From: Cong Wang <xiyou.wangcong@gmail.com>
To: Di Zhu <zhudi2@huawei.com>
Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net,
andrii@kernel.org, kafai@fb.com, songliubraving@fb.com,
yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org,
jakub@cloudflare.com, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH bpf-next v5 1/2] bpf: support BPF_PROG_QUERY for progs attached to sockmap
Date: Fri, 5 Nov 2021 12:51:55 -0700 [thread overview]
Message-ID: <YYWLW5IJhmIa2aVX@unknown> (raw)
In-Reply-To: <20211104010745.1177032-1-zhudi2@huawei.com>
On Thu, Nov 04, 2021 at 09:07:44AM +0800, Di Zhu wrote:
> +int sock_map_bpf_prog_query(const union bpf_attr *attr,
> + union bpf_attr __user *uattr)
> +{
> + __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
> + u32 prog_cnt = 0, flags = 0, ufd = attr->target_fd;
> + struct bpf_prog **pprog;
> + struct bpf_prog *prog;
> + struct bpf_map *map;
> + struct fd f;
> + u32 id = 0;
> + int ret;
> +
> + if (attr->query.query_flags)
> + return -EINVAL;
> +
> + f = fdget(ufd);
> + map = __bpf_map_get(f);
> + if (IS_ERR(map))
> + return PTR_ERR(map);
> +
> + rcu_read_lock();
> +
> + ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type);
> + if (ret)
> + goto end;
> +
> + prog = *pprog;
> + prog_cnt = (!prog) ? 0 : 1;
> +
> + if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
> + goto end;
This sanity check (except prog_cnt) can be moved before RCU read lock?
> +
> + id = prog->aux->id;
> + if (id == 0)
> + prog_cnt = 0;
The id seems generic, so why not handle it in bpf_prog_query() for all progs?
> +
> +end:
> + rcu_read_unlock();
> +
> + if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) ||
'flags' is always 0 here, right? So this is not needed as uattr has been already
cleared in __sys_bpf().
Thanks.
next prev parent reply other threads:[~2021-11-05 19:52 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-04 1:07 [PATCH bpf-next v5 1/2] bpf: support BPF_PROG_QUERY for progs attached to sockmap Di Zhu
2021-11-04 1:07 ` [PATCH bpf-next v5 2/2] selftests: bpf: test " Di Zhu
2021-11-04 5:51 ` Yonghong Song
2021-11-04 5:31 ` [PATCH bpf-next v5 1/2] bpf: support " Yonghong Song
2021-11-05 19:51 ` Cong Wang [this message]
2021-11-04 6:07 zhudi (E)
2021-11-04 6:30 ` Yonghong Song
2021-11-04 6:35 zhudi (E)
2021-11-05 1:57 Di Zhu
2021-11-05 4:23 ` Yonghong Song
2021-11-08 2:13 zhudi (E)
2022-01-13 9:00 Di Zhu
2022-01-13 16:15 ` Jakub Sitnicki
2022-01-15 1:22 ` Andrii Nakryiko
2022-01-14 5:44 zhudi (E)
2022-01-15 2:38 zhudi (E)
2022-01-15 2:53 ` Andrii Nakryiko
2022-01-15 19:09 ` Jakub Sitnicki
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