Re: [PATCH 25/25] arm64:ilp32: add ARM64_ILP32 to Kconfig

From: Yury Norov
Date: Fri Apr 29 2016 - 12:09:48 EST


On Fri, Apr 29, 2016 at 05:03:34PM +0100, Catalin Marinas wrote:
> On Wed, Apr 06, 2016 at 01:08:47AM +0300, Yury Norov wrote:
> > +config ARM64_ILP32
> > + bool "Kernel support for ILP32"
> > + select COMPAT_WRAPPER
> > + help
> > + This option enables support for AArch64 ILP32 user space. ILP32
> > + is an ABI where long and pointers are 32bits but it uses the AARCH64
> > + instruction set.
>
> Is there any penalty for AArch32 tasks when selecting COMPAT_WRAPPER?
>
> --
> Catalin

No. AARCH32 doesn't define __SC_WRAP and so __SYSCALL macro is used,
which fills syscall table with sys_xxx versions, not compat_sys_xxx.