From: Ben Pfaff <blp@nicira.com>
Date: Wed, 11 Mar 2009 20:41:15 +0000 (-0700)
Subject: datapath: Always return EFAULT to userspace when copy_to/from_user() fails.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=baddb36a93761de4b1c58ede7e43600389f7c9f0;p=openvswitch

datapath: Always return EFAULT to userspace when copy_to/from_user() fails.

copy_from_user() and copy_to_user() return the number of bytes that could
not be copied, not a conventional error code, so we need to translate it
into -EFAULT ourselves.
---

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 851af969..e636c8ad 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -779,6 +779,7 @@ static int set_flow_actions(struct datapath *dp, struct odp_flow __user *ufp)
 	error = -ENOMEM;
 	if (!new_acts)
 		goto error;
+	error = -EFAULT;
 	if (copy_from_user(new_acts->actions, uf.actions,
 			   uf.n_actions * sizeof *uf.actions))
 		goto error_free_actions;
@@ -1133,7 +1134,7 @@ get_dp_stats(struct datapath *dp, struct odp_stats __user *statsp)
 	}
 	stats.max_miss_queue = DP_MAX_QUEUE_LEN;
 	stats.max_action_queue = DP_MAX_QUEUE_LEN;
-	return copy_to_user(statsp, &stats, sizeof stats);
+	return copy_to_user(statsp, &stats, sizeof stats) ? -EFAULT : 0;
 }
 
 static int
@@ -1143,7 +1144,7 @@ put_port(const struct net_bridge_port *p, struct odp_port __user *uop)
 	memset(&op, 0, sizeof op);
 	strncpy(op.devname, p->dev->name, sizeof op.devname);
 	op.port = p->port_no;
-	return copy_to_user(uop, &op, sizeof op);
+	return copy_to_user(uop, &op, sizeof op) ? -EFAULT : 0;
 }
 
 static int