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| author | H. Peter Anvin <hpa@zytor.com> | 2012-02-19 19:56:26 +0400 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2012-02-21 00:52:05 +0400 |
| commit | fca460f95e928bae373daa8295877b6905bc62b8 (patch) | |
| tree | 96247518911543b252f4a79cfdf578001473ff3d /arch/x86/include/asm/unistd.h | |
| parent | 9d3897630e14b3d33bcb24a3c0fa9d60a01d3058 (diff) | |
| download | linux-fca460f95e928bae373daa8295877b6905bc62b8.tar.xz | |
x32: Handle the x32 system call flag
x32 shares most system calls with x86-64, but unfortunately some
subsystem (the input subsystem is the chief offender) which require
is_compat() when operating with a 32-bit userspace. The input system
actually has text files in sysfs whose meaning is dependent on
sizeof(long) in userspace!
We could solve this by having two completely disjoint system call
tables; requiring that each system call be duplicated. This patch
takes a different approach: we add a flag to the system call number;
this flag doesn't affect the system call dispatch but requests compat
treatment from affected subsystems for the duration of the system call.
The change of cmpq to cmpl is safe since it immediately follows the
and.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/include/asm/unistd.h')
| -rw-r--r-- | arch/x86/include/asm/unistd.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/include/asm/unistd.h b/arch/x86/include/asm/unistd.h index 7a48a5557470..37cdc9d99bb1 100644 --- a/arch/x86/include/asm/unistd.h +++ b/arch/x86/include/asm/unistd.h @@ -5,6 +5,13 @@ #define __X32_SYSCALL_BIT 0x40000000 #ifdef __KERNEL__ + +# ifdef CONFIG_X86_X32_ABI +# define __SYSCALL_MASK (~(__X32_SYSCALL_BIT)) +# else +# define __SYSCALL_MASK (~0) +# endif + # ifdef CONFIG_X86_32 # include <asm/unistd_32.h> |