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 35735382; Fri, 22 Mar 2024 00:09:36 +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=1711066179; cv=none; b=sLddYT33m/bE7xt6l01tdQ6c902zlQXa9IKCDB+n7y/FrBmF/TwFG4ybRiQCFzZjzh9b9CGDxEcxUrZOkPx8SUSAFByGa+blUPVCnwhGc3ppdr615kIvWa2AYDc3StsbT8k3r6qT5x/8uE6PwCI74E5vT6oSU+RXdyyV54LfMrE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711066179; c=relaxed/simple; bh=SgBVhDiLkqvj5heInVCpMQ/vA9DTmHwhTXsUN08CHaE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=sXrMb0Mb2Wc1Q3FO6QO0Fz2jxfmOPYxnT5YSX/4hMmMHmSjN4GTnB834sPHr/TyT1yS82ehSnxF2jh4s1+YDG+Zf6I2o6Dtg7L/3nU3247kwg2WGePzC4NdvxVUogjrEgEmqPpkZsPk6esHdZFSY5PHUO7RkXMjxmA7+Lvoo8sg= 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=aXkMMI0j; 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="aXkMMI0j" 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=2moEpAismjcawN+PGW1bmLh6TrJn1P653kp5rgnCLkg=; b=aXkMMI0ja+5UEUhZLzxrAJrkpo OggZC2nCb+f2Fc6/hgyq/dQ94GWFA01LJDDP2/qY/PfR0cOEEIRO7rDEZOR4X/evTYWr484x/xhO3 47CbPRUUvktN9l7IXCMsnWhcklfjWOYuw0E9d92IWt5TWXUCJkQDKh03JS9U77CcNYcMHVghXmFFu 2t4mOBimVFjY+Dib9ePoRuVpnTqqQ61NKl5z1snJ7I9je9VFA/RF6dHv7EuRNfac5ZN52xWm/ySPu Nb6YpH4MMb2hjDYG5OrQtutMpquZ7gmQOTxdeOUBXqEoAoqtZcYcCC66Uvr72DpXZJUlgnF69G1wf Ybls5MUA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:44658) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1rnST0-0008AS-2e; Fri, 22 Mar 2024 00:09:02 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1rnSSs-00049Z-Vr; Fri, 22 Mar 2024 00:08:55 +0000 Date: Fri, 22 Mar 2024 00:08:54 +0000 From: "Russell King (Oracle)" To: Ard Biesheuvel Cc: David Laight , Jiangfeng Xiao , "arnd@arndb.de" , "keescook@chromium.org" , "haibo.li@mediatek.com" , "angelogioacchino.delregno@collabora.com" , "amergnat@baylibre.com" , "akpm@linux-foundation.org" , "dave.hansen@linux.intel.com" , "douzhaolei@huawei.com" , "gustavoars@kernel.org" , "jpoimboe@kernel.org" , "kepler.chenxin@huawei.com" , "kirill.shutemov@linux.intel.com" , "linux-hardening@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "linux-arm-kernel@lists.infradead.org" , "nixiaoming@huawei.com" , "peterz@infradead.org" , "wangbing6@huawei.com" , "wangfangpeng1@huawei.com" , "jannh@google.com" , "willy@infradead.org" Subject: Re: [PATCH v2] ARM: unwind: improve unwinders for noreturn case Message-ID: References: <1709516385-7778-1-git-send-email-xiaojiangfeng@huawei.com> <1710906278-23851-1-git-send-email-xiaojiangfeng@huawei.com> <84a57ca8-8963-ca24-8bd1-ddc5c33bf4da@huawei.com> 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, Mar 21, 2024 at 11:43:41PM +0100, Ard Biesheuvel wrote: > Given that this particular issue would just disappear if the compiler > would just insert a BRK after the BL, I'd prefer to explore first > whether we can get this fixed on the compiler side. Arm32 doesn't have a BRK instruction. What would be appropriate after the no-return BL would be OS specific. Maybe a branch to "abort" would be a good idea though. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!