[PATCH bpf-next 1/2] bpf: Mark tracing_multi trampolines as ftrace managed

[Leon Hwang]

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")
Signed-off-by: Leon Hwang <leon.hw...@linux.dev>
---
 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