Re: [PATCH 07/39] mm: add mmap action for discontiguous kernel page mapping
From: sashiko-bot@kernel.org
Date: 2026-09-08 20:34:07
Also in:
bpf, dri-devel, kvm, kvmarm, linux-perf-users, linux-s390, linux-scsi, selinux
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [Low] The userland VMA testing header `dup.h` was not fully updated; the `map_kernel_discontig` field is missing from `struct mmap_action`. -- commit 0017a54bcba2043c3f552b308a32a39be664f463 Author: Lorenzo Stoakes (ARM) [off-list ref] mm: add mmap action for discontiguous kernel page mapping This commit introduces a new mmap action, MMAP_DISCONTIG_KERNEL_PAGES, to allow drivers to map discontiguous ranges of struct page pointers. It provides discontig_kernel_page_ops for drivers to specify how page batches should be retrieved, and updates the core mm and VMA test headers accordingly.
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diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 9ca2ea3664bc1..0cb4f96039568 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h
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@@ -844,6 +880,10 @@ struct mmap_action { unsigned long nr_pages; pgoff_t pgoff; } map_kernel; + struct { + void *init_private; + const struct discontig_kernel_page_ops *ops; + } map_kernel_discontig; }; enum mmap_action_type type;
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diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.h index 1098655a5f4a3..52eee05e6c322 100644 --- a/tools/testing/vma/include/dup.h +++ b/tools/testing/vma/include/dup.h@@ -457,8 +457,9 @@ enum mmap_action_type { MMAP_NOTHING, MMAP_REMAP_PFN, MMAP_IO_REMAP_PFN, - MMAP_SIMPLE_IO_REMAP, /* I/O remap with guardrails. */ - MMAP_KERNEL_PAGES, /* Map kernel page range from array. */ + MMAP_SIMPLE_IO_REMAP, /* I/O remap with guardrails. */ + MMAP_KERNEL_PAGES, /* Map kernel page range from array. */ + MMAP_DISCONTIG_KERNEL_PAGES, /* Map kernel discontig page range. */ }; /*
[Severity: Low] Does struct mmap_action in this userland VMA testing header also need to be updated? The map_kernel_discontig field was added to the kernel's mm_types.h, but it appears to be missing from the corresponding struct mmap_action defined in tools/testing/vma/include/dup.h. If a selftest attempts to access the map_kernel_discontig union member of struct mmap_action for MMAP_DISCONTIG_KERNEL_PAGES, it will fail to compile. -- Sashiko AI review · https://sashiko.dev/#/patchset/20260908-b4-mmap-prepare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org?part=7