Re: [patch] printk from userspace

[Andrew Morton <akpm@zip.com.au>]

Benjamin LaHaise wrote:
> 
> ...
> Something like the following untested code is much better.

I agree.  And it worked first time.


--- 2.5.31/drivers/char/mem.c~bcrl-printk	Tue Aug 13 21:53:24 2002
+++ 2.5.31-akpm/drivers/char/mem.c	Tue Aug 13 21:53:34 2002
@@ -579,6 +579,24 @@ static struct file_operations full_fops 
 	write:		write_full,
 };
 
+static ssize_t kmsg_write(struct file * file, const char * buf,
+			  size_t count, loff_t *ppos)
+{
+	char tmp[1025];
+
+	if (count > 1024)
+		count = 1024;
+	if (copy_from_user(tmp, buf, count))
+		return -EFAULT;
+	tmp[count] = 0;
+	printk("%s", tmp);
+	return count;
+}
+
+static struct file_operations kmsg_fops = {
+	write:		kmsg_write,
+};
+
 static int memory_open(struct inode * inode, struct file * filp)
 {
 	switch (minor(inode->i_rdev)) {
@@ -608,6 +626,9 @@ static int memory_open(struct inode * in
 		case 9:
 			filp->f_op = &urandom_fops;
 			break;
+		case 11:
+			filp->f_op = &kmsg_fops;
+			break;
 		default:
 			return -ENXIO;
 	}
@@ -634,7 +655,8 @@ void __init memory_devfs_register (void)
 	{5, "zero",    S_IRUGO | S_IWUGO,           &zero_fops},
 	{7, "full",    S_IRUGO | S_IWUGO,           &full_fops},
 	{8, "random",  S_IRUGO | S_IWUSR,           &random_fops},
-	{9, "urandom", S_IRUGO | S_IWUSR,           &urandom_fops}
+	{9, "urandom", S_IRUGO | S_IWUSR,           &urandom_fops},
+	{11,"kmsg",    S_IRUGO | S_IWUSR,           &kmsg_fops},
     };
     int i;
 

.