + * create performance issues due to cross cpu access. + */ + if (event->cpu == -1 && event->attr.inherit) + return -EINVAL; + if (!output_fd) goto set; @@ -4940,6 +4947,18 @@ static int perf_event_set_output(struct perf_event *event, int output_fd) if (event->data) goto out; + /* + * Don't allow cross-cpu buffers + */ + if (output_event->cpu != event->cpu) + goto out; + + /* + * If its not a per-cpu buffer, it must be the same task. + */ + if (output_event->cpu == -1 && output_event->ctx != event->ctx) + goto out; + atomic_long_inc(&output_file->f_count); set: |
