vmalloc: unmap vmalloc area after hiding it

dd32c279 · KAMEZAWA Hiroyuki <[email protected]> · 2009-09-21 17:02:32 -07:00

vmap area should be purged after vm_struct is removed from the list
because vread/vwrite etc...believes the range is valid while it's on
vm_struct list.

Signed-off-by: KAMEZAWA Hiroyuki <[email protected]>
Reviewed-by: WANG Cong <[email protected]>
Cc: Mike Smith <[email protected]>
Cc: Nick Piggin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: dd32c279983bf77fdcc8a9aa4a05b0ffdc75859c
Parents: 2f66a68f

Changes

1 files changed · +9 −5

File	Status	Add	Del	Content
mm/vmalloc.c	modified	+9	−5	View file

mm/vmalloc.c

View file

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 759deae..c4071fa 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1270,17 +1270,21 @@ struct vm_struct *remove_vm_area(const void *addr)
 	if (va && va->flags & VM_VM_AREA) {
 		struct vm_struct *vm = va->private;
 		struct vm_struct *tmp, **p;
-
-		vmap_debug_free_range(va->va_start, va->va_end);
-		free_unmap_vmap_area(va);
-		vm->size -= PAGE_SIZE;
-
+		/*
+		 * remove from list and disallow access to this vm_struct
+		 * before unmap. (address range confliction is maintained by
+		 * vmap.)
+		 */
 		write_lock(&vmlist_lock);
 		for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
 			;
 		*p = tmp->next;
 		write_unlock(&vmlist_lock);
 
+		vmap_debug_free_range(va->va_start, va->va_end);
+		free_unmap_vmap_area(va);
+		vm->size -= PAGE_SIZE;
+
 		return vm;
 	}
 	return NULL;