From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 364533242AC; Thu, 12 Mar 2026 20:27:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773347269; cv=none; b=YAL/wto9t1ZEgXR+rQnwGig2OZCew1g/dffUaeqPUvp/I18T84fY+zXZFX8jsFwC8LpATlxiz3jQLLbIXxYdGEnNJgb2faloYDX0d5cSZm6VdpyKVlhprSnhpVsqlXdIvcbHoasHwJCbtJ7rG2v611ZIkp2Gv675j/nSOtClK2Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773347269; c=relaxed/simple; bh=UHRT8qRmUgXL60CxpkG8XqJ40rRzobM0A/lzS/hpZy8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=DKPpvJr8qIBpX0owczbZEsYnnJIvxIcb6M1zvyQsGYo+CfOnmiAOWwBlLWqAVGzaT6su0ZIZw6ZupKJxSIHhoTWcjFLSYGpdVaeVOmSlXdBtHRk9+P85lr670jHTOlxuMT3kSYtya/JT8ngZs4j6MVXdGFPcWEyk1REtzDC2JmI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=craZlvZb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="craZlvZb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B0DDC4CEF7; Thu, 12 Mar 2026 20:27:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773347268; bh=UHRT8qRmUgXL60CxpkG8XqJ40rRzobM0A/lzS/hpZy8=; h=From:To:Cc:Subject:Date:From; b=craZlvZb5CGklOhHfqyBv/N2B4J7VOxsEGxAyy49uaJyF1Jyg/1A800kZeyO1k4yW d4nk35Hw7zkQKIqmK7i3AotkuZ9aCNg5kxBohTKgQiC/uPu/S8LiGo/e5ToGK1QfhL xDjyWyVf4HhkL/qRL1ZknbK8aS+MIfLKHEYCRjLEBYMJlSBM9eRsvDIYzl4YfSpmsj iB7IBjXqGYz+BNhwdRbqTNlG379au2uoUSMc6AvVYa8NoaP28LQ32Omvd8/6aW2CWE MvfLMlDkSAkFhGIFTmwORZMdnQ9l/wOcUhOFUQoYNegqsXtG1QaNKdM6TFCpqdII1U /nFm+u8VpBCFA== From: "Lorenzo Stoakes (Oracle)" To: Andrew Morton Cc: Jonathan Corbet , Clemens Ladisch , Arnd Bergmann , Greg Kroah-Hartman , "K . 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 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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