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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3835C7EE26 for ; Fri, 19 May 2023 17:42:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229849AbjESRmW (ORCPT ); Fri, 19 May 2023 13:42:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229545AbjESRmU (ORCPT ); Fri, 19 May 2023 13:42:20 -0400 Received: from mail-qk1-f169.google.com (mail-qk1-f169.google.com [209.85.222.169]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4533FFA; Fri, 19 May 2023 10:42:19 -0700 (PDT) Received: by mail-qk1-f169.google.com with SMTP id af79cd13be357-759413d99afso53462385a.1; Fri, 19 May 2023 10:42:19 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684518138; x=1687110138; h=user-agent:in-reply-to:content-transfer-encoding :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=MVBXORYA5fI/Y7ZPBzQO5l0Wm2EiovEm+KKQqG7za60=; b=G4gN9ZN+ovP33yjiR/vYliMLpmjjuBLfhXTMxYpLN+7GoOa8DdFe2rdEIA9y1Bwf8W OZHijvwy4zPFpbcE1dWlXA4yksk341FQoL7cbF7b6eCVM7FenvSuCTS9yyLAWHN8MlBX NW/uU/7mmbvb9mEU5C9vzEDtWzFNy9nn69Ev5np/phmVXpm1RothX3W9H6fP4Lf0kmPR hAKpeM0WmRDHxxpRXbhGS8FyjXQGII8f0+W46fg9Gd3Pt+tVVmvM0ZeSXaapcq/fVuBh AH1q951FnfeVXPaohMQKLjLD0P/PxmTFJB5djLPCevfd/yLNzjr0CQMVRIorZi2JxVCG qNPw== X-Gm-Message-State: AC+VfDzL8wXCVtA8jccqc4bKRu67ob1UUoGRf4ThRVjf+Jd1SumtJ7lA 3Wbkqraye1lPKZCLFGyqjWA= X-Google-Smtp-Source: ACHHUZ57aYaLkvcxZAWErCGtmjwOeb/l4TV4esRxYZQRZFbcTv3wtC3AKblwR/M8FCpNJSwkvBfpag== X-Received: by 2002:a05:6214:240c:b0:5ef:512d:2d47 with SMTP id fv12-20020a056214240c00b005ef512d2d47mr6116917qvb.19.1684518138069; Fri, 19 May 2023 10:42:18 -0700 (PDT) Received: from maniforge ([2620:10d:c091:400::5:311e]) by smtp.gmail.com with ESMTPSA id s1-20020a05621412c100b006166d870243sm1475313qvv.43.2023.05.19.10.42.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 May 2023 10:42:17 -0700 (PDT) Date: Fri, 19 May 2023 12:42:15 -0500 From: David Vernet To: Nick Desaulniers Cc: linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org, Nathan Chancellor , Michael Ellerman , Miguel Ojeda , "Peter Zijlstra (Intel)" , Josh Poimboeuf , x86@kernel.org, Linus Torvalds , clang-built-linux Subject: Re: [tip: objtool/core] start_kernel: Add __no_stack_protector function attribute Message-ID: <20230519174215.GA2158284@maniforge> References: <20230412-no_stackp-v2-1-116f9fe4bbe7@google.com> <168440808395.404.16801982965854981978.tip-bot2@tip-bot2> <20230519171120.GA1939377@maniforge> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.10 (2023-03-25) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 19, 2023 at 10:18:40AM -0700, Nick Desaulniers wrote: > On Fri, May 19, 2023 at 10:11 AM David Vernet wrote: > > > > On Thu, May 18, 2023 at 11:08:03AM -0000, tip-bot2 for ndesaulniers@google.com wrote: > > > The following commit has been merged into the objtool/core branch of tip: > > > > > > Commit-ID: 514ca14ed5444b911de59ed3381dfd195d99fe4b > > > Gitweb: https://git.kernel.org/tip/514ca14ed5444b911de59ed3381dfd195d99fe4b > > > Author: ndesaulniers@google.com > > > AuthorDate: Mon, 17 Apr 2023 15:00:05 -07:00 > > > Committer: Josh Poimboeuf > > > > Hi Nick, Josh, Peter, > > > > Do you have an ETA for when this will make its way to Linus' tree? > > clang-17 built kernels have failed to boot since [0], so it would be > > nice to get this in sooner rather than later if possible. > > David, > Can you confirm that your version of clang-17 is updated? clang-17 is > unreleased; ToT will become clang-17. > > https://reviews.llvm.org/rGfc4494dffa5422b2be5442c235554e76bed79c8a > should have fixed any boot failures related to stack protectors. That > is to say that Josh's series is irrelevant to anyone using either an > existing release of clang, or something closer to ToT than April 13. Thanks for the quick reply, Nick. The latest clang-17 does indeed fix the issue. Apologies for not trying that first -- I was using the only tagged verson of clang-17 (which admittedly is not a released version), and figured it wasn't a compiler bug given that the assembly looked sane, compilers are allowed to do all sorts of interesting things with __noreturn, and that [1] removes -fstack-protector from start_kernel() altogether. [1]: https://lore.kernel.org/lkml/20230412-no_stackp-v1-1-46a69b507a4b@google.com/ > LLVM commit fc4494dffa54 ("[StackProtector] don't check stack > protector before calling nounwind functions") > landed April 13, so please check that your build of clang-17 is after that date. > > Either way, thanks for testing with clang, and the report. You can > always file a bug at our issue tracker: > https://github.com/ClangBuiltLinux/linux/issues or see our page for > more ways to get in touch: > https://clangbuiltlinux.github.io/ > We're very active on our mailing list, and on IRC. Ack, thanks for letting me know for next time. - David