Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Cross-merge bpf fixes after downstream PR.

No conflicts.

Adjacent changes in:
Auto-merging include/linux/bpf.h
Auto-merging include/linux/bpf_verifier.h
Auto-merging kernel/bpf/btf.c
Auto-merging kernel/bpf/verifier.c
Auto-merging kernel/trace/bpf_trace.c
Auto-merging tools/testing/selftests/bpf/progs/test_tp_btf_nullable.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index c6946ae19066..48db147c6c7d 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2253,6 +2253,9 @@ void perf_event_detach_bpf_prog(struct perf_event *event)
 		goto unlock;
 
 	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
+	if (!old_array)
+		goto put;
+
 	ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
 	if (ret < 0) {
 		bpf_prog_array_delete_safe(old_array, event->prog);
@@ -2261,6 +2264,14 @@ void perf_event_detach_bpf_prog(struct perf_event *event)
 		bpf_prog_array_free_sleepable(old_array);
 	}
 
+put:
+	/*
+	 * It could be that the bpf_prog is not sleepable (and will be freed
+	 * via normal RCU), but is called from a point that supports sleepable
+	 * programs and uses tasks-trace-RCU.
+	 */
+	synchronize_rcu_tasks_trace();
+
 	bpf_prog_put(event->prog);
 	event->prog = NULL;