From: Kui-Feng Lee <sinquersw@gmail.com>
To: Martin KaFai Lau <martin.lau@linux.dev>, thinker.li@gmail.com
Cc: kuifeng@meta.com, bpf@vger.kernel.org, ast@kernel.org,
song@kernel.org, kernel-team@meta.com, andrii@kernel.org,
drosen@google.com
Subject: Re: [PATCH bpf-next v13 07/14] bpf: pass attached BTF to the bpf_struct_ops subsystem
Date: Fri, 15 Dec 2023 21:55:59 -0800 [thread overview]
Message-ID: <a3ab56ff-ca03-4f28-b2e7-4f0b50bfaaae@gmail.com> (raw)
In-Reply-To: <3fd164b6-622e-499e-9fa4-6d56442b086f@linux.dev>
On 12/15/23 16:19, Martin KaFai Lau wrote:
> On 12/15/23 2:10 PM, Kui-Feng Lee wrote:
>>
>>
>> On 12/14/23 18:44, Martin KaFai Lau wrote:
>>> On 12/8/23 4:27 PM, thinker.li@gmail.com wrote:
>>>> @@ -681,15 +682,30 @@ static struct bpf_map
>>>> *bpf_struct_ops_map_alloc(union bpf_attr *attr)
>>>> struct bpf_struct_ops_map *st_map;
>>>> const struct btf_type *t, *vt;
>>>> struct bpf_map *map;
>>>> + struct btf *btf;
>>>> int ret;
>>>> - st_ops_desc = bpf_struct_ops_find_value(btf_vmlinux,
>>>> attr->btf_vmlinux_value_type_id);
>>>> - if (!st_ops_desc)
>>>> - return ERR_PTR(-ENOTSUPP);
>>>> + if (attr->value_type_btf_obj_fd) {
>>>> + /* The map holds btf for its whole life time. */
>>>> + btf = btf_get_by_fd(attr->value_type_btf_obj_fd);
>>>> + if (IS_ERR(btf))
>>>> + return ERR_PTR(PTR_ERR(btf));
>>>
>>> return ERR_CAST(btf);
>>>
>>> It needs to check for btf_is_module:
>>>
>>> if (!btf_is_module(btf)) {
>>> btf_put(btf);
>>> return ERR_PTR(-EINVAL);
>>> }
>>
>> Even btf is btf_vmlinux the kernel's btf, it still works.
>
> btf could be a bpf program's btf. It needs to ensure it is a kernel
> module btf here.
Got it!
>
>> Although libbpf pass 0 as the value of value_type_btf_obj_fd for
>> btf_vmlinux now, it should be OK for a user space loader to
>> pass a fd of btf_vmlinux.
>>
>> WDYT?
>
next prev parent reply other threads:[~2023-12-16 5:56 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-09 0:26 [PATCH bpf-next v13 00/14] Registrating struct_ops types from modules thinker.li
2023-12-09 0:26 ` [PATCH bpf-next v13 01/14] bpf: refactory struct_ops type initialization to a function thinker.li
2023-12-09 0:26 ` [PATCH bpf-next v13 02/14] bpf: get type information with BPF_ID_LIST thinker.li
2023-12-15 1:59 ` Martin KaFai Lau
2023-12-09 0:26 ` [PATCH bpf-next v13 03/14] bpf, net: introduce bpf_struct_ops_desc thinker.li
2023-12-15 2:05 ` Martin KaFai Lau
2023-12-09 0:26 ` [PATCH bpf-next v13 04/14] bpf: add struct_ops_tab to btf thinker.li
2023-12-15 2:22 ` Martin KaFai Lau
2023-12-15 21:42 ` Kui-Feng Lee
2023-12-16 1:19 ` Martin KaFai Lau
2023-12-16 5:43 ` Kui-Feng Lee
2023-12-16 16:48 ` Martin KaFai Lau
2023-12-17 7:09 ` Kui-Feng Lee
2023-12-09 0:27 ` [PATCH bpf-next v13 05/14] bpf: make struct_ops_map support btfs other than btf_vmlinux thinker.li
2023-12-09 0:27 ` [PATCH bpf-next v13 06/14] bpf: lookup struct_ops types from a given module BTF thinker.li
2023-12-09 0:27 ` [PATCH bpf-next v13 07/14] bpf: pass attached BTF to the bpf_struct_ops subsystem thinker.li
2023-12-15 2:44 ` Martin KaFai Lau
2023-12-15 22:10 ` Kui-Feng Lee
2023-12-16 0:19 ` Martin KaFai Lau
2023-12-16 5:55 ` Kui-Feng Lee [this message]
2023-12-16 6:07 ` Kui-Feng Lee
2023-12-16 16:41 ` Martin KaFai Lau
2023-12-16 19:38 ` Kui-Feng Lee
2023-12-09 0:27 ` [PATCH bpf-next v13 08/14] bpf: hold module for bpf_struct_ops_map thinker.li
2023-12-15 5:54 ` Martin KaFai Lau
2023-12-15 23:25 ` Kui-Feng Lee
2023-12-09 0:27 ` [PATCH bpf-next v13 09/14] bpf: validate value_type thinker.li
2023-12-15 6:02 ` Martin KaFai Lau
2023-12-15 23:52 ` Kui-Feng Lee
2023-12-09 0:27 ` [PATCH bpf-next v13 10/14] bpf, net: switch to dynamic registration thinker.li
2023-12-15 6:51 ` Martin KaFai Lau
2023-12-09 0:27 ` [PATCH bpf-next v13 11/14] libbpf: Find correct module BTFs for struct_ops maps and progs thinker.li
2023-12-09 0:27 ` [PATCH bpf-next v13 12/14] bpf: export btf_ctx_access to modules thinker.li
2023-12-09 0:27 ` [PATCH bpf-next v13 13/14] selftests/bpf: test case for register_bpf_struct_ops() thinker.li
2023-12-15 7:17 ` Martin KaFai Lau
2023-12-17 7:32 ` Kui-Feng Lee
2023-12-09 0:27 ` [PATCH bpf-next v13 14/14] bpf: pass btf object id in bpf_map_info thinker.li
2023-12-15 7:46 ` Martin KaFai Lau
2023-12-17 7:35 ` Kui-Feng Lee
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=a3ab56ff-ca03-4f28-b2e7-4f0b50bfaaae@gmail.com \
--to=sinquersw@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=drosen@google.com \
--cc=kernel-team@meta.com \
--cc=kuifeng@meta.com \
--cc=martin.lau@linux.dev \
--cc=song@kernel.org \
--cc=thinker.li@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox