Re: [PATCH v2 00/21] arm64: Move overflow sp into SP_EL1 and kernel sp into SP_EL0

[Muhammad Usama Anjum]

On 01/10/2026 8:21 am, Will Deacon wrote:
> On Wed, Sep 30, 2026 at 11:42:51PM +0200, Linus Walleij wrote:
>> On Fri, Sep 18, 2026 at 6:14 PM Will Deacon <will@xxxxxxxxxx> wrote:
>>
>>> This is version two of the kernel stack juggling patches I previously
>>> posted here:
>>>
>>>   https://lore.kernel.org/r/20260907164247.17223-1-will@xxxxxxxxxx
>>>
>>> Changes since v1 include:
>>>   * Fixed suspend/resume paths to handle the stack pointers properly
>>>   * Fixed restoration of ptrauth keys on resume
>>>   * Added tags
>>
>> Overall I like what I see, but can we split it in two... like first the patches
>> up to fixing the overflow handling using SP_EL0 and finalize that?
> 
> Yes, that makes sense (and thanks for going through it). The whole thing
> is bisectable, so lemme go through the feedback I've got so far and send
> out a prefix that we could consider merging as preparatory work.

I'll trigger run on this prefix.

> 
>> Hopefully Usama can test just that part and see if it has a lesser
>> performance impact as well.
> 
> I'd like to see those numbers at various points during the series, tbh,
> so we can rule out any stack-protector changes etc.

Sure, I can trigger runs on different points if you can mention which would be
more valuable.

-- 
Thanks,
Usama