Re: [PATCH v3 5/5] x86/sgx: Remove redundant if conditions in sgx_encl_create

Jarkko Sakkinen
2021-01-30T16:35:31Z

On Sun, Jan 24, 2021 at 02:29:07PM +0800, Tianjia Zhang wrote:
> In this scenario, there is no case where va_page is NULL, and
> the error has been checked. The if condition statement here is
> redundant, so remove the condition detection.
>
> Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
> ---
> arch/x86/kernel/cpu/sgx/ioctl.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
> index 1c6ecf9fbeff..b0b829f1b761 100644
> --- a/arch/x86/kernel/cpu/sgx/ioctl.c
> +++ b/arch/x86/kernel/cpu/sgx/ioctl.c
> @@ -66,9 +66,11 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs)
> va_page = sgx_encl_grow(encl);
> if (IS_ERR(va_page))
> return PTR_ERR(va_page);
> - else if (va_page)
> - list_add(&va_page->list, &encl->va_pages);
> - /* else the tail page of the VA page list had free slots. */

This is fine. The check does not make sense.

> +
> + if (WARN_ONCE(!va_page, "non-empty VA page list before ECREATE"))
> + return -EIO;

No need for this WARN_ONCE().

> +
> + list_add(&va_page->list, &encl->va_pages);

This is fine.

>
> /* The extra page goes to SECS. */
> encl_size = secs->size + PAGE_SIZE;
> --
> 2.19.1.3.ge56e4f7
>
>

/Jarkko