static void __remove_shared_vm_struct(struct vm_area_struct *vma,
		struct file *file, struct address_space *mapping)
{
	if (vma->vm_flags & VM_DENYWRITE)
		atomic_inc(&file_inode(file)->i_writecount);
	if (vma->vm_flags & VM_SHARED)
		mapping_unmap_writable(mapping);

	flush_dcache_mmap_lock(mapping);
	vma_interval_tree_remove(vma, &mapping->i_mmap);
	flush_dcache_mmap_unlock(mapping);
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.