patches/kernel/0206-x86-mm-64-Make-a-full-PGD-entry-size-hole-in-the-mem.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Andy Lutomirski <luto@kernel.org>
   3 Date: Tue, 12 Dec 2017 07:56:44 -0800
   4 Subject: [PATCH] x86/mm/64: Make a full PGD-entry size hole in the memory map
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 CVE-2017-5754
  10
  11 Shrink vmalloc space from 16384TiB to 12800TiB to enlarge the hole starting
  12 at 0xff90000000000000 to be a full PGD entry.
  13
  14 A subsequent patch will use this hole for the pagetable isolation LDT
  15 alias.
  16
  17 Signed-off-by: Andy Lutomirski <luto@kernel.org>
  18 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  19 Cc: Borislav Petkov <bp@alien8.de>
  20 Cc: Brian Gerst <brgerst@gmail.com>
  21 Cc: Dave Hansen <dave.hansen@intel.com>
  22 Cc: Dave Hansen <dave.hansen@linux.intel.com>
  23 Cc: David Laight <David.Laight@aculab.com>
  24 Cc: H. Peter Anvin <hpa@zytor.com>
  25 Cc: Josh Poimboeuf <jpoimboe@redhat.com>
  26 Cc: Juergen Gross <jgross@suse.com>
  27 Cc: Kees Cook <keescook@chromium.org>
  28 Cc: Kirill A. Shutemov <kirill@shutemov.name>
  29 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  30 Cc: Peter Zijlstra <peterz@infradead.org>
  31 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  32 (cherry picked from commit 9f449772a3106bcdd4eb8fdeb281147b0e99fb30)
  33 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  34 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  35 (cherry picked from commit 29b1c137d449dfc8fdcb476158f236625691fd28)
  36 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  37 ---
  38  Documentation/x86/x86_64/mm.txt         | 4 ++--
  39  arch/x86/include/asm/pgtable_64_types.h | 4 ++--
  40  2 files changed, 4 insertions(+), 4 deletions(-)
  41
  42 diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
  43 index 51101708a03a..496a1dbf139d 100644
  44 --- a/Documentation/x86/x86_64/mm.txt
  45 +++ b/Documentation/x86/x86_64/mm.txt
  46 @@ -29,8 +29,8 @@ Virtual memory map with 5 level page tables:
  47  hole caused by [56:63] sign extension
  48  ff00000000000000 - ff0fffffffffffff (=52 bits) guard hole, reserved for hypervisor
  49  ff10000000000000 - ff8fffffffffffff (=55 bits) direct mapping of all phys. memory
  50 -ff90000000000000 - ff91ffffffffffff (=49 bits) hole
  51 -ff92000000000000 - ffd1ffffffffffff (=54 bits) vmalloc/ioremap space
  52 +ff90000000000000 - ff9fffffffffffff (=52 bits) hole
  53 +ffa0000000000000 - ffd1ffffffffffff (=54 bits) vmalloc/ioremap space (12800 TB)
  54  ffd2000000000000 - ffd3ffffffffffff (=49 bits) hole
  55  ffd4000000000000 - ffd5ffffffffffff (=49 bits) virtual memory map (512TB)
  56  ... unused hole ...
  57 diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
  58 index 42e2750da525..5932dead34ee 100644
  59 --- a/arch/x86/include/asm/pgtable_64_types.h
  60 +++ b/arch/x86/include/asm/pgtable_64_types.h
  61 @@ -78,8 +78,8 @@ typedef struct { pteval_t pte; } pte_t;
  62  #define MAXMEM                 _AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)
  63
  64  #ifdef CONFIG_X86_5LEVEL
  65 -# define VMALLOC_SIZE_TB       _AC(16384, UL)
  66 -# define __VMALLOC_BASE                _AC(0xff92000000000000, UL)
  67 +# define VMALLOC_SIZE_TB       _AC(12800, UL)
  68 +# define __VMALLOC_BASE                _AC(0xffa0000000000000, UL)
  69  # define __VMEMMAP_BASE                _AC(0xffd4000000000000, UL)
  70  #else
  71  # define VMALLOC_SIZE_TB       _AC(32, UL)
  72 --
  73 2.14.2
  74