[PATCH v2 bpf-next] bpf: return -ENOTSUPP when attaching to non-kernel BTF

[PATCH v2 bpf-next] bpf: return -ENOTSUPP when attaching to non-kernel BTF

[Andrii Nakryiko]

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>
---
 kernel/bpf/syscall.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

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) {
-- 
2.24.1

Re: [PATCH v2 bpf-next] bpf: return -ENOTSUPP when attaching to non-kernel BTF

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to bpf/bpf-next.git (refs/heads/master):

On Mon, 7 Dec 2020 22:43:26 -0800 you wrote:
> 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>
> 
> [...]

Here is the summary with links:
  - [v2,bpf-next] bpf: return -ENOTSUPP when attaching to non-kernel BTF
    https://git.kernel.org/bpf/bpf-next/c/8bdd8e275ede

You are awesome, thank you!
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