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Subject: Re: [PATCH v4] arm64, ia64, ppc, s390, sh, tile, um, x86, mm:
 Remove default gate area
From: Michael Ellerman <mpe@ellerman.id.au>
To: Andy Lutomirski <luto@amacapital.net>
Date: Tue, 29 Jul 2014 12:19:16 +1000
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Cc: linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org,
 Catalin Marinas <catalin.marinas@arm.com>,
 Heiko Carstens <heiko.carstens@de.ibm.com>, linux-mm@kvack.org,
 Paul Mackerras <paulus@samba.org>, "H. Peter Anvin" <hpa@zytor.com>,
 linux-arch@vger.kernel.org, linux-s390@vger.kernel.org,
 Richard Weinberger <richard@nod.at>, x86@kernel.org,
 Ingo Molnar <mingo@redhat.com>, Fenghua Yu <fenghua.yu@intel.com>,
 user-mode-linux-devel@lists.sourceforge.net, Will Deacon <will.deacon@arm.com>,
 Jeff Dike <jdike@addtoit.com>, Chris Metcalf <cmetcalf@tilera.com>,
 Thomas Gleixner <tglx@linutronix.de>, linux-arm-kernel@lists.infradead.org,
 Tony Luck <tony.luck@intel.com>, Nathan Lynch <Nathan_Lynch@mentor.com>,
 linux-kernel@vger.kernel.org, Martin Schwidefsky <schwidefsky@de.ibm.com>,
 linux390@de.ibm.com, Andrew Morton <akpm@linux-foundation.org>,
 linuxppc-dev@lists.ozlabs.org
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On Thu, 2014-07-24 at 13:56 -0700, Andy Lutomirski wrote:
> The core mm code will provide a default gate area based on
> FIXADDR_USER_START and FIXADDR_USER_END if
> !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
> 
> This default is only useful for ia64.  arm64, ppc, s390, sh, tile,
> 64-bit UML, and x86_32 have their own code just to disable it.  arm,
> 32-bit UML, and x86_64 have gate areas, but they have their own
> implementations.
> 
> This gets rid of the default and moves the code into ia64.
> 
> This should save some code on architectures without a gate area: it's
> now possible to inline the gate_area functions in the default case.

Looks good to me. Booted and everything seems happy, I still have a vdso etc.

Tested-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)

cheers