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/kernel/power/snapshot.c b/kernel/power/snapshot.c
index ac7eb109f196..9e3581f4619a 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -984,8 +984,8 @@ static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
                 src = kmap_atomic(s_page, KM_USER0);
                 dst = kmap_atomic(d_page, KM_USER1);
                 do_copy_page(dst, src);
-                kunmap_atomic(src, KM_USER0);
                 kunmap_atomic(dst, KM_USER1);
+                kunmap_atomic(src, KM_USER0);
         } else {
                 if (PageHighMem(d_page)) {
                         /* Page pointed to by src may contain some kernel
@@ -2273,8 +2273,8 @@ swap_two_pages_data(struct page *p1, struct page *p2, void *buf)
         memcpy(buf, kaddr1, PAGE_SIZE);
         memcpy(kaddr1, kaddr2, PAGE_SIZE);
         memcpy(kaddr2, buf, PAGE_SIZE);
-        kunmap_atomic(kaddr1, KM_USER0);
         kunmap_atomic(kaddr2, KM_USER1);
+        kunmap_atomic(kaddr1, KM_USER0);
 }
 
 /**