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 5B1DFC2BA4C for ; Wed, 26 Jan 2022 17:37:37 +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:From:References:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=JEfsYDwgI0Y9S8OMY4tZ/9FWVJL2TFad4kQ5tgyH2RY=; b=kArxtjh1FmhqHX QwTK7vZFgFkjChKajUmNFN6LkS3k9TWWddVFogjG5VBHTnjI7qyKXj3W9BRyp/+8m4JwB6Wn/Rexu ia9qbiyxSQCGjm2ktFtDgcXDIyAw0fy66wB7WXu3o/uPnYO1cxCWQYYNSpdefnvxL/Q0UT14/CAMA uKkFUMDSvb/e7Rbc010Qh13KSKZowkhG3o7Oetjt4NSvzw+79jkJXl/r2mZeBAiZ39fLtjDyhlxFd MKjs3G/KSrJd8YJfWKCgQ1ZrBcJu30McJxmLiNcBbUacdbIPRQvVm7fZawv2c3WuK1Fd6uBKWOqj5 9+ODsMT0r6Wt7idZM8Qg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCmD9-00D2pL-8U; Wed, 26 Jan 2022 17:35:59 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCls5-00CvCB-RO for linux-arm-kernel@lists.infradead.org; Wed, 26 Jan 2022 17:14:15 +0000 Received: from [192.168.254.32] (unknown [47.187.212.181]) by linux.microsoft.com (Postfix) with ESMTPSA id D0EBA20B6C61; Wed, 26 Jan 2022 09:14:10 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D0EBA20B6C61 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1643217251; bh=qjst+qeWYxaDU+MRKQkL6zF+4RSRzRgazary5tstvLY=; h=Date:Subject:To:References:From:In-Reply-To:From; b=XtrB4oV5zRlyA6UFpPm1uaOM2KvUJchClLB2PNDJMzq/z7dDHar0dbVIIQ78/SgcT Pz00QqrEL8silAQ/SwbN/N/8G0jAu+aKD8F0w+ySTEEdxPV1jgiaGl2MqvyP2w5V14 xFCoG4XyjjRh129nmkTz041zpJ5zX/y8ZWRLu3cE= Message-ID: <1a0e19db-a7f8-4c8e-0163-398fcd364d54@linux.microsoft.com> Date: Wed, 26 Jan 2022 11:14:10 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v13 11/11] arm64: Select HAVE_RELIABLE_STACKTRACE Content-Language: en-US To: "nobuta.keiya@fujitsu.com" , "mark.rutland@arm.com" , "broonie@kernel.org" , "jpoimboe@redhat.com" , "ardb@kernel.org" , "sjitindarsingh@gmail.com" , "catalin.marinas@arm.com" , "will@kernel.org" , "jmorris@namei.org" , "linux-arm-kernel@lists.infradead.org" , "live-patching@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <95691cae4f4504f33d0fc9075541b1e7deefe96f> <20220117145608.6781-1-madvenka@linux.microsoft.com> <20220117145608.6781-12-madvenka@linux.microsoft.com> <825b8b72-c746-ba24-7142-3fff481e82d6@linux.microsoft.com> From: "Madhavan T. Venkataraman" In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220126_091414_054303_8ECA299D X-CRM114-Status: GOOD ( 20.48 ) 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 1/26/22 04:20, nobuta.keiya@fujitsu.com wrote: >> I have not seen any activity on that in a long time. IIRC, Julien quit RedHat. >> I don't know if anyone else has taken over this work in RedHat. >> >> Sorry, I don't have any more information. >> >> Madhavan > > Thanks for your information. > > By the way, I'm considering test code for arch_stack_walk_reliable(). > Specifically, I apply Suraj's patch to enable livepatch, and added a function > that sleeps between SYM_CODE_START and SYM_CODE_END, then livepatch > checks if the task has an unreliable stack. > For now my internal test code working correctly, but my Kconfig excludes > STACK_VALIDATION dependency. > > It seems that objtool will not be enabled yet, so I would like to test it easier. > If you are already testing with this patch, could you tell me how to do it? > > For now, I have an instrumented kernel that directly invokes arch_stack_walk_reliable() from various places in the kernel (interrupt handlers, exception handlers, ftrace entry, kprobe handler, etc). I also have a test driver to induce conditions like null pointer dereference. I use this to test different cases where arch_stack_walk_reliable() should return an error. As for livepatch testing, I have enhanced objtool and the kernel so the frame pointer can be validated dynamically rather than statically. I have tested various different livepatch selftests successfully. I have also written my own livepatch tests to add to the selftests. I am currently working on preparing an RFC patch series for review. Basically, this series implements STACK_VALIDATION in a different way. I plan to publish my work soon (hopefully Feb 2022). I was going to do in December. However, my workload in Microsoft did not permit me to do that. I am also planning to set up a github repo so people can try out my changes, if they are interested. So, stay tuned. Madhavan _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel