From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-o94.zoho.com (sender4-pp-o94.zoho.com [136.143.188.94]) (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 6620B280CD5 for ; Tue, 21 Apr 2026 10:48:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.94 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776768522; cv=pass; b=ObZ5yLqWorDxGhyly3nSnzN9wsYpUgqTd0hPKWxKns6WsYpglR6+GHs6CBfyv2HB1s9ucfZWbrR3jyUTLR8FTvWtAVffmRtIFfrvHXbY7RrVEKn1kRUMd6+gbRxmb+MWEW9SKqUDrgAfiaWz7msBMpReNJ4mfKgBulM+dCe7JyQ= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776768522; c=relaxed/simple; bh=QXeXJxwR4AAain/grzb6VTedX2LJK87P722v0plWi8o=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=WsC2CYncyEjpACbRbH2Udk8fUfDwFV+p6ThN3gFZsQDx86utiXAQoJ4qkUM1OP/z9+Wvsy7akp8SVk5am6Q5kzgIWrMFzYd6Jk+LNP91LdQRDlMnD36OOaCzHjKsJzX9DkfkA0xgodMGeNJhc2hiuLfpSOsdR0ibCtvPtvrAI2Y= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=zohomail.com; spf=pass smtp.mailfrom=zohomail.com; dkim=pass (1024-bit key) header.d=zohomail.com header.i=ming.li@zohomail.com header.b=CXwyeCV3; arc=pass smtp.client-ip=136.143.188.94 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=zohomail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zohomail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zohomail.com header.i=ming.li@zohomail.com header.b="CXwyeCV3" ARC-Seal: i=1; a=rsa-sha256; t=1776768516; cv=none; d=zohomail.com; s=zohoarc; b=ADmiVXrqFg8Pudfbv4gHsuCgjoBxYWO9x7PcIN8uJCp4k3yQ8eT3KhOMguJBwUCXWkr+AGHDMtq5RqMm6MCdA2pYosbCKfiPqZv2c3GGQ8NSIIdKrqs7lOhEWglLTuo7ruQEjCVHcX21EduVc+MEab64q+x6kak7FeNxK3ptgSI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1776768516; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=QtUSpS5xgMacdNEe4xOf2Z4l0paD0rzRkJfr1DJn9Ho=; b=Fk6C98y8Br2SfThu5Y62scef/RMiHQM9mgG8QdKpYTKaqWUcZ2/LLJlmnYXpxE2/XReDIBv11Lq1ajRSYUQ6U3i0+nLCKNrdei9f0+++5WrMu/4++SbTHryccWfQGxPMLCP5GzL3Mb28EvsXVsLK9Ex68Zgjgd3WVdWHkY7N5VQ= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=zohomail.com; spf=pass smtp.mailfrom=ming.li@zohomail.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1776768516; s=zm2022; d=zohomail.com; i=ming.li@zohomail.com; h=Message-ID:Date:Date:MIME-Version:Subject:Subject:To:To:Cc:Cc:References:From:From:In-Reply-To:Content-Type:Content-Transfer-Encoding:Feedback-ID:Message-Id:Reply-To; bh=QtUSpS5xgMacdNEe4xOf2Z4l0paD0rzRkJfr1DJn9Ho=; b=CXwyeCV3L++l/RfSD4ZKau6jse2KqTHVErtym8NdaBjspZBN7JSPsXWIe45VY9Hq f1QiygQvX7AScbcy31Mya/m2p3fe4vNodv8OeX0F6PEYeY2u9JLqNKgHgYYL0NHmUi/ WRwfC90WJSL35Zi/sD+UCHalDgJa/3yK9bY/ur9c= Received: by mx.zohomail.com with SMTPS id 1776768512771721.4392572083452; Tue, 21 Apr 2026 03:48:32 -0700 (PDT) Message-ID: <778c8dc5-b65e-4b1f-be13-8bfb960cefc3@zohomail.com> Date: Tue, 21 Apr 2026 18:48:21 +0800 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: Dave Jiang 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> From: Li Ming In-Reply-To: <69da9fa696d0f_6c31a100e8@djbw-dev.notmuch> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Feedback-ID: zu08011227cfef9a97a59ddb595874eb010000dc9efed156263c5b4e6893bca069031c7de30715a95f280bf9:ZohoMail X-Zoho-CM-AccountID: abd763e7b9fa23acf4f42a44f9876d2d993e05abdb9290f9ccb1008c977bf7f0 X-ZohoMailClient: External 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? Ming