linux-stable/arch
Thomas Garnier 45fc8757d1 x86: Make the GDT remapping read-only on 64-bit
This patch makes the GDT remapped pages read-only, to prevent accidental
(or intentional) corruption of this key data structure.

This change is done only on 64-bit, because 32-bit needs it to be writable
for TSS switches.

The native_load_tr_desc function was adapted to correctly handle a
read-only GDT. The LTR instruction always writes to the GDT TSS entry.
This generates a page fault if the GDT is read-only. This change checks
if the current GDT is a remap and swap GDTs as needed. This function was
tested by booting multiple machines and checking hibernation works
properly.

KVM SVM and VMX were adapted to use the writeable GDT. On VMX, the
per-cpu variable was removed for functions to fetch the original GDT.
Instead of reloading the previous GDT, VMX will reload the fixmap GDT as
expected. For testing, VMs were started and restored on multiple
configurations.

Signed-off-by: Thomas Garnier <thgarnie@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Luis R . Rodriguez <mcgrof@kernel.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rafael J . Wysocki <rjw@rjwysocki.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: kasan-dev@googlegroups.com
Cc: kernel-hardening@lists.openwall.com
Cc: kvm@vger.kernel.org
Cc: lguest@lists.ozlabs.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-pm@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Cc: zijun_hu <zijun_hu@htc.com>
Link: http://lkml.kernel.org/r/20170314170508.100882-3-thgarnie@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16 09:06:35 +01:00
..
alpha sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
arc arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
arm KVM fixes for v4.11-rc2 2017-03-11 14:24:58 -08:00
arm64 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-12 14:11:38 -07:00
avr32 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
blackfin sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
c6x sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
cris Merge branch 'prep-for-5level' 2017-03-10 08:59:07 -08:00
frv arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
h8300 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
hexagon arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
ia64 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
m32r sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
m68k sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
metag arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
microblaze arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
mips arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
mn10300 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
nios2 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
openrisc arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
parisc Merge branch 'parisc-4.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2017-03-03 16:20:06 -08:00
powerpc Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-12 14:18:49 -07:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-03-12 14:22:25 -07:00
score Fixup for arch/score after extable.h introduction 2017-03-11 14:16:50 -08:00
sh Merge branch 'prep-for-5level' 2017-03-10 08:59:07 -08:00
sparc arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
tile arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
um arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
unicore32 arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
x86 x86: Make the GDT remapping read-only on 64-bit 2017-03-16 09:06:35 +01:00
xtensa arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
.gitignore
Kconfig x86/mm: Introduce mmap_compat_base() for 32-bit mmap() 2017-03-13 14:59:22 +01:00