The patch titled
Subject: mm/vma: introduce vmi_complete_munmap_vmas()
has been added to the -mm mm-unstable branch. Its filename is
mm-vma-introduce-vmi_complete_munmap_vmas.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vma-introduce-vmi_complete_munmap_vmas.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: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Subject: mm/vma: introduce vmi_complete_munmap_vmas()
Date: Fri, 30 Aug 2024 00:00:43 -0400
Extract all necessary operations that need to be completed after the vma
maple tree is updated from a munmap() operation. Extracting this makes
the later patch in the series easier to understand.
Link: https://lkml.kernel.org/r/20240830040101.822209-4-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Reviewed-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Bert Karwatzki <spasswolf@xxxxxx>
Cc: Jeff Xu <jeffxu@xxxxxxxxxxxx>
Cc: Jiri Olsa <olsajiri@xxxxxxxxx>
Cc: Kees Cook <kees@xxxxxxxxxx>
Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Cc: Paul Moore <paul@xxxxxxxxxxxxxx>
Cc: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vma.c | 80 ++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 55 insertions(+), 25 deletions(-)
--- a/mm/vma.c~mm-vma-introduce-vmi_complete_munmap_vmas
+++ a/mm/vma.c
@@ -685,6 +685,58 @@ static inline void abort_munmap_vmas(str
}
/*
+ * vmi_complete_munmap_vmas() - Finish the munmap() operation
+ * @vmi: The vma iterator
+ * @vma: The first vma to be munmapped
+ * @mm: The mm struct
+ * @start: The start address
+ * @end: The end address
+ * @unlock: Unlock the mm or not
+ * @mas_detach: them maple state of the detached vma maple tree
+ * @locked_vm: The locked_vm count in the detached vmas
+ *
+ * This function updates the mm_struct, unmaps the region, frees the resources
+ * used for the munmap() and may downgrade the lock - if requested. Everything
+ * needed to be done once the vma maple tree is updated.
+ */
+static void
+vmi_complete_munmap_vmas(struct vma_iterator *vmi, struct vm_area_struct *vma,
+ struct mm_struct *mm, unsigned long start, unsigned long end,
+ bool unlock, struct ma_state *mas_detach,
+ unsigned long locked_vm)
+{
+ struct vm_area_struct *prev, *next;
+ int count;
+
+ count = mas_detach->index + 1;
+ mm->map_count -= count;
+ mm->locked_vm -= locked_vm;
+ if (unlock)
+ mmap_write_downgrade(mm);
+
+ prev = vma_iter_prev_range(vmi);
+ next = vma_next(vmi);
+ if (next)
+ vma_iter_prev_range(vmi);
+
+ /*
+ * We can free page tables without write-locking mmap_lock because VMAs
+ * were isolated before we downgraded mmap_lock.
+ */
+ mas_set(mas_detach, 1);
+ unmap_region(mm, mas_detach, vma, prev, next, start, end, count,
+ !unlock);
+ /* Statistics and freeing VMAs */
+ mas_set(mas_detach, 0);
+ remove_mt(mm, mas_detach);
+ validate_mm(mm);
+ if (unlock)
+ mmap_read_unlock(mm);
+
+ __mt_destroy(mas_detach->tree);
+}
+
+/*
* do_vmi_align_munmap() - munmap the aligned region from @start to @end.
* @vmi: The vma iterator
* @vma: The starting vm_area_struct
@@ -703,7 +755,7 @@ do_vmi_align_munmap(struct vma_iterator
struct mm_struct *mm, unsigned long start,
unsigned long end, struct list_head *uf, bool unlock)
{
- struct vm_area_struct *prev, *next = NULL;
+ struct vm_area_struct *next = NULL;
struct maple_tree mt_detach;
int count = 0;
int error = -ENOMEM;
@@ -818,31 +870,9 @@ do_vmi_align_munmap(struct vma_iterator
goto clear_tree_failed;
/* Point of no return */
- mm->locked_vm -= locked_vm;
- mm->map_count -= count;
- if (unlock)
- mmap_write_downgrade(mm);
-
- prev = vma_iter_prev_range(vmi);
- next = vma_next(vmi);
- if (next)
- vma_iter_prev_range(vmi);
-
- /*
- * We can free page tables without write-locking mmap_lock because VMAs
- * were isolated before we downgraded mmap_lock.
- */
- mas_set(&mas_detach, 1);
- unmap_region(mm, &mas_detach, vma, prev, next, start, end, count,
- !unlock);
- /* Statistics and freeing VMAs */
- mas_set(&mas_detach, 0);
- remove_mt(mm, &mas_detach);
- validate_mm(mm);
- if (unlock)
- mmap_read_unlock(mm);
+ vmi_complete_munmap_vmas(vmi, vma, mm, start, end, unlock, &mas_detach,
+ locked_vm);
- __mt_destroy(&mt_detach);
return 0;
modify_vma_failed:
_
Patches currently in -mm which might be from Liam.Howlett@xxxxxxxxxx are
maple_tree-remove-rcu_read_lock-from-mt_validate.patch
mm-vma-correctly-position-vma_iterator-in-__split_vma.patch
mm-vma-introduce-abort_munmap_vmas.patch
mm-vma-introduce-vmi_complete_munmap_vmas.patch
mm-vma-extract-the-gathering-of-vmas-from-do_vmi_align_munmap.patch
mm-vma-introduce-vma_munmap_struct-for-use-in-munmap-operations.patch
mm-vma-change-munmap-to-use-vma_munmap_struct-for-accounting-and-surrounding-vmas.patch
mm-vma-extract-validate_mm-from-vma_complete.patch
mm-vma-inline-munmap-operation-in-mmap_region.patch
mm-vma-expand-mmap_region-munmap-call.patch
mm-vma-support-vma-==-null-in-init_vma_munmap.patch
mm-mmap-reposition-vma-iterator-in-mmap_region.patch
mm-vma-track-start-and-end-for-munmap-in-vma_munmap_struct.patch
mm-clean-up-unmap_region-argument-list.patch
mm-mmap-avoid-zeroing-vma-tree-in-mmap_region.patch
mm-change-failure-of-map_fixed-to-restoring-the-gap-on-failure.patch
mm-mmap-use-phys_pfn-in-mmap_region.patch
mm-mmap-use-vms-accounted-pages-in-mmap_region.patch
ipc-shm-mm-drop-do_vma_munmap.patch
mm-move-may_expand_vm-check-in-mmap_region.patch
mm-vma-drop-incorrect-comment-from-vms_gather_munmap_vmas.patch
mm-vmah-optimise-vma_munmap_struct.patch
