On Fri, Sep 24, 2021 at 12:41:32PM +0300, Kirill A. Shutemov wrote: > On Thu, Sep 23, 2021 at 08:21:03PM +0200, Borislav Petkov wrote: > > On Thu, Sep 23, 2021 at 12:05:58AM +0300, Kirill A. Shutemov wrote: > > > Unless we find other way to guarantee RIP-relative access, we must use > > > fixup_pointer() to access any global variables. > > > > Yah, I've asked compiler folks about any guarantees we have wrt > > rip-relative addresses but it doesn't look good. Worst case, we'd have > > to do the fixup_pointer() thing. > > > > In the meantime, Tom and I did some more poking at this and here's a > > diff ontop. > > > > The direction being that we'll stick both the AMD and Intel > > *cc_platform_has() call into cc_platform.c for which instrumentation > > will be disabled so no issues with that. > > > > And that will keep all that querying all together in a single file. > > And still do cc_platform_has() calls in __startup_64() codepath? > > It's broken. > > Intel detection in cc_platform_has() relies on boot_cpu_data.x86_vendor > which is not initialized until early_cpu_init() in setup_arch(). Given > that X86_VENDOR_INTEL is 0 it leads to false-positive. Yeah, Tom, I had the same question yesterday. /me looks in his direction. :-) -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec