On Tue, Feb 15, 2022 at 09:01:54PM -0500, Brian Geffon wrote: > On Tue, Feb 15, 2022 at 4:42 PM Dave Hansen <dave.hansen@xxxxxxxxx> wrote: > > > > On 2/15/22 13:32, Brian Geffon wrote: > > >> How was this tested, and what do the maintainers of this subsystem > > >> think? And will you be around to fix the bugs in this when they are > > >> found? > > > This has been trivial to reproduce, I've used a small repro which I've > > > put here: https://gist.github.com/bgaff/9f8cbfc8dd22e60f9492e4f0aff8f04f > > > , I also was able to reproduce this using the protection_keys self > > > tests on a 11th Gen Core i5-1135G7. > > > > I've got an i7-1165G7, but I'm not seeing any failures on a > > 5.11 distro kernel. > > > > Hi Dave, > I suspect the reason you're not seeing it is toolchain related, I'm > building with clang 14.0.0 and it produces the sequence of > instructions which use the cached value. Let me know if there is > anything I can do to help you investigate this further. Do older versions of clang have this problem? thanks, greg k-h
