[PATCH] RTC: rtc-dev tweak for 64-bit kernel (3418ff76) · Commits · 戴 / test

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

+11 −6

Original line number	Diff line number	Diff line
		@@ -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;
		}

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