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 42D5AF31E22 for ; Thu, 9 Apr 2026 14:47:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Date:Cc:To:From :Subject:Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=vtWvECdJsOce5KQBkQ6BB16WnHR2lmUFEE8FNue2MfA=; b=OloF115nAeofaywWE9Z8Xpb8sp 96FEUtgipZkuXNaVE7CPxtScDt0/iMmWjhbgnftpxKokZUr0HSCXRMx4T3wcS6LmbZgsmFdnCVE5b 2ulFQpGkVug5vno+pfZ0AZK28V7lM+/vnI26seaTH4GA5c//P+/VhIYMjGj5S61+FanOV65Q8Jj/7 Hpd7iBvcUguocGcais/zCzbOaeE56fMFFHpdnhlWP+MBd3eW2Mzs04ElH0xq094LqxMFKbcJPPe26 0nM3O0fN1TAt6fdqGx2YcgYcrpaiUOTdr//D77C7C9E4F3HoJ1pe+uqXx6IB8o2pGTRK2FG4IHLqI D32T4HXQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wAqff-0000000AjMv-2b5b; Thu, 09 Apr 2026 14:47:51 +0000 Received: from s3.sipsolutions.net ([2a01:4f8:242:246e::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wAqfa-0000000AjL8-2yzn for linux-um@lists.infradead.org; Thu, 09 Apr 2026 14:47:48 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=vtWvECdJsOce5KQBkQ6BB16WnHR2lmUFEE8FNue2MfA=; t=1775746066; x=1776955666; b=Y9nZ3aZXL84eklteleQagr5/yKCru9IJbxiTW93Akva6F6c O97wqTp+KnfuGJZJDAfiJpCW3tP346syGhzwN39TM4QIjhifoGTuATCwOVZFfcTusBNek/GzWjOcO 4B6AD7F9lkWI8wosGaq8mqfXLrFNw/jBBc+cFxKrq2wkWGilx0WT896kf1vQagMWuQOe8LY01stJw T87r98ushe7T/exjFZRiP4D94XY59Pz5p4Ym0Xjg2lg0WFruSANIW1QcuZiE+uvJhTRZOVkxUSFjH 8iySGUlp6hNCG376LuhJTQJLUWps7u79d3xWEkUj9O8PJF2uoRb+XfVrRhCQtICA==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1wAqfN-0000000G2eD-3CNn; Thu, 09 Apr 2026 16:47:33 +0200 Message-ID: <5cf1d83227fd5a6af784f0b11fcdebf9a0bc9f94.camel@sipsolutions.net> Subject: Re: [PATCH v3] gcov: Disable GCOV_PROFILE_ALL on 32-bit UML with Clang 20/21 From: Johannes Berg To: Kees Cook , Richard Weinberger Cc: kernel test robot , Nathan Chancellor , Anton Ivanov , Peter Oberparleiter , Nick Desaulniers , Bill Wendling , Justin Stitt , llvm@lists.linux.dev, linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Date: Thu, 09 Apr 2026 16:47:32 +0200 In-Reply-To: <20260409052038.make.995-kees@kernel.org> References: <20260409052038.make.995-kees@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.3 (3.58.3-1.fc43) MIME-Version: 1.0 X-malware-bazaar: not-scanned X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260409_074746_748137_0B5EDB44 X-CRM114-Status: UNSURE ( 7.24 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org Hi, Maybe the subject should say "um:" instead of "gcov:" now? (I'm assuming you want us to apply it to uml tree.) > Prevent the bad combination by disabling UML's ARCH_HAS_GCOV_PROFILE_ALL > on 32-bit when using Clang 20.x or 21.x. You say 20.x or 21.x, > + # Clang 20 & 21 miscompute __builtin_object_size() under -fprofile-arcs > + # on 32-bit, causing spurious compile-time errors in check_copy_size(). > + select ARCH_HAS_GCOV_PROFILE_ALL if !(!64BIT && CLANG_VERSION >=3D 2000= 00 && CLANG_VERSION < 220100) and I see that 22.0 doesn't even exist, and maybe that's a general pattern, but it still looks confusing? Wouldn't it be better simpler to say < 220000? At least to me that more obviously is "up to 21.x". After all, 20.0 also didn't exist, and you did >=3D200000, not >200000 or >=3D200100? johannes