From 0abff462d802a352c87b7f5e71b442b09bf9cfff Mon Sep 17 00:00:00 2001 From: Levi Zim Date: Tue, 4 Feb 2025 10:00:21 +0800 Subject: [PATCH] bpf: Add comment about helper freeze Put a comment after the bpf helper list in uapi bpf.h to prevent people from trying to add new helpers there and direct them to kfuncs. Suggested-by: Andrii Nakryiko Signed-off-by: Levi Zim Signed-off-by: Andrii Nakryiko Reviewed-by: Bagas Sanjaya Acked-by: Daniel Xu Link: https://lore.kernel.org/bpf/CAEf4BzZvQF+QQ=oip4vdz5A=9bd+OmN-CXk5YARYieaipK9s+A@mail.gmail.com/ Link: https://lore.kernel.org/bpf/20221231004213.h5fx3loccbs5hyzu@macbook-pro-6.dhcp.thefacebook.com/ Link: https://lore.kernel.org/bpf/20250204-bpf-helper-freeze-v1-1-46efd9ff20dc@outlook.com --- include/uapi/linux/bpf.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 2acf9b3363717..fff6cdb8d11a2 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6019,7 +6019,10 @@ union bpf_attr { FN(user_ringbuf_drain, 209, ##ctx) \ FN(cgrp_storage_get, 210, ##ctx) \ FN(cgrp_storage_delete, 211, ##ctx) \ - /* */ + /* This helper list is effectively frozen. If you are trying to \ + * add a new helper, you should add a kfunc instead which has \ + * less stability guarantees. See Documentation/bpf/kfuncs.rst \ + */ /* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't * know or care about integer value that is now passed as second argument -- 2.39.5