From: Zach Brown <zach.brown@oracle.com>
Date: Fri, 4 Jun 2010 21:25:27 +0000 (-0700)
Subject: rds: block ints when acquiring c_lock in rds_conn_message_info()
X-Git-Tag: MMI-PSA29.97-13-9~21994^2~499^2~29
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=501dcccdb7a2335cde07d4acb56e636182d62944;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

rds: block ints when acquiring c_lock in rds_conn_message_info()

conn->c_lock is acquired in interrupt context.  rds_conn_message_info() is
called from user context and was acquiring c_lock without blocking interrupts,
leading to possible deadlocks.

Signed-off-by: Zach Brown <zach.brown@oracle.com>
---

diff --git a/net/rds/connection.c b/net/rds/connection.c
index 5bd96d538fb9..5bb0eec5ada3 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -375,6 +375,7 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 	struct rds_connection *conn;
 	struct rds_message *rm;
 	unsigned int total = 0;
+	unsigned long flags;
 	size_t i;
 
 	len /= sizeof(struct rds_info_message);
@@ -389,7 +390,7 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 			else
 				list = &conn->c_retrans;
 
-			spin_lock(&conn->c_lock);
+			spin_lock_irqsave(&conn->c_lock, flags);
 
 			/* XXX too lazy to maintain counts.. */
 			list_for_each_entry(rm, list, m_conn_item) {
@@ -400,7 +401,7 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 							  conn->c_faddr, 0);
 			}
 
-			spin_unlock(&conn->c_lock);
+			spin_unlock_irqrestore(&conn->c_lock, flags);
 		}
 	}
 	rcu_read_unlock();