From: Julia Lawall <julia@diku.dk>
Date: Sun, 20 Jun 2010 11:24:54 +0000 (+0000)
Subject: arch/sh/mm: Eliminate a double lock
X-Git-Tag: v2.6.35-rc4~56^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0e6f989ba83e6fa64e979d3488f01670b8be7959;p=profile%2Fivi%2Fkernel-adaptation-intel-automotive.git

arch/sh/mm: Eliminate a double lock

The function begins and ends with a read_lock.  The latter is changed to a
read_unlock.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@locked@
expression E1;
position p;
@@

read_lock(E1@p,...);

@r exists@
expression x <= locked.E1;
expression locked.E1;
expression E2;
identifier lock;
position locked.p,p1,p2;
@@

*lock@p1 (E1@p,...);
... when != E1
    when != \(x = E2\|&x\)
*lock@p2 (E1,...);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
---

diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
index 18623ba..6379091 100644
--- a/arch/sh/mm/pmb.c
+++ b/arch/sh/mm/pmb.c
@@ -770,7 +770,7 @@ static void __init pmb_resize(void)
 		spin_unlock_irqrestore(&pmbe->lock, flags);
 	}
 
-	read_lock(&pmb_rwlock);
+	read_unlock(&pmb_rwlock);
 }
 #endif