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Y . Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Alexander Shishkin , Maxime Coquelin , Alexandre Torgue , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Bodo Stroesser , "Martin K . Petersen" , David Howells , Marc Dionne , Alexander Viro , Christian Brauner , Jan Kara , David Hildenbrand , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-mtd@lists.infradead.org, linux-staging@lists.linux.dev, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Ryan Roberts Subject: [PATCH 00/15] mm: expand mmap_prepare functionality and usage Date: Thu, 12 Mar 2026 20:27:15 +0000 Message-ID: X-Mailer: git-send-email 2.53.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 4B616A0002 X-Stat-Signature: nguq6ynqrrsyi1w7g9qguoahz53tuutm X-HE-Tag: 1773347270-202056 X-HE-Meta: U2FsdGVkX18kn3w4+LlNJzwGdChd+BuJuOVhMNQhETNUJoyy+TOrYbIptCXSmzd5ULXrzkgJFY300PrmNtpvhjIeXA9s7SHSbFSB1coSJD1pXQ73W01COw1F4agiK6QaAICiS7Pf+UV6snpTvr2LHtwEkcqI60MM8aezHgLc0H1Pxj2FsnexrRGz38A710paJlG0hfwyBA03RFQhgCWc2BwYsZilQ50krXIbZWBgeFZfKnvvVILhhpjY6FPpSgVPoUGpkvr4yUA62b/k73B/lK8fnA/TViBP+nD1LZ2htHQsJ72w8eEf/yJAvf45FLH6Wwzt5eirO3bYqBgP/GcHE8VktkQfJP/QoblBqAeNJhsX2RPKcgKkXBax/Kl+ekrryhmCMX1SStXooS/rakMU0d/6nEpxv9gh0JRpIjq3x7swdHNsXKR0odux1QPH9zhShe8DmvXNKzv+e63PqhcjGRGdV7z9737LY1bf11iqKPPRh98l+Jr60B3TUFKJ5Ox1HaRdPy6DTKGGcucG0GR4POpfHRDp9T56851J7Ed763rOCs/HH1dg+/XsOVXH/wtrfllZmAuc/7UnGXMILr7QbeFE++NmsBTpVQrKDC+5vlZ179AZXwyRr4l+BDiFfsLMBM4NzzurCyTyS8B9sA0InrNgCq49dkR9zSsgo7xr0x4NYtDUJFmedJc0pE2YJ5JTm4ybmJZc8V+vkxioSzi0kceIPILankBG9ACSggnRKJegARogvW65NgKan7ytUT1EpANe63jHSHOjWoRKPYfjA4UGgvHTpuuz6zBpLXho25tb51cWEgsjnV+WxOLZ29mW0SAQZ2gq7bpi1f4t/BoB4m4kPqFoaXrdRKHjQ7JcRai+SG1Krfouhn2d19HCT9zHAtlq5Mv0cV/p1SBZTXMEB7dsm8juoD3PSzIZxOQUVTxkjFEIuF0aY3y5kdT5l3tTdtzA+2TNG/aCx7fTaGt 78Z1TCaq BW6sRQM670akaWTnIccLnZ4BK4w9qsqggB4B0y+LNhVkfU6yYbLEa4w/JG0CMAY5b7GG1zWs5yVhJo7/+hh69OUJarFiXvb6BJ5QsxSW6VLgOci1VNaJn9dtbLcKKTmelNwfXDnqSWEwLV9K5aEtBYYw7HfFI6DKfvnXIGwqp/AKiSMNTG/XaMPpcm/WfIleB6S9crAoKo4a8PJhoL6nfyh49QibOvSdHcuep80USQHqa8cDPkJ1pU0VWhP6y1bPvCN0Oi3fdZKW2rLRjkNIrYtuSgj7Rr3TrzVRjjujxKskW665Xrua9WoNVNsCXhoe+6kfHzADdEzRqgd0= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: This series expands the mmap_prepare functionality, which is intended to replace the deprecated f_op->mmap hook which has been the source of bugs and security issues for some time. This series starts with some cleanup of existing mmap_prepare logic, then adds documentation for the mmap_prepare call to make it easier for filesystem and driver writers to understand how it works. It then importantly adds a vm_ops->mapped hook, a key feature that was missing from mmap_prepare previously - this is invoked when a driver which specifies mmap_prepare has successfully been mapped but not merged with another VMA. Importantly, mmap_prepare is invoked prior to a merge being attempted, so you cannot manipulate state such as reference counts as if it were a new mapping. The vm_ops->mapped hook allows a driver to perform tasks required at this stage, and provides symmetry against subsequent vm_ops->open,close calls. The series uses this to correct the afs implementation which wrongly manipulated reference count at mmap_prepare time. It then adds an mmap_prepare equivalent of vm_iomap_memory() - mmap_action_simple_ioremap(), then uses this to update a number of drivers. It then splits out the mmap_prepare compatibility layer (which allows for invocation of mmap_prepare hooks in an mmap() hook) in such a way as to allow for more incremental implementation of mmap_prepare hooks. It then uses this to extend mmap_prepare usage in drivers. Finally it adds an mmap_prepare equivalent of vm_map_pages(), which lays the foundation for future work which will extend mmap_prepare to DMA coherent mappings. Lorenzo Stoakes (Oracle) (15): mm: various small mmap_prepare cleanups mm: add documentation for the mmap_prepare file operation callback mm: document vm_operations_struct->open the same as close() mm: add vm_ops->mapped hook fs: afs: correctly drop reference count on mapping failure mm: add mmap_action_simple_ioremap() misc: open-dice: replace deprecated mmap hook with mmap_prepare hpet: replace deprecated mmap hook with mmap_prepare mtdchar: replace deprecated mmap hook with mmap_prepare, clean up stm: replace deprecated mmap hook with mmap_prepare staging: vme_user: replace deprecated mmap hook with mmap_prepare mm: allow handling of stacked mmap_prepare hooks in more drivers drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare uio: replace deprecated mmap hook with mmap_prepare in uio_info mm: add mmap_action_map_kernel_pages[_full]() Documentation/driver-api/vme.rst | 2 +- Documentation/filesystems/mmap_prepare.rst | 141 ++++++++++++++ drivers/char/hpet.c | 12 +- drivers/hv/hyperv_vmbus.h | 4 +- drivers/hv/vmbus_drv.c | 27 ++- drivers/hwtracing/stm/core.c | 31 ++- drivers/misc/open-dice.c | 19 +- drivers/mtd/mtdchar.c | 21 +- drivers/staging/vme_user/vme.c | 20 +- drivers/staging/vme_user/vme.h | 2 +- drivers/staging/vme_user/vme_user.c | 51 +++-- drivers/target/target_core_user.c | 26 ++- drivers/uio/uio.c | 10 +- drivers/uio/uio_hv_generic.c | 11 +- fs/afs/file.c | 20 +- include/linux/fs.h | 14 +- include/linux/hyperv.h | 4 +- include/linux/mm.h | 158 +++++++++++++-- include/linux/mm_types.h | 17 +- include/linux/uio_driver.h | 4 +- mm/internal.h | 41 ++-- mm/memory.c | 174 ++++++++++++----- mm/util.c | 213 +++++++++++++++------ mm/vma.c | 56 ++++-- mm/vma.h | 2 +- tools/testing/vma/include/dup.h | 143 ++++++++++---- tools/testing/vma/include/stubs.h | 9 +- 27 files changed, 933 insertions(+), 299 deletions(-) create mode 100644 Documentation/filesystems/mmap_prepare.rst -- 2.53.0