From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755427AbbLCRRj (ORCPT ); Thu, 3 Dec 2015 12:17:39 -0500 Received: from foss.arm.com ([217.140.101.70]:50358 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752749AbbLCRRg (ORCPT ); Thu, 3 Dec 2015 12:17:36 -0500 Date: Thu, 3 Dec 2015 17:17:31 +0000 From: Catalin Marinas To: Yury Norov Cc: Arnd Bergmann , pinskia@gmail.com, Prasun.Kapoor@caviumnetworks.com, Andreas Schwab , Nathan_Lynch@mentor.com, linux-kernel@vger.kernel.org, agraf@suse.de, klimov.linux@gmail.com, broonie@kernel.org, jan.dakinevich@gmail.com, joseph@codesourcery.com, ddaney.cavm@gmail.com, bamvor.zhangjian@huawei.com, philipp.tomsich@theobroma-systems.com, andrey.konovalov@linaro.org, linux-arm-kernel@lists.infradead.org, christoph.muellner@theobroma-systems.com Subject: Re: [PATCH v6 14/19] arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it Message-ID: <20151203171730.GN10747@e104818-lin.cambridge.arm.com> References: <1447795019-30176-1-git-send-email-ynorov@caviumnetworks.com> <2776283.xtmDQm6BqS@wuerfel> <87zixue8lj.fsf@igel.home> <1608639.5Yic1PH469@wuerfel> <20151202002430.GB23156@yury-N73SV> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151202002430.GB23156@yury-N73SV> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 02, 2015 at 03:24:30AM +0300, Yury Norov wrote: > On Tue, Dec 01, 2015 at 12:30:56PM +0100, Arnd Bergmann wrote: > > On Tuesday 01 December 2015 12:01:12 Andreas Schwab wrote: > > > Arnd Bergmann writes: > > > > > > > On Tuesday 01 December 2015 10:20:59 Andreas Schwab wrote: > > > >> Yury Norov writes: > > > >> > > > >> > There's a tricky bug with signal stack, that Andreas also discovered. > > > >> > > > >> That was only a confusion about the compat state of sys_rt_sigaction. > > > >> It just requires making sure glibc uses the correct (64bit layout) > > > >> struct kernel_sigaction. > > > > > > > > I don't think we need to use the 64-bit version of sigaction, both > > > > kernel and libc are simpler if we use the normal 32-bit version. > > > > > > Since glibc has to do the conversion anyway (due to sigset_t), using the > > > 64bit layout avoids a second conversion in the kernel. > > > > I don't get the part about sigset_t. Why would glibc want to use the > > 64-bit layout? This one looks like one of the cases where we absolutely > > want to use the 32-bit layout or otherwise get into big trouble if > > we ever want to support native ILP32 kernels. > > > > Arnd > > So, we drop patch #6, and use 32-bit layout for all signal structures. > > Correct? I would vote for this as well. I think it probably removes patch 12 as well (COMPAT_USE_NATIVE_SIGINFO). -- Catalin From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Thu, 3 Dec 2015 17:17:31 +0000 Subject: [PATCH v6 14/19] arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it In-Reply-To: <20151202002430.GB23156@yury-N73SV> References: <1447795019-30176-1-git-send-email-ynorov@caviumnetworks.com> <2776283.xtmDQm6BqS@wuerfel> <87zixue8lj.fsf@igel.home> <1608639.5Yic1PH469@wuerfel> <20151202002430.GB23156@yury-N73SV> Message-ID: <20151203171730.GN10747@e104818-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Dec 02, 2015 at 03:24:30AM +0300, Yury Norov wrote: > On Tue, Dec 01, 2015 at 12:30:56PM +0100, Arnd Bergmann wrote: > > On Tuesday 01 December 2015 12:01:12 Andreas Schwab wrote: > > > Arnd Bergmann writes: > > > > > > > On Tuesday 01 December 2015 10:20:59 Andreas Schwab wrote: > > > >> Yury Norov writes: > > > >> > > > >> > There's a tricky bug with signal stack, that Andreas also discovered. > > > >> > > > >> That was only a confusion about the compat state of sys_rt_sigaction. > > > >> It just requires making sure glibc uses the correct (64bit layout) > > > >> struct kernel_sigaction. > > > > > > > > I don't think we need to use the 64-bit version of sigaction, both > > > > kernel and libc are simpler if we use the normal 32-bit version. > > > > > > Since glibc has to do the conversion anyway (due to sigset_t), using the > > > 64bit layout avoids a second conversion in the kernel. > > > > I don't get the part about sigset_t. Why would glibc want to use the > > 64-bit layout? This one looks like one of the cases where we absolutely > > want to use the 32-bit layout or otherwise get into big trouble if > > we ever want to support native ILP32 kernels. > > > > Arnd > > So, we drop patch #6, and use 32-bit layout for all signal structures. > > Correct? I would vote for this as well. I think it probably removes patch 12 as well (COMPAT_USE_NATIVE_SIGINFO). -- Catalin