From: Andy Lutomirski 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: Kees Cook Cc: Peter Zijlstra Cc: Brian Gerst Cc: Dave Hansen Cc: David Laight Cc: Borislav Petkov Cc: "Kirill A. Shutemov" --- Documentation/x86/x86_64/mm.txt | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/Documentation/x86/x86_64/mm.txt +++ b/Documentation/x86/x86_64/mm.txt @@ -19,8 +19,9 @@ ffffff0000000000 - ffffff7fffffffff (=39 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 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