[SPARC64]: store-init needs trailing membar.

The manual says that it is required and we actually have crash reports
where loads see stale data due to not having membars here.

In one case the networking does:

	memset(skb, 0, offsetof(struct sk_buff, truesize));

and then some code later checks skb->nohdr for zero, but it's still
the value that was there before the memset().

Note that arch/sparc64/lib/xor.S already got this right.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/sparc64/lib/NGpage.S b/arch/sparc64/lib/NGpage.S
index 7d7c3bb8dcb..8ce3a0c9c53 100644
--- a/arch/sparc64/lib/NGpage.S
+++ b/arch/sparc64/lib/NGpage.S
@@ -41,6 +41,7 @@ NGcopy_user_page:	/* %o0=dest, %o1=src, %o2=vaddr */
         subcc           %g7, 64, %g7
         bne,pt          %xcc, 1b
          add            %o0, 32, %o0
+        membar          #Sync
         retl
          nop
 
@@ -63,6 +64,7 @@ NGclear_user_page:	/* %o0=dest, %o1=vaddr */
         subcc           %g7, 64, %g7
         bne,pt          %xcc, 1b
          add            %o0, 32, %o0
+        membar          #Sync
         retl
          nop