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 6CEECCA5FC4 for ; Fri, 2 Oct 2026 09:49:51 +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: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-Owner; bh=O1NvwTXORD+Bb07RA52Wu5WZWJqKJmdYmCUZOMWRc5g=; b=BT9pn0lPV0DGO0r4ixWjjBN2xm jXao6w395dEGBbEMT1naGlPP96J3o7h0DKeZAw3ZrGf6Xo0qS7EqZeXipFTyR5RpeRLIU9O3CS2KJ gHc7DGnOzxs0g4hT2RfMPlFW6/BNklGqTDK77PrYc5Yq7pDP5JIekGAHdZFsNjHVnfnV3l1dYQeHA UgKp1jVXpn+EcS3aY4ZqHZ9THoZ0X/O5gPIa4nIIl3U038c6un4rD09J5wbFes6Lp9tt5R7mKOp4N HtIB7YsNnJ9VNFzSbfofstJORCnwOKK+YGrDXeXjP7rEyiTSJAHL4AZOQQVJAKESqaEeg0nX4OMA6 Lo4UT1GQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCZth-0000000BCTO-0GW7; Fri, 02 Oct 2026 09:49:45 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCZtg-0000000BCT4-0B0I; Fri, 02 Oct 2026 09:49:44 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 2F6F060A70; Fri, 2 Oct 2026 09:49:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89C201F00898; Fri, 2 Oct 2026 09:49:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790934582; bh=O1NvwTXORD+Bb07RA52Wu5WZWJqKJmdYmCUZOMWRc5g=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=aOMAm0+cj8fILcHV8Uj0RSZsjvcpY1RGYRxgNmibtLJucq4PJOFYlIeiGQVMfrMtH DuOOY8IKcr5yOnM73cxavmFw/nMHIjF2qDFrl5uDmTm4oMLgD066mfJFMfXw9Bc49t csqzp1wUBMrdSv3SghZJ/e5GLtijiu6xy2aZ5PO4v+0coTfSNOC/XZkaenDtUej0CP i/q/JrIeY1TU8Nol9o5vJO8rP4m5pAttrz6dh8syfIsV6x0pir8FExIzAdOKEXHnA9 Cm8d729oJ1G8qj87sC00EzJFfXA+tDEZru+V9USQSA1Xg//ndb/O3J7bRLVs8z/I4V zfigDTcHw5t/g== Date: Fri, 2 Oct 2026 11:49:32 +0200 From: Nathan Chancellor To: "Jason A. Donenfeld" Cc: "Christophe Leroy (CS GROUP)" , Nick Desaulniers , Andy Lutomirski , Thomas Gleixner , Theodore Ts'o , Vincenzo Frascino , 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() Message-ID: <20261002094932.GA3435055@ax162> References: <20260930133813.GA3142230@ax162> <20260930151337.GD3142230@ax162> <20261001102059.GA4176271@ax162> <20261001110310.GA138012@ax162> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261001110310.GA138012@ax162> 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 Thu, Oct 01, 2026 at 01:03:10PM +0200, Nathan Chancellor wrote: > On Thu, Oct 01, 2026 at 12:48:10PM +0200, Jason A. Donenfeld wrote: > > Does this commit seem okay with you? I used the diff you sent below and > > adjusted the commit message: https://git.zx2c4.com/linux-rng/commit/?id=56ff95ee85715047eb5b5220243778af657778c8 > > Yeah, that seems fine to me, thanks for taking care of it! Can you adjust the LLVM value by one from 4294967295 to 4294967294? ~0U is actually a special value, so we hit an assertion in the SystemZ backend. https://github.com/llvm/llvm-project/blob/3f48e22a1f321d5d3341bd812803694cea588785/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp#L9547 https://github.com/llvm/llvm-project/blob/3f48e22a1f321d5d3341bd812803694cea588785/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp#L1470-L1471 clang: llvm/lib/Target/SystemZ/SystemZISelLowering.cpp:1471: virtual bool llvm::SystemZTargetLowering::findOptimalMemOpLowering(LLVMContext &, std::vector &, unsigned int, const MemOp &, unsigned int, unsigned int, const AttributeList &, EVT *) const: Assertion `Limit != ~0U && "Expected EmitTargetCodeForMemXXX() to handle AlwaysInline cases."' failed. PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and dumped files. Stack dump: 0. Program arguments: ... 1. parser at end of file 2. Code generation 3. Running pass 'Function Pass Manager' on module 'arch/s390/kernel/vdso/vgetrandom.c'. 4. Running pass 'SystemZ DAG->DAG Pattern Instruction Selection' on function '@__kernel_getrandom' ... -- Cheers, Nathan