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b=gBaw/DQHE+HCt6pgA2K22JnPxufqmdmb70RTz6zh2rh6lcVOvYytTGcYnND/l19Wn OYpFhHDZgUkF/qRDpnS5wakWtsv1IrEWO2Tx82L7oopmkW1vHH3I8Wry3t6GB8EzHk K1DaLmCizuUM5I4uwa/xV5CxGICy3FOVV1cB1Tr7cpvP++FmOejT2gt+S1MJp9qNYn NDrQ2kLGCuJx01c613gbf+TNsdJNKNTi//4d+gqHHXb94fPou4M5QRAQ7Hvbel4f4I 8H8QppBMlDCxPoB0HF9xxWB5Xbjv24TB1ybA56gIHhhwrzDdL5ArR2ySyDFey6RDPo pzdpJnT4Qugbg== Date: Sat, 14 Nov 2026 17:24:33 +0000 From: "Lorenzo Stoakes (ARM)" To: shao.mingyin@zte.com.cn Cc: akpm@linux-foundation.org, liam@infradead.org, linux-mm@kvack.org, vbabka@kernel.org, jannh@google.com, pfalcato@suse.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/mremap: enforce the driver's page size on resize and move Message-ID: References: <20261115004700194_SpQtdnE3JL6bzx51l-a5@zte.com.cn> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261115004700194_SpQtdnE3JL6bzx51l-a5@zte.com.cn> X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: CA47740004 X-Stat-Signature: d48wqiqdbmorj4swuktqr5koyyxh8wcn X-Rspam-User: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-HE-Tag: 1794677079-67302 X-HE-Meta: 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 qyZI7mnn Pxt+9WATTXwzmQTpUuquBJKoSFlpG181zWL6KIz6EXVGRbpXeuT++Pvr5rxUjttB243BJaSaS8Rpt4BpC6A3BM5T6kHocYfJuuyIEPW9BiwvD6Wl+DmZSQJRPoVYUrpd0JwE5lcpC1dXW+fCNyomJ5L6sHOI7PLmXlf8WC2TRv0AZtue56D0n++SqdmrpJo7zNXt1zF2yLJ4VkTmRpmqrlZw/gMlWxjPWCq5JLVwb4HOyNlxKw4TT5NFLgn9sW8APXMqIZPGQE886q58aOvwAQNqNdsZO1tPSMnmNeMnCt14Cr88DDfMUHvM1C9CAaWHNRpY8X3RYDXNx/ZI= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Sun, Nov 15, 2026 at 12:47:00AM +0800, shao.mingyin@zte.com.cn wrote: > From: Shao Mingyin > > mm/mremap: enforce the driver's page size on resize and move > > device-dax exposes its mapping granularity through vm_ops->pagesize() > and requires both VMA boundaries to be aligned to it. mremap() checks > may_split() when moving a subrange, but does not validate the new end of > an in-place expansion or both boundaries of the destination VMA. > > An unaligned expansion or move can therefore succeed and leave a VMA > that device-dax rejects at fault time with SIGBUS. Check the final > new_addr and new_len before moving, and check vm_end + delta before > expanding in place. > > Checking the actual boundaries preserves an expansion starting inside a > VMA when its resulting end remains aligned. The move check also covers > equal-length MREMAP_FIXED moves. Existing PAGE_SIZE mappings pass both > checks, and the existing hugetlb restrictions remain in effect. > > Signed-off-by: Shao Mingyin NAK obviously. This patch is broken, wrong, and it's not even a bug. Also, you are flooding the kernel with patches, 17 series across 7 subsystems over 23 hrs: https://lore.kernel.org/all/?q=f%3Ashao.mingyin%40zte.com.cn Please just go away. Nobody wants your AI slop. -- Cheers, Lorenzo