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References: <20220304172852.274126-1-benjamin.tissoires@redhat.com> <20220304172852.274126-3-benjamin.tissoires@redhat.com>
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From:   Song Liu <song@kernel.org>
Date:   Fri, 4 Mar 2022 16:20:46 -0800
Message-ID: <CAPhsuW62DZzYb6RwDETNB7u2gMWw2GRwQ_60-363PSvHWEyhUA@mail.gmail.com>
Subject: Re: [PATCH bpf-next v2 02/28] bpf: introduce hid program type
To:     Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc:     Greg KH <gregkh@linuxfoundation.org>,
        Jiri Kosina <jikos@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>, Shuah Khan <shuah@kernel.org>,
        Dave Marchevsky <davemarchevsky@fb.com>,
        Joe Stringer <joe@cilium.io>,
        Tero Kristo <tero.kristo@linux.intel.com>,
        open list <linux-kernel@vger.kernel.org>,
        "open list:HID CORE LAYER" <linux-input@vger.kernel.org>,
        Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
        linux-kselftest@vger.kernel.org
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On Fri, Mar 4, 2022 at 9:31 AM Benjamin Tissoires
<benjamin.tissoires@redhat.com> wrote:
>
[...]
> +#endif
> +
> +static inline bool bpf_hid_link_empty(struct bpf_hid *bpf,
> +                                     enum bpf_hid_attach_type type)
> +{
> +       return list_empty(&bpf->links[type]);
> +}
> +
> +struct bpf_hid_hooks {
> +       struct hid_device *(*hdev_from_fd)(int fd);
> +       int (*link_attach)(struct hid_device *hdev, enum bpf_hid_attach_type type);
> +       void (*array_detached)(struct hid_device *hdev, enum bpf_hid_attach_type type);

shall we call this array_detach()? detached sounds like a function that
checks the status of link/hook.

[...]

> --- /dev/null
> +++ b/kernel/bpf/hid.c
> @@ -0,0 +1,437 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * based on kernel/bpf/net-namespace.c
> + */

I guess we don't need this comment.

> +
> +#include <linux/bpf.h>
> +#include <linux/bpf-hid.h>
> +#include <linux/filter.h>
> +#include <linux/hid.h>
> +#include <linux/hidraw.h>
[...]