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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2F347ECAAD1 for ; Thu, 1 Sep 2022 16:04:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=MmbD2ea1oQH/JQMA35SbQEdaSYUjoy/OaFseaQNz7xc=; b=SNuADVSw71sFIo F8UPMZ0WISYHUUfQ6a4Zj7S+N5Ayv50guJBWbe3TEN/a8P+UhruOTaM7tMYkez3Evj0g5kC3umaAw FBdKrrp76GG6x8wIYwo4ykmjq5WVNGPYBgCxhoJwsPXZIJ6RNPQ/bsEBj6Xy63alhLGY0qu0wO4Li AosmJFg8JdA6NMVCupM+K8B93V9i1998FA5B0uP884TLa+3PQ9Box7OkU1lCEYkcOjHe5gXpB8LA1 DbikPF2gvyQ4d7VjEg8SzEODg0ZAPdxRkk3mhdyrtM3RLaY5Kbp6aOvUAVEMaC7ONsW2MtnOqsPcB mP0Cmho/+OO1yFESzN2w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oTmef-00D8AH-9W; Thu, 01 Sep 2022 16:02:57 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oTmec-00D895-OP for linux-arm-kernel@lists.infradead.org; Thu, 01 Sep 2022 16:02:56 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=GBlUubwJ1i0equBHz0UkOl5oW4gbLV35bFtJwXHHFxI=; b=cUG+AuwP77hxFFWtKjzkj2qp+d eUdcmutkFl/GVgNiPYfxGoDvmkj/0FQ0A/LZyJ1OU3pkF71krhZskSAWnblJ6+m33HIFP/+UTj/Jt qZtSm47djLuTp9MWfFmakE6EFthPvS37PkqrH1bmCEP+R8qVGJm4TvWk7mF6zwnaA+klbKGPrisV6 hILkdcBDFK35zQk9n56YQCLVm56aGcxKCKLDyd7bFCTA8jAzZaWtVDjvcxLGlHMgUJUhh83h/Sg8y TsDtywUUS555H87/Q51XkiOVt66mYCRNzrWWr2GjH3PEI8n4q6BQ9bpe38GljDARPmyeIRCsgDrbd 2HA5a9Xw==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:34048) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1oTmea-0006CW-7w; Thu, 01 Sep 2022 17:02:52 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1oTmeZ-0003ag-Ee; Thu, 01 Sep 2022 17:02:51 +0100 Date: Thu, 1 Sep 2022 17:02:51 +0100 From: "Russell King (Oracle)" To: Arnd Bergmann Cc: Alexandre Belloni , linux-arm-kernel@lists.infradead.org, y2038@lists.linaro.org Subject: Re: [Y2038] Re: RTC hctosys disabled for 32-bit systems Message-ID: References: <802ca9c8-4b61-4568-a946-8e6330807eb3@www.fastmail.com> <8eca48d9-bd10-4857-9e43-a5b20a8db625@www.fastmail.com> <511f86d8-eadf-40ba-9f0c-022cc4d251fb@www.fastmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <511f86d8-eadf-40ba-9f0c-022cc4d251fb@www.fastmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220901_090254_822439_7F9FD7FF X-CRM114-Status: GOOD ( 31.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Sep 01, 2022 at 05:48:01PM +0200, Arnd Bergmann wrote: > On Thu, Sep 1, 2022, at 3:46 PM, Russell King (Oracle) wrote: > > On Thu, Sep 01, 2022 at 03:12:57PM +0200, Arnd Bergmann wrote: > >> Ah, I forgot that systemd actually needs it. So I guess there is > >> currently no way to use systemd on 32-bit machines that are > >> meant to survive 2038, regardless of whether systemd and glibc are > >> built with a 64-bit time_t or not, right? > >> > >> Is there perhaps a way to change the logic in a way that > >> it does not depend on the current time but instead depends > >> on a property of the RTC device itself, so we make systems > >> break immediately instead of by surprise in 2038? > > > > Are you seriously suggesting to cause regressions on systems where > > the RTC can send the kernel's timekeeping back to the early 1900s, > > rather than printing a big fat warning message in the kernel log? > > I think the systems that can send the timekeeping back into the early > 1900s (or at least after 1970) are fine, the problem is the systems > that can randomly send the timekeeping into the post-2038 future. I believe Armada 388 systems can do that - and since Armada 388 systems are involved in my connectivity, I would very much prefer it if someone doesn't patch stuff that causes them to explode when I decide to upgrade the kernel. (Yes, I've run into the broken systemd issue with them when the RTC was not correctly set on platform delivery.) > What kind of warning would you suggest to print here? I don't see > how warning about broken hardware at every boot would help, since > there is no way for users to react to that warning. Similarly, > warning about a time_t value past 2038 does not help because > at that time one either has a bricked system (if using a systemd > with 32-bit time_t) or it is actually 2038 and the system > reverts back to 1970. > > What might work is to have all drivers for broken RTC devices > default to a 1902-2037 (or 1970-2037) date range to ensure > that only those devices are broken in 2038, but still allow > overriding the "start-year" property in DT for machines that > don't use the broken systemd. I don't care too much how it's handled, but my objection is purely against the intentional breaking of platforms such that they cause people pain. Sure, they will break in 2038, but that's no reason to break them in 2022/3. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel