drivers/watchdog/lantiq_wdt.c: drop iounmap for devm_ allocated data
authorJulia Lawall <julia@diku.dk>
Mon, 26 Dec 2011 17:38:00 +0000 (18:38 +0100)
committerWim Van Sebroeck <wim@iguana.be>
Fri, 6 Jan 2012 14:27:30 +0000 (15:27 +0100)
Data allocated with devm_ioremap or devm_ioremap_nocache should not be
freed using iounmap, because doing so causes a dangling pointer, and a
subsequent double free.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
expression x;
@@
(
 x = devm_ioremap(...)
|
 x = devm_ioremap_nocache(...)
)

@@
expression r.x;
@@
* iounmap(x)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
drivers/watchdog/lantiq_wdt.c

index 102aed0efbf158a02271cb06dc25b1388a899736..d3a63be2e28d07974249b082749781dbc46df2f1 100644 (file)
@@ -222,9 +222,6 @@ ltq_wdt_remove(struct platform_device *pdev)
 {
        misc_deregister(&ltq_wdt_miscdev);
 
-       if (ltq_wdt_membase)
-               iounmap(ltq_wdt_membase);
-
        return 0;
 }