vmalloc: unmap vmalloc area after hiding it
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 <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Mike Smith <scgtrp@gmail.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 @@
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;