Commit 1d96469a authored Aug 20, 2008 by Atsushi Nemoto Committed by Linus Torvalds Aug 20, 2008

rtc: fix double lock on UIE emulation



With commit 5ad31a57 ("rtc: remove BKL
for ioctl()"), RTC_UIE_ON ioctl cause double lock on rtc->ops_lock.
The ops_lock must not be held while set_uie() calls rtc_read_time()
which takes the lock.  Also clear_uie() does not need ops_lock.  This
patch fixes return value of RTC_UIE_OFF ioctl too.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: David Brownell <david-b@pacbell.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent ff9bc512

drivers/rtc/rtc-dev.c

+4 −1

Original line number	Original line	Diff line number	Diff line
	@@ -403,11 +403,14 @@ static long rtc_dev_ioctl(struct file *file,

	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL		#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	case RTC_UIE_OFF:		case RTC_UIE_OFF:
			mutex_unlock(&rtc->ops_lock);
	clear_uie(rtc);		clear_uie(rtc);
	break;		return 0;

	case RTC_UIE_ON:		case RTC_UIE_ON:
			mutex_unlock(&rtc->ops_lock);
	err = set_uie(rtc);		err = set_uie(rtc);
			return err;
	#endif		#endif
	default:		default:
	err = -ENOTTY;		err = -ENOTTY;