// SPDX-License-Identifier: GPL-2.0-or-later #include "shared.h"  bool fail_prealloc;unsigned long mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR;unsigned long dac_mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR;unsigned long stack_guard_gap = 256UL<<PAGE_SHIFT; const struct vm_operations_struct vma_dummy_vm_ops;struct anon_vma dummy_anon_vma;struct task_struct __current; struct vm_area_struct *alloc_vma(struct mm_struct *mm,		unsigned long start, unsigned long end,		pgoff_t pgoff, vma_flags_t vma_flags){	struct vm_area_struct *vma = vm_area_alloc(mm); 	if (vma == NULL)		return NULL; 	vma->vm_start = start;	vma->vm_end = end;	vma->vm_pgoff = pgoff;	vma->flags = vma_flags;	vma_assert_detached(vma); 	return vma;} void detach_free_vma(struct vm_area_struct *vma){	vma_mark_detached(vma);	vm_area_free(vma);} struct vm_area_struct *alloc_and_link_vma(struct mm_struct *mm,		unsigned long start, unsigned long end,		pgoff_t pgoff, vma_flags_t vma_flags){	struct vm_area_struct *vma = alloc_vma(mm, start, end, pgoff, vma_flags); 	if (vma == NULL)		return NULL; 	if (attach_vma(mm, vma)) {		detach_free_vma(vma);		return NULL;	} 	/*	 * Reset this counter which we use to track whether writes have	 * begun. Linking to the tree will have caused this to be incremented,	 * which means we will get a false positive otherwise.	 */	vma->vm_lock_seq = UINT_MAX; 	return vma;} void reset_dummy_anon_vma(void){	dummy_anon_vma.was_cloned = false;	dummy_anon_vma.was_unlinked = false;} int cleanup_mm(struct mm_struct *mm, struct vma_iterator *vmi){	struct vm_area_struct *vma;	int count = 0; 	fail_prealloc = false;	reset_dummy_anon_vma(); 	vma_iter_set(vmi, 0);	for_each_vma(*vmi, vma) {		detach_free_vma(vma);		count++;	} 	mtree_destroy(&mm->mm_mt);	mm->map_count = 0;	return count;} bool vma_write_started(struct vm_area_struct *vma){	int seq = vma->vm_lock_seq; 	/* We reset after each check. */	vma->vm_lock_seq = UINT_MAX; 	/* The vma_start_write() stub simply increments this value. */	return seq > -1;} void __vma_set_dummy_anon_vma(struct vm_area_struct *vma,		struct anon_vma_chain *avc, struct anon_vma *anon_vma){	vma->anon_vma = anon_vma;	INIT_LIST_HEAD(&vma->anon_vma_chain);	list_add(&avc->same_vma, &vma->anon_vma_chain);	avc->anon_vma = vma->anon_vma;} void vma_set_dummy_anon_vma(struct vm_area_struct *vma,		struct anon_vma_chain *avc){	__vma_set_dummy_anon_vma(vma, avc, &dummy_anon_vma);} struct task_struct *get_current(void){	return &__current;} unsigned long rlimit(unsigned int limit){	return (unsigned long)-1;} void vma_set_range(struct vm_area_struct *vma,		   unsigned long start, unsigned long end,		   pgoff_t pgoff){	vma->vm_start = start;	vma->vm_end = end;	vma->vm_pgoff = pgoff;}