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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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260312_132749_880975_122CA3A9 X-CRM114-Status: GOOD ( 16.53 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org 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 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/