linux-kernel - [PATCH] rtc: (x1205) use sign_extend32() for sign extension

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 for Android: free password hash cracker in your pocket

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

Date:	Sat, 24 Jan 2015 17:05:24 +0100
From:	Martin Kepplinger <martink@...teo.de>
To:	a.zummo@...ertech.it
Cc:	rtc-linux@...glegroups.com, linux-kernel@...r.kernel.org,
	Martin Kepplinger <martink@...teo.de>
Subject: [PATCH] rtc: (x1205) use sign_extend32() for sign extension

Signed-off-by: Martin Kepplinger <martink@...teo.de>
---
Despite it's name, sign_extend32() is safe to use for 8 bit types
too. (see https://lkml.org/lkml/2015/1/18/289 if interested)

 drivers/rtc/rtc-x1205.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-x1205.c b/drivers/rtc/rtc-x1205.c
index b1de58e..5638b7b 100644
--- a/drivers/rtc/rtc-x1205.c
+++ b/drivers/rtc/rtc-x1205.c
@@ -22,6 +22,7 @@
 #include <linux/rtc.h>
 #include <linux/delay.h>
 #include <linux/module.h>
+#include <linux/bitops.h>
 
 #define DRV_VERSION "1.0.8"
 
@@ -366,8 +367,7 @@ static int x1205_get_atrim(struct i2c_client *client, int *trim)
 	 * perform sign extension. The formula is
 	 * Catr = (atr * 0.25pF) + 11.00pF.
 	 */
-	if (atr & 0x20)
-		atr |= 0xC0;
+	atr = sign_extend32(atr, 5);
 
 	dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __func__, atr, atr);
 
-- 
2.1.4

--
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/