From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (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 E878F132120; Thu, 30 May 2024 12:26:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717072005; cv=none; b=twMxuLnvAxedO6OzIv7aUcI67107J8DGjE4/99AyOt8myhHcERJs9GR7Q6ejd340vNuP4pBojre17F2+7yg3cGrPfs5uHSebSfEdhmSxuz00MT6/Q1W2zk70AmOsmGUBMZOwQDOtSjZfE46aB7xOrJ8jylZdmwKO9UoHXs6Z3qo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717072005; c=relaxed/simple; bh=Ki0PXwDcgKCwKxNmPedJebPKiDnnFLgJd0CWDkQGwlk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Lxt5ViFLEO5UN6XD6AvWqQEAVnqd1WgodosqbmHOmgpGhGzFzNrUT5Gnrk8xFga5uyJx05XTdhnnUHiqfCdsnvuF6nc6xyWlqeRGD+teRsC7w0o0k2myDZVQon3ZCifkI7+otc3UXhmb2RBLqxaNOGIl3V/XqPKpSeDaWhbTaZU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=HAi0ODxC; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="HAi0ODxC" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=xesVBLyk2WRbDcXVWG0pEUYP3V61JmuSdVX8kyL/MGM=; b=HAi0ODxC1fc7rpfK3TIamNoDMg oEvRbbOfGupH4U/eg772GjYV89EKYxfiWHLPeEhV31kx4FNifX89nFjzAyNpSyh3PKxQd+IOp8YAa VZbU7PyIdszPWInRtS65Pi6XwXMz6VnEEkRmd/JHUy0+kb0S32WkJ3gTfUjwnnSqzRmfvNwmEAUY6 zOwdabiUEvbVTJI1jt4jEpGHNjoVfZOT7tWis+uLc+HMQhKg+91OIwfhBM7f0rERt7ovM/a7hnTpg YAyKIgt3CUbQs2z4fX9PerPd6ysN7aXjTb/693olm/+sbG/bJN7/HP02c1DME89H+xEOZji+7I/WY AtpbyyDA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:47132) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1sCerb-0007MG-0r; Thu, 30 May 2024 13:26:35 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1sCerc-00058h-BI; Thu, 30 May 2024 13:26:36 +0100 Date: Thu, 30 May 2024 13:26:35 +0100 From: "Russell King (Oracle)" To: Naresh Kamboju Cc: open list , Linux ARM , lkft-triage@lists.linaro.org, Linux Regressions , rcu , Arnd Bergmann , Dan Carpenter , "Paul E. McKenney" , Joel Fernandes , eeraj.upadhyay@kernel.org, John Ogness Subject: Re: arm-linux-gnueabihf-ld: kernel/rcu/update.o:update.c:(.text+0x1cc4): more undefined references to `__bad_cmpxchg' follow Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Russell King (Oracle) On Thu, May 30, 2024 at 05:50:52PM +0530, Naresh Kamboju wrote: > The arm builds failed on Linux next with gcc-13 and clang-18. > > Config: arm imx_v6_v7_defconfig - failed > > Reported-by: Linux Kernel Functional Testing > > Build log: > ----- > arm-linux-gnueabihf-ld: kernel/rcu/update.o: in function > `rcu_trc_cmpxchg_need_qs': > update.c:(.text+0x348): undefined reference to `__bad_cmpxchg' > arm-linux-gnueabihf-ld: kernel/rcu/update.o: in function > `rcu_read_unlock_trace_special': > update.c:(.text+0x41c): undefined reference to `__bad_cmpxchg' > arm-linux-gnueabihf-ld: kernel/rcu/update.o: in function > `trc_read_check_handler': > update.c:(.text+0x4b0): undefined reference to `__bad_cmpxchg' > arm-linux-gnueabihf-ld: kernel/rcu/update.o: in function `trc_inspect_reader': > update.c:(.text+0x1518): undefined reference to `__bad_cmpxchg' > arm-linux-gnueabihf-ld: update.c:(.text+0x1548): undefined reference > to `__bad_cmpxchg' > arm-linux-gnueabihf-ld: kernel/rcu/update.o:update.c:(.text+0x1cc4): > more undefined references to `__bad_cmpxchg' follow > make[3]: *** [/builds/linux/scripts/Makefile.vmlinux:34: vmlinux] Error 1 You get a reference to __bad_cmpxchg() when someone uses cmpxchg() on a datatype that there are no CPU instructions to perform the atomic compare-and-exchange. As we support 8-bit, 16-bit and 32-bit, I would expect that we're now seeing cmpxchg() being used on 64-bit values, which are unsupportable on 32-bit Arm. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!