From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Tue, 12 Dec 2017 07:56:43 -0800 Subject: [PATCH] x86/mm/64: Improve the memory map documentation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit CVE-2017-5754 The old docs had the vsyscall range wrong and were missing the fixmap. Fix both. There used to be 8 MB reserved for future vsyscalls, but that's long gone. Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Dave Hansen Cc: David Laight Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Kees Cook Cc: Kirill A. Shutemov Cc: Linus Torvalds Cc: Peter Zijlstra Signed-off-by: Ingo Molnar (cherry picked from commit 5a7ccf4754fb3660569a6de52ba7f7fc3dfaf280) Signed-off-by: Andy Whitcroft Signed-off-by: Kleber Sacilotto de Souza (cherry picked from commit d694898656126d8a04e86f681c8fe34ea57f1b85) Signed-off-by: Fabian Grünbichler --- Documentation/x86/x86_64/mm.txt | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt index 3448e675b462..83ca5a3b90ac 100644 --- a/Documentation/x86/x86_64/mm.txt +++ b/Documentation/x86/x86_64/mm.txt @@ -19,8 +19,9 @@ ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space ... unused hole ... ffffffff80000000 - ffffffff9fffffff (=512 MB) kernel text mapping, from phys 0 -ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space (variable) -ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls +ffffffffa0000000 - [fixmap start] (~1526 MB) module mapping space (variable) +[fixmap start] - ffffffffff5fffff kernel-internal fixmap range +ffffffffff600000 - ffffffffff600fff (=4 kB) legacy vsyscall ABI ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole Virtual memory map with 5 level page tables: @@ -41,8 +42,9 @@ ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space ... unused hole ... ffffffff80000000 - ffffffff9fffffff (=512 MB) kernel text mapping, from phys 0 -ffffffffa0000000 - ffffffffff5fffff (=1526 MB) module mapping space -ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls +ffffffffa0000000 - [fixmap start] (~1526 MB) module mapping space +[fixmap start] - ffffffffff5fffff kernel-internal fixmap range +ffffffffff600000 - ffffffffff600fff (=4 kB) legacy vsyscall ABI ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole Architecture defines a 64-bit virtual address. Implementations can support -- 2.14.2