[PATCH 3/4] btf: Switch vmlinux BTF attribute to sysfs_bin_attr_simple_read()

[Andrii Nakryiko]

On Thu, Dec 5, 2024 at 9:35 AM Thomas Weißschuh <linux at weissschuh.net> wrote:
>
> The generic function from the sysfs core can replace the custom one.
>
> Signed-off-by: Thomas Weißschuh <linux at weissschuh.net>
>
> ---
> This is a replacement for [0], as Alexei was not happy about BIN_ATTR_SIMPLE_RO()
>
> [0] https://lore.kernel.org/lkml/20241122-sysfs-const-bin_attr-bpf-v1-1-823aea399b53@weissschuh.net/
> ---
>  kernel/bpf/sysfs_btf.c | 12 ++----------
>  1 file changed, 2 insertions(+), 10 deletions(-)
>

Acked-by: Andrii Nakryiko <andrii at kernel.org>

> diff --git a/kernel/bpf/sysfs_btf.c b/kernel/bpf/sysfs_btf.c
> index fedb54c94cdb830a4890d33677dcc5a6e236c13f..81d6cf90584a7157929c50f62a5c6862e7a3d081 100644
> --- a/kernel/bpf/sysfs_btf.c
> +++ b/kernel/bpf/sysfs_btf.c
> @@ -12,24 +12,16 @@
>  extern char __start_BTF[];
>  extern char __stop_BTF[];
>
> -static ssize_t
> -btf_vmlinux_read(struct file *file, struct kobject *kobj,
> -                struct bin_attribute *bin_attr,
> -                char *buf, loff_t off, size_t len)
> -{
> -       memcpy(buf, __start_BTF + off, len);
> -       return len;
> -}
> -
>  static struct bin_attribute bin_attr_btf_vmlinux __ro_after_init = {
>         .attr = { .name = "vmlinux", .mode = 0444, },
> -       .read = btf_vmlinux_read,
> +       .read_new = sysfs_bin_attr_simple_read,
>  };
>
>  struct kobject *btf_kobj;
>
>  static int __init btf_vmlinux_init(void)
>  {
> +       bin_attr_btf_vmlinux.private = __start_BTF;
>         bin_attr_btf_vmlinux.size = __stop_BTF - __start_BTF;
>
>         if (bin_attr_btf_vmlinux.size == 0)
>
> --
> 2.47.1
>