Re: [PATCH v3 5/8] x86/sme: Replace occurrences of sme_active() with cc_platform_has()
From: Kirill A. Shutemov <hidden>
Date: 2021-09-22 21:06:01
Also in:
amd-gfx, dri-devel, kexec, kvm, linux-efi, linux-fsdevel, linux-iommu, linux-s390, lkml, platform-driver-x86
On Wed, Sep 22, 2021 at 09:52:07PM +0200, Borislav Petkov wrote:
On Wed, Sep 22, 2021 at 05:30:15PM +0300, Kirill A. Shutemov wrote:quoted
Not fine, but waiting to blowup with random build environment change.Why is it not fine? Are you suspecting that the compiler might generate something else and not a rip-relative access?
Yes. We had it before for __supported_pte_mask and other users of
fixup_pointer().
See for instance 4a09f0210c8b ("x86/boot/64/clang: Use fixup_pointer() to
access '__supported_pte_mask'")
Unless we find other way to guarantee RIP-relative access, we must use
fixup_pointer() to access any global variables.
--
Kirill A. Shutemov