Re: [PATCH] x86/sgx: handle VA page allocation failure for EAUG on PF.

[Jarkko Sakkinen <jarkko@kernel.org>]

On Fri, Aug 12, 2022 at 12:12:24PM -0700, Haitao Huang wrote:
> Return VM_FAULT_NOPAGE to allow the swapping thread to catch up.
> 
> link: https://lore.kernel.org/all/20220804201456.33418-1-vijay.dhanraj@intel.com/
> 
> Signed-off-by: Haitao Huang <haitao.huang@linux.intel.com>
> ---
>  arch/x86/kernel/cpu/sgx/encl.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> index 24c1bb8eb196..1f88f80c4477 100644
> --- a/arch/x86/kernel/cpu/sgx/encl.c
> +++ b/arch/x86/kernel/cpu/sgx/encl.c
> @@ -344,8 +344,11 @@ static vm_fault_t sgx_encl_eaug_page(struct vm_area_struct *vma,
>  	}
>  
>  	va_page = sgx_encl_grow(encl, false);
> -	if (IS_ERR(va_page))
> -		goto err_out_epc;
> +	if (IS_ERR(va_page)) {
> +        if (PTR_ERR(va_page) == -EBUSY)
> +            vmret =  VM_FAULT_NOPAGE;
> +        goto err_out_epc;
> +    }
>  
>  	if (va_page)
>  		list_add(&va_page->list, &encl->va_pages);
> -- 
> 2.25.1
> 

Indentation is probably not right, but the fix look legit.

You need to use real tab-characters to fix that. Run the
patch with scripts/checkpatch.pl and it will report you
these issues.

Vijay, can you check if this fixes the issue for you?

BR, Jarkko