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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6DB46C04A68 for ; Thu, 28 Jul 2022 15:25:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6RjcyLvlVzDH0zsPavp8t5ptWGtxG6zUQEEx48oG9qI=; b=awHGGZa3aGGNlu lD4oEKjok4VcCb/GDbfY8aj//L2moYl9r90hX9u5CjdWSRkwCXM/IGsh9MZDsLjt0Nk/xT8nZ417l ECEIV6IOMY+atrK81Jw+b38gSKp2aA4KUVVpgYLf8L7BzOQWyPlgsRBPNG8xWCaPy/ryI0eW1uPGV o2SQW3731Ntf6Venvh3VYDf7uaVsmGtfcBsVWi2uqRlST80oOaAPjK7HrSD7nOaUL6xMc/x3XtPh7 1cX3DzhaPSY4b+DBIRL4/4FNfClfwJKN3OXeh4N67eJcV+zjfxUfZV6eGLAt/Hkmpir9XRaPmz83A k5hK03hUa6K/ilYYqmCw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oH5ML-00AU9B-8N; Thu, 28 Jul 2022 15:23:33 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oH5MH-00AU4R-CB for linux-arm-kernel@lists.infradead.org; Thu, 28 Jul 2022 15:23:30 +0000 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=p51XCyM0/9Op3tGJvSfAei+sAauz8ZTUgYSQ1KOv5gU=; b=CAPY7vodsvCQOB9tVU/RXlUe5n kvgZdWoCWzOlMhC4p8lF4klOmaIA3aCCzViAn9iAS21HeYQVZAgbOupG8mN6LieZOLQS6k2IS39Xi hK4hivDj0gAeFNeseFdt9hGNz9iGgFPpjwiA4riWf+6BUvTcEUjlW+TRe6PrinXMw9DhoriANu3um YocRnPUKdbKp7F8z/FGEHzZTHaAUXKs6KAdU2jFzf6FUwhrzeTxCuPSMuN/jzYYOMqxvv+1NT+bUT 7HfHuuzeuUBeLIBHIxRRfXTXZYPfToAwGKJB3mKjFReyG2y+G7ODriZoQEQcnTpFFBGpoFuAkKL2i gZiCmTUQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:33608) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1oH5M8-0006RK-FS; Thu, 28 Jul 2022 16:23:22 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1oH5M5-0003JZ-IS; Thu, 28 Jul 2022 16:23:17 +0100 Date: Thu, 28 Jul 2022 16:23:17 +0100 From: "Russell King (Oracle)" To: Baruch Siach Cc: Ard Biesheuvel , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] ARM: traps: print un-hashed user pc on undefined instruction Message-ID: References: <515f8c621449e0f9aa7d11f998ce010676ba35fd.1658938681.git.baruch@tkos.co.il> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <515f8c621449e0f9aa7d11f998ce010676ba35fd.1658938681.git.baruch@tkos.co.il> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220728_082329_428454_FD6AB4B3 X-CRM114-Status: GOOD ( 11.92 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Wed, Jul 27, 2022 at 07:18:01PM +0300, Baruch Siach wrote: > When user undefined instruction debug is enabled pc value is hashed like > kernel pointers for security reason. But the security benefit of this > hash is very limited because the code goes on to call __show_regs() that > prints the plain pointer value. pc is a user pointer anyway, so the > kernel does not leak anything. The only result is confusion about the > difference between the pc value on the first printed line, and the value > that __show_regs() prints. > > Always print the plain value of pc. > > Signed-off-by: Baruch Siach Looks sensible to me. Please drop it in the patch system, thanks. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel