From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8141FC2D0C2 for ; Mon, 30 Dec 2019 15:47:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 534342071E for ; Mon, 30 Dec 2019 15:47:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727531AbfL3Pr4 (ORCPT ); Mon, 30 Dec 2019 10:47:56 -0500 Received: from mout.kundenserver.de ([217.72.192.74]:37727 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727397AbfL3Prz (ORCPT ); Mon, 30 Dec 2019 10:47:55 -0500 Received: from mail-qt1-f172.google.com ([209.85.160.172]) by mrelayeu.kundenserver.de (mreue107 [212.227.15.145]) with ESMTPSA (Nemesis) id 1M58SY-1in3CY0kHk-0017mD; Mon, 30 Dec 2019 16:47:54 +0100 Received: by mail-qt1-f172.google.com with SMTP id e5so29857594qtm.6; Mon, 30 Dec 2019 07:47:53 -0800 (PST) X-Gm-Message-State: APjAAAWxHvcFVLv1Cs8FC/eIa2GG266m8Xis5ID6vHSqXu5Z4p9FpFIa c+fl+Dknj+BkC7PFHSeEYqHfKCim6NBrEhAwzfM= X-Google-Smtp-Source: APXvYqzS9Daau4V6KdFtMzVDpaHEdaxphNfcAOGaF7CR6jf69NGaa3wFFDLjiwkZ+wtx1QS+13hvCMDyUD2ID479i1E= X-Received: by 2002:ac8:709a:: with SMTP id y26mr49110478qto.304.1577720873024; Mon, 30 Dec 2019 07:47:53 -0800 (PST) MIME-Version: 1.0 References: <20191223130834.GA102399@zx2c4.com> <20191224135404.389039-1-Jason@zx2c4.com> In-Reply-To: From: Arnd Bergmann Date: Mon, 30 Dec 2019 16:47:37 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] mips: vdso: conditionalize 32-bit time functions on COMPAT_32BIT_TIME To: "Jason A. Donenfeld" Cc: "linux-kernel@vger.kernel.org" , "open list:BROADCOM NVRAM DRIVER" , Paul Burton , Vincenzo Frascino , Christian Brauner Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:evaCvZk8IUe5DvZ2WF2ej/4JZiaCp6VDfXgAASc3StzTy+WWyux 9q/Fe1VLxcTyurCjEbpHcvcGJiwvUYV582B9WHcgfaGRc/9SPpeqDlQuECyaylFN3lxXK66 7WGy4AstLRmSndFk78TaiQZfLzQciuyELEZCvMZAr/YBJoZiBljgZYQKSdPWW/W89SY7qSk 53MuPvPSxgt8bRz8Ium4w== X-UI-Out-Filterresults: notjunk:1;V03:K0:/oHvFZngoeg=:Xo2Ww0CgxaMTEALgxQtEFW 3R2fS9honTvQy9E6Dlg+ok2VaaaCKbHQEagpbNtNX3ramhc+0FFM+MvLAR5hSlqDI3emjV13J tnviOrVt9AzEZHayALsgC15Q2GpnPDNZ1CvWSQ8XMwlgACkGBJhYjaMWKGU8aQ+5dGVw3HbJq TYyv/urUvyiOObm3Sed+/mCAPZzxemMPLZWw39TWY1oizXiMdXNh/giobItiwwLWSxG3LDZCn M8OOCFgaLAJQoAr/BcdZ7HdADXpycgkX2W2mYBv1CwNkDf3Wtv5dcciyFByOQr/rs2kX4T7UW UybFKrsmIVDBK8PowVMEZcDlVcrQ27JImyAQehm2CA8yVjgQMg2qdK4EtKSt9zb/kiILhNiZF ulCs20ibaCs+qO1XGPcZedqB9TTmQrEA5mvAxj3CyBe60iNQZqzmiZ+2cbmTuJwuzAVfTk6jB d5+AQI2EkDUN5VTzeyNpw5+Hjp/YQzczhuBhK9ak2ajOapb3bG+BFTnkJXsYBlposab5kwVKL BagpAHwUdIjgcEDvwVrdc+U3YUG0zgn37dKZ7ZO9Ms+/KQLkIqDuZrZYL4pcB/5467IY1arOT T5Qn58IMUbjIN98r1tvtxRDDBWe224mSIzXMlIjuukDa3X2WDGJB0CgrJgcms/2h7vMqEWQlr mCwdhDAdPJWDr+05gFETuiubBNSrxbrKQafPZ36rVBxbssPCKl1Et6SSJCHbTsGizrVz1kGhM e+VAlry16Fn7qRCSz5//EvdB4D6HfcfgTIb+F5LyO8QwfTZmfrEMJC6QcKxIg/ewkvtG4/ynd hPqNmsymey24asg8Zft48oBfklJuqoVCTyy0BmEmACsGiXByRRIK8JyMMRwNwNcyvoQPXoUmv zmLxS8ZhhSyS0+GDUf7g== Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Mon, Dec 30, 2019 at 4:39 PM Jason A. Donenfeld wrote: > > On Mon, Dec 30, 2019 at 4:37 PM Arnd Bergmann wrote: > > > > On Mon, Dec 30, 2019 at 3:37 PM Jason A. Donenfeld wrote: > > > > > > On Mon, Dec 30, 2019 at 1:34 PM Arnd Bergmann wrote: > > Returning success from clock_gettime() on a kernel with only > > time64 support and a libc with only time32 support (or vice > > versa) would be a bug. > > Ah, right, hence why the 32-bit compat code is behind a > still-on-by-default-but-not-for-long menu option. I expect this to remain on-by-default for a rather long time, as we still to run old binaries well into 2030s. Making it configurable is done for two reasons: - on embedded systems that have all user space built with time64, turning this off can make the kernel slightly smaller - turning it off lets you check that no code relies on calling the old interfaces internally, bypassing the C library, in a way that works at the moment but may break after 2038. Arnd