The else branch are broken for taskctx: two events can on the same
taskctx, but on different cpu. This patch fix it, we don't need to
check move_group. We first make sure we're on the same task, or both
per-cpu events, and then make sure we're events for the same cpu.
Signed-off-by: Zhou Chengming <zhouchengmi...@huawei.com>
---
kernel/events/core.c | 31 +++++++++++--------------------
1 file changed, 11 insertions(+), 20 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 6c4e523..59270bd 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10010,28 +10010,19 @@ static int perf_event_set_clock(struct perf_event
*event, clockid_t clk_id)
goto err_context;
/*
- * Do not allow to attach to a group in a different
- * task or CPU context:
+ * Make sure we're both on the same task, or both
+ * per-cpu events.
*/
- if (move_group) {
- /*
- * Make sure we're both on the same task, or both
- * per-cpu events.
- */
- if (group_leader->ctx->task != ctx->task)
- goto err_context;
+ if (group_leader->ctx->task != ctx->task)
+ goto err_context;
- /*
- * Make sure we're both events for the same CPU;
- * grouping events for different CPUs is broken; since
- * you can never concurrently schedule them anyhow.
- */
- if (group_leader->cpu != event->cpu)
- goto err_context;
- } else {
- if (group_leader->ctx != ctx)
- goto err_context;
- }
+ /*
+ * Make sure we're both events for the same CPU;
+ * grouping events for different CPUs is broken; since
+ * you can never concurrently schedule them anyhow.
+ */
+ if (group_leader->cpu != event->cpu)
+ goto err_context;
/*
* Only a group leader can be exclusive or pinned
--
1.8.3.1
