2022-09-13 22:33:15

by Stanislav Fomichev

[permalink] [raw]
Subject: Re: [bpf-next v2] bpf: use kvmemdup_bpfptr helper

On Tue, Sep 13, 2022 at 1:29 AM Wang Yufen <[email protected]> wrote:
>
> Use kvmemdup_bpfptr helper instead of open-coding to
> simplify the code.
>
> Signed-off-by: Wang Yufen <[email protected]>

Acked-by: Stanislav Fomichev <[email protected]>

> ---
> kernel/bpf/syscall.c | 13 ++++---------
> 1 file changed, 4 insertions(+), 9 deletions(-)
>
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index 4fb08c4..f862406 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -1416,19 +1416,14 @@ static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
> }
>
> value_size = bpf_map_value_size(map);
> -
> - err = -ENOMEM;
> - value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
> - if (!value)
> + value = kvmemdup_bpfptr(uvalue, value_size);
> + if (IS_ERR(value)) {
> + err = PTR_ERR(value);
> goto free_key;
> -
> - err = -EFAULT;
> - if (copy_from_bpfptr(value, uvalue, value_size) != 0)
> - goto free_value;
> + }
>
> err = bpf_map_update_value(map, f, key, value, attr->flags);
>
> -free_value:
> kvfree(value);
> free_key:
> kvfree(key);
> --
> 1.8.3.1
>