diff options
Diffstat (limited to 'old/xenolinux-2.4.16-sparse/mm/mremap.c')
| -rw-r--r-- | old/xenolinux-2.4.16-sparse/mm/mremap.c | 354 |
1 files changed, 0 insertions, 354 deletions
diff --git a/old/xenolinux-2.4.16-sparse/mm/mremap.c b/old/xenolinux-2.4.16-sparse/mm/mremap.c deleted file mode 100644 index a2e0d860dd..0000000000 --- a/old/xenolinux-2.4.16-sparse/mm/mremap.c +++ /dev/null @@ -1,354 +0,0 @@ -/* - * linux/mm/remap.c - * - * (C) Copyright 1996 Linus Torvalds - */ - -#include <linux/slab.h> -#include <linux/smp_lock.h> -#include <linux/shm.h> -#include <linux/mman.h> -#include <linux/swap.h> - -#include <asm/uaccess.h> -#include <asm/pgalloc.h> - -extern int vm_enough_memory(long pages); - -static inline pte_t *get_one_pte(struct mm_struct *mm, unsigned long addr) -{ - pgd_t * pgd; - pmd_t * pmd; - pte_t * pte = NULL; - - pgd = pgd_offset(mm, addr); - if (pgd_none(*pgd)) - goto end; - if (pgd_bad(*pgd)) { - pgd_ERROR(*pgd); - pgd_clear(pgd); - goto end; - } - - pmd = pmd_offset(pgd, addr); - if (pmd_none(*pmd)) - goto end; - if (pmd_bad(*pmd)) { - pmd_ERROR(*pmd); - pmd_clear(pmd); - goto end; - } - - pte = pte_offset(pmd, addr); - if (pte_none(*pte)) - pte = NULL; -end: - return pte; -} - -static inline pte_t *alloc_one_pte(struct mm_struct *mm, unsigned long addr) -{ - pmd_t * pmd; - pte_t * pte = NULL; - - pmd = pmd_alloc(mm, pgd_offset(mm, addr), addr); - if (pmd) - pte = pte_alloc(mm, pmd, addr); - return pte; -} - -static inline int copy_one_pte(struct mm_struct *mm, pte_t * src, pte_t * dst) -{ - int error = 0; - pte_t pte; - - if (!pte_none(*src)) { - pte = ptep_get_and_clear(src); - if (!dst) { - /* No dest? We must put it back. */ - dst = src; - error++; - } - set_pte(dst, pte); - } - return error; -} - -static int move_one_page(struct mm_struct *mm, unsigned long old_addr, unsigned long new_addr) -{ - int error = 0; - pte_t * src; - - spin_lock(&mm->page_table_lock); - src = get_one_pte(mm, old_addr); - if (src) - error = copy_one_pte(mm, src, alloc_one_pte(mm, new_addr)); - spin_unlock(&mm->page_table_lock); - return error; -} - -static int move_page_tables(struct mm_struct * mm, - unsigned long new_addr, unsigned long old_addr, unsigned long len) -{ - unsigned long offset = len; - - flush_cache_range(mm, old_addr, old_addr + len); - - /* - * This is not the clever way to do this, but we're taking the - * easy way out on the assumption that most remappings will be - * only a few pages.. This also makes error recovery easier. - */ - while (offset) { - offset -= PAGE_SIZE; - if (move_one_page(mm, old_addr + offset, new_addr + offset)) - goto oops_we_failed; - } - flush_tlb_range(mm, old_addr, old_addr + len); - return 0; - - /* - * Ok, the move failed because we didn't have enough pages for - * the new page table tree. This is unlikely, but we have to - * take the possibility into account. In that case we just move - * all the pages back (this will work, because we still have - * the old page tables) - */ -oops_we_failed: - XENO_flush_page_update_queue(); - flush_cache_range(mm, new_addr, new_addr + len); - while ((offset += PAGE_SIZE) < len) - move_one_page(mm, new_addr + offset, old_addr + offset); - XENO_flush_page_update_queue(); - zap_page_range(mm, new_addr, len); - return -1; -} - -static inline unsigned long move_vma(struct vm_area_struct * vma, - unsigned long addr, unsigned long old_len, unsigned long new_len, - unsigned long new_addr) -{ - struct mm_struct * mm = vma->vm_mm; - struct vm_area_struct * new_vma, * next, * prev; - int allocated_vma; - - new_vma = NULL; - next = find_vma_prev(mm, new_addr, &prev); - if (next) { - if (prev && prev->vm_end == new_addr && - can_vma_merge(prev, vma->vm_flags) && !vma->vm_file && !(vma->vm_flags & VM_SHARED)) { - spin_lock(&mm->page_table_lock); - prev->vm_end = new_addr + new_len; - spin_unlock(&mm->page_table_lock); - new_vma = prev; - if (next != prev->vm_next) - BUG(); - if (prev->vm_end == next->vm_start && can_vma_merge(next, prev->vm_flags)) { - spin_lock(&mm->page_table_lock); - prev->vm_end = next->vm_end; - __vma_unlink(mm, next, prev); - spin_unlock(&mm->page_table_lock); - - mm->map_count--; - kmem_cache_free(vm_area_cachep, next); - } - } else if (next->vm_start == new_addr + new_len && - can_vma_merge(next, vma->vm_flags) && !vma->vm_file && !(vma->vm_flags & VM_SHARED)) { - spin_lock(&mm->page_table_lock); - next->vm_start = new_addr; - spin_unlock(&mm->page_table_lock); - new_vma = next; - } - } else { - prev = find_vma(mm, new_addr-1); - if (prev && prev->vm_end == new_addr && - can_vma_merge(prev, vma->vm_flags) && !vma->vm_file && !(vma->vm_flags & VM_SHARED)) { - spin_lock(&mm->page_table_lock); - prev->vm_end = new_addr + new_len; - spin_unlock(&mm->page_table_lock); - new_vma = prev; - } - } - - allocated_vma = 0; - if (!new_vma) { - new_vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); - if (!new_vma) - goto out; - allocated_vma = 1; - } - - if (!move_page_tables(current->mm, new_addr, addr, old_len)) { - if (allocated_vma) { - *new_vma = *vma; - new_vma->vm_start = new_addr; - new_vma->vm_end = new_addr+new_len; - new_vma->vm_pgoff += (addr - vma->vm_start) >> PAGE_SHIFT; - new_vma->vm_raend = 0; - if (new_vma->vm_file) - get_file(new_vma->vm_file); - if (new_vma->vm_ops && new_vma->vm_ops->open) - new_vma->vm_ops->open(new_vma); - insert_vm_struct(current->mm, new_vma); - } - do_munmap(current->mm, addr, old_len); - current->mm->total_vm += new_len >> PAGE_SHIFT; - if (new_vma->vm_flags & VM_LOCKED) { - current->mm->locked_vm += new_len >> PAGE_SHIFT; - make_pages_present(new_vma->vm_start, - new_vma->vm_end); - } - return new_addr; - } - if (allocated_vma) - kmem_cache_free(vm_area_cachep, new_vma); - out: - return -ENOMEM; -} - -/* - * Expand (or shrink) an existing mapping, potentially moving it at the - * same time (controlled by the MREMAP_MAYMOVE flag and available VM space) - * - * MREMAP_FIXED option added 5-Dec-1999 by Benjamin LaHaise - * This option implies MREMAP_MAYMOVE. - */ -unsigned long do_mremap(unsigned long addr, - unsigned long old_len, unsigned long new_len, - unsigned long flags, unsigned long new_addr) -{ - struct vm_area_struct *vma; - unsigned long ret = -EINVAL; - - if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE)) - goto out; - - if (addr & ~PAGE_MASK) - goto out; - - old_len = PAGE_ALIGN(old_len); - new_len = PAGE_ALIGN(new_len); - - /* new_addr is only valid if MREMAP_FIXED is specified */ - if (flags & MREMAP_FIXED) { - if (new_addr & ~PAGE_MASK) - goto out; - if (!(flags & MREMAP_MAYMOVE)) - goto out; - - if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len) - goto out; - - /* Check if the location we're moving into overlaps the - * old location at all, and fail if it does. - */ - if ((new_addr <= addr) && (new_addr+new_len) > addr) - goto out; - - if ((addr <= new_addr) && (addr+old_len) > new_addr) - goto out; - - do_munmap(current->mm, new_addr, new_len); - } - - /* - * Always allow a shrinking remap: that just unmaps - * the unnecessary pages.. - */ - ret = addr; - if (old_len >= new_len) { - do_munmap(current->mm, addr+new_len, old_len - new_len); - if (!(flags & MREMAP_FIXED) || (new_addr == addr)) - goto out; - } - - /* - * Ok, we need to grow.. or relocate. - */ - ret = -EFAULT; - vma = find_vma(current->mm, addr); - if (!vma || vma->vm_start > addr) - goto out; - /* We can't remap across vm area boundaries */ - if (old_len > vma->vm_end - addr) - goto out; - if (vma->vm_flags & VM_DONTEXPAND) { - if (new_len > old_len) - goto out; - } - if (vma->vm_flags & VM_LOCKED) { - unsigned long locked = current->mm->locked_vm << PAGE_SHIFT; - locked += new_len - old_len; - ret = -EAGAIN; - if (locked > current->rlim[RLIMIT_MEMLOCK].rlim_cur) - goto out; - } - ret = -ENOMEM; - if ((current->mm->total_vm << PAGE_SHIFT) + (new_len - old_len) - > current->rlim[RLIMIT_AS].rlim_cur) - goto out; - /* Private writable mapping? Check memory availability.. */ - if ((vma->vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE && - !(flags & MAP_NORESERVE) && - !vm_enough_memory((new_len - old_len) >> PAGE_SHIFT)) - goto out; - - /* old_len exactly to the end of the area.. - * And we're not relocating the area. - */ - if (old_len == vma->vm_end - addr && - !((flags & MREMAP_FIXED) && (addr != new_addr)) && - (old_len != new_len || !(flags & MREMAP_MAYMOVE))) { - unsigned long max_addr = TASK_SIZE; - if (vma->vm_next) - max_addr = vma->vm_next->vm_start; - /* can we just expand the current mapping? */ - if (max_addr - addr >= new_len) { - int pages = (new_len - old_len) >> PAGE_SHIFT; - spin_lock(&vma->vm_mm->page_table_lock); - vma->vm_end = addr + new_len; - spin_unlock(&vma->vm_mm->page_table_lock); - current->mm->total_vm += pages; - if (vma->vm_flags & VM_LOCKED) { - current->mm->locked_vm += pages; - make_pages_present(addr + old_len, - addr + new_len); - } - ret = addr; - goto out; - } - } - - /* - * We weren't able to just expand or shrink the area, - * we need to create a new one and move it.. - */ - ret = -ENOMEM; - if (flags & MREMAP_MAYMOVE) { - if (!(flags & MREMAP_FIXED)) { - unsigned long map_flags = 0; - if (vma->vm_flags & VM_SHARED) - map_flags |= MAP_SHARED; - - new_addr = get_unmapped_area(vma->vm_file, 0, new_len, vma->vm_pgoff, map_flags); - ret = new_addr; - if (new_addr & ~PAGE_MASK) - goto out; - } - ret = move_vma(vma, addr, old_len, new_len, new_addr); - } -out: - return ret; -} - -asmlinkage unsigned long sys_mremap(unsigned long addr, - unsigned long old_len, unsigned long new_len, - unsigned long flags, unsigned long new_addr) -{ - unsigned long ret; - - down_write(¤t->mm->mmap_sem); - ret = do_mremap(addr, old_len, new_len, flags, new_addr); - up_write(¤t->mm->mmap_sem); - return ret; -} |