From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66EC52119 for ; Thu, 10 Nov 2022 20:50:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 347CEC433C1; Thu, 10 Nov 2022 20:50:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1668113443; bh=+Guk1PkqtF3DpNjrdmxtlIWa68p9aMRWj4vAUJaMUvo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=atcUOoui1uX1GR5cDuSN2A9FTOxwO2+gcf/ddhU6byVh6QfoC4TApGFTzNnmGMBPw 9Ho+rb2YsPI1r7E3M8liPiJ1QK3IF0yP3TngZJaWTmGrxtrqt5ChUqg/u3YVqrv/4B qf1JIh4YI+6EoxAJKOjm6A9ZghuXKcincJLqmwtv62IFWGUJ5QQyTdUg0065uvOBlA pKBZBqq3/qrD6oLiwez66anLmsi2MyX7NUMhG2qQV/S10kv7q6RZVsk7CpJRLSjwbA SUotMk7wSwSCXJGRXvZZ+zHr+PPWiFqxt9VA2MFXKslIX5EevPY+jri/pkTS9PQLSg cIhFKSIsITOfA== Date: Thu, 10 Nov 2022 13:50:40 -0700 From: Nathan Chancellor To: huyd12@chinatelecom.cn Cc: guoj17@chinatelecom.cn, peterz@infradead.org, mingo@redhat.com, will@kernel.org, tglx@linutronix.de, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, longman@redhat.com, boqun.feng@gmail.com, linux-kernel@vger.kernel.org, hpa@zytor.com, ndesaulniers@google.com, trix@redhat.com, llvm@lists.linux.dev Subject: Re: =?utf-8?B?5Zue5aSN?= =?utf-8?Q?=3A?= [PATCH] locking: fix kernel/locking/ inline asm error Message-ID: References: <20221108060126.2505-1-guoj17@chinatelecom.cn> <001d01d8f4eb$f0f37a90$d2da6fb0$@chinatelecom.cn> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <001d01d8f4eb$f0f37a90$d2da6fb0$@chinatelecom.cn> On Thu, Nov 10, 2022 at 06:05:13PM +0800, huyd12@chinatelecom.cn wrote: > > Thanks your comments, > And if any concern to apply it on upstream? Unfortunately, I am not the one who gets to make that decision; one of the maintainers of this file will have to pick it up, assuming they see no issue with it. Cheers, Nathan > -----邮件原件----- > 发件人: nathan@kernel.org > 发送时间: 2022年11月9日 6:40 > 收件人: guoj17@chinatelecom.cn > 抄送: peterz@infradead.org; mingo@redhat.com; will@kernel.org; > tglx@linutronix.de; bp@alien8.de; dave.hansen@linux.intel.com; > x86@kernel.org; longman@redhat.com; boqun.feng@gmail.com; linux-kernel@vger. > kernel.org; hpa@zytor.com; ndesaulniers@google.com; trix@redhat.com; > llvm@lists.linux.dev; huyd12@chinatelecom.cn > 主题: Re: [PATCH] locking: fix kernel/locking/ inline asm error > > On Tue, Nov 08, 2022 at 02:01:26PM +0800, guoj17@chinatelecom.cn wrote: > > From: Guo Jin > > > > When compiling linux 6.1.0-rc3 configured with CONFIG_64BIT=y and > > CONFIG_PARAVIRT_SPINLOCKS=y on x86_64 using LLVM 11.0, an error: > > " error: changed section flags for .spinlock.text, > > expected:: 0x6" occurred. > > > > The reason is the .spinlock.text in kernel/locking/qspinlock.o is used > > many times, but its flags are omitted in subsequent use. > > > > LLVM 11.0 assembler didn't permit to > > leave out flags in subsequent uses of the same sections. > > > > So this patch adds the corresponding flags to avoid above error. > > > > Signed-off-by: Guo Jin > > Right, my reverse bisect tells me that this error was fixed by [1] in LLVM, > which landed in 12.0.0 and was backported to LLVM 11.0.1 [2]. > > We could bump the minimum supported version of LLVM for building the kernel > to 11.0.1 over this, just to avoid further issues like this down the road, > as the kernel will always be adding new sections for various things. That > change would not appear to be disruptive, as all the major distros either > have 11.0.1 or newer or older than the current minimum of 11.0.0, so they > need to get clang from elsewhere already. > > archlinux:latest: clang version 14.0.6 > > debian:oldoldstable-slim: clang version 3.8.1-24 (tags/RELEASE_381/final) > debian:oldstable-slim: clang version 7.0.1-8+deb10u2 > (tags/RELEASE_701/final) > debian:stable-slim: Debian clang version 11.0.1-2 > debian:testing-slim: Debian clang version 14.0.6-2 > debian:unstable-slim: Debian clang version 14.0.6-7 > > fedora:35: clang version 13.0.1 (Fedora 13.0.1-1.fc35) > fedora:latest: clang version 14.0.5 (Fedora 14.0.5-1.fc36) > fedora:rawhide: clang version 15.0.4 (Fedora 15.0.4-1.fc38) > > opensuse/leap:15: clang version 13.0.1 > opensuse/leap:latest: clang version 13.0.1 > opensuse/tumbleweed:latest: clang version 15.0.3 > > ubuntu:bionic: clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final) > ubuntu:focal: clang version 10.0.0-4ubuntu1 > ubuntu:latest: Ubuntu clang version 14.0.0-1ubuntu1 > ubuntu:kinetic: Ubuntu clang version 15.0.2-1 > ubuntu:rolling: Ubuntu clang version 15.0.2-1 > ubuntu:devel: Ubuntu clang version 15.0.2-1 > > At the same time, you are clearly using LLVM 11.0.0, so I think this is a > reasonable fix in the immediate term. > > Reviewed-by: Nathan Chancellor > > [1]: > https://github.com/llvm/llvm-project/commit/1deff4009e0ae661b03682901bf69322 > 97ce7ea1 > [2]: > https://github.com/llvm/llvm-project/commit/700baa009dc685a0adc5f94d258be4ae > 24742471 > > > --- > > arch/x86/include/asm/qspinlock_paravirt.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/x86/include/asm/qspinlock_paravirt.h > > b/arch/x86/include/asm/qspinlock_paravirt.h > > index 60ece592b220..dbb38a6b4dfb 100644 > > --- a/arch/x86/include/asm/qspinlock_paravirt.h > > +++ b/arch/x86/include/asm/qspinlock_paravirt.h > > @@ -37,7 +37,7 @@ > __PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath, > ".spinlock.text"); > > * rsi = lockval (second argument) > > * rdx = internal variable (set to 0) > > */ > > -asm (".pushsection .spinlock.text;" > > +asm (".pushsection .spinlock.text, \"ax\";" > > ".globl " PV_UNLOCK ";" > > ".type " PV_UNLOCK ", @function;" > > ".align 4,0x90;" > > -- > > 2.25.1 > > >