X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fmremap.c;h=1903bdf65e428d88e5bf124243d99ee7ab7c51e3;hb=9ba0883cfc5ab69820c05f1bf2b7711bb0a0103c;hp=8de77b632a206b5865a8d3a59c3c89cd25d4fa28;hpb=c74df32c724a1652ad8399b4891bb02c9d43743a;p=safe%2Fjmp%2Flinux-2.6

diff --git a/mm/mremap.c b/mm/mremap.c
index 8de77b6..1903bdf 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -13,6 +13,7 @@
 #include <linux/shm.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
+#include <linux/capability.h>
 #include <linux/fs.h>
 #include <linux/highmem.h>
 #include <linux/security.h>
@@ -72,7 +73,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
 	struct address_space *mapping = NULL;
 	struct mm_struct *mm = vma->vm_mm;
 	pte_t *old_pte, *new_pte, pte;
-	spinlock_t *old_ptl;
+	spinlock_t *old_ptl, *new_ptl;
 
 	if (vma->vm_file) {
 		/*
@@ -88,8 +89,15 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
 			new_vma->vm_truncate_count = 0;
 	}
 
+	/*
+	 * We don't have to worry about the ordering of src and dst
+	 * pte locks because exclusive mmap_sem prevents deadlock.
+	 */
 	old_pte = pte_offset_map_lock(mm, old_pmd, old_addr, &old_ptl);
  	new_pte = pte_offset_map_nested(new_pmd, new_addr);
+	new_ptl = pte_lockptr(mm, new_pmd);
+	if (new_ptl != old_ptl)
+		spin_lock(new_ptl);
 
 	for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE,
 				   new_pte++, new_addr += PAGE_SIZE) {
@@ -101,6 +109,8 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
 		set_pte_at(mm, new_addr, new_pte, pte);
 	}
 
+	if (new_ptl != old_ptl)
+		spin_unlock(new_ptl);
 	pte_unmap_nested(new_pte - 1);
 	pte_unmap_unlock(old_pte - 1, old_ptl);
 	if (mapping)
@@ -314,7 +324,7 @@ unsigned long do_mremap(unsigned long addr,
 	/* We can't remap across vm area boundaries */
 	if (old_len > vma->vm_end - addr)
 		goto out;
-	if (vma->vm_flags & VM_DONTEXPAND) {
+	if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP)) {
 		if (new_len > old_len)
 			goto out;
 	}