Allow mlx4 devices to switch from Ethernet to Infiniband (and vice versa):

- Fix sysctl wrapper for sysfs attributes to properly handle new string
  values similar to sysctl_handle_string() (only copyin the user's
  supplied length and nul-terminate the string).
- Don't check for a trailing newline when evaluating the desired operating
  mode of a mlx4 device.

PR:		kern/179999
Submitted by:	Shahar Klein <shahark@mellanox.com>
MFC after:	1 week

1 files changed, 7 insertions, 2 deletions

diff --git a/sys/ofed/include/linux/sysfs.h b/sys/ofed/include/linux/sysfs.h
index 698f75e..ca2d71e 100644
--- a/sys/ofed/include/linux/sysfs.h
+++ b/sys/ofed/include/linux/sysfs.h
@@ -104,10 +104,15 @@ sysctl_handle_attr(SYSCTL_HANDLER_ARGS)
 	error = SYSCTL_OUT(req, buf, len);
 	if (error || !req->newptr || ops->store == NULL)
 		goto out;
-	error = SYSCTL_IN(req, buf, PAGE_SIZE);
+	len = req->newlen - req->newidx;
+	if (len >= PAGE_SIZE)
+		error = EINVAL;
+	else 
+		error = SYSCTL_IN(req, buf, len);
 	if (error)
 		goto out;
-	len = ops->store(kobj, attr, buf, req->newlen);
+	((char *)buf)[len] = '\0';
+	len = ops->store(kobj, attr, buf, len);
 	if (len < 0)
 		error = -len;
 out: