diff options
| author | Andy Lutomirski <luto@kernel.org> | 2018-03-07 11:12:27 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-03-08 06:48:15 +0100 |
| commit | 076ca272a14cea558b1092ec85cea08510283f2a (patch) | |
| tree | 0a64e5c6a05353554b6f0d2100aebd4b7cc070df /arch/x86/include | |
| parent | 91c5f0de64a226e0d9c558b26ef7c2655ef31cca (diff) | |
| download | linux-076ca272a14cea558b1092ec85cea08510283f2a.tar.bz2 | |
x86/vsyscall/64: Drop "native" vsyscalls
Since Linux v3.2, vsyscalls have been deprecated and slow. From v3.2
on, Linux had three vsyscall modes: "native", "emulate", and "none".
"emulate" is the default. All known user programs work correctly in
emulate mode, but vsyscalls turn into page faults and are emulated.
This is very slow. In "native" mode, the vsyscall page is easily
usable as an exploit gadget, but vsyscalls are a bit faster -- they
turn into normal syscalls. (This is in contrast to vDSO functions,
which can be much faster than syscalls.) In "none" mode, there are
no vsyscalls.
For all practical purposes, "native" was really just a chicken bit
in case something went wrong with the emulation. It's been over six
years, and nothing has gone wrong. Delete it.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/519fee5268faea09ae550776ce969fa6e88668b0.1520449896.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/pgtable_types.h | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 246f15b4e64c..acfe755562a6 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -174,7 +174,6 @@ enum page_cache_mode { #define __PAGE_KERNEL_RO (__PAGE_KERNEL & ~_PAGE_RW) #define __PAGE_KERNEL_RX (__PAGE_KERNEL_EXEC & ~_PAGE_RW) #define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL | _PAGE_NOCACHE) -#define __PAGE_KERNEL_VSYSCALL (__PAGE_KERNEL_RX | _PAGE_USER) #define __PAGE_KERNEL_VVAR (__PAGE_KERNEL_RO | _PAGE_USER) #define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE) #define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE) @@ -206,7 +205,6 @@ enum page_cache_mode { #define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE | _PAGE_ENC) #define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE | _PAGE_ENC) #define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC | _PAGE_ENC) -#define PAGE_KERNEL_VSYSCALL __pgprot(__PAGE_KERNEL_VSYSCALL | _PAGE_ENC) #define PAGE_KERNEL_VVAR __pgprot(__PAGE_KERNEL_VVAR | _PAGE_ENC) #define PAGE_KERNEL_IO __pgprot(__PAGE_KERNEL_IO) |