linux/arch/arm64/kernel/sys32.S
Matthew Leach 55b89540b0 arm64: compat: correct register concatenation for syscall wrappers
The arm64 port contains wrappers for arm32 syscalls that pass 64-bit
values. These wrappers concatenate the two registers to hold a 64-bit
value in a single X register. On BE, however, the lower and higher
words are swapped.

Create a new assembler macro, regs_to_64, that when on BE systems
swaps the registers in the orr instruction.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-10-25 15:59:36 +01:00

116 lines
2.8 KiB
ArmAsm

/*
* Compat system call wrappers
*
* Copyright (C) 2012 ARM Ltd.
* Authors: Will Deacon <will.deacon@arm.com>
* Catalin Marinas <catalin.marinas@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
/*
* System call wrappers for the AArch32 compatibility layer.
*/
compat_sys_sigreturn_wrapper:
mov x0, sp
mov x27, #0 // prevent syscall restart handling (why)
b compat_sys_sigreturn
ENDPROC(compat_sys_sigreturn_wrapper)
compat_sys_rt_sigreturn_wrapper:
mov x0, sp
mov x27, #0 // prevent syscall restart handling (why)
b compat_sys_rt_sigreturn
ENDPROC(compat_sys_rt_sigreturn_wrapper)
compat_sys_statfs64_wrapper:
mov w3, #84
cmp w1, #88
csel w1, w3, w1, eq
b compat_sys_statfs64
ENDPROC(compat_sys_statfs64_wrapper)
compat_sys_fstatfs64_wrapper:
mov w3, #84
cmp w1, #88
csel w1, w3, w1, eq
b compat_sys_fstatfs64
ENDPROC(compat_sys_fstatfs64_wrapper)
/*
* Wrappers for AArch32 syscalls that either take 64-bit parameters
* in registers or that take 32-bit parameters which require sign
* extension.
*/
compat_sys_pread64_wrapper:
regs_to_64 x3, x4, x5
b sys_pread64
ENDPROC(compat_sys_pread64_wrapper)
compat_sys_pwrite64_wrapper:
regs_to_64 x3, x4, x5
b sys_pwrite64
ENDPROC(compat_sys_pwrite64_wrapper)
compat_sys_truncate64_wrapper:
regs_to_64 x1, x2, x3
b sys_truncate
ENDPROC(compat_sys_truncate64_wrapper)
compat_sys_ftruncate64_wrapper:
regs_to_64 x1, x2, x3
b sys_ftruncate
ENDPROC(compat_sys_ftruncate64_wrapper)
compat_sys_readahead_wrapper:
regs_to_64 x1, x2, x3
mov w2, w4
b sys_readahead
ENDPROC(compat_sys_readahead_wrapper)
compat_sys_fadvise64_64_wrapper:
mov w6, w1
regs_to_64 x1, x2, x3
regs_to_64 x2, x4, x5
mov w3, w6
b sys_fadvise64_64
ENDPROC(compat_sys_fadvise64_64_wrapper)
compat_sys_sync_file_range2_wrapper:
regs_to_64 x2, x2, x3
regs_to_64 x3, x4, x5
b sys_sync_file_range2
ENDPROC(compat_sys_sync_file_range2_wrapper)
compat_sys_fallocate_wrapper:
regs_to_64 x2, x2, x3
regs_to_64 x3, x4, x5
b sys_fallocate
ENDPROC(compat_sys_fallocate_wrapper)
#undef __SYSCALL
#define __SYSCALL(x, y) .quad y // x
/*
* The system calls table must be 4KB aligned.
*/
.align 12
ENTRY(compat_sys_call_table)
#include <asm/unistd32.h>