Commit b5df0922 authored by Liam R. Howlett's avatar Liam R. Howlett Committed by Andrew Morton
Browse files

mm: set up vma iterator for vma_iter_prealloc() calls 

Set the correct limits for vma_iter_prealloc() calls so that the maple
tree can be smarter about how many nodes are needed.

Link: https://lkml.kernel.org/r/20230724183157.3939892-11-Liam.Howlett@oracle.com


Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f72cf24a

fs/exec.c

+1 −0
Original line number Diff line number Diff line
@@ -701,6 +701,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) 
	if (vma != vma_next(&vmi))

		return -EFAULT;



	vma_iter_prev_range(&vmi);

	/*

	 * cover the whole range: [new_start, old_end)

	 */

mm/internal.h

+7 −11
Original line number Diff line number Diff line
@@ -1052,23 +1052,21 @@ static inline void vma_iter_config(struct vma_iterator *vmi, 
/*

 * VMA Iterator functions shared between nommu and mmap

 */

static inline int vma_iter_prealloc(struct vma_iterator *vmi)

static inline int vma_iter_prealloc(struct vma_iterator *vmi,

		struct vm_area_struct *vma)

{

	return mas_preallocate(&vmi->mas, NULL, GFP_KERNEL);

	return mas_preallocate(&vmi->mas, vma, GFP_KERNEL);

}



static inline void vma_iter_clear(struct vma_iterator *vmi,

				  unsigned long start, unsigned long end)

static inline void vma_iter_clear(struct vma_iterator *vmi)

{

	mas_set_range(&vmi->mas, start, end - 1);

	mas_store_prealloc(&vmi->mas, NULL);

}



static inline int vma_iter_clear_gfp(struct vma_iterator *vmi,

			unsigned long start, unsigned long end, gfp_t gfp)

{

	vmi->mas.index = start;

	vmi->mas.last = end - 1;

	__mas_set_range(&vmi->mas, start, end - 1);

	mas_store_gfp(&vmi->mas, NULL, gfp);

	if (unlikely(mas_is_err(&vmi->mas)))

		return -ENOMEM;
@@ -1105,8 +1103,7 @@ static inline void vma_iter_store(struct vma_iterator *vmi, 
	    ((vmi->mas.index > vma->vm_start) || (vmi->mas.last < vma->vm_start)))

		vma_iter_invalidate(vmi);



	vmi->mas.index = vma->vm_start;

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

	__mas_set_range(&vmi->mas, vma->vm_start, vma->vm_end - 1);

	mas_store_prealloc(&vmi->mas, vma);

}
@@ -1117,8 +1114,7 @@ static inline int vma_iter_store_gfp(struct vma_iterator *vmi, 
	    ((vmi->mas.index > vma->vm_start) || (vmi->mas.last < vma->vm_start)))

		vma_iter_invalidate(vmi);



	vmi->mas.index = vma->vm_start;

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

	__mas_set_range(&vmi->mas, vma->vm_start, vma->vm_end - 1);

	mas_store_gfp(&vmi->mas, vma, gfp);

	if (unlikely(mas_is_err(&vmi->mas)))

		return -ENOMEM;

mm/mmap.c

+42 −27
Original line number Diff line number Diff line
@@ -397,7 +397,8 @@ static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma) 
	VMA_ITERATOR(vmi, mm, 0);

	struct address_space *mapping = NULL;



	if (vma_iter_prealloc(&vmi))

	vma_iter_config(&vmi, vma->vm_start, vma->vm_end);

	if (vma_iter_prealloc(&vmi, vma))

		return -ENOMEM;



	vma_iter_store(&vmi, vma);
@@ -649,19 +650,16 @@ int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma, 
	/* Only handles expanding */

	VM_WARN_ON(vma->vm_start < start || vma->vm_end > end);



	if (vma_iter_prealloc(vmi))

	/* Note: vma iterator must be pointing to 'start' */

	vma_iter_config(vmi, start, end);

	if (vma_iter_prealloc(vmi, vma))

		goto nomem;



	vma_prepare(&vp);

	vma_adjust_trans_huge(vma, start, end, 0);

	/* VMA iterator points to previous, so set to start if necessary */

	if (vma_iter_addr(vmi) != start)

		vma_iter_set(vmi, start);



	vma->vm_start = start;

	vma->vm_end = end;

	vma->vm_pgoff = pgoff;

	/* Note: mas must be pointing to the expanding VMA */

	vma_iter_store(vmi, vma);



	vma_complete(&vp, vmi, vma->vm_mm);
@@ -687,19 +685,19 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma, 


	WARN_ON((vma->vm_start != start) && (vma->vm_end != end));



	if (vma_iter_prealloc(vmi))

	if (vma->vm_start < start)

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

	else

		vma_iter_config(vmi, end, vma->vm_end);



	if (vma_iter_prealloc(vmi, NULL))

		return -ENOMEM;



	init_vma_prep(&vp, vma);

	vma_prepare(&vp);

	vma_adjust_trans_huge(vma, start, end, 0);



	if (vma->vm_start < start)

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



	if (vma->vm_end > end)

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



	vma_iter_clear(vmi);

	vma->vm_start = start;

	vma->vm_end = end;

	vma->vm_pgoff = pgoff;
@@ -973,7 +971,17 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, 
	if (err)

		return NULL;



	if (vma_iter_prealloc(vmi))

	if (vma_start < vma->vm_start || vma_end > vma->vm_end)

		vma_expanded = true;



	if (vma_expanded) {

		vma_iter_config(vmi, vma_start, vma_end);

	} else {

		vma_iter_config(vmi, adjust->vm_start + adj_start,

				adjust->vm_end);

	}



	if (vma_iter_prealloc(vmi, vma))

		return NULL;



	init_multi_vma_prep(&vp, vma, adjust, remove, remove2);
@@ -982,8 +990,6 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, 


	vma_prepare(&vp);

	vma_adjust_trans_huge(vma, vma_start, vma_end, adj_start);

	if (vma_start < vma->vm_start || vma_end > vma->vm_end)

		vma_expanded = true;



	vma->vm_start = vma_start;

	vma->vm_end = vma_end;
@@ -1923,7 +1929,7 @@ static int expand_upwards(struct vm_area_struct *vma, unsigned long address) 
	struct vm_area_struct *next;

	unsigned long gap_addr;

	int error = 0;

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

	MA_STATE(mas, &mm->mm_mt, vma->vm_start, address);



	if (!(vma->vm_flags & VM_GROWSUP))

		return -EFAULT;
@@ -1948,6 +1954,10 @@ static int expand_upwards(struct vm_area_struct *vma, unsigned long address) 
		/* Check that both stack segments have the same anon_vma? */

	}



	if (next)

		mas_prev_range(&mas, address);



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

	if (mas_preallocate(&mas, vma, GFP_KERNEL))

		return -ENOMEM;
@@ -1993,7 +2003,6 @@ static 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. */

				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);
@@ -2038,6 +2047,10 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address) 
			return -ENOMEM;

	}



	if (prev)

		mas_next_range(&mas, vma->vm_start);



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

	if (mas_preallocate(&mas, vma, GFP_KERNEL))

		return -ENOMEM;
@@ -2084,7 +2097,6 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address) 
				vma->vm_start = address;

				vma->vm_pgoff -= grow;

				/* Overwrite old entry in mtree. */

				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);
@@ -2325,10 +2337,6 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, 
	if (!new)

		return -ENOMEM;



	err = -ENOMEM;

	if (vma_iter_prealloc(vmi))

		goto out_free_vma;



	if (new_below) {

		new->vm_end = addr;

	} else {
@@ -2336,6 +2344,11 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, 
		new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT);

	}



	err = -ENOMEM;

	vma_iter_config(vmi, new->vm_start, new->vm_end);

	if (vma_iter_prealloc(vmi, new))

		goto out_free_vma;



	err = vma_dup_policy(vma, new);

	if (err)

		goto out_free_vmi;
@@ -2693,7 +2706,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr, 
		vma_iter_next_range(&vmi);

	}





	/* Actually expand, if possible */

	if (vma &&

	    !vma_expand(&vmi, vma, merge_start, merge_end, vm_pgoff, next)) {
@@ -2790,7 +2802,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, 
		goto close_and_free_vma;



	error = -ENOMEM;

	if (vma_iter_prealloc(&vmi))

	if (vma_iter_prealloc(&vmi, vma))

		goto close_and_free_vma;



	/* Lock the VMA since it is modified after insertion into VMA tree */
@@ -3053,7 +3065,8 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma, 
	if (vma && vma->vm_end == addr && !vma_policy(vma) &&

	    can_vma_merge_after(vma, flags, NULL, NULL,

				addr >> PAGE_SHIFT, NULL_VM_UFFD_CTX, NULL)) {

		if (vma_iter_prealloc(vmi))

		vma_iter_config(vmi, vma->vm_start, addr + len);

		if (vma_iter_prealloc(vmi, vma))

			goto unacct_fail;



		init_vma_prep(&vp, vma);
@@ -3068,6 +3081,8 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma, 
		goto out;

	}



	if (vma)

		vma_iter_next_range(vmi);

	/* create a vma struct for an anonymous mapping */

	vma = vm_area_alloc(mm);

	if (!vma)

mm/nommu.c

+14 −19
Original line number Diff line number Diff line
@@ -583,7 +583,8 @@ static int delete_vma_from_mm(struct vm_area_struct *vma) 
{

	VMA_ITERATOR(vmi, vma->vm_mm, vma->vm_start);



	if (vma_iter_prealloc(&vmi)) {

	vma_iter_config(&vmi, vma->vm_start, vma->vm_end);

	if (vma_iter_prealloc(&vmi, vma)) {

		pr_warn("Allocation of vma tree for process %d failed\n",

		       current->pid);

		return -ENOMEM;
@@ -591,7 +592,7 @@ static int delete_vma_from_mm(struct vm_area_struct *vma) 
	cleanup_vma_from_mm(vma);



	/* remove from the MM's tree and list */

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

	vma_iter_clear(&vmi);

	return 0;

}

/*
@@ -1054,9 +1055,6 @@ unsigned long do_mmap(struct file *file, 
	if (!vma)

		goto error_getting_vma;



	if (vma_iter_prealloc(&vmi))

		goto error_vma_iter_prealloc;



	region->vm_usage = 1;

	region->vm_flags = vm_flags;

	region->vm_pgoff = pgoff;
@@ -1198,6 +1196,10 @@ unsigned long do_mmap(struct file *file, 


share:

	BUG_ON(!vma->vm_region);

	vma_iter_config(&vmi, vma->vm_start, vma->vm_end);

	if (vma_iter_prealloc(&vmi, vma))

		goto error_just_free;



	setup_vma_to_mm(vma, current->mm);

	current->mm->map_count++;

	/* add the VMA to the tree */
@@ -1244,14 +1246,6 @@ unsigned long do_mmap(struct file *file, 
			len, current->pid);

	show_mem();

	return -ENOMEM;



error_vma_iter_prealloc:

	kmem_cache_free(vm_region_jar, region);

	vm_area_free(vma);

	pr_warn("Allocation of vma tree for process %d failed\n", current->pid);

	show_mem();

	return -ENOMEM;



}



unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
@@ -1336,12 +1330,6 @@ int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, 
	if (!new)

		goto err_vma_dup;



	if (vma_iter_prealloc(vmi)) {

		pr_warn("Allocation of vma tree for process %d failed\n",

			current->pid);

		goto err_vmi_preallocate;

	}



	/* most fields are the same, copy all, and then fixup */

	*region = *vma->vm_region;

	new->vm_region = region;
@@ -1355,6 +1343,13 @@ int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, 
		region->vm_pgoff = new->vm_pgoff += npages;

	}



	vma_iter_config(vmi, new->vm_start, new->vm_end);

	if (vma_iter_prealloc(vmi, vma)) {

		pr_warn("Allocation of vma tree for process %d failed\n",

			current->pid);

		goto err_vmi_preallocate;

	}



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

		new->vm_ops->open(new);