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Peter Anvin" , Tony Luck , Andy Lutomirski , Peter Zijlstra , Andrew Morton , Naoya Horiguchi , , , , Guohanjun References: <20240204082627.3892816-1-tongtiangen@huawei.com> <20240204082627.3892816-3-tongtiangen@huawei.com> <20240207122942.GRZcN3tqWkV-WE-pak@fat_crate.local> <100198dd-320f-68e6-9c09-210620940a74@huawei.com> <20240327220511.GCZgSYF6lJ3U1CaKV0@fat_crate.local> From: Tong Tiangen In-Reply-To: <20240327220511.GCZgSYF6lJ3U1CaKV0@fat_crate.local> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.179.234] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemm600017.china.huawei.com (7.193.23.234) X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 6E7B2100002 X-Stat-Signature: q8rff8ah5f7p61399xd8cwon1gwa7mcg X-Rspam-User: X-HE-Tag: 1711942922-730749 X-HE-Meta: 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 19dkZMI3 a3jWkTfP/KY/wtCZkknkGqGq9fj66b8/p81KE5T1PRkN3kBrugdIbxRSD3K5mtPYkJOaJtR0V95pgTMXr4xZ+4bLQ6p2rMkpCJGDoX8uX+qpWazG+4xFDzRjAThpS9qyYZX/CsJW0Z6mzoXEiGmkYhOK4fd9bo7O8ezkTw9yML6xVrkY5XHH2jtsTO5ckzVwkN5mxPcKMqw199Ws= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 在 2024/3/28 6:05, Borislav Petkov 写道: > On Sun, Feb 18, 2024 at 06:08:14PM +0800, Tong Tiangen wrote: >> 1. The copy_mc_to_kernel() is used in the coredump, KSM, and COW >> scenarios, in these scenarios, the src mem stores the user data and the >> kernel use kernel address to access the src mem(using kmap()). >> >> 2. the src mem of copy_mc_to_user() is currently only used by the DAX: > > You mean just because it currently is used somewhere which probably is > ok - no clue what DAX does - and even if the source address is still > *kernel* memory and even at the danger that someone else might use it in > the future and think the handling on a potential #MC is ok, you're still > arguing that this is the right thing to do perhaps because it fits your > use case?! > > Sorry Tiangen, not gonna happen. > I left the office last week and felt sorry for the lateness of the reply. You are right. Our current processing is based on "experience" rather than interface constraints. is_copy_from_user() determines whether a user is a "copy user" based on fault_in_kernel_space(). Therefore, it returns false for copy_mc_to_kernel()/copy_mc_to_user(). As a result, MCE_IN_KERNEL_COPYIN cannot be set in error_context(). Comprehensive consideration of all factors, it is better to manually call memory_failure_queue() to handle this problem case by case. Finally, do we consider accepting only the patch 1/3 ? Thanks, Tong.