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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 9DDAAC4363A for ; Tue, 27 Oct 2020 20:01:26 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0D7322076B for ; Tue, 27 Oct 2020 20:01:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="XFwSN+UR"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="mP0vr1qR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D7322076B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=alum.mit.edu Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:Date:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=XQB3PZo9j4XTWdrI1tvRlG3InRUeNO8U/rNlt/FT2Ao=; b=XFwSN+URUPy9E6khsAyx8z6c9 gdcf/Aj1B/of6p7LVeqNWcr98CVVKTF5g4s3HpbZ6Z5B2hh8J0ay3svcfdflxHhbJHzpZIV0qj6og BQEBMcifDlofoja3nOmYn9c6pHAfhI1IVKGQizjSDn50v0cYwm4FfkbZfKvEWKMejDJse6n62zYi0 kAOFPVrbzcp5xtuaiFSuT+XkpKscNetz1BQ77Nbc48Ct/tdABjMXeJHZCyl1y4SJDYNC1r3ZYEDWI swyk2fj7rLCT//wmpP7Bv0vfEeYQD+PSDT24dZl2DkBwzRyGyCx3DnXyk5IcYldNJXcI+FIuKqtuK 1q9DiT2KA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kXV99-0007dr-0a; Tue, 27 Oct 2020 20:00:43 +0000 Received: from mail-qt1-x843.google.com ([2607:f8b0:4864:20::843]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kXV95-0007cc-I1 for linux-arm-kernel@lists.infradead.org; Tue, 27 Oct 2020 20:00:40 +0000 Received: by mail-qt1-x843.google.com with SMTP id c5so1985802qtw.3 for ; Tue, 27 Oct 2020 13:00:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=TVuLHKcXENXuQnK7BbqbATj1Ow+/O3OET0tWd5g550g=; b=mP0vr1qRuUQR81DKmnV8194x/AjZPMsguc2eq/A5LnYQc8WN31EdpclRq5QVEiguNC viciyDYZqo+cja357tj67V9Ldk0LSraSsvStPxeETJwDvUyDE0QqkcWdodVZFQKVwWxL epou4TbwiMHu7YGhXYGrCAeTC0M9FwqgpQSze1vdX6jE1Hycg9mcVCPQLugXG7BO4n3f ZKNCIrqLrRLE/IRXNhwwU6cP1LaeM2czwNcLqri8C9uV5dM+QmnFUKEZdmkSyS5SkMpZ 6NJMI/dGiMEUrcA1CaTUHfY+8FHHy99q4+iH591UceHfx51c0qvDioxTaXMjQDk4tcQp Mr+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:date:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=TVuLHKcXENXuQnK7BbqbATj1Ow+/O3OET0tWd5g550g=; b=E9exVx+BZRrmD0s8Nfh2FSlRh3E3RlHtWOvgtY99Zp+SsZaoEQqthu4fjG5j7u9ZHD EdgiO/We+mmnKZzS7Wy3LvZ6/B+UQXMQnCd2xpX1QLXV2SSQ6hn6RtITIwmWyce6NI8e IpM4/C/UvF9rYAGtEapVk64Q8W/YgQ5g29ZbJn/PkR5Ef+CfMgiB0atwl615+VgOfkOM zDWoGFDPEPCqovNt+JlLUQPQ7ExtVrCsGlA1QrDEg7CeWo9ME3YFrLc51STXMlnvSobt dSlzzOTrGRecFayPqz0vm7LGG1j4rHb0ksA4JawCUqyIzFioJer4A9Pa6Cjmc7E1NcPl KNNQ== X-Gm-Message-State: AOAM531prEQ4pP2XEP8IxynZiwUv2uFmJudQaN8jbBswzesXZhhGoLUQ 2RdNHJSXLbttN3AnIEQwvRk= X-Google-Smtp-Source: ABdhPJxU2pZfgj9I3plzFh3cez4o/WkT19yFU0erA2KwXzjCWYK8HyryZLdTY2tsgV+PFXrSig2WwQ== X-Received: by 2002:ac8:4295:: with SMTP id o21mr3704200qtl.313.1603828836358; Tue, 27 Oct 2020 13:00:36 -0700 (PDT) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id z6sm1479349qtw.36.2020.10.27.13.00.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Oct 2020 13:00:35 -0700 (PDT) From: Arvind Sankar X-Google-Original-From: Arvind Sankar Date: Tue, 27 Oct 2020 16:00:33 -0400 To: Ard Biesheuvel Subject: Re: [PATCH v6 13/29] arm64/build: Assert for unwanted sections Message-ID: <20201027200033.GA1826217@rani.riverdale.lan> References: <20200821194310.3089815-1-keescook@chromium.org> <20200821194310.3089815-14-keescook@chromium.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201027_160039_630203_B278066B X-CRM114-Status: GOOD ( 19.33 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-efi , Catalin Marinas , Arvind Sankar , Ingo Molnar , Linux-Arch , Masahiro Yamada , the arch/x86 maintainers , Russell King , clang-built-linux , Ingo Molnar , Geert Uytterhoeven , Borislav Petkov , Kees Cook , Arnd Bergmann , Josh Poimboeuf , Nathan Chancellor , Peter Collingbourne , Linux ARM , Nick Desaulniers , Linux Kernel Mailing List , Linux-Renesas , James Morse Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Oct 27, 2020 at 08:33:00PM +0100, Ard Biesheuvel wrote: > On Tue, 27 Oct 2020 at 20:25, Geert Uytterhoeven wrote: > > > > > > When I see .eh_frame, I think -fno-asynchronous-unwind-tables is > > > missing from someone's KBUILD_CFLAGS. > > > But I don't see anything curious in kernel/bpf/Makefile, unless > > > cc-disable-warning is somehow broken. > > > > I tracked it down to kernel/bpf/core.c:___bpf_prog_run() being tagged > > with __no_fgcse aka __attribute__((optimize("-fno-gcse"))). > > > > Even if the function is trivially empty ("return 0;"), a ".eh_frame" section > > is generated. Removing the __no_fgcse tag fixes that. > > > > > Given that it was added for issues related to retpolines, ORC and > objtool, it should be safe to make that annotation x86-only. The optimize attribute is not meant for production use. I had mentioned this at the time but it got lost: the optimize attribute apparently does not add options, it replaces them completely. So I'm guessing this one is dropping the -fno-asynchronous-unwind-tables and causing the eh_frame sections, though I don't know why that doesn't cause eh_frame on x86? https://lore.kernel.org/lkml/alpine.LSU.2.21.2004151445520.11688@wotan.suse.de/ _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel