+ mm-frame-vector-remove-foll_force-usage.patch added to mm-unstable branch

+ mm-frame-vector-remove-foll_force-usage.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/frame-vector: remove FOLL_FORCE usage
has been added to the -mm mm-unstable branch.  Its filename is
     mm-frame-vector-remove-foll_force-usage.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-frame-vector-remove-foll_force-usage.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: David Hildenbrand <david@redhat.com>
Subject: mm/frame-vector: remove FOLL_FORCE usage
Date: Wed, 16 Nov 2022 11:26:55 +0100

FOLL_FORCE is really only for ptrace access. According to commit
707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always
writable"), get_vaddr_frames() currently pins all pages writable as a
workaround for issues with read-only buffers.

FOLL_FORCE, however, seems to be a legacy leftover as it predates
commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are
always writable"). Let's just remove it.

Once the read-only buffer issue has been resolved, FOLL_WRITE could
again be set depending on the DMA direction.

Link: https://lkml.kernel.org/r/20221116102659.70287-17-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Tomasz Figa <tfiga@chromium.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/media/common/videobuf2/frame_vector.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/media/common/videobuf2/frame_vector.c~mm-frame-vector-remove-foll_force-usage
+++ a/drivers/media/common/videobuf2/frame_vector.c
@@ -50,7 +50,7 @@ int get_vaddr_frames(unsigned long start
 	start = untagged_addr(start);
 
 	ret = pin_user_pages_fast(start, nr_frames,
-				  FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM,
+				  FOLL_WRITE | FOLL_LONGTERM,
 				  (struct page **)(vec->ptrs));
 	if (ret > 0) {
 		vec->got_ref = true;
_

Patches currently in -mm which might be from david@redhat.com are

selftests-vm-add-ksm-unmerge-tests.patch
mm-pagewalk-dont-trigger-test_walk-in-walk_page_vma.patch
selftests-vm-add-test-to-measure-madv_unmergeable-performance.patch
mm-ksm-simplify-break_ksm-to-not-rely-on-vm_fault_write.patch
mm-remove-vm_fault_write.patch
mm-ksm-fix-ksm-cow-breaking-with-userfaultfd-wp-via-fault_flag_unshare.patch
mm-pagewalk-add-walk_page_range_vma.patch
mm-ksm-convert-break_ksm-to-use-walk_page_range_vma.patch
mm-gup-remove-foll_migration.patch
mm-mprotect-minor-can_change_pte_writable-cleanups.patch
mm-huge_memory-try-avoiding-write-faults-when-changing-pmd-protection.patch
mm-mprotect-factor-out-check-whether-manual-pte-write-upgrades-are-required.patch
mm-autonuma-use-can_change_ptepmd_writable-to-replace-savedwrite.patch
mm-remove-unused-savedwrite-infrastructure.patch
selftests-vm-anon_cow-add-mprotect-optimization-tests.patch
selftests-vm-anon_cow-prepare-for-non-anonymous-cow-tests.patch
selftests-vm-cow-basic-cow-tests-for-non-anonymous-pages.patch
selftests-vm-cow-r-o-long-term-pinning-reliability-tests-for-non-anon-pages.patch
mm-add-early-fault_flag_unshare-consistency-checks.patch
mm-add-early-fault_flag_write-consistency-checks.patch
mm-rework-handling-in-do_wp_page-based-on-private-vs-shared-mappings.patch
mm-dont-call-vm_ops-huge_fault-in-wp_huge_pmd-wp_huge_pud-for-private-mappings.patch
mm-extend-fault_flag_unshare-support-to-anything-in-a-cow-mapping.patch
mm-gup-reliable-r-o-long-term-pinning-in-cow-mappings.patch
rdma-umem-remove-foll_force-usage.patch
rdma-usnic-remove-foll_force-usage.patch
rdma-siw-remove-foll_force-usage.patch
media-videobuf-dma-sg-remove-foll_force-usage.patch
drm-etnaviv-remove-foll_force-usage.patch
media-pci-ivtv-remove-foll_force-usage.patch
mm-frame-vector-remove-foll_force-usage.patch
drm-exynos-remove-foll_force-usage.patch
rdma-hw-qib-qib_user_pages-remove-foll_force-usage.patch
habanalabs-remove-foll_force-usage.patch