]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
x32: Handle the x32 system call flag
authorH. Peter Anvin <hpa@zytor.com>
Sun, 19 Feb 2012 15:56:26 +0000 (07:56 -0800)
committerH. Peter Anvin <hpa@zytor.com>
Mon, 20 Feb 2012 20:52:05 +0000 (12:52 -0800)
commitfca460f95e928bae373daa8295877b6905bc62b8
tree96247518911543b252f4a79cfdf578001473ff3d
parent9d3897630e14b3d33bcb24a3c0fa9d60a01d3058
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>
arch/x86/include/asm/compat.h
arch/x86/include/asm/syscall.h
arch/x86/include/asm/unistd.h
arch/x86/kernel/entry_64.S