Commit b2b3b886 authored by Liam R. Howlett's avatar Liam R. Howlett Committed by Andrew Morton
Browse files

mm: don't use __vma_adjust() in __split_vma() 

Use the abstracted locking and maple tree operations.  Since __split_vma()
is the only user of the __vma_adjust() function to use the insert
argument, drop that argument.  Remove the NULL passed through from
fs/exec's shift_arg_pages() and mremap() at the same time.

Link: https://lkml.kernel.org/r/20230120162650.984577-44-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 68cefec5

fs/exec.c

+2 −2
Original line number Diff line number Diff line
@@ -699,7 +699,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) 
	/*

	 * cover the whole range: [new_start, old_end)

	 */

	if (vma_adjust(&vmi, vma, new_start, old_end, vma->vm_pgoff, NULL))

	if (vma_adjust(&vmi, vma, new_start, old_end, vma->vm_pgoff))

		return -ENOMEM;



	/*
@@ -733,7 +733,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) 


	vma_prev(&vmi);

	/* Shrink the vma to just the new range */

	return vma_adjust(&vmi, vma, new_start, new_end, vma->vm_pgoff, NULL);

	return vma_adjust(&vmi, vma, new_start, new_end, vma->vm_pgoff);

}



/*

include/linux/mm.h

+3 −4
Original line number Diff line number Diff line
@@ -2832,13 +2832,12 @@ void anon_vma_interval_tree_verify(struct anon_vma_chain *node); 
/* mmap.c */

extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);

extern int __vma_adjust(struct vma_iterator *vmi, struct vm_area_struct *vma, unsigned long start,

	unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert,

	struct vm_area_struct *expand);

	unsigned long end, pgoff_t pgoff, struct vm_area_struct *expand);

static inline int vma_adjust(struct vma_iterator *vmi,

	struct vm_area_struct *vma, unsigned long start, unsigned long end,

	pgoff_t pgoff, struct vm_area_struct *insert)

	pgoff_t pgoff)

{

	return __vma_adjust(vmi, vma, start, end, pgoff, insert, NULL);

	return __vma_adjust(vmi, vma, start, end, pgoff, NULL);

}

extern struct vm_area_struct *vma_merge(struct vma_iterator *vmi,

	struct mm_struct *, struct vm_area_struct *prev, unsigned long addr,

mm/mmap.c

+55 −63
Original line number Diff line number Diff line
@@ -691,7 +691,7 @@ inline int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma, 
 */

int __vma_adjust(struct vma_iterator *vmi, struct vm_area_struct *vma,

	unsigned long start, unsigned long end, pgoff_t pgoff,

	struct vm_area_struct *insert, struct vm_area_struct *expand)

	struct vm_area_struct *expand)

{

	struct mm_struct *mm = vma->vm_mm;

	struct vm_area_struct *remove2 = NULL;
@@ -704,7 +704,7 @@ int __vma_adjust(struct vma_iterator *vmi, struct vm_area_struct *vma, 
	struct vm_area_struct *exporter = NULL, *importer = NULL;

	struct vma_prepare vma_prep;



	if (next && !insert) {

	if (next) {

		if (end >= next->vm_end) {

			/*

			 * vma expands, overlapping all the next, and
@@ -795,39 +795,25 @@ int __vma_adjust(struct vma_iterator *vmi, struct vm_area_struct *vma, 
	VM_WARN_ON(vma_prep.anon_vma && adjust_next && next->anon_vma &&

		   vma_prep.anon_vma != next->anon_vma);



	vma_prep.insert = insert;

	vma_prepare(&vma_prep);



	if (start != vma->vm_start) {

		if (vma->vm_start < start) {

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

	if (vma->vm_start < start)

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

				vma_iter_set(vmi, start);

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

			}

		} else {

	else if (start != vma->vm_start)

		vma_changed = true;

		}

		vma->vm_start = start;

	}

	if (end != vma->vm_end) {

		if (vma->vm_end > end) {

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



	if (vma->vm_end > end)

		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);

			}

		} else {

	else if (end != vma->vm_end)

		vma_changed = true;

		}



	vma->vm_start = start;

	vma->vm_end = end;

	}

	vma->vm_pgoff = pgoff;



	if (vma_changed)

		vma_iter_store(vmi, vma);



	vma->vm_pgoff = pgoff;

	if (adjust_next) {

		next->vm_start += adjust_next;

		next->vm_pgoff += adjust_next >> PAGE_SHIFT;
@@ -1030,20 +1016,19 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, 
			is_mergeable_anon_vma(prev->anon_vma,

				next->anon_vma, NULL)) {	 /* cases 1, 6 */

		err = __vma_adjust(vmi, prev, prev->vm_start,

					next->vm_end, prev->vm_pgoff, NULL,

					prev);

					next->vm_end, prev->vm_pgoff, prev);

		res = prev;

	} else if (merge_prev) {			/* cases 2, 5, 7 */

		err = __vma_adjust(vmi, prev, prev->vm_start,

					end, prev->vm_pgoff, NULL, prev);

					end, prev->vm_pgoff, prev);

		res = prev;

	} else if (merge_next) {

		if (prev && addr < prev->vm_end)	/* case 4 */

			err = __vma_adjust(vmi, prev, prev->vm_start,

					addr, prev->vm_pgoff, NULL, next);

					addr, prev->vm_pgoff, next);

		else					/* cases 3, 8 */

			err = __vma_adjust(vmi, mid, addr, next->vm_end,

					next->vm_pgoff - pglen, NULL, next);

					next->vm_pgoff - pglen, next);

		res = next;

	}
@@ -2187,11 +2172,15 @@ static void unmap_region(struct mm_struct *mm, struct maple_tree *mt, 
int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,

		unsigned long addr, int new_below)

{

	struct vma_prepare vp;

	struct vm_area_struct *new;

	int err;



	validate_mm_mt(vma->vm_mm);



	WARN_ON(vma->vm_start >= addr);

	WARN_ON(vma->vm_end <= addr);



	if (vma->vm_ops && vma->vm_ops->may_split) {

		err = vma->vm_ops->may_split(vma, addr);

		if (err)
@@ -2202,16 +2191,20 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, 
	if (!new)

		return -ENOMEM;



	if (new_below)

	err = -ENOMEM;

	if (vma_iter_prealloc(vmi))

		goto out_free_vma;



	if (new_below) {

		new->vm_end = addr;

	else {

	} else {

		new->vm_start = addr;

		new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT);

	}



	err = vma_dup_policy(vma, new);

	if (err)

		goto out_free_vma;

		goto out_free_vmi;



	err = anon_vma_clone(new, vma);

	if (err)
@@ -2223,32 +2216,31 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, 
	if (new->vm_ops && new->vm_ops->open)

		new->vm_ops->open(new);



	if (new_below)

		err = vma_adjust(vmi, vma, addr, vma->vm_end,

			vma->vm_pgoff + ((addr - new->vm_start) >> PAGE_SHIFT),

			new);

	else

		err = vma_adjust(vmi, vma, vma->vm_start, addr, vma->vm_pgoff,

				 new);

	vma_adjust_trans_huge(vma, vma->vm_start, addr, 0);

	init_vma_prep(&vp, vma);

	vp.insert = new;

	vma_prepare(&vp);



	if (new_below) {

		vma->vm_start = addr;

		vma->vm_pgoff += (addr - new->vm_start) >> PAGE_SHIFT;

	} else {

		vma->vm_end = addr;

	}



	/* vma_complete stores the new vma */

	vma_complete(&vp, vmi, vma->vm_mm);



	/* Success. */

	if (!err) {

	if (new_below)

		vma_next(vmi);

	validate_mm_mt(vma->vm_mm);

	return 0;

	}



	/* Avoid vm accounting in close() operation */

	new->vm_start = new->vm_end;

	new->vm_pgoff = 0;

	/* Clean everything up if vma_adjust failed. */

	if (new->vm_ops && new->vm_ops->close)

		new->vm_ops->close(new);

	if (new->vm_file)

		fput(new->vm_file);

	unlink_anon_vmas(new);

out_free_mpol:

	mpol_put(vma_policy(new));

out_free_vmi:

	vma_iter_free(vmi);

out_free_vma:

	vm_area_free(new);

	validate_mm_mt(vma->vm_mm);

mm/mremap.c

+1 −1
Original line number Diff line number Diff line
@@ -1054,7 +1054,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, 
					vma->vm_file, extension_pgoff, vma_policy(vma),

					vma->vm_userfaultfd_ctx, anon_vma_name(vma));

			} else if (vma_adjust(&vmi, vma, vma->vm_start,

					addr + new_len, vma->vm_pgoff, NULL)) {

					addr + new_len, vma->vm_pgoff)) {

				vma = NULL;

			}

			if (!vma) {