From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 EA3B73E9F97 for ; Wed, 22 Apr 2026 14:43:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776868982; cv=none; b=B8Rw1Ic5S5johuTvq1/ReLHJlNBOiaqG1A+VdH2wDpWoe48lSehK4kMy9h8DuQ4nQaRNmVMYEU5TRuYTC6/OzWaHGIifdQ4Pns1DYAyq87PzVob5wEuNc3itEJ4IdfMLYnIs9NdeCPIij/61iJG48N8Wj4CzWZp/+fF0vYiYuGI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776868982; c=relaxed/simple; bh=QLmTzE04VCPNN3oLklmEfcXshpdYx0l3Gur3dKpm9JY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DYQUvZ79mYVj/H/QMNYwknVzpjOELVElSShXv3+K1IMZoo3TL29MiKIro1Ei+15eu95xGeeyQdrmW3zYA9Uac449xFCtf/jVuSfezXS8T8/IV+xyC3lgaiBgnPPRp8C5dp2F8HlTJ+PtdoMkT4RsE/1ZLvXFL1EH8pGfYEEOoTg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=ihFQkusi; arc=none smtp.client-ip=198.175.65.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ihFQkusi" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1776868981; x=1808404981; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=QLmTzE04VCPNN3oLklmEfcXshpdYx0l3Gur3dKpm9JY=; b=ihFQkusiDbbGbAjV50gymM8QJ59AhHCVlARtDuhutmoq8SYdbaFMZkR9 TmU5eQeF0VGqxNiytnfgR66kvH5RZVzdPG/o6vGWD6JujlqKpFTXqX7/0 HrsV8v7WQrJyUKehLGtGGz/gxd/yP0tC3WQBlfCR0ewsZUbjAYdstQq8m Z/03ZgRGb1DVTgIfK+13wzXy4u/vANBZqnI0mV8RL5rvneg7E+RkS6yBf msUrCwp3LK2Wus4zhmrAYE46hKYO2VhDo/hCJVC/yGr8fuvl35uhRgnRc GK8lrjW46N1Mhpq1GcYcDuh/yk+e0wg0h3wDrGdv/3e0ULFpib/WHtSJa A==; X-CSE-ConnectionGUID: qKNg3NfBSIqK7u6vyUdQhg== X-CSE-MsgGUID: N6K8Ay4ETvq2MsyA85bWZQ== X-IronPort-AV: E=McAfee;i="6800,10657,11764"; a="95237550" X-IronPort-AV: E=Sophos;i="6.23,193,1770624000"; d="scan'208";a="95237550" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Apr 2026 07:43:01 -0700 X-CSE-ConnectionGUID: s7P7ceMmRa6XgjqvtARLNQ== X-CSE-MsgGUID: 8zM6YAHZRrGtvjiFB/r1XA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,193,1770624000"; d="scan'208";a="227789130" Received: from dwoodwor-mobl2.amr.corp.intel.com (HELO [10.125.111.207]) ([10.125.111.207]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Apr 2026 07:42:59 -0700 Message-ID: <91a0734e-09df-4172-a28b-a6443dfe313a@intel.com> Date: Wed, 22 Apr 2026 07:42:57 -0700 Precedence: bulk X-Mailing-List: driver-core@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/4] cxl/memdev: Hold memdev lock during memdev poison injection/clear To: Li Ming Cc: driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, Greg Kroah-Hartman , "Rafael J. Wysocki" , Ira Weiny , Bjorn Helgaas , Danilo Krummrich , Davidlohr Bueso , Jonathan Cameron , Vishal Verma , Ben Cheatham , Dan Williams References: <20260314-fix_access_endpoint_without_drv_check-v2-0-4c09edf2e1db@zohomail.com> <20260314-fix_access_endpoint_without_drv_check-v2-2-4c09edf2e1db@zohomail.com> <69da9fa696d0f_6c31a100e8@djbw-dev.notmuch> <778c8dc5-b65e-4b1f-be13-8bfb960cefc3@zohomail.com> <92f138f9-b041-461d-b159-ff1bc265bbee@intel.com> <6b967b54-ade8-4398-b4c1-2cdb755ab684@zohomail.com> Content-Language: en-US From: Dave Jiang In-Reply-To: <6b967b54-ade8-4398-b4c1-2cdb755ab684@zohomail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 4/22/26 5:09 AM, Li Ming wrote: > > 在 2026/4/21 23:29, Dave Jiang 写道: >> >> On 4/21/26 3:48 AM, Li Ming wrote: >>> 在 2026/4/12 03:23, Dan Williams 写道: >>>> Dave Jiang wrote: >>>>> On 3/18/26 4:59 AM, Li Ming wrote: >>>>>> 在 2026/3/17 23:00, Dave Jiang 写道: >>>>>>> On 3/14/26 12:06 AM, Li Ming wrote: >>>>>>>> CXL memdev poison injection/clearing debugfs interfaces are visible >>>>>>>> before the CXL memdev endpoint initialization, If user accesses the >>>>>>>> interfaces before cxlmd->endpoint updated, it is possible to access an >>>>>>>> invalid endpoint in cxl_dpa_to_region(). >>>>>>>> >>>>>>>> Hold CXL memdev lock at the beginning of the interfaces, this blocks the >>>>>>>> interfaces until CXL memdev probing completed. >>>>>>>> >>>>>>>> The following patch will check the given endpoint validity in >>>>>>>> cxl_dpa_to_region(). >>>>>>>> >>>>>>>> Suggested-by: Dan Williams >>>>>>>> Reviewed-by: Dave Jiang >>>>>>>> Reviewed-by: Alison Schofield >>>>>>>> Signed-off-by: Li Ming >>>>>>> Hi Ming, I dropped this patch with Dan's comments [1] and updated cxl/next. Please check and make sure everything looks ok to you. Thanks! >>>>>>> >>>>>>> [1]: https://lore.kernel.org/linux-cxl/69b8b81621e16_452b100e@dwillia2-mobl4.notmuch/ >>>>>> Hi Dave, >>>>>> >>>>>> I think there is no change needed in this patch, just need a independent patch for holding memdev lock in cxl_region_debugfs_poison_inject/clear. >>>>>> >>>>>> Or you want to review this patch again? >>>>> No. Maybe I misunderstood the comment from Dan. So we should keep this patch? >>>> tl;dr: yes, this patch is *now* valid. >>>> >>>> As originally structured having patch2 before patch3 added no value. >>>> Going forward I would say do not structure a series such that a new lock >>>> taken in patch N starts being useful in patch N+1. >>>> >>>> I assume that is what: >>>> >>>> "The following patch will check the given endpoint validity in >>>> cxl_dpa_to_region()." >>>> >>>> ...is trying to say, but when commits are applied to the tree it is >>>> difficult to see that this commit was from a series. >>>> >>>> So do pick this one up, but the changelog needs adjusting. Something >>>> like: >>>> >>>> "cxl_dpa_to_region() assumes that it is running a context where it is not >>>> racing changes to "cxlmd->dev.driver". Acquire the memdev device lock in >>>> the debugfs entry points to preclude debugfs usage racing cxl_mem driver >>>> detach." >>>> >>>> With that you can add: >>>> >>>> Reviewed-by: Dan Williams >>> Hi Dave, >>> >>> Will you pick this patch with changes from Dan's comment? Or I need to send out a new version? >> I believe it's merged into linus/master already. Can you check and see if everything looks correct? > > I don't see this patch in linus/master or cxl/next. I remember you dropped it after applying the patchset to cxl/next. Oh then can you please just resubmit it with updates? That way I don't mess it up. Thanks! > > > Ming >