Re: [RFC 1/2] x86/mm/cpa: always fail when user address is passed

[Hyeonggon Yoo <42.hyeyoo@gmail.com>]

On Wed, Jun 15, 2022 at 06:11:03AM -0700, Christoph Hellwig wrote:
> On Tue, Jun 14, 2022 at 03:39:32PM +0900, Hyeonggon Yoo wrote:
> > +
> > +	if (WARN((IS_ENABLED(CONFIG_EFI) ? cpa->pgd != efi_mm.pgd : true)
> > +		  && address <= TASK_SIZE_MAX,
> > +		 KERN_WARNING "CPA: Got a user address"))
> > +		return -EINVAL;
> 
> This looks rather unreadable.
> 
> Why not something like:
> 
> static bool cpa_addr_valid(struct cpa_data *cpa, unsigned long address)
> {
> 	if (address > TASK_SIZE_MAX)
> 		return true;
> 	if (IS_ENABLED(CONFIG_EFI) && cpa->pgd == efi_mm.pgd)
> 		return true;
> 	return false;
> }
> 
> ....
> 
> 	if (WARN_ON_ONCE(!cpa_addr_valid(cpa, address)))
> 		return -EINVAL;
>

Thank your for feedback. I'll care more about readability in v2.

-- 
Thanks,
Hyeonggon