linux/tools/testing/vma/include/custom.h

/* SPDX-License-Identifier: GPL-2.0+ */

#pragma once

/*
 * Contains declarations that exist in the kernel which have been CUSTOMISED for
 * testing purposes to faciliate userland VMA testing.
 */

#ifdef CONFIG_MMU
extern unsigned long mmap_min_addr;
extern unsigned long dac_mmap_min_addr;
#else
#define mmap_min_addr		0UL
#define dac_mmap_min_addr	0UL
#endif

#define TASK_SIZE ((1ul << 47)-PAGE_SIZE)

/*
 * The shared stubs do not implement this, it amounts to an fprintf(STDERR,...)
 * either way :)
 */
#define pr_warn_once pr_err

struct anon_vma {
	struct anon_vma *root;
	struct rb_root_cached rb_root;

	/* Test fields. */
	bool was_cloned;
	bool was_unlinked;
};

static inline void unlink_anon_vmas(struct vm_area_struct *vma)
{
	/* For testing purposes, indicate that the anon_vma was unlinked. */
	vma->anon_vma->was_unlinked = true;
}

static inline void vma_start_write(struct vm_area_struct *vma)
{
	/* Used to indicate to tests that a write operation has begun. */
	vma->vm_lock_seq++;
}

static inline __must_check
int vma_start_write_killable(struct vm_area_struct *vma)
{
	/* Used to indicate to tests that a write operation has begun. */
	vma->vm_lock_seq++;
	return 0;
}

static inline int anon_vma_clone(struct vm_area_struct *dst, struct vm_area_struct *src,
				 enum vma_operation operation)
{
	/* For testing purposes. We indicate that an anon_vma has been cloned. */
	if (src->anon_vma != NULL) {
		dst->anon_vma = src->anon_vma;
		dst->anon_vma->was_cloned = true;
	}

	return 0;
}

static inline int __anon_vma_prepare(struct vm_area_struct *vma)
{
	struct anon_vma *anon_vma = calloc(1, sizeof(struct anon_vma));

	if (!anon_vma)
		return -ENOMEM;

	anon_vma->root = anon_vma;
	vma->anon_vma = anon_vma;

	return 0;
}

static inline int anon_vma_prepare(struct vm_area_struct *vma)
{
	if (likely(vma->anon_vma))
		return 0;

	return __anon_vma_prepare(vma);
}

static inline void vma_lock_init(struct vm_area_struct *vma, bool reset_refcnt)
{
	if (reset_refcnt)
		refcount_set(&vma->vm_refcnt, 0);
}

static inline unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
{
	return PAGE_SIZE;
}