[PATCH] x86_64: Fixed guard page handling again in iounmap

Caused oopses again.  Also fix potential mismatch in checking if
change_page_attr was needed.

To do it without races I needed to change mm/vmalloc.c to export a
__remove_vm_area that does not take vmlist lock.

Noticed by Terence Ripperda and based on a patch of his.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 3a358c895188..6409d9cf5965 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -41,6 +41,7 @@ extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
 extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
                                         unsigned long start, unsigned long end);
 extern struct vm_struct *remove_vm_area(void *addr);
+extern struct vm_struct *__remove_vm_area(void *addr);
 extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
                         struct page ***pages);
 extern void unmap_vm_area(struct vm_struct *area);