mm: strictly nested kmap_atomic()

Ensure kmap_atomic() usage is strictly nested

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index e3060ef85b6d..283cd47bb34c 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -201,8 +201,8 @@ static inline void copy_user_highpage(struct page *to, struct page *from,
         vfrom = kmap_atomic(from, KM_USER0);
         vto = kmap_atomic(to, KM_USER1);
         copy_user_page(vto, vfrom, vaddr, to);
-        kunmap_atomic(vfrom, KM_USER0);
         kunmap_atomic(vto, KM_USER1);
+        kunmap_atomic(vfrom, KM_USER0);
 }
 
 #endif
@@ -214,8 +214,8 @@ static inline void copy_highpage(struct page *to, struct page *from)
         vfrom = kmap_atomic(from, KM_USER0);
         vto = kmap_atomic(to, KM_USER1);
         copy_page(vto, vfrom);
-        kunmap_atomic(vfrom, KM_USER0);
         kunmap_atomic(vto, KM_USER1);
+        kunmap_atomic(vfrom, KM_USER0);
 }
 
 #endif /* _LINUX_HIGHMEM_H */