Commit fbcc3104 authored by Liam R. Howlett's avatar Liam R. Howlett Committed by Andrew Morton
Browse files

mmap: convert __vma_adjust() to use vma iterator 

Use the vma iterator internally for __vma_adjust().  Avoid using the maple
tree interface directly for type safety.

Link: https://lkml.kernel.org/r/20230120162650.984577-32-Liam.Howlett@oracle.com


Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 34403fa5

include/linux/mm.h

+0 −3
Original line number Diff line number Diff line
@@ -2856,9 +2856,6 @@ extern struct vm_area_struct *copy_vma(struct vm_area_struct **, 
	bool *need_rmap_locks);

extern void exit_mmap(struct mm_struct *);



void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas);

void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas);



static inline int check_data_rlimit(unsigned long rlim,

				    unsigned long new,

				    unsigned long start,

mm/mmap.c

+13 −62
Original line number Diff line number Diff line
@@ -432,56 +432,6 @@ static void __vma_link_file(struct vm_area_struct *vma, 
	flush_dcache_mmap_unlock(mapping);

}



/*

 * vma_mas_store() - Store a VMA in the maple tree.

 * @vma: The vm_area_struct

 * @mas: The maple state

 *

 * Efficient way to store a VMA in the maple tree when the @mas has already

 * walked to the correct location.

 *

 * Note: the end address is inclusive in the maple tree.

 */

void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas)

{

	trace_vma_store(mas->tree, vma);

	mas_set_range(mas, vma->vm_start, vma->vm_end - 1);

	mas_store_prealloc(mas, vma);

}



/*

 * vma_mas_remove() - Remove a VMA from the maple tree.

 * @vma: The vm_area_struct

 * @mas: The maple state

 *

 * Efficient way to remove a VMA from the maple tree when the @mas has already

 * been established and points to the correct location.

 * Note: the end address is inclusive in the maple tree.

 */

void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas)

{

	trace_vma_mas_szero(mas->tree, vma->vm_start, vma->vm_end - 1);

	mas->index = vma->vm_start;

	mas->last = vma->vm_end - 1;

	mas_store_prealloc(mas, NULL);

}



/*

 * vma_mas_szero() - Set a given range to zero.  Used when modifying a

 * vm_area_struct start or end.

 *

 * @mas: The maple tree ma_state

 * @start: The start address to zero

 * @end: The end address to zero.

 */

static inline void vma_mas_szero(struct ma_state *mas, unsigned long start,

				unsigned long end)

{

	trace_vma_mas_szero(mas->tree, start, end - 1);

	mas_set_range(mas, start, end - 1);

	mas_store_prealloc(mas, NULL);

}



static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma)

{

	VMA_ITERATOR(vmi, mm, 0);
@@ -641,7 +591,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, 
	bool vma_changed = false;

	long adjust_next = 0;

	int remove_next = 0;

	MA_STATE(mas, &mm->mm_mt, 0, 0);

	VMA_ITERATOR(vmi, mm, 0);

	struct vm_area_struct *exporter = NULL, *importer = NULL;



	if (next && !insert) {
@@ -726,7 +676,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, 
		}

	}



	if (mas_preallocate(&mas, GFP_KERNEL))

	if (vma_iter_prealloc(&vmi))

		return -ENOMEM;



	vma_adjust_trans_huge(orig_vma, start, end, adjust_next);
@@ -772,7 +722,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, 
	if (start != vma->vm_start) {

		if ((vma->vm_start < start) &&

		    (!insert || (insert->vm_end != start))) {

			vma_mas_szero(&mas, vma->vm_start, start);

			vma_iter_clear(&vmi, vma->vm_start, start);

			VM_WARN_ON(insert && insert->vm_start > vma->vm_start);

		} else {

			vma_changed = true;
@@ -782,8 +732,8 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, 
	if (end != vma->vm_end) {

		if (vma->vm_end > end) {

			if (!insert || (insert->vm_start != end)) {

				vma_mas_szero(&mas, end, vma->vm_end);

				mas_reset(&mas);

				vma_iter_clear(&vmi, end, vma->vm_end);

				vma_iter_set(&vmi, vma->vm_end);

				VM_WARN_ON(insert &&

					   insert->vm_end < vma->vm_end);

			}
@@ -794,13 +744,13 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, 
	}



	if (vma_changed)

		vma_mas_store(vma, &mas);

		vma_iter_store(&vmi, vma);



	vma->vm_pgoff = pgoff;

	if (adjust_next) {

		next->vm_start += adjust_next;

		next->vm_pgoff += adjust_next >> PAGE_SHIFT;

		vma_mas_store(next, &mas);

		vma_iter_store(&vmi, next);

	}



	if (file) {
@@ -820,8 +770,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, 
		 * us to insert it before dropping the locks

		 * (it may either follow vma or precede it).

		 */

		mas_reset(&mas);

		vma_mas_store(insert, &mas);

		vma_iter_store(&vmi, insert);

		mm->map_count++;

	}
@@ -867,7 +816,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start, 
	if (insert && file)

		uprobe_mmap(insert);



	mas_destroy(&mas);

	vma_iter_free(&vmi);

	validate_mm(mm);



	return 0;
@@ -1999,7 +1948,8 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) 
				anon_vma_interval_tree_pre_update_vma(vma);

				vma->vm_end = address;

				/* Overwrite old entry in mtree. */

				vma_mas_store(vma, &mas);

				mas_set_range(&mas, vma->vm_start, address - 1);

				mas_store_prealloc(&mas, vma);

				anon_vma_interval_tree_post_update_vma(vma);

				spin_unlock(&mm->page_table_lock);
@@ -2081,7 +2031,8 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address) 
				vma->vm_start = address;

				vma->vm_pgoff -= grow;

				/* Overwrite old entry in mtree. */

				vma_mas_store(vma, &mas);

				mas_set_range(&mas, address, vma->vm_end - 1);

				mas_store_prealloc(&mas, vma);

				anon_vma_interval_tree_post_update_vma(vma);

				spin_unlock(&mm->page_table_lock);