From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 9DF57155757 for ; Fri, 26 Jun 2026 15:31:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782487873; cv=none; b=M1cfxgUJL6DvyT51q7JQ8K9b+NDMitJ9QCzgQAGdtyAd+9TQZ9rXB8ra1AReagUXi9nnlR9Gij3yKXCLcc/KXphat5XKZ8ncssCdzNErmDeBuxUyaGiQJf6Ub7pbjBO9kOxk0iSFnNvJc7mht1pEBReD8jlnyrpNsitvo7AUEu4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782487873; c=relaxed/simple; bh=vW3G1J4YDebpMIkqsfVvqzdmb+BSFDkcRC3MLaZ+F2M=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=eDRJKDxyU0Lh2VqShHjOmT6sbQicfKo0kNeI0DdQ79m14wQW2xXD2R31UeW0ZBXhUF8AlXRE7qQ/5B5Q8DyngEFk7CLjW/MWMjFX0aj9epxK6qUaVl5KRroh2m8yfmsA011qCno/8OqcQJhSkRgpW9p51GgbDU8GNjbF7gvKDx8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XL2+saor; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XL2+saor" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 762001F000E9; Fri, 26 Jun 2026 15:31:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782487872; bh=owGqSZp7QzVujsnsQualuFCtYKxndQjEWGbcu4HEMyo=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=XL2+saorLatjHNh2ZZ1PnODieCkxMzSzz10yZlxNYJsV1xsQHbLS3BHY0tFTdMmVR LUSk/vHgFfP0KgJLJ+xqiEZEleKF8pp1iP1WxwcFpth4hgz3qGeS+N/LrnDAEnrp7p 9du1INCXPxHaz+/Vus22bZTxYWhwPcKr1BEINtedadceKsSthiDGEhz0jHJtOMOWrc eBfOilO9rt1KEgmWtcfTM2ZuFO3W2Kmv0Gg3ATgVNtaWIiLEVWF2+gtZtMkRZe8VvV n2yboyKGb/i4+g3hEp4qp0+Q4dIxp9MdwHTK1DJzu6qg6jw8OEEnUT9SeVzxNTTUJ3 GR6YRKmyB9kyg== From: Thomas Gleixner To: Feng Tang Cc: "David Hildenbrand (Arm)" , Andrew Morton , Petr Mladek , Steven Rostedt , paulmck@kernel.org, Douglas Anderson , Peter Zijlstra , Vlastimil Babka , linux-kernel@vger.kernel.org, Ard Biesheuvel Subject: Re: [PATCH v1] kernel: add a simple timer based software watchpoint In-Reply-To: References: <20260622081430.37557-1-feng.tang@linux.alibaba.com> <0c39c459-306f-49f5-b08e-e7b9b27b6352@kernel.org> <87a4skl36t.ffs@fw13> <87pl1ejoj4.ffs@fw13> <87jyrlk6g7.ffs@fw13> Date: Fri, 26 Jun 2026 17:31:09 +0200 Message-ID: <87cxxdiaiq.ffs@fw13> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Fri, Jun 26 2026 at 22:33, Feng Tang wrote: > As HW jtag debugger is expensive and not generally available for > software developer, also many production hardware don't have their > jtag interface open for security reason, I think monitoring the > abnormal changes to dram/mmio is convenient for debugging memory > corruption issues. Could you help to give some suggestion on > how to redesign this? Many thanks! If you can reproduce in a VM, you have qemu + gdb, which allows you even to debug the BIOS. If it's bare metal you can use kgdb or perf events. All of those allow you to set watchpoints, data breakpoints etc. If you end up with no hit on a watch/breakpoint then you're lost in that case as you can't debug the BIOS w/o a hardware debugger, but that's not any different than with your magic hack. The tools are all there you just have to use them correctly, no? Thanks, tglx