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 706F7C433F5 for ; Mon, 3 Jan 2022 17:58:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234896AbiACR6J (ORCPT ); Mon, 3 Jan 2022 12:58:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232091AbiACR6I (ORCPT ); Mon, 3 Jan 2022 12:58:08 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B111CC061761; Mon, 3 Jan 2022 09:58:08 -0800 (PST) Received: from zn.tnic (dslb-088-067-202-008.088.067.pools.vodafone-ip.de [88.67.202.8]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 28C1A1EC0118; Mon, 3 Jan 2022 18:58:03 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1641232683; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=lg6/SYBjwUEm8ZWAi8vMp09yL3c8/qSiwWmVSfDOZsI=; b=cigFZ3t+av441lOj6j6kLxBruXe7oY02YdcKvTWUtOdgK+yXsRxtr2QH6Ji1J5C6xMDYNI 3OT2Lyz79LWuY2XjIVwXoH12SqzYMa8NLLExRsTBhbb4mPdi51hkdpojujEj0mlU0WUt+L 69kmi6dje7xywQzF0lEj9yye60AiCPk= Date: Mon, 3 Jan 2022 18:58:02 +0100 From: Borislav Petkov To: llvm@lists.linux.dev Cc: Josh Poimboeuf , linux-tip-commits@vger.kernel.org, kernel test robot , Peter Zijlstra , x86@kernel.org, Vasily Gorbik , Miroslav Benes , linux-kernel@vger.kernel.org Subject: Re: [tip: objtool/urgent] compiler.h: Fix annotation macro misplacement with Clang Message-ID: References: <0417e96909b97a406323409210de7bf13df0b170.1636410380.git.jpoimboe@redhat.com> <164016423099.16921.16996655982787145621.tip-bot2@tip-bot2> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <164016423099.16921.16996655982787145621.tip-bot2@tip-bot2> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I wonder if clang folks have seen this and perhaps have a comment as to why the volatile gets ingored... Added. On Wed, Dec 22, 2021 at 09:10:30AM -0000, tip-bot2 for Josh Poimboeuf wrote: > The following commit has been merged into the objtool/urgent branch of tip: > > Commit-ID: dcce50e6cc4d86a63dc0a9a6ee7d4f948ccd53a1 > Gitweb: https://git.kernel.org/tip/dcce50e6cc4d86a63dc0a9a6ee7d4f948ccd53a1 > Author: Josh Poimboeuf > AuthorDate: Mon, 08 Nov 2021 14:35:59 -08:00 > Committer: Josh Poimboeuf > CommitterDate: Tue, 21 Dec 2021 15:09:46 -08:00 > > compiler.h: Fix annotation macro misplacement with Clang > > When building with Clang and CONFIG_TRACE_BRANCH_PROFILING, there are a > lot of unreachable warnings, like: > > arch/x86/kernel/traps.o: warning: objtool: handle_xfd_event()+0x134: unreachable instruction > > Without an input to the inline asm, 'volatile' is ignored for some > reason and Clang feels free to move the reachable() annotation away from > its intended location. > > Fix that by re-adding the counter value to the inputs. > > Fixes: f1069a8756b9 ("compiler.h: Avoid using inline asm operand modifiers") > Fixes: c199f64ff93c ("instrumentation.h: Avoid using inline asm operand modifiers") > Reported-by: kernel test robot > Signed-off-by: Josh Poimboeuf > Link: https://lore.kernel.org/r/0417e96909b97a406323409210de7bf13df0b170.1636410380.git.jpoimboe@redhat.com > Cc: Peter Zijlstra > Cc: x86@kernel.org > Cc: Vasily Gorbik > Cc: Miroslav Benes > --- > include/linux/compiler.h | 4 ++-- > include/linux/instrumentation.h | 4 ++-- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/include/linux/compiler.h b/include/linux/compiler.h > index 3d5af56..429dceb 100644 > --- a/include/linux/compiler.h > +++ b/include/linux/compiler.h > @@ -121,7 +121,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, > asm volatile(__stringify_label(c) ":\n\t" \ > ".pushsection .discard.reachable\n\t" \ > ".long " __stringify_label(c) "b - .\n\t" \ > - ".popsection\n\t"); \ > + ".popsection\n\t" : : "i" (c)); \ > }) > #define annotate_reachable() __annotate_reachable(__COUNTER__) > > @@ -129,7 +129,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, > asm volatile(__stringify_label(c) ":\n\t" \ > ".pushsection .discard.unreachable\n\t" \ > ".long " __stringify_label(c) "b - .\n\t" \ > - ".popsection\n\t"); \ > + ".popsection\n\t" : : "i" (c)); \ > }) > #define annotate_unreachable() __annotate_unreachable(__COUNTER__) > > diff --git a/include/linux/instrumentation.h b/include/linux/instrumentation.h > index fa2cd8c..24359b4 100644 > --- a/include/linux/instrumentation.h > +++ b/include/linux/instrumentation.h > @@ -11,7 +11,7 @@ > asm volatile(__stringify(c) ": nop\n\t" \ > ".pushsection .discard.instr_begin\n\t" \ > ".long " __stringify(c) "b - .\n\t" \ > - ".popsection\n\t"); \ > + ".popsection\n\t" : : "i" (c)); \ > }) > #define instrumentation_begin() __instrumentation_begin(__COUNTER__) > > @@ -50,7 +50,7 @@ > asm volatile(__stringify(c) ": nop\n\t" \ > ".pushsection .discard.instr_end\n\t" \ > ".long " __stringify(c) "b - .\n\t" \ > - ".popsection\n\t"); \ > + ".popsection\n\t" : : "i" (c)); \ > }) > #define instrumentation_end() __instrumentation_end(__COUNTER__) > #else -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette