We currently set x27 in compat_sys_sigreturn_wrapper and
compat_sys_rt_sigreturn_wrapper, similarly to what we do with r8/why on
32-bit ARM, in an attempt to prevent sigreturns from being restarted.

However, on arm64 we have always used pt_regs::syscallno for syscall
restarting (for both native and compat tasks), and x27 is never
inspected again before being overwritten in kernel_exit.

This patch removes the pointless register assignments.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The arm mmap2 syscall takes the offset in units of 4K, thus with 64K pages
the offset needs to be scaled to units of pages.
Signed-off-by: NAndreas Schwab <schwab@suse.de>
Signed-off-by: NAlexander Graf <agraf@suse.de>
[will: removed redundant lr parameter, localised PAGE_SHIFT #if check]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Unlike the sys_call_table[], the compat one was implemented in sys32.S
making it impossible to notice discrepancies between the number of
compat syscalls and the __NR_compat_syscalls macro, the latter having to
be defined in asm/unistd.h as including asm/unistd32.h would cause
conflicts on __NR_* definitions. With this patch, incorrect
__NR_compat_syscalls values will result in a build-time error.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Suggested-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>

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: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NMatthew Leach <matthew.leach@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

[fixes from Catalin Marinas folded]
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch converts the arm64 port to use the generic sys_execve()
implementation removing the arm64-specific (compat_)sys_execve_wrapper()
functions.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch only includes asm/unistd32.h where necessary and removes its
inclusion in the asm/unistd.h file. The __SYSCALL_COMPAT guard is
dropped.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>

This patch removes the compat __NR_* definitions from the unistd32.h
file and only keeps those that are used by the AArch64 kernel with a new
__NR_compat_* prefix. The additional wrapper definitions in
arch/arm64/kernel/sys32.S have been removed and the actual wrapper names
included in the asm/unistd32.h file.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>

This patch adds support for 32-bit applications. The vectors page is a
binary blob mapped into the application user space at 0xffff0000 (the
AArch64 toolchain does not support compilation of AArch32 code). Full
compatibility with ARMv7 user space is supported. The use of deprecated
ARMv7 functionality (SWP, CP15 barriers) has been disabled by default on
AArch64 kernels and unaligned LDM/STM is not supported.

Please note that only the ARM 32-bit EABI is supported, so no OABI
compatibility.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NOlof Johansson <olof@lixom.net>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>