drivers/rtc: correct error-handling code

This code is not executed before ds1307->rtc has been successfully
initialized to the result of calling rtc_device_register.  Thus the test
that ds1307->rtc is not NULL is always true.

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

// <smpl>
@match exists@
expression x, E;
statement S1, S2;
@@

x = rtc_device_register(...)
... when != x = E
(
*  if (x == NULL || ...) S1 else S2
|
*  if (x == NULL && ...) S1 else S2
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Julia Lawall 2009-09-22 16:46:29 -07:00 committed by Linus Torvalds
parent d3c7a3f71a
commit 72445af880

View File

@ -896,8 +896,7 @@ read_rtc:
return 0;
exit_irq:
if (ds1307->rtc)
rtc_device_unregister(ds1307->rtc);
rtc_device_unregister(ds1307->rtc);
exit_free:
kfree(ds1307);
return err;