Since tracing_multi link does not set ftrace_managed, it would fail to release the tracing_multi link when attaching tracing_multi link and then attaching fentry link. [ 3.714215] WARNING: kernel/bpf/trampoline.c:1727 at bpf_trampoline_multi_detach+0x20b/0x240, CPU#1: test_progs/97 ... [ 3.733170] bpf_tracing_multi_link_release+0x14/0x30 [ 3.733890] bpf_link_free+0x58/0x130 [ 3.734414] bpf_link_release+0x23/0x30 Fix it by setting 'ftrace_managed = true' in register_fentry_multi(). Fixes: aef4dfa790b2 ("bpf: Add bpf_trampoline_multi_attach/detach functions") Acked-by: Jiri Olsa Signed-off-by: Leon Hwang --- kernel/bpf/trampoline.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 1a721fc4bef5..6eadf64f7ec9 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -1536,6 +1536,7 @@ static int register_fentry_multi(struct bpf_trampoline *tr, struct bpf_tramp_ima if (bpf_trampoline_use_jmp(tr->flags)) addr = ftrace_jmp_set(addr); + tr->func.ftrace_managed = true; ftrace_hash_add(data->reg, data->entry, ip, addr); tr->cur_image = im; return 0; -- 2.55.0