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Date:   Thu, 13 Dec 2018 12:12:13 +0000
From:   Kevin Easton <kevin@guarana.org>
To:     Richard Weinberger <richard.weinberger@gmail.com>
Cc:     glaubitz@physik.fu-berlin.de, Andy Lutomirski <luto@kernel.org>,
        x86@kernel.org, LKML <linux-kernel@vger.kernel.org>,
        "open list:ABI/API" <linux-api@vger.kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Borislav Petkov <bp@alien8.de>, fweimer@redhat.com,
        Mike Frysinger <vapier@gentoo.org>,
        "H.J. Lu" <hjl.tools@gmail.com>, dalias@libc.org,
        x32@buildd.debian.org, Arnd Bergmann <arnd@arndb.de>,
        Will Deacon <will.deacon@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: Can we drop upstream Linux x32 support?
Message-ID: <20181213121213.GA28833@ip-172-31-15-78>
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On Thu, Dec 13, 2018 at 10:05:14AM +0100, Richard Weinberger wrote:
> On Thu, Dec 13, 2018 at 6:03 AM Kevin Easton <kevin@guarana.org> 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