Re: [PATCH v14 2/8] arm64: Handle MTE tags zeroing in __alloc_zeroed_user_highpage()

[Steven Price]

On 07/06/2021 18:07, Catalin Marinas wrote:
> On Mon, Jun 07, 2021 at 12:08:10PM +0100, Steven Price wrote:
>> From: Catalin Marinas <catalin.marinas@xxxxxxx>
>>
>> Currently, on an anonymous page fault, the kernel allocates a zeroed
>> page and maps it in user space. If the mapping is tagged (PROT_MTE),
>> set_pte_at() additionally clears the tags under a spinlock to avoid a
>> race on the page->flags. In order to optimise the lock, clear the page
>> tags on allocation in __alloc_zeroed_user_highpage() if the vma flags
>> have VM_MTE set.
>>
>> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
>> Signed-off-by: Steven Price <steven.price@xxxxxxx>
> 
> I think you can drop this patch now that Peter's series has been queued
> via the arm64 tree:
> 
> https://lore.kernel.org/r/20210602235230.3928842-4-pcc@xxxxxxxxxx
> 

Thanks for the heads up - I hadn't seen that land. I'll drop this patch
from the next posting.

Steve