From: Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx>
Usage of RCU list looks not reasonalbe for a number of reasons:
our code sleep and we have to use socket spinlocks, some parts
of code are updaters thus we need to use mutexes anyway.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx>
---
net/bluetooth/l2cap_core.c | 98 ++++++++++++++++++++-----------------------
1 files changed, 46 insertions(+), 52 deletions(-)
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 63539f9..109b62d 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -77,36 +77,24 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn,
static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn, u16 cid)
{
- struct l2cap_chan *c, *r = NULL;
-
- rcu_read_lock();
+ struct l2cap_chan *c;
- list_for_each_entry_rcu(c, &conn->chan_l, list) {
- if (c->dcid == cid) {
- r = c;
- break;
- }
+ list_for_each_entry(c, &conn->chan_l, list) {
+ if (c->dcid == cid)
+ return c;
}
-
- rcu_read_unlock();
- return r;
+ return NULL;
}
static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 cid)
{
- struct l2cap_chan *c, *r = NULL;
-
- rcu_read_lock();
+ struct l2cap_chan *c;
- list_for_each_entry_rcu(c, &conn->chan_l, list) {
- if (c->scid == cid) {
- r = c;
- break;
- }
+ list_for_each_entry(c, &conn->chan_l, list) {
+ if (c->scid == cid)
+ return c;
}
-
- rcu_read_unlock();
- return r;
+ return NULL;
}
/* Find channel with given SCID.
@@ -115,36 +103,34 @@ static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn, u16 ci
{
struct l2cap_chan *c;
+ mutex_lock(&conn->chan_lock);
c = __l2cap_get_chan_by_scid(conn, cid);
if (c)
lock_sock(c->sk);
+ mutex_unlock(&conn->chan_lock);
return c;
}
static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn, u8 ident)
{
- struct l2cap_chan *c, *r = NULL;
-
- rcu_read_lock();
+ struct l2cap_chan *c;
- list_for_each_entry_rcu(c, &conn->chan_l, list) {
- if (c->ident == ident) {
- r = c;
- break;
- }
+ list_for_each_entry(c, &conn->chan_l, list) {
+ if (c->ident == ident)
+ return c;
}
-
- rcu_read_unlock();
- return r;
+ return NULL;
}
static inline struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn, u8 ident)
{
struct l2cap_chan *c;
+ mutex_lock(&conn->chan_lock);
c = __l2cap_get_chan_by_ident(conn, ident);
if (c)
lock_sock(c->sk);
+ mutex_unlock(&conn->chan_lock);
return c;
}
@@ -331,7 +317,9 @@ static void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
l2cap_chan_hold(chan);
- list_add_rcu(&chan->list, &conn->chan_l);
+ mutex_lock(&conn->chan_lock);
+ list_add(&chan->list, &conn->chan_l);
+ mutex_unlock(&conn->chan_lock);
}
/* Delete channel.
@@ -348,8 +336,7 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
if (conn) {
/* Delete from channel list */
- list_del_rcu(&chan->list);
- synchronize_rcu();
+ list_del(&chan->list);
l2cap_chan_put(chan);
@@ -400,10 +387,12 @@ static void l2cap_chan_cleanup_listen(struct sock *parent)
/* Close not yet accepted channels */
while ((sk = bt_accept_dequeue(parent, NULL))) {
struct l2cap_chan *chan = l2cap_pi(sk)->chan;
+
__clear_chan_timer(chan);
lock_sock(sk);
l2cap_chan_close(chan, ECONNRESET);
release_sock(sk);
+
chan->ops->close(chan->data);
}
}
@@ -718,13 +707,13 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct l2cap_chan *c
/* ---- L2CAP connections ---- */
static void l2cap_conn_start(struct l2cap_conn *conn)
{
- struct l2cap_chan *chan;
+ struct l2cap_chan *chan, *tmp;
BT_DBG("conn %p", conn);
- rcu_read_lock();
+ mutex_lock(&conn->chan_lock);
- list_for_each_entry_rcu(chan, &conn->chan_l, list) {
+ list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
struct sock *sk = chan->sk;
bh_lock_sock(sk);
@@ -804,7 +793,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
bh_unlock_sock(sk);
}
- rcu_read_unlock();
+ mutex_unlock(&conn->chan_lock);
}
/* Find socket with cid and source bdaddr.
@@ -916,9 +905,9 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
if (conn->hcon->out && conn->hcon->type == LE_LINK)
smp_conn_security(conn, conn->hcon->pending_sec_level);
- rcu_read_lock();
+ mutex_lock(&conn->chan_lock);
- list_for_each_entry_rcu(chan, &conn->chan_l, list) {
+ list_for_each_entry(chan, &conn->chan_l, list) {
struct sock *sk = chan->sk;
bh_lock_sock(sk);
@@ -938,7 +927,7 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
bh_unlock_sock(sk);
}
- rcu_read_unlock();
+ mutex_unlock(&conn->chan_lock);
}
/* Notify sockets that we cannot guaranty reliability anymore */
@@ -948,16 +937,16 @@ static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
BT_DBG("conn %p", conn);
- rcu_read_lock();
+ mutex_lock(&conn->chan_lock);
- list_for_each_entry_rcu(chan, &conn->chan_l, list) {
+ list_for_each_entry(chan, &conn->chan_l, list) {
struct sock *sk = chan->sk;
if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
sk->sk_err = err;
}
- rcu_read_unlock();
+ mutex_unlock(&conn->chan_lock);
}
static void l2cap_info_timeout(struct work_struct *work)
@@ -984,6 +973,8 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
kfree_skb(conn->rx_skb);
+ mutex_lock(&conn->chan_lock);
+
/* Kill channels */
list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
sk = chan->sk;
@@ -993,6 +984,8 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
chan->ops->close(chan->data);
}
+ mutex_unlock(&conn->chan_lock);
+
hci_chan_del(conn->hchan);
if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
@@ -1050,6 +1043,7 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon, u8 status)
conn->feat_mask = 0;
spin_lock_init(&conn->lock);
+ mutex_init(&conn->chan_lock);
INIT_LIST_HEAD(&conn->chan_l);
@@ -1792,9 +1786,9 @@ static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
BT_DBG("conn %p", conn);
- rcu_read_lock();
+ mutex_lock(&conn->chan_lock);
- list_for_each_entry_rcu(chan, &conn->chan_l, list) {
+ list_for_each_entry(chan, &conn->chan_l, list) {
struct sock *sk = chan->sk;
if (chan->chan_type != L2CAP_CHAN_RAW)
continue;
@@ -1810,7 +1804,7 @@ static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
kfree_skb(nskb);
}
- rcu_read_unlock();
+ mutex_unlock(&conn->chan_lock);
}
/* ---- L2CAP signalling commands ---- */
@@ -4492,9 +4486,9 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
cancel_delayed_work(&conn->security_timer);
}
- rcu_read_lock();
+ mutex_lock(&conn->chan_lock);
- list_for_each_entry_rcu(chan, &conn->chan_l, list) {
+ list_for_each_entry(chan, &conn->chan_l, list) {
struct sock *sk = chan->sk;
bh_lock_sock(sk);
@@ -4574,7 +4568,7 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
bh_unlock_sock(sk);
}
- rcu_read_unlock();
+ mutex_unlock(&conn->chan_lock);
return 0;
}
--
1.7.9
--
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