vma: Introduce vma_premapped flag

Not all private VMA-s will be premmaped, so a separate sign of
a VMA being on the premap area is needed.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/include/image.h

@@ -89,6 +89,7 @@
 #define VMA_AREA_VVAR		(1 <<  12)
 #define VMA_AREA_AIORING	(1 <<  13)
 
+#define VMA_PREMMAPED		(1 <<  30)
 #define VMA_UNSUPP		(1 <<  31)
 
 #define CR_CAP_SIZE	2

criu/mem.c

@@ -522,7 +522,7 @@ int prepare_mm_pid(struct pstree_item *i)
 }
 
 /* Map a private vma, if it is not mapped by a parent yet */
-static int map_private_vma(struct pstree_item *t,
+static int premap_private_vma(struct pstree_item *t,
 		struct vma_area *vma, void **tgt_addr,
 		struct vma_area **pvma, struct list_head *pvma_list)
 {
@@ -550,7 +550,7 @@ static int map_private_vma(struct pstree_item *t,
 		if (p->e->start > vma->e->start)
 			 break;
 
-		if (!vma_area_is_private(p, kdat.task_size))
+		if (!vma_area_is(p, VMA_PREMMAPED))
 			continue;
 
 		 if (p->e->end != vma->e->end ||
@@ -627,6 +627,7 @@ static int map_private_vma(struct pstree_item *t,
 		*pvma = list_entry(p->list.next, struct vma_area, list);
 	}
 
+	vma->e->status |= VMA_PREMMAPED;
 	vma->premmaped_addr = (unsigned long) addr;
 	pr_debug("\tpremap %#016"PRIx64"-%#016"PRIx64" -> %016lx\n",
 		vma->e->start, vma->e->end, (unsigned long)addr);
@@ -654,7 +655,7 @@ static int premap_priv_vmas(struct pstree_item *t, struct vm_area_list *vmas,
 
 	/*
 	 * Keep parent vmas at hands to check whether we can "inherit" them.
-	 * See comments in map_private_vma.
+	 * See comments in premap_private_vma.
 	 */
 	if (t->parent)
 		parent_vmas = &rsti(t->parent)->vmas.h;
@@ -674,7 +675,7 @@ static int premap_priv_vmas(struct pstree_item *t, struct vm_area_list *vmas,
 		if (!vma_area_is_private(vma, kdat.task_size))
 			continue;
 
-		ret = map_private_vma(t, vma, &at, &pvma, parent_vmas);
+		ret = premap_private_vma(t, vma, &at, &pvma, parent_vmas);
 		if (ret < 0)
 			break;
 	}
@@ -901,7 +902,7 @@ int unmap_guard_pages(struct pstree_item *t)
 	struct list_head *vmas = &rsti(t)->vmas.h;
 
 	list_for_each_entry(vma, vmas, list) {
-		if (!vma_area_is_private(vma, kdat.task_size))
+		if (!vma_area_is(vma, VMA_PREMMAPED))
 			continue;
 
 		if (vma->e->flags & MAP_GROWSDOWN) {
@@ -961,7 +962,7 @@ int prepare_vmas(struct pstree_item *t, struct task_restore_args *ta)
 		 */
 		*vme = *vma->e;
 
-		if (vma_area_is_private(vma, kdat.task_size))
+		if (vma_area_is(vma, VMA_PREMMAPED))
 			vma_premmaped_start(vme) = vma->premmaped_addr;
 	}
 

criu/pie/restorer.c

@@ -624,7 +624,7 @@ static unsigned long restore_mapping(VmaEntry *vma_entry)
  * of tail. To set tail, we write to /dev/null and use the fact this
  * operation is synchronious for the device. Also, we unmap temporary
  * anonymous area, used to store content of ring buffer during restore
- * and mapped in map_private_vma().
+ * and mapped in premap_private_vma().
  */
 static int restore_aio_ring(struct rst_aio_ring *raio)
 {
@@ -1141,7 +1141,7 @@ long __export_restore_task(struct task_restore_args *args)
 	for (i = 0; i < args->vmas_n; i++) {
 		vma_entry = args->vmas + i;
 
-		if (!vma_entry_is_private(vma_entry, args->task_size))
+		if (!vma_entry_is(vma_entry, VMA_PREMMAPED))
 			continue;
 
 		if (vma_entry->end >= args->task_size)
@@ -1159,7 +1159,7 @@ long __export_restore_task(struct task_restore_args *args)
 	for (i = args->vmas_n - 1; i >= 0; i--) {
 		vma_entry = args->vmas + i;
 
-		if (!vma_entry_is_private(vma_entry, args->task_size))
+		if (!vma_entry_is(vma_entry, VMA_PREMMAPED))
 			continue;
 
 		if (vma_entry->start > args->task_size)
@@ -1182,7 +1182,7 @@ long __export_restore_task(struct task_restore_args *args)
 		if (!vma_entry_is(vma_entry, VMA_AREA_REGULAR))
 			continue;
 
-		if (vma_entry_is_private(vma_entry, args->task_size))
+		if (vma_entry_is(vma_entry, VMA_PREMMAPED))
 			continue;
 
 		va = restore_mapping(vma_entry);