Re: [PATCH 15/22] bsd-user/freebsd/os-syscall.c: unlock_iovec

[Kyle Evans]

On Tue, Feb 1, 2022 at 5:15 AM Warner Losh <imp@bsdimp.com> wrote:
>
> Releases the references to the iovec created by lock_iovec.
>
> Signed-off-by: Warner Losh <imp@bsdimp.com>
> ---
>  bsd-user/freebsd/os-syscall.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>

Reviewed-by: Kyle Evans <kevans@FreeBSD.org>

> diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c
> index c21759ae7ce..d49945f0fcc 100644
> --- a/bsd-user/freebsd/os-syscall.c
> +++ b/bsd-user/freebsd/os-syscall.c
> @@ -167,6 +167,29 @@ struct iovec *lock_iovec(int type, abi_ulong target_addr,
>      return NULL;
>  }
>
> +void unlock_iovec(struct iovec *vec, abi_ulong target_addr,
> +        int count, int copy)
> +{
> +    struct target_iovec *target_vec;
> +    int i;
> +
> +    target_vec = lock_user(VERIFY_READ, target_addr,
> +                           count * sizeof(struct target_iovec), 1);
> +    if (target_vec) {
> +        for (i = 0; i < count; i++) {
> +            abi_ulong base = tswapal(target_vec[i].iov_base);
> +            abi_long len = tswapal(target_vec[i].iov_len);
> +            if (len < 0) {
> +                break;
> +            }
> +            unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
> +        }
> +        unlock_user(target_vec, target_addr, 0);
> +    }
> +
> +    free(vec);
> +}
> +
>  /*
>   * do_syscall() should always have a single exit point at the end so that
>   * actions, such as logging of syscall results, can be performed.  All errnos
> --
> 2.33.1
>