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Commit c654d60e authored by Jan Beulich's avatar Jan Beulich Committed by Linus Torvalds
Browse files

[PATCH] adjust /dev/{kmem,mem,port} write handlers 



The /dev/mem and /dev/kmem write handlers weren't fully POSIX compliant in
that they wouldn't always force the file pointer to be updated when
returning success status.

The /dev/port write handler was inconsistent with the /dev/mem and
/dev/kmem handlers in that when encountering a -EFAULT condition after
already having written a number of items it would return -EFAULT rather
than the number of bytes written.

Signed-off-by: default avatarJan Beulich <jbeulich@novell.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 58bf6a2d

drivers/char/mem.c

+13 −15
Original line number Diff line number Diff line
@@ -216,11 +216,9 @@ static ssize_t write_mem(struct file * file, const char __user * buf, 


		copied = copy_from_user(ptr, buf, sz);

		if (copied) {

			ssize_t ret;



			ret = written + (sz - copied);

			if (ret)

				return ret;

			written += sz - copied;

			if (written)

				break;

			return -EFAULT;

		}

		buf += sz;
@@ -456,11 +454,9 @@ do_write_kmem(void *p, unsigned long realp, const char __user * buf, 


		copied = copy_from_user(ptr, buf, sz);

		if (copied) {

			ssize_t ret;



			ret = written + (sz - copied);

			if (ret)

				return ret;

			written += sz - copied;

			if (written)

				break;

			return -EFAULT;

		}

		buf += sz;
@@ -514,11 +510,10 @@ static ssize_t write_kmem(struct file * file, const char __user * buf, 
			if (len) {

				written = copy_from_user(kbuf, buf, len);

				if (written) {

					ssize_t ret;



					if (wrote + virtr)

						break;

					free_page((unsigned long)kbuf);

					ret = wrote + virtr + (len - written);

					return ret ? ret : -EFAULT;

					return -EFAULT;

				}

			}

			len = vwrite(kbuf, (char *)p, len);
@@ -563,8 +558,11 @@ static ssize_t write_port(struct file * file, const char __user * buf, 
		return -EFAULT;

	while (count-- > 0 && i < 65536) {

		char c;

		if (__get_user(c, tmp)) 

		if (__get_user(c, tmp)) {

			if (tmp > buf)

				break;

			return -EFAULT; 

		}

		outb(c,i);

		i++;

		tmp++;