From mboxrd@z Thu Jan  1 00:00:00 1970
From: catalin.marinas@arm.com (Catalin Marinas)
Date: Fri, 29 Apr 2016 17:14:46 +0100
Subject: [PATCH 25/25] arm64:ilp32: add ARM64_ILP32 to Kconfig
In-Reply-To: <20160429160855.GA16451@yury-N73SV>
References: <1459894127-17698-1-git-send-email-ynorov@caviumnetworks.com>
 <1459894127-17698-26-git-send-email-ynorov@caviumnetworks.com>
 <20160429160334.GD30316@e104818-lin.cambridge.arm.com>
 <20160429160855.GA16451@yury-N73SV>
Message-ID: <20160429161445.GE30316@e104818-lin.cambridge.arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Fri, Apr 29, 2016 at 07:08:55PM +0300, Yury Norov wrote:
> 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?
> 
> 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.

Ah, I forgot it has its own unistd32.h.

Thanks.

-- 
Catalin