From: Yonghong Song <yhs@fb.com>
To: Roberto Sassu <roberto.sassu@huaweicloud.com>
Cc: andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org,
daniel@iogearbox.net, deso@posteo.net, dhowells@redhat.com,
haoluo@google.com, jarkko@kernel.org, jmorris@namei.org,
joannelkoong@gmail.com, john.fastabend@gmail.com,
jolsa@kernel.org, keyrings@vger.kernel.org, kpsingh@kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
linux-security-module@vger.kernel.org, martin.lau@linux.dev,
memxor@gmail.com, mingo@redhat.com, mykolal@fb.com,
paul@paul-moore.com, roberto.sassu@huawei.com,
rostedt@goodmis.org, sdf@google.com, serge@hallyn.com,
shuah@kernel.org, song@kernel.org
Subject: Re: [PATCH v18 02/13] btf: Export bpf_dynptr definition
Date: Mon, 19 Sep 2022 22:30:16 -0700 [thread overview]
Message-ID: <1e8f3fb4-a014-8146-70ba-65e451a64e18@fb.com> (raw)
In-Reply-To: <20220919142754.626564-1-roberto.sassu@huaweicloud.com>
On 9/19/22 7:27 AM, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
>
> eBPF dynamic pointers is a new feature recently added to upstream. It binds
> together a pointer to a memory area and its size. The internal kernel
> structure bpf_dynptr_kern is not accessible by eBPF programs in user space.
> They instead see bpf_dynptr, which is then translated to the internal
> kernel structure by the eBPF verifier.
>
> The problem is that it is not possible to include at the same time the uapi
> include linux/bpf.h and the vmlinux BTF vmlinux.h, as they both contain the
> definition of some structures/enums. The compiler complains saying that the
> structures/enums are redefined.
>
> As bpf_dynptr is defined in the uapi include linux/bpf.h, this makes it
> impossible to include vmlinux.h. However, in some cases, e.g. when using
> kfuncs, vmlinux.h has to be included. The only option until now was to
> include vmlinux.h and add the definition of bpf_dynptr directly in the eBPF
> program source code from linux/bpf.h.
>
> Solve the problem by using the same approach as for bpf_timer (which also
> follows the same scheme with the _kern suffix for the internal kernel
> structure).
>
> Add the following line in one of the dynamic pointer helpers,
> bpf_dynptr_from_mem():
>
> BTF_TYPE_EMIT(struct bpf_dynptr);
>
> Cc: stable@vger.kernel.org
> Cc: Joanne Koong <joannelkoong@gmail.com>
> Fixes: 97e03f521050c ("bpf: Add verifier support for dynptrs")
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
next prev parent reply other threads:[~2022-09-20 5:31 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-09 12:07 [PATCH v17 00/12] bpf: Add kfuncs for PKCS#7 signature verification Roberto Sassu
2022-09-09 12:07 ` [PATCH v17 01/12] bpf: Allow kfuncs to be used in LSM programs Roberto Sassu
2022-09-09 12:07 ` [PATCH v17 02/12] bpf: Move dynptr type check to is_dynptr_type_expected() Roberto Sassu
2022-09-09 12:07 ` [PATCH v17 03/12] btf: Allow dynamic pointer parameters in kfuncs Roberto Sassu
2022-09-09 12:07 ` [PATCH v17 04/12] bpf: Export bpf_dynptr_get_size() Roberto Sassu
2022-09-09 12:07 ` [PATCH v17 05/12] KEYS: Move KEY_LOOKUP_ to include/linux/key.h and define KEY_LOOKUP_ALL Roberto Sassu
2022-09-09 12:07 ` [PATCH v17 06/12] bpf: Add bpf_lookup_*_key() and bpf_key_put() kfuncs Roberto Sassu
2022-09-09 16:05 ` Song Liu
2022-09-09 12:07 ` [PATCH v17 07/12] bpf: Add bpf_verify_pkcs7_signature() kfunc Roberto Sassu
2022-09-09 16:06 ` Song Liu
2022-09-11 11:40 ` KP Singh
2022-09-11 21:08 ` Kumar Kartikeya Dwivedi
2022-09-09 12:07 ` [PATCH v17 08/12] selftests/bpf: Compile kernel with everything as built-in Roberto Sassu
2022-09-09 12:07 ` [PATCH v17 09/12] selftests/bpf: Add verifier tests for bpf_lookup_*_key() and bpf_key_put() Roberto Sassu
2022-09-09 12:07 ` [PATCH v17 10/12] selftests/bpf: Add additional tests for bpf_lookup_*_key() Roberto Sassu
2022-09-09 12:07 ` [PATCH v17 11/12] selftests/bpf: Add test for bpf_verify_pkcs7_signature() kfunc Roberto Sassu
2022-09-15 16:11 ` KP Singh
2022-09-19 11:17 ` Roberto Sassu
2022-09-19 13:09 ` Roberto Sassu
2022-09-19 14:27 ` [PATCH v18 02/13] btf: Export bpf_dynptr definition Roberto Sassu
2022-09-20 5:30 ` Yonghong Song [this message]
2022-09-22 1:10 ` patchwork-bot+netdevbpf
2022-09-20 5:26 ` [PATCH v17 11/12] selftests/bpf: Add test for bpf_verify_pkcs7_signature() kfunc Yonghong Song
2022-09-20 4:21 ` Yonghong Song
2022-09-09 12:07 ` [PATCH v17 12/12] selftests/bpf: Add tests for dynamic pointers parameters in kfuncs Roberto Sassu
2022-09-20 7:59 [PATCH v18 00/13] bpf: Add kfuncs for PKCS#7 signature verification Roberto Sassu
2022-09-20 7:59 ` [PATCH v18 02/13] btf: Export bpf_dynptr definition Roberto Sassu
2022-09-21 13:43 ` KP Singh
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