linux/arch/x86
Dave Hansen d1440b23c9 x86/mm: Factor out pageattr _PAGE_GLOBAL setting
The pageattr code has a pattern repeated where it sets _PAGE_GLOBAL
for present PTEs but clears it for non-present PTEs.  The intention
is to keep _PAGE_GLOBAL from getting confused with _PAGE_PROTNONE
since _PAGE_GLOBAL is for present PTEs and _PAGE_PROTNONE is for
non-present

But, this pattern makes no sense.  Effectively, it says, if you use
the pageattr code, always set _PAGE_GLOBAL when _PAGE_PRESENT.
canon_pgprot() will clear it if unsupported (because it masks the
value with __supported_pte_mask) but we *always* set it. Even if
canon_pgprot() did not filter _PAGE_GLOBAL, it would be OK.
_PAGE_GLOBAL is ignored when CR4.PGE=0 by the hardware.

This unconditional setting of _PAGE_GLOBAL is a problem when we have
PTI and non-PTI and we want some areas to have _PAGE_GLOBAL and some
not.

This updated version of the code says:
1. Clear _PAGE_GLOBAL when !_PAGE_PRESENT
2. Never set _PAGE_GLOBAL implicitly
3. Allow _PAGE_GLOBAL to be in cpa.set_mask
4. Allow _PAGE_GLOBAL to be inherited from previous PTE

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180406205502.86E199DA@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-09 18:27:32 +02:00
..
boot Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 17:46:37 -07:00
configs x86/unwind: Rename unwinder config options to 'CONFIG_UNWINDER_*' 2017-10-14 10:12:12 +02:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-02-12 08:57:21 -08:00
entry Merge branch 'linus' into x86/pti to pick up upstream changes 2018-04-09 18:24:58 +02:00
events Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 16:18:31 -07:00
hyperv KVM changes for 4.16 2018-02-10 13:16:35 -08:00
ia32 x86/entry: Do not special-case clone(2) in compat entry 2018-03-07 07:57:31 +01:00
include Merge branch 'linus' into x86/pti to pick up upstream changes 2018-04-09 18:24:58 +02:00
kernel Merge branch 'x86-dma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 17:18:45 -07:00
kvm Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 15:16:43 -07:00
lib Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 15:16:43 -07:00
math-emu License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mm x86/mm: Factor out pageattr _PAGE_GLOBAL setting 2018-04-09 18:27:32 +02:00
net bpf, x64: increase number of passes 2018-03-07 14:47:24 -08:00
oprofile x86/oprofile: Fix bogus GCC-8 warning in nmi_setup() 2018-02-21 09:54:17 +01:00
pci Merge branch 'x86-dma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 17:18:45 -07:00
platform Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 17:46:37 -07:00
power x86/mm: Replace compile-time checks for 5-level paging with runtime-time checks 2018-02-16 10:48:49 +01:00
purgatory x86/purgatory: Avoid creating stray .<pid>.d files, remove -MD from KBUILD_CFLAGS 2018-03-25 11:04:02 +02:00
ras License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
realmode x86-64/realmode: Add instruction suffix 2018-02-20 09:33:41 +01:00
tools x86: Treat R_X86_64_PLT32 as R_X86_64_PC32 2018-02-22 09:01:10 -08:00
um x86/cpu: Remove the CONFIG_X86_PPRO_FENCE=y quirk 2018-03-20 10:01:05 +01:00
video
xen Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 15:45:30 -07:00
.gitignore x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore 2018-02-13 14:10:29 +01:00
Kbuild
Kconfig Merge branch 'x86-dma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 17:18:45 -07:00
Kconfig.cpu Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-03-25 07:36:02 -10:00
Kconfig.debug Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-01-30 13:01:09 -08:00
Makefile Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 14:37:03 -07:00
Makefile_32.cpu License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile.um License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00