[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>
This commit is contained in:
Atsushi Nemoto 2006-05-01 12:16:16 -07:00 committed by Linus Torvalds
parent b44df334a7
commit 3418ff7611

View file

@ -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);
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);
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;
}