Skip to content

Commit

Permalink
net: add __rcu annotations to sk_wq and wq
Browse files Browse the repository at this point in the history 
Add proper RCU annotations/verbs to sk_wq and wq members

Fix __sctp_write_space() sk_sleep() abuse (and sock->wq access)

Fix sunrpc sk_sleep() abuse too

Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
  • Loading branch information
@davem330
Eric Dumazet authored and davem330 committed Feb 22, 2011
1 parent 04cfa85 commit eaefd11
Show file tree
Hide file tree
Showing 6 changed files with 46 additions and 30 deletions.
3 changes: 2 additions & 1 deletion include/linux/net.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -118,6 +118,7 @@ enum sock_shutdown_cmd {
};

struct socket_wq {
/* Note: wait MUST be first field of socket_wq */
wait_queue_head_t wait;
struct fasync_struct *fasync_list;
struct rcu_head rcu;
Expand All @@ -142,7 +143,7 @@ struct socket {

unsigned long flags;

struct socket_wq *wq;
struct socket_wq __rcu *wq;

struct file *file;
struct sock *sk;
Expand Down
7 changes: 4 additions & 3 deletions include/net/sock.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -281,7 +281,7 @@ struct sock {
int sk_rcvbuf;

struct sk_filter __rcu *sk_filter;
struct socket_wq *sk_wq;
struct socket_wq __rcu *sk_wq;

#ifdef CONFIG_NET_DMA
struct sk_buff_head sk_async_wait_queue;
Expand Down Expand Up @@ -1266,7 +1266,8 @@ static inline void sk_set_socket(struct sock *sk, struct socket *sock)

static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
return &sk->sk_wq->wait;
BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
return &rcu_dereference_raw(sk->sk_wq)->wait;
}
/* Detach socket from process context.
* Announce socket dead, detach it from wait queue and inode.
Expand All @@ -1287,7 +1288,7 @@ static inline void sock_orphan(struct sock *sk)
static inline void sock_graft(struct sock *sk, struct socket *parent)
{
write_lock_bh(&sk->sk_callback_lock);
rcu_assign_pointer(sk->sk_wq, parent->wq);
sk->sk_wq = parent->wq;
parent->sk = sk;
sk_set_socket(sk, parent);
security_sock_graft(sk, parent);
Expand Down
9 changes: 5 additions & 4 deletions net/sctp/socket.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6102,15 +6102,16 @@ static void __sctp_write_space(struct sctp_association *asoc)
wake_up_interruptible(&asoc->wait);

if (sctp_writeable(sk)) {
if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
wake_up_interruptible(sk_sleep(sk));
wait_queue_head_t *wq = sk_sleep(sk);

if (wq && waitqueue_active(wq))
wake_up_interruptible(wq);

/* Note that we try to include the Async I/O support
* here by modeling from the current TCP/UDP code.
* We have not tested with it yet.
*/
if (sock->wq->fasync_list &&
!(sk->sk_shutdown & SEND_SHUTDOWN))
if (!(sk->sk_shutdown & SEND_SHUTDOWN))
sock_wake_async(sock,
SOCK_WAKE_SPACE, POLL_OUT);
}
Expand Down
23 changes: 14 additions & 9 deletions net/socket.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -240,17 +240,19 @@ static struct kmem_cache *sock_inode_cachep __read_mostly;
static struct inode *sock_alloc_inode(struct super_block *sb)
{
struct socket_alloc *ei;
struct socket_wq *wq;

ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
ei->socket.wq = kmalloc(sizeof(struct socket_wq), GFP_KERNEL);
if (!ei->socket.wq) {
wq = kmalloc(sizeof(*wq), GFP_KERNEL);
if (!wq) {
kmem_cache_free(sock_inode_cachep, ei);
return NULL;
}
init_waitqueue_head(&ei->socket.wq->wait);
ei->socket.wq->fasync_list = NULL;
init_waitqueue_head(&wq->wait);
wq->fasync_list = NULL;
RCU_INIT_POINTER(ei->socket.wq, wq);

ei->socket.state = SS_UNCONNECTED;
ei->socket.flags = 0;
Expand All @@ -273,9 +275,11 @@ static void wq_free_rcu(struct rcu_head *head)
static void sock_destroy_inode(struct inode *inode)
{
struct socket_alloc *ei;
struct socket_wq *wq;

ei = container_of(inode, struct socket_alloc, vfs_inode);
call_rcu(&ei->socket.wq->rcu, wq_free_rcu);
wq = rcu_dereference_protected(ei->socket.wq, 1);
call_rcu(&wq->rcu, wq_free_rcu);
kmem_cache_free(sock_inode_cachep, ei);
}

Expand Down Expand Up @@ -524,7 +528,7 @@ void sock_release(struct socket *sock)
module_put(owner);
}

if (sock->wq->fasync_list)
if (rcu_dereference_protected(sock->wq, 1)->fasync_list)
printk(KERN_ERR "sock_release: fasync list not empty!\n");

percpu_sub(sockets_in_use, 1);
Expand Down Expand Up @@ -1108,15 +1112,16 @@ static int sock_fasync(int fd, struct file *filp, int on)
{
struct socket *sock = filp->private_data;
struct sock *sk = sock->sk;
struct socket_wq *wq;

if (sk == NULL)
return -EINVAL;

lock_sock(sk);
wq = rcu_dereference_protected(sock->wq, sock_owned_by_user(sk));
fasync_helper(fd, filp, on, &wq->fasync_list);

fasync_helper(fd, filp, on, &sock->wq->fasync_list);

if (!sock->wq->fasync_list)
if (!wq->fasync_list)
sock_reset_flag(sk, SOCK_FASYNC);
else
sock_set_flag(sk, SOCK_FASYNC);
Expand Down
32 changes: 20 additions & 12 deletions net/sunrpc/svcsock.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -420,6 +420,7 @@ static void svc_sock_setbufsize(struct socket *sock, unsigned int snd,
static void svc_udp_data_ready(struct sock *sk, int count)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
wait_queue_head_t *wq = sk_sleep(sk);

if (svsk) {
dprintk("svc: socket %p(inet %p), count=%d, busy=%d\n",
Expand All @@ -428,8 +429,8 @@ static void svc_udp_data_ready(struct sock *sk, int count)
set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
svc_xprt_enqueue(&svsk->sk_xprt);
}
if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
wake_up_interruptible(sk_sleep(sk));
if (wq && waitqueue_active(wq))
wake_up_interruptible(wq);
}

/*
Expand All @@ -438,17 +439,18 @@ static void svc_udp_data_ready(struct sock *sk, int count)
static void svc_write_space(struct sock *sk)
{
struct svc_sock *svsk = (struct svc_sock *)(sk->sk_user_data);
wait_queue_head_t *wq = sk_sleep(sk);

if (svsk) {
dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
svsk, sk, test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
svc_xprt_enqueue(&svsk->sk_xprt);
}

if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk))) {
if (wq && waitqueue_active(wq)) {
dprintk("RPC svc_write_space: someone sleeping on %p\n",
svsk);
wake_up_interruptible(sk_sleep(sk));
wake_up_interruptible(wq);
}
}

Expand Down Expand Up @@ -739,6 +741,7 @@ static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
static void svc_tcp_listen_data_ready(struct sock *sk, int count_unused)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
wait_queue_head_t *wq;

dprintk("svc: socket %p TCP (listen) state change %d\n",
sk, sk->sk_state);
Expand All @@ -761,8 +764,9 @@ static void svc_tcp_listen_data_ready(struct sock *sk, int count_unused)
printk("svc: socket %p: no user data\n", sk);
}

if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
wake_up_interruptible_all(sk_sleep(sk));
wq = sk_sleep(sk);
if (wq && waitqueue_active(wq))
wake_up_interruptible_all(wq);
}

/*
Expand All @@ -771,6 +775,7 @@ static void svc_tcp_listen_data_ready(struct sock *sk, int count_unused)
static void svc_tcp_state_change(struct sock *sk)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
wait_queue_head_t *wq = sk_sleep(sk);

dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
sk, sk->sk_state, sk->sk_user_data);
Expand All @@ -781,22 +786,23 @@ static void svc_tcp_state_change(struct sock *sk)
set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
svc_xprt_enqueue(&svsk->sk_xprt);
}
if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
wake_up_interruptible_all(sk_sleep(sk));
if (wq && waitqueue_active(wq))
wake_up_interruptible_all(wq);
}

static void svc_tcp_data_ready(struct sock *sk, int count)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
wait_queue_head_t *wq = sk_sleep(sk);

dprintk("svc: socket %p TCP data ready (svsk %p)\n",
sk, sk->sk_user_data);
if (svsk) {
set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
svc_xprt_enqueue(&svsk->sk_xprt);
}
if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
wake_up_interruptible(sk_sleep(sk));
if (wq && waitqueue_active(wq))
wake_up_interruptible(wq);
}

/*
Expand Down Expand Up @@ -1531,6 +1537,7 @@ static void svc_sock_detach(struct svc_xprt *xprt)
{
struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
struct sock *sk = svsk->sk_sk;
wait_queue_head_t *wq;

dprintk("svc: svc_sock_detach(%p)\n", svsk);

Expand All @@ -1539,8 +1546,9 @@ static void svc_sock_detach(struct svc_xprt *xprt)
sk->sk_data_ready = svsk->sk_odata;
sk->sk_write_space = svsk->sk_owspace;

if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
wake_up_interruptible(sk_sleep(sk));
wq = sk_sleep(sk);
if (wq && waitqueue_active(wq))
wake_up_interruptible(wq);
}

/*
Expand Down
2 changes: 1 addition & 1 deletion net/unix/af_unix.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1171,7 +1171,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
newsk->sk_type = sk->sk_type;
init_peercred(newsk);
newu = unix_sk(newsk);
newsk->sk_wq = &newu->peer_wq;
RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq);
otheru = unix_sk(other);

/* copy address information from listening to new sock*/
Expand Down

0 comments on commit eaefd11

Please sign in to comment.