Re: [tip: x86/shstk] mm: Don't allow write GUPs to shadow stack memory

From: Edgecombe, Rick P
Date: Wed Jul 26 2023 - 14:11:59 EST


On Fri, 2023-07-21 at 09:24 -0700, Rick Edgecombe wrote:
> As for the build breakage, I'm not sure how this slipped through. My
> runtime test environment was missing CONFIG_WERROR, but I got 0day
> build successes for the x86_64 and i386 defconfigs specifically. I'll
> have to follow up with the 0day people.

Yea, there was a 0-day bug that caused it to ignore Wunused-function
warnings. Apparently 0-day also forces CONFIG_WERROR=n, so the build
erroneously succeeded.

The Wunused-function bug is fixed now on 0-day, and the fixed shadow
stack branch re-tested by it. Dave had pushed the shadow stack fix to
his repo as well, so I'm assuming he will handle getting the fix into
tip. But please let me know if you need anything from me, and sorry for
the hassle.