From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (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 41A0D3D7D7E for ; Tue, 21 Apr 2026 15:29:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776785379; cv=none; b=AbNy0+ciNASXypcXbN9bXyyDT8XyGYtlH0rsb9gP511d89HXJjnEoxmQ5MIrKXs4VQXlLXfXgCQiFzNn9+9XPP3YPY1tYKmL904Qd4sGc7sYg+QhD0bx/5D9Z9s1J4Uepi+6fgEiUlkatIXHTyLfKmVfe2OJrCWLisKlSVvz6GU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776785379; c=relaxed/simple; bh=cCow88+KpwoaT+jjVfBphsGIAeg+It2AfwBtddoaiKc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=lyHKe5O/wS2Ad7lU/BaaP8TZmHRzhc5Ba21syAyzJZIT8qZUOqCstypX4qZDP00sYz5NE5XjXCGHqWTnZfetZa78Xb3aqvWVK/itdM6L26b0XI0lWV+10HORX72yNMG/rRkFgWNitLeLtXFmprcgnBne5X5aZFSpC1pN1U5nmxM= 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=hJ7H723R; arc=none smtp.client-ip=192.198.163.16 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="hJ7H723R" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1776785377; x=1808321377; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=cCow88+KpwoaT+jjVfBphsGIAeg+It2AfwBtddoaiKc=; b=hJ7H723RZwuwPk4eMds0fgmh7Vg7m0Kzi1J5GfLEKfLQb08yiFh9chn3 fsJn+geDSDpa01r/a/czRnMov8que7WLgJdp88iWyd8qjtmAEOuLlh/Ma 2zc57VmF+57doCdHsy8mCF3XM7UmPdOwnUthX+COtVXiQwTtUFCt+X3VP N8l9Ttjb1CXsP/em/ItNKbn/R2TrFH3zkesaPyAKrt79Bgn0ypy9SB8Jp 2u5H6EhvFVMdROie17vViGToMsaSmf8JtnzSykUjW38pG4vN/+6OBRtnC 3cFKe/tTAqMbCbei2A489L2WCHaFzYAxDKLnTf2pXBxMaw7jkiW7pszPQ Q==; X-CSE-ConnectionGUID: APG2AdMIRXmS5CPj4Q28bQ== X-CSE-MsgGUID: 1TgR++6nQx2AA2sDBDPVmg== X-IronPort-AV: E=McAfee;i="6800,10657,11763"; a="65255666" X-IronPort-AV: E=Sophos;i="6.23,191,1770624000"; d="scan'208";a="65255666" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2026 08:29:36 -0700 X-CSE-ConnectionGUID: 5d4Jbz1RTgulzaJLRRff6Q== X-CSE-MsgGUID: VFFvl/qRQ9i0y3gPsUufww== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,191,1770624000"; d="scan'208";a="233848885" Received: from dwoodwor-mobl2.amr.corp.intel.com (HELO [10.125.111.122]) ([10.125.111.122]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2026 08:29:35 -0700 Message-ID: <92f138f9-b041-461d-b159-ff1bc265bbee@intel.com> Date: Tue, 21 Apr 2026 08:29:33 -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> Content-Language: en-US From: Dave Jiang In-Reply-To: <778c8dc5-b65e-4b1f-be13-8bfb960cefc3@zohomail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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? > > > Ming >