Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754420Ab3ETJqh (ORCPT ); Mon, 20 May 2013 05:46:37 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:44814 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750928Ab3ETJqg (ORCPT ); Mon, 20 May 2013 05:46:36 -0400 Date: Mon, 20 May 2013 10:46:04 +0100 From: Will Deacon To: David Daney Cc: Catalin Marinas , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "david.daney@cavium.com" Subject: Re: [PATCH] arm64: extable: sort the exception table at build time Message-ID: <20130520094604.GF31359@mudshark.cambridge.arm.com> References: <1368809021-25130-1-git-send-email-will.deacon@arm.com> <51967811.7090709@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51967811.7090709@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2330 Lines: 68 Hi David, On Fri, May 17, 2013 at 07:33:53PM +0100, David Daney wrote: > On 05/17/2013 09:43 AM, Will Deacon wrote: > > As is done for other architectures, sort the exception table at > > build-time rather than during boot. > > > > Since sortextable appears to be a standalone C program relying on the > > host elf.h to provide EM_AARCH64, I've had to add a conditional check in > > order to allow cross-compilation on machines that aren't running a > > bleeding-edge libc-dev. > > > > Signed-off-by: Will Deacon > > --- > > arch/arm64/Kconfig | 1 + > > arch/arm64/kernel/vmlinux.lds.S | 15 +++++++-------- > > scripts/sortextable.c | 5 +++++ > > 3 files changed, 13 insertions(+), 8 deletions(-) > > > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > index 48347dc..fb8fd90 100644 > > --- a/arch/arm64/Kconfig > > +++ b/arch/arm64/Kconfig > > @@ -7,6 +7,7 @@ config ARM64 > > select ARM_AMBA > > select ARM_ARCH_TIMER > > select ARM_GIC > > + select BUILDTIME_EXTABLE_SORT > > select CLONE_BACKWARDS > > select COMMON_CLK > > select GENERIC_CLOCKEVENTS > > diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S > > index 3fae2be..3d527726 100644 > > --- a/arch/arm64/kernel/vmlinux.lds.S > > +++ b/arch/arm64/kernel/vmlinux.lds.S > > @@ -57,6 +57,13 @@ SECTIONS > > > > RO_DATA(PAGE_SIZE) > > > > + . = ALIGN(8); > > + __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { > > + __start___ex_table = .; > > + *(__ex_table) > > + __stop___ex_table = .; > > + } > > + > > _etext = .; /* End of text and rodata section */ > > > You have moved this to rodata. I don't think I have moved this to rodata. The RO_DATA macro expands to a bunch of sections, but it doesn't leave any of them open at the end. > o Will the runtime sort still work like this? > > o Do we care? Maybe not. For arm64 we'd be moving exclusively to build-time sorting, so I guess we *could* stick the thing in rodata if we wanted to. Not sure it's worth the linker script munging though. Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/