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 X-Spam-Level: X-Spam-Status: No, score=-6.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E904EC433E6 for ; Sat, 16 Jan 2021 15:37:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 698892311F for ; Sat, 16 Jan 2021 15:37:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 698892311F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5496C8D0200; Sat, 16 Jan 2021 10:37:03 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4F8968D01D5; Sat, 16 Jan 2021 10:37:03 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 40F5A8D0200; Sat, 16 Jan 2021 10:37:03 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0086.hostedemail.com [216.40.44.86]) by kanga.kvack.org (Postfix) with ESMTP id 2C2588D01D5 for ; Sat, 16 Jan 2021 10:37:03 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id ECB281DE3 for ; Sat, 16 Jan 2021 15:37:02 +0000 (UTC) X-FDA: 77712041484.22.page42_0f0d87b27539 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id D08BC18038E89 for ; Sat, 16 Jan 2021 15:37:02 +0000 (UTC) X-HE-Tag: page42_0f0d87b27539 X-Filterd-Recvd-Size: 4034 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Sat, 16 Jan 2021 15:37:02 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 2D73423370 for ; Sat, 16 Jan 2021 15:37:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610811421; bh=x4l1R8gCEd4dz4+3VSqSCWo48nh0BvgITV/Eyfeqkk4=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=il3FDsOsXPawNmBAj4NyVMR6qeFnMj5y5nlBbKHXjQHI/B/NfN+I/BkeDaQWlrFZI ROuO0cTh6v/lOfgv075bMj/C31hadQNUNxXUukPeyhcS1RTaWCexBcHjGFUSxlBFnp 4DQzuSAKNCa9WvzTpj0/fF6kr1/NPzGcfErQhrPMAqyx65K9IczeEIbrhLcoiEcRsF N0KUwq0DiAeD1C5nvHvk2O6fM9aIw85sW1dl5cBpLqqYFT+zk+0b/wpp56U7HaGFnO F8zjTTLc2DufQGolP9shEHCc8842fXUM1+pk3zYqiMM20jo9lHo535bNcOUiwHO/R/ qeJW+dlOIHbcg== Received: by mail-ot1-f48.google.com with SMTP id 36so191284otp.2 for ; Sat, 16 Jan 2021 07:37:01 -0800 (PST) X-Gm-Message-State: AOAM530gwW9HqOp8Jyh3iC3j35uu7xgXHZ078pO7HWjiP2/JXdm4+28B kDeM/zYfQgAxBipQdb/8bmM39Mr2BxfdBXm2z70= X-Google-Smtp-Source: ABdhPJzz80o1MaCOj5HW0Hp2A2E0kn95lxBT8fGlBkJHK/Z9C2eOXyrULwJQJFAOQK2f9sPxPN9OR1frSgv/b3rvIdk= X-Received: by 2002:a9d:7a4b:: with SMTP id z11mr12332724otm.305.1610811420486; Sat, 16 Jan 2021 07:37:00 -0800 (PST) MIME-Version: 1.0 References: <202101160841.jUXjdS7j-lkp@intel.com> In-Reply-To: From: Arnd Bergmann Date: Sat, 16 Jan 2021 16:36:44 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [linux-next:master 952/3956] crypto/blake2b_generic.c:73:13: warning: stack frame size of 9776 bytes in function 'blake2b_compress_one_generic' To: Eric Biggers Cc: kernel test robot , kbuild-all@lists.01.org, clang-built-linux , Linux Memory Management List , Herbert Xu , "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" , Arnd Bergmann , Kees Cook , Marco Elver , George Popescu Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, Jan 16, 2021 at 2:59 AM Eric Biggers wrote: > On Sat, Jan 16, 2021 at 08:59:50AM +0800, kernel test robot wrote > > Looks like the clang bug that causes large stack usage in this function > (https://bugs.llvm.org/show_bug.cgi?id=45803 which is still unfixed) got > triggered again. Note that the function only has 264 bytes of local variables, > so there's no reason why it should use anywhere near 9776 bytes of stack space. > > I'm not sure what we can do about this. Last time the solution was commit > 0c0408e86dbe which randomly added a 'pragma nounroll' to the loop at the end. > > Anyone have any better idea than randomly trying adding optimization pragmas and > seeing what makes the report go away? > > Also this was reported with clang 12.0.0 which is a prerelease version, so I'm > not sure how much I'm supposed to care about this report. I sent a workaround to disable UBSAN_UNSIGNED_OVERFLOW an x86-32, after showing that this did not affect arm32, arm64 or x86-64: 27c287b41659 ("ubsan: disable unsigned-overflow check for i386") As the report is for ppc64, it appears that this is not just specific to x86-32 after all. I have had no success in isolating the problem in clang, but I did not try too hard either. I see this .config also enables CONFIG_UBSAN_UNSIGNED_OVERFLOW=y, so it would be a reasonable assumption that this is the same problem as on x86-32. There is also another thread on CONFIG_UBSAN_UNSIGNED_OVERFLOW causing BUILD_BUG_ON() failures. Arnd