Messages in this thread | | | Date | Tue, 12 Dec 2017 20:18:50 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH PTI v3 01/10] x86/espfix/64: Fix espfix double-fault handling on 5-level systems |
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On Tue, Dec 12, 2017 at 07:56:36AM -0800, Andy Lutomirski wrote: > Using PGDIR_SHIFT to identify espfix64 addresses on 5-level systems > was wrong, and it resulted in panics due to unhandled double faults. > Use P4D_SHIFT instead, which is correct on 4-level and 5-level > machines. > > This fixes a panic when running x86 selftests on 5-level machines. > > Fixes: 1d33b219563f ("x86/espfix: Add support for 5-level paging") > Cc: stable@vger.kernel.org > Cc: "Kirill A. Shutemov" <kirill@shutemov.name> > Cc: Dave Hansen <dave.hansen@intel.com> > Signed-off-by: Andy Lutomirski <luto@kernel.org>
Thanks for catching this.
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
I remember that I tested espfix before and it was fine. That's strange.
With this patch on top of tip/WIP.x86/pti plus the change I've mentioned before, sigreturn_64 doesn't crash qemu for me anymore.
-- Kirill A. Shutemov
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