lkml.org 
[lkml]   [2024]   [Feb]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] arm64/sve: Lower the maximum allocation for the SVE ptrace regset
On Wed, Feb 07, 2024 at 01:51:42PM +0000, Dave Martin wrote:
> On Wed, Feb 07, 2024 at 01:09:51PM +0000, Mark Brown wrote:

> > I think if we fix the ptrace regset issue we're doing a good enough job
> > of just using fully dynamic sizing with no limits other than what's been
> > enumerated there. We could possibly deal with the enumberation code by
> > changing it to use ZCR/SMCR_ELx_LEN_ based defines so that it's
> > obviously coming from what we can possibly write to the register but
> > it's a bit less clear how to do that neatly.

> OK, but we still seem to have two competing approaches: clamp SVE_VQ_MAX
> for kernel internal purposes, or restore the dynamic sizing of
> NT_ARM_SVE based on the new regset core behaviour.

> Are you saying we should or both, or otherwise which one?

I'd like to remove uses of SVE_VQ_MAX, to the extent possible by making
things dynamic but if not by not using it I would like to not use
SVE_VQ_MAX partly due to the considerations you mentioned about people
picking up from looking at the kernel source that it's a good idea.
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2024-05-27 14:53    [W:0.051 / U:0.536 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site