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

Tianjia Zhang
2021-02-01T12:41:07Z

On 1/30/21 10:33 PM, Jarkko Sakkinen wrote:
> 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
>

Will be improved in the next version.

Thanks,
Tianjia