From 3418ff76119da52f808eb496191d1fd380f53f3d Mon Sep 17 00:00:00 2001
From: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Date: Mon, 1 May 2006 12:16:16 -0700
Subject: [PATCH] [PATCH] RTC: rtc-dev tweak for 64-bit kernel
Make rtc-dev work well on 64-bit platforms with 32-bit userland. On those
platforms, users might try to read 32-bit integer value. This patch make
rtc-dev's read() work well for both "int" and "long" size. This tweak is came
from genrtc driver.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
drivers/rtc/rtc-dev.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index b1e3e6179e569..6c9ad92747fdd 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -58,7 +58,7 @@ rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
unsigned long data;
ssize_t ret;
- if (count < sizeof(unsigned long))
+ if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
return -EINVAL;
add_wait_queue(&rtc->irq_queue, &wait);
@@ -90,11 +90,16 @@ rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
if (ret == 0) {
/* Check for any data updates */
if (rtc->ops->read_callback)
- data = rtc->ops->read_callback(rtc->class_dev.dev, data);
-
- ret = put_user(data, (unsigned long __user *)buf);
- if (ret == 0)
- ret = sizeof(unsigned long);
+ data = rtc->ops->read_callback(rtc->class_dev.dev,
+ data);
+
+ if (sizeof(int) != sizeof(long) &&
+ count == sizeof(unsigned int))
+ ret = put_user(data, (unsigned int __user *)buf) ?:
+ sizeof(unsigned int);
+ else
+ ret = put_user(data, (unsigned long __user *)buf) ?:
+ sizeof(unsigned long);
}
return ret;
}
--
2.30.2