-static int __handle_fault(struct mm_struct *mm, unsigned long address,
- int write_access)
-{
- struct vm_area_struct *vma;
- int ret = -EFAULT;
- int fault;
-
- if (in_atomic())
- return ret;
- down_read(&mm->mmap_sem);
- vma = find_vma(mm, address);
- if (unlikely(!vma))
- goto out;
- if (unlikely(vma->vm_start > address)) {
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto out;
- if (expand_stack(vma, address))
- goto out;
- }
-
- if (!write_access) {
- /* page not present, check vm flags */
- if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
- goto out;
- } else {
- if (!(vma->vm_flags & VM_WRITE))
- goto out;
- }
-
-survive:
- fault = handle_mm_fault(mm, vma, address, write_access ? FAULT_FLAG_WRITE : 0);
- if (unlikely(fault & VM_FAULT_ERROR)) {
- if (fault & VM_FAULT_OOM)
- goto out_of_memory;
- else if (fault & VM_FAULT_SIGBUS)
- goto out_sigbus;
- BUG();
- }
- if (fault & VM_FAULT_MAJOR)
- current->maj_flt++;
- else
- current->min_flt++;
- ret = 0;
-out:
- up_read(&mm->mmap_sem);
- return ret;
-
-out_of_memory:
- up_read(&mm->mmap_sem);
- if (is_global_init(current)) {
- yield();
- down_read(&mm->mmap_sem);
- goto survive;
- }
- printk("VM: killing process %s\n", current->comm);
- return ret;
-
-out_sigbus:
- up_read(&mm->mmap_sem);
- current->thread.prot_addr = address;
- current->thread.trap_no = 0x11;
- force_sig(SIGBUS, current);
- return ret;
-}
-
-static size_t __user_copy_pt(unsigned long uaddr, void *kptr,
- size_t n, int write_user)