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-rw-r--r--kernel/events/core.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 523106a506ee..c552e1bfcaea 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6526,18 +6526,25 @@ static void perf_pending_event(struct irq_work *entry)
* Later on, we might change it to a list if there is
* another virtualization implementation supporting the callbacks.
*/
-struct perf_guest_info_callbacks *perf_guest_cbs;
+struct perf_guest_info_callbacks __rcu *perf_guest_cbs;
int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
{
- perf_guest_cbs = cbs;
+ if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs)))
+ return -EBUSY;
+
+ rcu_assign_pointer(perf_guest_cbs, cbs);
return 0;
}
EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
{
- perf_guest_cbs = NULL;
+ if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs) != cbs))
+ return -EINVAL;
+
+ rcu_assign_pointer(perf_guest_cbs, NULL);
+ synchronize_rcu();
return 0;
}
EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);