From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 8 Dec 2020 06:43:26 +0000 (-0800)
Subject: bpf: Return -ENOTSUPP when attaching to non-kernel BTF
X-Git-Tag: microblaze-v5.12~172^2~26^2~14
X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=8bdd8e275ede9786d845b3ec952836e61fd824e9;p=linux-2.6-microblaze.git

bpf: Return -ENOTSUPP when attaching to non-kernel BTF

Return -ENOTSUPP if tracing BPF program is attempted to be attached with
specified attach_btf_obj_fd pointing to non-kernel (neither vmlinux nor
module) BTF object. This scenario might be supported in the future and isn't
outright invalid, so -EINVAL isn't the most appropriate error code.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20201208064326.667389-1-andrii@kernel.org
---

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0cd3cc2af9c1..287be337d5f6 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2121,8 +2121,11 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
 			if (IS_ERR(attach_btf))
 				return -EINVAL;
 			if (!btf_is_kernel(attach_btf)) {
+				/* attaching through specifying bpf_prog's BTF
+				 * objects directly might be supported eventually
+				 */
 				btf_put(attach_btf);
-				return -EINVAL;
+				return -ENOTSUPP;
 			}
 		}
 	} else if (attr->attach_btf_id) {