From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) (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 AEB6B22615 for ; Tue, 16 Sep 2025 04:56:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757998618; cv=none; b=DYpksF+g/ASJyDZNIqKR1CAmGHY/yo8CADWQ69STl7fU4uAglwSZPX/fIHe2ROzNNqxEoQfTCLO2almuRTUQx/wul8JirQ9sbOxYa6NX4ezBuGhNeOAOYy8OTZ54geXpm6AMcoh1CBTuW+PRnHbkgOeqdlXx9z2UFmTbX+giFtA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757998618; c=relaxed/simple; bh=qcmb/u0/h7fVujYCrvk2eC9JZFnU0rmO/ckEWLGqQJ8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Ujzmj5bhs08BnxYfRrup7MWBCL7Bcxqcd+p0OVarBPMa2SYfS4/DsLNn/A4BxiW+7c5XXacl9gDi/D/v4/5Js+XgSDewHFxrY2mf3lvQD30U5C0AvQM+jvuETi8SKa329ezleoTFhM42bg1OV8JejgxztdgE/IwCyIyYG0JPqDc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=L+6hFHzD; arc=none smtp.client-ip=192.198.163.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="L+6hFHzD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1757998617; x=1789534617; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=qcmb/u0/h7fVujYCrvk2eC9JZFnU0rmO/ckEWLGqQJ8=; b=L+6hFHzDfoXyV8nvd1I5nnxYr5Uny8x96c+TLYQynzNTX/YPlqGKlCeC VVGHxcyCx8RolKCUCJpHauIGuNDjjlH+MXXeCB6+zmOOnFIMw72RXO//5 ZX+Ic5x+XC2EMV8h/go1iocb0XlmzxXawP8VoOsPtUaR+aJi8rI6yMt6L X3gRkNKP0m39+Tpq/hrvPeP9mUPmQkeTPoBeQp2PSZDZmfcyMmL8ws+Rh GZ8NfWLB8RTwMNzZSQa2xrnThmhORTHF/NS731v07mMXiF3cDaPANWSeM FDyEkCqaYmMQD486x5SFYiT23H4+tvYbPQ/OA2rfpn3KFdulkJdGgNzD2 g==; X-CSE-ConnectionGUID: VrPVaUNPRr6IvY8O7fBCGA== X-CSE-MsgGUID: bYnyzYVkRdavB6Ow92TLtw== X-IronPort-AV: E=McAfee;i="6800,10657,11554"; a="59489703" X-IronPort-AV: E=Sophos;i="6.18,268,1751266800"; d="scan'208";a="59489703" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Sep 2025 21:56:56 -0700 X-CSE-ConnectionGUID: XOjfK0zWQ7yE45Vk36v+DQ== X-CSE-MsgGUID: fSrB5XgfTO+stsFpw+NbWQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,268,1751266800"; d="scan'208";a="174382420" Received: from allen-sbox.sh.intel.com (HELO [10.239.159.30]) ([10.239.159.30]) by orviesa009-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Sep 2025 21:56:55 -0700 Message-ID: <3205569f-2870-40ab-bcc8-c99639e501ae@linux.intel.com> Date: Tue, 16 Sep 2025 12:54:05 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] iommu/vt-d: debugfs: fix legacy mode page table dump logic To: "Vineeth Pillai (Google)" , David Woodhouse Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org References: <20250814163026.634182-1-vineeth@bitbyteword.org> Content-Language: en-US From: Baolu Lu In-Reply-To: <20250814163026.634182-1-vineeth@bitbyteword.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/15/25 00:30, Vineeth Pillai (Google) wrote: > In legacy mode, SSPTPTR is ignored if TT is not 00b or 01b. SSPTPTR > maybe uninitialized or zero in that case and may cause oops like: > > Oops: general protection fault, probably for non-canonical address 0xf00087d3f000f000: 0000 [#1] SMP NOPTI > CPU: 2 UID: 0 PID: 786 Comm: cat Not tainted 6.16.0 #191 PREEMPT(voluntary) > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-5.fc42 04/01/2014 > RIP: 0010:pgtable_walk_level+0x98/0x150 > RSP: 0018:ffffc90000f279c0 EFLAGS: 00010206 > RAX: 0000000040000000 RBX: ffffc90000f27ab0 RCX: 000000000000001e > RDX: 0000000000000003 RSI: f00087d3f000f000 RDI: f00087d3f0010000 > RBP: ffffc90000f27a00 R08: ffffc90000f27a98 R09: 0000000000000002 > R10: 0000000000000000 R11: 0000000000000000 R12: f00087d3f000f000 > R13: 0000000000000000 R14: 0000000040000000 R15: ffffc90000f27a98 > FS: 0000764566dcb740(0000)GS:ffff8881f812c000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000764566d44000 CR3: 0000000109d81003 CR4: 0000000000772ef0 > PKRU: 55555554 > Call Trace: > > pgtable_walk_level+0x88/0x150 > domain_translation_struct_show.isra.0+0x2d9/0x300 > dev_domain_translation_struct_show+0x20/0x40 > seq_read_iter+0x12d/0x490 > ... > > Avoid walking the page table if TT is not 00b or 01b. > > Signed-off-by: Vineeth Pillai (Google) > --- > drivers/iommu/intel/debugfs.c | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) Add the fixes tag and queue it for v6.18. Thanks, baolu