X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fmremap.c;h=cde56ee51ef7a6b10e18f860bd7be08df07f2407;hb=e854df613fe934c94a0b39eccb4104e72ccbbded;hp=5f346178f16f5492034f59ad6c40e5584d40109c;hpb=ecc1a8993751de4e82eb18640d631dae1f626bd6;p=safe%2Fjmp%2Flinux-2.6

diff --git a/mm/mremap.c b/mm/mremap.c
index 5f34617..cde56ee 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -9,7 +9,6 @@
 
 #include <linux/mm.h>
 #include <linux/hugetlb.h>
-#include <linux/slab.h>
 #include <linux/shm.h>
 #include <linux/ksm.h>
 #include <linux/mman.h>
@@ -285,7 +284,7 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
 	if (vma->vm_flags & VM_LOCKED) {
 		unsigned long locked, lock_limit;
 		locked = mm->locked_vm << PAGE_SHIFT;
-		lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+		lock_limit = rlimit(RLIMIT_MEMLOCK);
 		locked += new_len - old_len;
 		if (locked > lock_limit && !capable(CAP_IPC_LOCK))
 			goto Eagain;
@@ -321,6 +320,7 @@ static unsigned long mremap_to(unsigned long addr,
 	struct vm_area_struct *vma;
 	unsigned long ret = -EINVAL;
 	unsigned long charged = 0;
+	unsigned long map_flags;
 
 	if (new_addr & ~PAGE_MASK)
 		goto out;
@@ -358,14 +358,39 @@ static unsigned long mremap_to(unsigned long addr,
 		goto out;
 	}
 
-	ret = move_vma(vma, addr, old_len, new_len, new_addr);
+	map_flags = MAP_FIXED;
+	if (vma->vm_flags & VM_MAYSHARE)
+		map_flags |= MAP_SHARED;
+
+	ret = get_unmapped_area(vma->vm_file, new_addr, new_len, vma->vm_pgoff +
+				((addr - vma->vm_start) >> PAGE_SHIFT),
+				map_flags);
 	if (ret & ~PAGE_MASK)
-		vm_unacct_memory(charged);
+		goto out1;
+
+	ret = move_vma(vma, addr, old_len, new_len, new_addr);
+	if (!(ret & ~PAGE_MASK))
+		goto out;
+out1:
+	vm_unacct_memory(charged);
 
 out:
 	return ret;
 }
 
+static int vma_expandable(struct vm_area_struct *vma, unsigned long delta)
+{
+	unsigned long end = vma->vm_end + delta;
+	if (end < vma->vm_end) /* overflow */
+		return 0;
+	if (vma->vm_next && vma->vm_next->vm_start < end) /* intersection */
+		return 0;
+	if (get_unmapped_area(NULL, vma->vm_start, end - vma->vm_start,
+			      0, MAP_FIXED) & ~PAGE_MASK)
+		return 0;
+	return 1;
+}
+
 /*
  * Expand (or shrink) an existing mapping, potentially moving it at the
  * same time (controlled by the MREMAP_MAYMOVE flag and available VM space)
@@ -430,15 +455,15 @@ unsigned long do_mremap(unsigned long addr,
 	/* old_len exactly to the end of the area..
 	 */
 	if (old_len == vma->vm_end - addr) {
-		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) {
+		if (vma_expandable(vma, new_len - old_len)) {
 			int pages = (new_len - old_len) >> PAGE_SHIFT;
 
-			vma_adjust(vma, vma->vm_start,
-				addr + new_len, vma->vm_pgoff, NULL);
+			if (vma_adjust(vma, vma->vm_start, addr + new_len,
+				       vma->vm_pgoff, NULL)) {
+				ret = -ENOMEM;
+				goto out;
+			}
 
 			mm->total_vm += pages;
 			vm_stat_account(mm, vma->vm_flags, vma->vm_file, pages);
@@ -463,7 +488,9 @@ unsigned long do_mremap(unsigned long addr,
 			map_flags |= MAP_SHARED;
 
 		new_addr = get_unmapped_area(vma->vm_file, 0, new_len,
-					vma->vm_pgoff, map_flags);
+					vma->vm_pgoff +
+					((addr - vma->vm_start) >> PAGE_SHIFT),
+					map_flags);
 		if (new_addr & ~PAGE_MASK) {
 			ret = new_addr;
 			goto out;