linux-kernel - [PATCH 2/4] RTC: Fix rtc driver ioctl specific shortcutting

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1296699283-6784-3-git-send-email-john.stultz@linaro.org>
Date:	Wed,  2 Feb 2011 18:14:41 -0800
From:	John Stultz <john.stultz@...aro.org>
To:	linux-kernel@...r.kernel.org
Cc:	John Stultz <john.stultz@...aro.org>,
	Alessandro Zummo <a.zummo@...ertech.it>,
	Marcelo Roberto Jimenez <mroberto@...i.cetuc.puc-rio.br>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 2/4] RTC: Fix rtc driver ioctl specific shortcutting

Some RTC drivers enable functionality directly via their ioctl method
instead of using the generic ioctl handling code. With the recent
virtualization of the RTC layer, its now important that the generic
layer always be used.

This patch moved the rtc driver ioctl method call to after the generic
ioctl processing is done. This allows hardware specific features or
ioctls to still function, while relying on the generic code for handling
everything else.

This patch on its own may more obviously break rtc drivers that
implement the alarm irq enablement via their ioctl method instead of
implementing the alarm_irq_enable method. Those drivers will be fixed
in a following patch. Additionaly, those drivers are already likely to
not be functioning reliably even without this patch.

CC: Alessandro Zummo <a.zummo@...ertech.it>
CC: Marcelo Roberto Jimenez <mroberto@...i.cetuc.puc-rio.br>
CC: Thomas Gleixner <tglx@...utronix.de>
Reported-by: Marcelo Roberto Jimenez <mroberto@...i.cetuc.puc-rio.br>
Signed-off-by: John Stultz <john.stultz@...aro.org>
---
 drivers/rtc/rtc-dev.c |   21 +++++++--------------
 1 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 212b16e..37c3cc1 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -154,19 +154,7 @@ static long rtc_dev_ioctl(struct file *file,
 	if (err)
 		goto done;
 
-	/* try the driver's ioctl interface */
-	if (ops->ioctl) {
-		err = ops->ioctl(rtc->dev.parent, cmd, arg);
-		if (err != -ENOIOCTLCMD) {
-			mutex_unlock(&rtc->ops_lock);
-			return err;
-		}
-	}
-
-	/* if the driver does not provide the ioctl interface
-	 * or if that particular ioctl was not implemented
-	 * (-ENOIOCTLCMD), we will try to emulate here.
-	 *
+	/*
 	 * Drivers *SHOULD NOT* provide ioctl implementations
 	 * for these requests.  Instead, provide methods to
 	 * support the following code, so that the RTC's main
@@ -329,7 +317,12 @@ static long rtc_dev_ioctl(struct file *file,
 		return err;
 
 	default:
-		err = -ENOTTY;
+		/* Finally try the driver's ioctl interface */
+		if (ops->ioctl) {
+			err = ops->ioctl(rtc->dev.parent, cmd, arg);
+			if (err == -ENOIOCTLCMD)
+				err = -ENOTTY;
+		}
 		break;
 	}
 
-- 
1.7.3.2.146.gca209

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/