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 14:10:23 -0800 [thread overview]
Message-ID: <e2222287-6438-4de7-a747-9e04c5fd3f55@gmail.com> (raw)
In-Reply-To: <4e6bff53-a219-4c69-a662-75e097100c9c@linux.dev>
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.
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?
>
>> + } else {
>> + btf = btf_vmlinux;
>> + btf_get(btf);
>
> btf_vmlinux could be NULL or a ERR_PTR? Lets take this chance to use
> bpf_get_btf_vmlinux():
> btf = bpf_get_btf_vmlinux();
> if (IS_ERR(btf))
> return ERR_CAST(btf);
Sure!
>
> Going back to patch 4. This should be the only case that btf will be
> NULL or ERR_PTR?
>
> will continue the remaining review later tonight.
>
> pw-bot: cr
>
>> + }
>> +
>> + st_ops_desc = bpf_struct_ops_find_value(btf,
>> attr->btf_vmlinux_value_type_id);
>> + if (!st_ops_desc) {
>> + ret = -ENOTSUPP;
>> + goto errout;
>> + }
>> vt = st_ops_desc->value_type;
>> - if (attr->value_size != vt->size)
>> - return ERR_PTR(-EINVAL);
>> + if (attr->value_size != vt->size) {
>> + ret = -EINVAL;
>> + goto errout;
>> + }
>> t = st_ops_desc->type;
>
next prev parent reply other threads:[~2023-12-15 22:10 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 [this message]
2023-12-16 0:19 ` Martin KaFai Lau
2023-12-16 5:55 ` Kui-Feng Lee
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
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