From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 40B003164BB for ; Tue, 15 Sep 2026 01:08:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789434540; cv=none; b=vDVp2ggA6NO22gwExEG61xRcakrj+FNayqTdf0JXXfqz1Z+Ww/JZ6DW86fE723SnHHWE+uLQXWg4fMpNHawo/BGRyn/LioA4deMnNA0gUXtQURhb6fEX3BkfNu9Q2uwgdNIJrnvsdrXM/3Yaz7pcmlhTIj3XRDezlHDbR/5xmcc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789434540; c=relaxed/simple; bh=rSgxEuA1KnKr4daoCpMrM4HyARimMl8t0dkjxSR/kIY=; h=Date:To:From:Subject:Message-Id; b=bHJCx1GvlodUC/1hYMqAfZ1bCtaxK5wFlUF+32L3Fr84ti5u8IkxBdrVZeF2OC3nL/WXusfX6ElnWTybRGHO/5FU+qVFY+FBRojfNrn2Vg6+vPvDtQp4DA7AdcJdrtQqfw6UCn4eYAOWHok/sUQ7Xz20Kb+bfALguxqwWF3CLtc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=VX4rNF3J; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="VX4rNF3J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2F581F000FF; Tue, 15 Sep 2026 01:08:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789434538; bh=ZPK2phK1pKwcfpe9zSCQa21Gl6O5/hlEPfQnYoqBVFM=; h=Date:To:From:Subject; b=VX4rNF3Jlrrd0AZVjNXj8WKe8uwys7s5rhvSlUOJr9ewDW/06ZcUXY32ErKarh3C/ 6NINJ93FZ0iRNvwP+0AWP3X5MyDDVxKmeFS6Qg9O3q+k57ZGP/UTR8jl5e2dkaXjKu KIkV+y+bSW2mnMcIu7YZ/agfy6yy1mb+N89dOOxA= Date: Mon, 14 Sep 2026 18:08:58 -0700 To: mm-commits@vger.kernel.org,tiwai@suse.de,ljs@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + alsa-pcm-use-vm_insert_page-to-map-pcm-status-page.patch added to mm-new branch Message-Id: <20260915010858.C2F581F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: ALSA: pcm: use vm_insert_page() to map PCM status page has been added to the -mm mm-new branch. Its filename is alsa-pcm-use-vm_insert_page-to-map-pcm-status-page.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/alsa-pcm-use-vm_insert_page-to-map-pcm-status-page.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: "Lorenzo Stoakes (ARM)" Subject: ALSA: pcm: use vm_insert_page() to map PCM status page Date: Mon, 14 Sep 2026 15:57:33 +0100 There's no need to keep a fault handler around for this, instead map on mmap. While we're here, rename area to vma to be consistent. This correctly makes the mapping a mixed map mapping. This works towards establishing the invariant that only PFN mapped or mixed map mappings may clear the VM_MAYWRITE flag. The status page mapping clears VM_MAYWRITE, so it must be kernel-owned; the control page mapping remains writable and is left fault-based. The assumption is made that the struct pcm_mmap_status structure is at most a page in size, which is asserted as a build bug. This is safe to assume, as the size of the structure is 56 bytes at most. Link: https://lore.kernel.org/20260914-b4-mmap-prepare-vma-flag-sanify-v2-13-7d9781ed5361@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) Signed-off-by: Andrew Morton Acked-by: Takashi Iwai --- sound/core/pcm_native.c | 38 +++++++++++++------------------------- 1 file changed, 13 insertions(+), 25 deletions(-) --- a/sound/core/pcm_native.c~alsa-pcm-use-vm_insert_page-to-map-pcm-status-page +++ a/sound/core/pcm_native.c @@ -3760,39 +3760,27 @@ static __poll_t snd_pcm_poll(struct file /* * mmap status record */ -static vm_fault_t snd_pcm_mmap_status_fault(struct vm_fault *vmf) +static int snd_pcm_mmap_status(struct snd_pcm_substream *substream, struct file *file, + struct vm_area_struct *vma) { - struct snd_pcm_substream *substream = vmf->vma->vm_private_data; + const unsigned long size = vma->vm_end - vma->vm_start; struct snd_pcm_runtime *runtime; - - if (substream == NULL) - return VM_FAULT_SIGBUS; - runtime = substream->runtime; - vmf->page = virt_to_page(runtime->status); - get_page(vmf->page); - return 0; -} + struct page *page; -static const struct vm_operations_struct snd_pcm_vm_ops_status = -{ - .fault = snd_pcm_mmap_status_fault, -}; + BUILD_BUG_ON(sizeof(struct snd_pcm_mmap_status) > PAGE_SIZE); -static int snd_pcm_mmap_status(struct snd_pcm_substream *substream, struct file *file, - struct vm_area_struct *area) -{ - long size; - if (!(area->vm_flags & VM_READ)) + if (!(vma->vm_flags & VM_READ)) return -EINVAL; - size = area->vm_end - area->vm_start; - if (size != PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status))) + if (size != PAGE_SIZE) return -EINVAL; - area->vm_ops = &snd_pcm_vm_ops_status; - area->vm_private_data = substream; - vm_flags_mod(area, VM_DONTEXPAND | VM_DONTDUMP, + + vm_flags_mod(vma, VM_DONTEXPAND | VM_DONTDUMP, VM_WRITE | VM_MAYWRITE); + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); - return 0; + runtime = substream->runtime; + page = virt_to_page(runtime->status); + return vm_insert_page(vma, vma->vm_start, page); } /* _ Patches currently in -mm which might be from ljs@kernel.org are mm-vmpressure-remove-window-size-todo.patch tools-testing-selftests-mm-add-missing-gitignore-entries.patch mm-move-drivers-char-memc-to-mm-char-memc.patch mm-implement-file_is_dev_zero-to-uniquely-identify-dev-zero.patch mm-vma-only-permit-map_private-dev-zero-to-be-mapped-anonymous.patch mm-vma-make-map_private-mapped-dev-zero-mappings-truly-anonymous.patch tools-testing-vma-add-test-to-assert-map_private-dev-zero-is-anon.patch tools-testing-selftests-mm-add-map_private-dev-zero-merge-tests.patch mm-madvise-swap-in-cowd-map_private-file-mappings-on-madv_willneed.patch mm-huge_memory-zap-deposited-page-tables-after-an-rcu-grace-period.patch mm-enable-mmu_gather_rcu_table_free-for-most-2-level-architectures.patch mm-enable-mmu_gather_rcu_table_free-for-mmu-riscv.patch mm-enable-mmu_gather_rcu_table_free-for-mmu-arm.patch mm-enable-mmu_gather_rcu_table_free-for-arc-microblaze-xtensa.patch mm-enable-mmu_gather_rcu_table_free-for-sparc64.patch mm-enable-mmu_gather_rcu_table_free-for-m68k-coldfire.patch mm-enable-mmu_gather_rcu_table_free-for-sh-x2.patch mm-enable-mmu_gather_rcu_table_free-for-m68k-motorola.patch mm-enable-mmu_gather_rcu_table_free-for-sparc32.patch mm-make-userland-page-table-freeing-rcu-safe.patch mm-change-the-contract-for-free_pgtables-update-docs.patch mm-vma-fix-mmap_prepare-file-handling-remove-file_doesnt_need_get.patch mm-vma-predicate-setting-mmap_prepare-vma-fields-on-new-vma-alloc.patch mm-vma-introduce-and-use-vma_can_merge.patch mm-consistently-validate-vma-state-after-mmap-hooks.patch mm-vma-ensure-mmap_prepare-doesnt-set-actions-on-a-mergeable-vma.patch mm-make-map_kernel_pages_-internal-and-unexported.patch mm-vma-tidy-up-map-kernel-pages-enum-values.patch mm-add-mmap-action-for-discontiguous-kernel-page-mapping.patch docs-filesystems-update-mmap_prepare-docs-for-discontig-kernel-pgs.patch drivers-usb-mon-update-to-use-mmap_prepare-map-kernel-pages.patch infiniband-update-hfi1-to-use-remap_vmalloc_range.patch selinux-reject-writable-opens-of-policy-file-drop-mmap-shared-write-check.patch alsa-pcm-use-vm_insert_page-to-map-pcm-status-page.patch bpf-arena-mark-arena_map_mmap-mappings-vm_mixedmap.patch mm-vma-add-vma_is_kernel_owned-predicates.patch mm-vma-only-allow-mmap-to-clear-vma_maywrite_bit-if-kernel-owned.patch mm-vma-add-and-use-vma__is_fixed_mapping.patch scsi-sg-convert-mmap-hook-to-mmap_prepare-and-rework.patch fbdev-defio-assert-fbinfo_virtfb-drop-vm_io-add-vm_mixedmap.patch hsi-cmt_speech-convert-mmap-hook-to-mmap_prepare-refactor.patch mm-gup-error-out-early-on-vma_mayread_bit-vmas.patch uprobes-remove-vm_io-set-vm_mixedmap-for-mapped-kernel-pages.patch mm-mlock-clear-vma_locked_mask-over-mmap-callback.patch mm-mlock-eliminate-weird-vma_io_bit-abuse-and-simplify.patch mm-vma-enforce-that-only-kernel-owned-mappings-may-set-vma_io_bit.patch mm-remove-vma_io_bit-check-in-vma_is_kernel_owned.patch mm-remove-hugetlb_inlineh.patch mm-rename-is_vm_hugetlb_page-to-vma_is_hugetlb.patch mm-drop-some-redundant-checks-around-hugetlb-vmas.patch mm-madvise-update-is_valid_guard_vma-to-use-vma_can_merge.patch mm-vma-introduce-vma_is_persistent.patch mm-uffd-use-predicates-for-userfaultfd-checks.patch mm-madvise-use-predicates-for-madvise-madv_dofork.patch mm-eliminate-vma_special_flags-usage-when-hugetlb-explicitly-tested.patch mm-eliminate-vma_special_flags-check-in-lru_gen_look_around.patch mm-avoid-use-of-vma_special_flags-in-migrate_vma_setup.patch mm-eliminate-vm_special-vma_special_flags.patch fuse-dax-do-not-set-vm_mixedmap.patch mm-huge_memory-remove-vma_is_special_huge.patch mm-vma-introduce-and-use-vma_can_gup.patch