From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5821D371D13; Fri, 6 Mar 2026 20:53:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772830413; cv=none; b=cVKzGUaC6Vz+zi+Kvr9Pfq9gFJXN7PwZnh+BP9TOkHJMAUlO1eT9AT4vOlGk/8aK31rYpQskT8RmcIdvC5UyDLy7TqxNKhTBSPbLfKqyxZNrG+HqgUBDDyUQcUAcOKt+1dkgTIVpSXQLtgs548Fs+CsV+1vGXtGSO1J4l9I/Aek= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772830413; c=relaxed/simple; bh=t5jttNPZKFxy6e3UDlTOBng4frqdcf3GdkXXjwI4w+M=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=CeAjK4256ekRG6WizX3sZxyXcQ0Z0Y5rxObX4ShbfYVhj+sX8d073q1YA4HjZQcdRFxdrkY8USBwUa3ge2bnRJnnGudWl3+Fyodqzf4UzpF9wuGUx+rw9JKfnZAy1iDS2XOLHdCvL8C/vVHjUIop5GpjGfFT18WUOs/73zTaNzc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=EQ2m+UyI; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="EQ2m+UyI" Received: from ehlo.thunderbird.net (c-76-133-66-138.hsd1.ca.comcast.net [76.133.66.138]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 626KqRb51958825 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Fri, 6 Mar 2026 12:52:28 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 626KqRb51958825 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2026022301; t=1772830352; bh=t5jttNPZKFxy6e3UDlTOBng4frqdcf3GdkXXjwI4w+M=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=EQ2m+UyIgHt4NPpBkDK9oDRl5sriE4QzwZICCF14NYbr9o9jnA4P5x6Ki7PI/c1Pq MuB2CVSSZ1iN8/dlczEbnC0/V+ODW0STv+tMDFCGAqTNta3kvUwK3wx7igCIxtYepf WP4Xgt2sBbl4oyXlo1NEh/P7iQ1F8nGYKsh0x45/4ix+F4yHgCtkuzJkzYrwYPKOfj ZGBQDFMVCSRv3f1XvPA5D4Ut5gSR5N9/iNyb0omf0tkCFi13Z6kw+SSDHf0RObIZBO eFidDjr3ZT6lb7idOI/GLFTlUAcnpNsbe7YnJMV2SZmCjXKy6cCOrXgsYEUmxi7GJ3 06pqSMGXttJhQ== Date: Fri, 06 Mar 2026 12:52:21 -0800 From: "H. Peter Anvin" To: =?ISO-8859-1?Q?Thomas_Wei=DFschuh?= CC: Arnd Bergmann , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Russell King , Catalin Marinas , Will Deacon , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Thomas Bogendoerfer , Vincenzo Frascino , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-mips@vger.kernel.org Subject: Re: [PATCH 1/7] x86/vdso: Respect COMPAT_32BIT_TIME User-Agent: K-9 Mail for Android In-Reply-To: <20260306103113-ae63c668-2921-4ac1-84f6-35fbc8a6397d@linutronix.de> References: <20260227-vdso-compat_32bit_time-v1-0-3f0286a7bac3@linutronix.de> <20260227-vdso-compat_32bit_time-v1-1-3f0286a7bac3@linutronix.de> <03cd1e21-a2f2-46a1-a674-cbaef9712016@app.fastmail.com> <20260227103226-cc3bb32c-0107-4c09-b81a-ca33ea03ad5c@linutronix.de> <49b7c9f9-198a-49f7-880b-6ae74d7bd985@zytor.com> <20260304081505-a2a3a376-20c9-46cb-8dc9-2c4deec1a55e@linutronix.de> <6909A81E-AE50-459C-9604-3EEAEFE3838E@zytor.com> <20260305080950-ff43457b-0551-480f-916e-6c252e6a64af@linutronix.de> <2e609a1b-62de-4688-b363-58025ab9e703@zytor.com> <20260306103113-ae63c668-2921-4ac1-84f6-35fbc8a6397d@linutronix.de> Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On March 6, 2026 1:42:25 AM PST, "Thomas Wei=C3=9Fschuh" wrote: >On Thu, Mar 05, 2026 at 03:57:59PM -0800, H=2E Peter Anvin wrote: >> On 2026-03-05 01:24, Thomas Wei=C3=9Fschuh wrote: >> >=20 >> >> Weak references would be a way to work around the link failures=2E= =20 >> >=20 >> > I am still not sure where "the link failures" should be coming from= =2E >> > The only sense I can make out of it, is if somebody manually and dire= ctly links >> > to vdso=2Eso=2E Like in the following example: > >(=2E=2E=2E) > >> > This actually works on glibc (not on musl)=2E But it is highly non-st= andard and >> > relies on multiple implementation details=2E Furthermore it can fail = to run on >> > systems without a vDSO, as mentioned before=2E >> >=20 >> > Is this the usage pattern you have in mind? >> > Do you know of anybody doing things this way? >> >=20 >>=20 >> Yes, and yes, I do=2E > >Thanks=2E > >Do you know why it is done this way? Are these applications public and >if so, could you point me to them? >In case we stub out the vDSO functions with ENOSYS, would these >applications be able to handle that error gracefully? > >Personally I am still in favor of removing these functions completely >when !COMPAT_32BIT_TIME=2E > > >Thomas I think I agree with you (and sadly, no, I can't point at them directly=2E= )