This is a note to let you know that I've just added the patch titled bpf: don't emit warnings intended for global subprogs for static subprogs to the 6.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bpf-don-t-emit-warnings-intended-for-global-subprogs.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 1cfc35d0eb86343fb61465a176b8447301e3e92a Author: Andrii Nakryiko <andrii@xxxxxxxxxx> Date: Fri Feb 2 11:05:29 2024 -0800 bpf: don't emit warnings intended for global subprogs for static subprogs [ Upstream commit 1eb986746a67952df86eb2c50a36450ef103d01b ] When btf_prepare_func_args() was generalized to handle both static and global subprogs, a few warnings/errors that are meant only for global subprog cases started to be emitted for static subprogs, where they are sort of expected and irrelavant. Stop polutting verifier logs with irrelevant scary-looking messages. Fixes: e26080d0da87 ("bpf: prepare btf_prepare_func_args() for handling static subprogs") Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240202190529.2374377-4-andrii@xxxxxxxxxx Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index dbe7a590f565a..92aa3cf0396b8 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -7009,6 +7009,8 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog) args = (const struct btf_param *)(t + 1); nargs = btf_type_vlen(t); if (nargs > MAX_BPF_FUNC_REG_ARGS) { + if (!is_global) + return -EINVAL; bpf_log(log, "Global function %s() with %d > %d args. Buggy compiler.\n", tname, nargs, MAX_BPF_FUNC_REG_ARGS); return -EINVAL; @@ -7018,6 +7020,8 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog) while (btf_type_is_modifier(t)) t = btf_type_by_id(btf, t->type); if (!btf_type_is_int(t) && !btf_is_any_enum(t)) { + if (!is_global) + return -EINVAL; bpf_log(log, "Global function %s() doesn't return scalar. Only those are supported.\n", tname); @@ -7091,6 +7095,8 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog) sub->args[i].arg_type = ARG_ANYTHING; continue; } + if (!is_global) + return -EINVAL; bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n", i, btf_type_str(t), tname); return -EINVAL;