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 26FF3CA5FD4 for ; Fri, 2 Oct 2026 10:57:52 +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:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=XhYZeDORiSI8/JK5prOnI48AZTeR83aeNlRw2yNVr5w=; b=QvY/mIlKRg0vtMWmSzd+f6wT8N QHDMbejQ5gfXUbAFcGvX9xq15rYrC8tKby4baUVslxgUKe2JxQAJBZIHRYA9Yx1YcFp3f1Z6GSZc8 69jHjKXk64OnnTQgrSqozW2ZyGybDCoP+P9BucDfJ84jJHC6RahoWzI6y547jfge8UZqZIYtKA3Xe 0dyyMiwfLYZAM+4x80ef9SDjq40q5EEPZgb+f2I7N2c5nmADrMH8RZipwfj4JH7Et/jxDk2B9v/5U dmJG+D2LyTlWx2Xz8SuVZ+9SgvWArSfIQ0K21YMldJp+tWX6ucaJdd8szBeQafAmwnjsvLJlIvvGO Y9UiRkWw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCaxU-0000000BOXj-450i; Fri, 02 Oct 2026 10:57:44 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCaxU-0000000BOXM-2KMr; Fri, 02 Oct 2026 10:57:44 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 0B0FA43E34; Fri, 2 Oct 2026 10:57:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AFC801F000FF; Fri, 2 Oct 2026 10:57:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790938663; bh=XhYZeDORiSI8/JK5prOnI48AZTeR83aeNlRw2yNVr5w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aWofcNL0IpfhNz1F+V5tIezxAIC+6gSsXgAkREeV4BVed+0FiauQXMNWVw9LKPLB6 ir4DE+mQOj7fAnn9wWN24mGIs2yiLoWuxDgSoIcePHXYebp3Jn+1nUa9x2wySQefzf WQmIi/OFo2WoqQKAzGhoPoMrrzBB5bUlFah8eMf2FJVRJ6H6P9gC/qpBZuRnPjv0y/ F5TtGt5oyxTCxCgpw9JS+D+Ugcg53pdmW58E1qfTVRE4UNxCd1Jv8/fulyxe9xvM3n QuSyWTZZF/fLNAxS4cWJJyIBxQRSN/S3tMrqSUHZbQdB27JrxaRUMLy+tg6NqQf98F +C8Ubag62FOcA== From: "Christophe Leroy (CS GROUP)" To: Andy Lutomirski , Thomas Gleixner , Theodore Ts'o , "Jason A. Donenfeld" , Nathan Chancellor Cc: Christophe Leroy , Vincenzo Frascino , Nick Desaulniers , Bill Wendling , Justin Stitt , Catalin Marinas , Will Deacon , Mark Rutland , Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH v2] random: vDSO: Avoid call to memset() when zeroing reserved in __cvdso_getrandom_data() Date: Fri, 2 Oct 2026 12:57:06 +0200 Message-ID: <179093852073.149722.832232613857480812.b4-ty@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260925-vdso-getrandom-avoid-memset-llvm-24-v2-1-ce640f872393@kernel.org> References: <20260925-vdso-getrandom-avoid-memset-llvm-24-v2-1-ce640f872393@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" X-Developer-Signature: v=1; a=openpgp-sha256; l=948; i=chleroy@kernel.org; h=from:subject:message-id; bh=cZWyz0y5XGYe9zKs9PNHSxiUlxW65egvfT4xEgdntpI=; b=owGbwMvMwCV2d0KB2p7V54MZT6slMWTt7+OJ/rvq89WD/OHOTgfiuFYb3eV9siQjX6ZB4uV8W fGZTfsNOkpZGMS4GGTFFFmO/+feNaPrS2r+1F36MHNYmUCGMHBxCsBElsQyMkw/0pmesd3U1s2/ +cCt35+i1GxcP3PlXZzn80qx+rxOmQLD/5gj9bZ29RUatWfD9vbt1+NKmTHbS7kya1+avMNCTlt NfgA= X-Developer-Key: i=chleroy@kernel.org; a=openpgp; fpr=10FFE6F8B390DE17ACC2632368A92FEB01B8DD78 Content-Transfer-Encoding: 8bit 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 25 Sep 2026 22:46:32 +0100, Nathan Chancellor wrote: > After a recent change in LLVM [1], builds with the random vDSO > implementation, such as PowerPC and RISC-V, fail when checking the vDSO: > > arch/powerpc/kernel/vdso/vdso32.so.dbg: dynamic relocations are not supported > arch/riscv/kernel/vdso/vdso.so.dbg: dynamic relocations are not supported > > memset() is now generated when zeroing params->reserved for some builds > because LLVM has an optimization (now run in more instances) that can > recognize at compile time when it is assigning a static value to a > contiguous area of memory and turn that into a call to memset(). Both > clang and GCC assume memset() is always available [2]. > > [...] Applied, thanks! [1/1] random: vDSO: Avoid call to memset() when zeroing reserved in __cvdso_getrandom_data() (no commit info) Best regards, -- Christophe Leroy (CS GROUP)