patch-2.0.34 linux/mm/mremap.c

• Lines: 36
• Date: Wed Jun 3 15:17:50 1998
• Orig file: v2.0.33/linux/mm/mremap.c
• Orig date: Fri Nov 22 06:25:17 1996

diff -u --recursive --new-file v2.0.33/linux/mm/mremap.c linux/mm/mremap.c
@@ -19,6 +19,8 @@
 #include <asm/system.h>
 #include <asm/pgtable.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;
@@ -173,7 +175,7 @@
 	 * Always allow a shrinking remap: that just unmaps
 	 * the unnecessary pages..
 	 */
-	if (old_len > new_len) {
+	if (old_len >= new_len) {
 		do_munmap(addr+new_len, old_len - new_len);
 		return addr;
 	}
@@ -196,11 +198,16 @@
 	if ((current->mm->total_vm << PAGE_SHIFT) + (new_len - old_len)
 	    > current->rlim[RLIMIT_AS].rlim_cur)
 		return -ENOMEM;
+	/* Private writable mapping? Check memory availability.. */
+	if ((vma->vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE) {
+		if (!vm_enough_memory((new_len - old_len) >> PAGE_SHIFT))
+			return -ENOMEM;
+	}
 
 	/* old_len exactly to the end of the area.. */
 	if (old_len == vma->vm_end - addr &&
 	    (old_len != new_len || !(flags & MREMAP_MAYMOVE))) {
-		unsigned long max_addr = TASK_SIZE;
+		unsigned long max_addr = MAX_USER_ADDR;
 		if (vma->vm_next)
 			max_addr = vma->vm_next->vm_start;
 		/* can we just expand the current mapping? */