Re: [GIT PULL] x86/urgent for 7.4-rc4

[Dave Hansen]

On 9/13/26 18:04, Linus Torvalds wrote:
> On Sun, 13 Sept 2026 at 17:18, Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
...
> This does not seem to be a bug in MADV_FREE at all, and isn't even
> really related to MADV_FREE. I think MADV_FREE just happened to be a
> way to trigger it.

Ahh, I see your point. Agreed. It's really about mprotect() on a PMD
versus the dirty bit.

> I'd love for somebody to hit me with a clue hammer on how this all
> happened, but I guess that's not required for the fix.

Rick dug back in some old versions of the shadow stack patches to look
for the origin:

> https://lore.kernel.org/lkml/c15c2b17e110782d966751dbf3c487a6db837a87.camel@xxxxxxxxx/

It does seem to just be cruft from old versions that snuck through as
opposed to something intentional.