Commit efc3dbc3 authored by David S. Miller's avatar David S. Miller
Browse files

rds: Make rds_sock_lock BH rather than IRQ safe. 



rds_sock_info() triggers locking warnings because we try to perform a
local_bh_enable() (via sock_i_ino()) while hardware interrupts are
disabled (via taking rds_sock_lock).

There is no reason for rds_sock_lock to be a hardware IRQ disabling
lock, none of these access paths run in hardware interrupt context.

Therefore making it a BH disabling lock is safe and sufficient to
fix this bug.

Reported-by: default avatarKumar Sanghvi <kumaras@chelsio.com>
Reported-by: default avatarJosh Boyer <jwboyer@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 36a12119

net/rds/af_rds.c

+8 −12
Original line number Diff line number Diff line
@@ -68,7 +68,6 @@ static int rds_release(struct socket *sock) 
{

	struct sock *sk = sock->sk;

	struct rds_sock *rs;

	unsigned long flags;



	if (!sk)

		goto out;
@@ -94,10 +93,10 @@ static int rds_release(struct socket *sock) 
	rds_rdma_drop_keys(rs);

	rds_notify_queue_get(rs, NULL);



	spin_lock_irqsave(&rds_sock_lock, flags);

	spin_lock_bh(&rds_sock_lock);

	list_del_init(&rs->rs_item);

	rds_sock_count--;

	spin_unlock_irqrestore(&rds_sock_lock, flags);

	spin_unlock_bh(&rds_sock_lock);



	rds_trans_put(rs->rs_transport);
@@ -409,7 +408,6 @@ static const struct proto_ops rds_proto_ops = { 


static int __rds_create(struct socket *sock, struct sock *sk, int protocol)

{

	unsigned long flags;

	struct rds_sock *rs;



	sock_init_data(sock, sk);
@@ -426,10 +424,10 @@ static int __rds_create(struct socket *sock, struct sock *sk, int protocol) 
	spin_lock_init(&rs->rs_rdma_lock);

	rs->rs_rdma_keys = RB_ROOT;



	spin_lock_irqsave(&rds_sock_lock, flags);

	spin_lock_bh(&rds_sock_lock);

	list_add_tail(&rs->rs_item, &rds_sock_list);

	rds_sock_count++;

	spin_unlock_irqrestore(&rds_sock_lock, flags);

	spin_unlock_bh(&rds_sock_lock);



	return 0;

}
@@ -471,12 +469,11 @@ static void rds_sock_inc_info(struct socket *sock, unsigned int len, 
{

	struct rds_sock *rs;

	struct rds_incoming *inc;

	unsigned long flags;

	unsigned int total = 0;



	len /= sizeof(struct rds_info_message);



	spin_lock_irqsave(&rds_sock_lock, flags);

	spin_lock_bh(&rds_sock_lock);



	list_for_each_entry(rs, &rds_sock_list, rs_item) {

		read_lock(&rs->rs_recv_lock);
@@ -492,7 +489,7 @@ static void rds_sock_inc_info(struct socket *sock, unsigned int len, 
		read_unlock(&rs->rs_recv_lock);

	}



	spin_unlock_irqrestore(&rds_sock_lock, flags);

	spin_unlock_bh(&rds_sock_lock);



	lens->nr = total;

	lens->each = sizeof(struct rds_info_message);
@@ -504,11 +501,10 @@ static void rds_sock_info(struct socket *sock, unsigned int len, 
{

	struct rds_info_socket sinfo;

	struct rds_sock *rs;

	unsigned long flags;



	len /= sizeof(struct rds_info_socket);



	spin_lock_irqsave(&rds_sock_lock, flags);

	spin_lock_bh(&rds_sock_lock);



	if (len < rds_sock_count)

		goto out;
@@ -529,7 +525,7 @@ out: 
	lens->nr = rds_sock_count;

	lens->each = sizeof(struct rds_info_socket);



	spin_unlock_irqrestore(&rds_sock_lock, flags);

	spin_unlock_bh(&rds_sock_lock);

}



static void rds_exit(void)

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