Commit cd140a5c authored Jan 08, 2006 by Guillaume Chazarain Committed by Linus Torvalds Jan 08, 2006

[PATCH] kmsg_write: don't return printk return value



kmsg_write returns with printk, so some programs may be confused by a
successful write() with a return value different than the buffer length.

# /bin/echo something > /dev/kmsg
/bin/echo: write error: Inappropriate ioctl for device

The drawbacks is that the printk return value can no more be quickly
checked from userspace.

Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 025510cd

drivers/char/mem.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -817,7 +817,7 @@ static ssize_t kmsg_write(struct file * file, const char __user * buf,
		size_t count, loff_t *ppos)
		{
		char *tmp;
		int ret;
		ssize_t ret;

		tmp = kmalloc(count + 1, GFP_KERNEL);
		if (tmp == NULL)
		@@ -826,6 +826,9 @@ static ssize_t kmsg_write(struct file * file, const char __user * buf,
		if (!copy_from_user(tmp, buf, count)) {
		tmp[count] = 0;
		ret = printk("%s", tmp);
		if (ret > count)
		/* printk can add a prefix */
		ret = count;
		}
		kfree(tmp);
		return ret;