Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751758AbdFHPJ5 (ORCPT ); Thu, 8 Jun 2017 11:09:57 -0400 Received: from foss.arm.com ([217.140.101.70]:53382 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751463AbdFHPJz (ORCPT ); Thu, 8 Jun 2017 11:09:55 -0400 Date: Thu, 8 Jun 2017 16:09:50 +0100 From: Catalin Marinas To: Yury Norov Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Arnd Bergmann , Andrew Pinski , Heiko Carstens , Chris Metcalf , philipp.tomsich@theobroma-systems.com, Joseph Myers , zhouchengming1@huawei.com, Steve Ellcey , Prasun.Kapoor@caviumnetworks.com, Andreas Schwab , agraf@suse.de, szabolcs.nagy@arm.com, geert@linux-m68k.org, Adam Borowski , manuel.montezelo@gmail.com, Chris Metcalf , Andrew Pinski , linyongting@huawei.com, klimov.linux@gmail.com, broonie@kernel.org, Bamvor Zhangjian , Maxim Kuvyrkov , Florian Weimer , Nathan_Lynch@mentor.com, Ramana Radhakrishnan , schwidefsky@de.ibm.com, davem@davemloft.net, christoph.muellner@theobroma-systems.com Subject: Re: [PATCH 02/20] 32-bit ABI: introduce ARCH_32BIT_OFF_T config option Message-ID: <20170608150950.iqq4xgxu6zsa7m52@localhost> References: <20170604120009.342-1-ynorov@caviumnetworks.com> <20170604120009.342-3-ynorov@caviumnetworks.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170604120009.342-3-ynorov@caviumnetworks.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1794 Lines: 42 On Sun, Jun 04, 2017 at 02:59:51PM +0300, Yury Norov wrote: > All new 32-bit architectures should have 64-bit off_t type, but existing > architectures has 32-bit ones. > > To handle it, new config option is added to arch/Kconfig that defaults > ARCH_32BIT_OFF_T to be disabled for non-64 bit architectures. All existing > 32-bit architectures enable it explicitly here. > > New option affects force_o_largefile() behaviour. Namely, if off_t is > 64-bits long, we have no reason to reject user to open big files. > > Note that even if architectures has only 64-bit off_t in the kernel > (arc, c6x, h8300, hexagon, metag, nios2, openrisc, tile32 and unicore32), > a libc may use 32-bit off_t, and therefore want to limit the file size > to 4GB unless specified differently in the open flags. > > Signed-off-by: Yury Norov > Acked-by: Arnd Bergmann [...] > diff --git a/include/linux/fcntl.h b/include/linux/fcntl.h > index 1b48d9c9a561..297993c92490 100644 > --- a/include/linux/fcntl.h > +++ b/include/linux/fcntl.h > @@ -11,7 +11,7 @@ > O_NOATIME | O_CLOEXEC | O_PATH | __O_TMPFILE) > > #ifndef force_o_largefile > -#define force_o_largefile() (BITS_PER_LONG != 32) > +#define force_o_largefile() (!IS_ENABLED(CONFIG_ARCH_32BIT_OFF_T)) > #endif I may have confused myself with which off_t is 64-bit here for new 32-bit architectures. Are we referring to the glibc definition, the kernel one or simply that force_o_largefile() is true by default. Because the type off_t for 32-bit kernel builds is still, well, 32-bit. Otherwise it seems that the first paragraph in the description above should read "all new 32-bit ABIs on a 64-bit kernel..." but then AArch64/ILP32 is no longer the same as a new, pure 32-bit architecture. -- Catalin