From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Easton Subject: Re: Can we drop upstream Linux x32 support? Date: Thu, 13 Dec 2018 12:12:13 +0000 Message-ID: <20181213121213.GA28833@ip-172-31-15-78> References: <70bb54b2-8ed3-b5ee-c02d-6ef66c4f27eb@physik.fu-berlin.de> <20181213050313.GA21201@ip-172-31-15-78> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Richard Weinberger Cc: glaubitz@physik.fu-berlin.de, Andy Lutomirski , x86@kernel.org, LKML , "open list:ABI/API" , "H. Peter Anvin" , Peter Zijlstra , Borislav Petkov , fweimer@redhat.com, Mike Frysinger , "H.J. Lu" , dalias@libc.org, x32@buildd.debian.org, Arnd Bergmann , Will Deacon , Catalin Marinas , Linus Torvalds List-Id: linux-api@vger.kernel.org On Thu, Dec 13, 2018 at 10:05:14AM +0100, Richard Weinberger wrote: > On Thu, Dec 13, 2018 at 6:03 AM Kevin Easton wrote: > > > > On Tue, Dec 11, 2018 at 11:29:14AM +0100, John Paul Adrian Glaubitz wrote: > > ... > > > I can't say anything about the syscall interface. However, what I do know > > > is that the weird combination of a 32-bit userland with a 64-bit kernel > > > interface is sometimes causing issues. For example, application code usually > > > expects things like time_t to be 32-bit on a 32-bit system. However, this > > > isn't the case for x32 which is why code fails to build. > > > > OpenBSD and NetBSD both have 64-bit time_t on 32-bit systems and have > > had for four or five years at this point. > > They can also do flag-day changes and break existing applications, Linux not. Sure, but the point is that most widely-used software has probably by now come in to contact with systems where time_t is bigger than long. - Kevin