Under rtnl_lock protection, we should use __dev_get_name/index()
rather than dev_get_name()/index() to find interface handlers
because the former interfaces can help us avoid to change interface
reference counter.
Ying Xue (10):
Drivers: Staging: cxt1e1: use __dev_get_name instead of dev_get_name
to find interfaces
bonding: use __dev_get_by_name instead of dev_get_by_name to find
interface
eql: use __dev_get_by_name instead of dev_get_by_name to find
interface
dcb: use __dev_get_by_name instead of dev_get_by_name to find
interface
decnet: use __dev_get_by_index instead of dev_get_by_index to find
interface
vxlan: use __dev_get_by_index instead of dev_get_by_index to find
interface
batman-adv: use __dev_get_by_index instead of dev_get_by_index to
find interface
caif: __dev_get_by_index instead of dev_get_by_index to find
interface
can: use __dev_get_by_index instead of dev_get_by_index to find
interface
net: nl80211: __dev_get_by_index instead of dev_get_by_index to find
interface
drivers/net/bonding/bond_main.c | 49 +++++++++----------
drivers/net/eql.c | 95 ++++++++++++++++---------------------
drivers/net/vxlan.c | 3 +-
drivers/staging/cxt1e1/linux.c | 15 +++---
net/batman-adv/hard-interface.c | 4 +-
net/caif/chnl_net.c | 3 +-
net/can/gw.c | 15 ++----
net/dcb/dcbnl.c | 15 ++----
net/decnet/dn_route.c | 6 +--
net/wireless/nl80211.c | 100 ++++++++++++++-------------------------
10 files changed, 123 insertions(+), 182 deletions(-)
--
1.7.9.5
The following call chain indicates that bond_do_ioctl() is protected
under rtnl_lock. If we use __dev_get_by_name() instead of
dev_get_by_name() to find interface handler in it, this would
help us avoid to change reference counter of interface once.
dev_ioctl()
rtnl_lock()
dev_ifsioc()
bond_do_ioctl()
rtnl_unlock()
Additionally we also change the coding style in bond_do_ioctl(),
letting it more readable for us.
Cc: Jay Vosburgh <[email protected]>
Cc: Veaceslav Falico <[email protected]>
Signed-off-by: Ying Xue <[email protected]>
---
drivers/net/bonding/bond_main.c | 49 ++++++++++++++++++---------------------
1 file changed, 23 insertions(+), 26 deletions(-)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index e06c445..a69afbf 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -3213,37 +3213,34 @@ static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
- slave_dev = dev_get_by_name(net, ifr->ifr_slave);
+ slave_dev = __dev_get_by_name(net, ifr->ifr_slave);
pr_debug("slave_dev=%p:\n", slave_dev);
if (!slave_dev)
- res = -ENODEV;
- else {
- pr_debug("slave_dev->name=%s:\n", slave_dev->name);
- switch (cmd) {
- case BOND_ENSLAVE_OLD:
- case SIOCBONDENSLAVE:
- res = bond_enslave(bond_dev, slave_dev);
- break;
- case BOND_RELEASE_OLD:
- case SIOCBONDRELEASE:
- res = bond_release(bond_dev, slave_dev);
- break;
- case BOND_SETHWADDR_OLD:
- case SIOCBONDSETHWADDR:
- bond_set_dev_addr(bond_dev, slave_dev);
- res = 0;
- break;
- case BOND_CHANGE_ACTIVE_OLD:
- case SIOCBONDCHANGEACTIVE:
- res = bond_option_active_slave_set(bond, slave_dev);
- break;
- default:
- res = -EOPNOTSUPP;
- }
+ return -ENODEV;
- dev_put(slave_dev);
+ pr_debug("slave_dev->name=%s:\n", slave_dev->name);
+ switch (cmd) {
+ case BOND_ENSLAVE_OLD:
+ case SIOCBONDENSLAVE:
+ res = bond_enslave(bond_dev, slave_dev);
+ break;
+ case BOND_RELEASE_OLD:
+ case SIOCBONDRELEASE:
+ res = bond_release(bond_dev, slave_dev);
+ break;
+ case BOND_SETHWADDR_OLD:
+ case SIOCBONDSETHWADDR:
+ bond_set_dev_addr(bond_dev, slave_dev);
+ res = 0;
+ break;
+ case BOND_CHANGE_ACTIVE_OLD:
+ case SIOCBONDCHANGEACTIVE:
+ res = bond_option_active_slave_set(bond, slave_dev);
+ break;
+ default:
+ res = -EOPNOTSUPP;
}
return res;
--
1.7.9.5
The following call chain indicates that eql_ioctl(), eql_enslave(),
eql_emancipate(), eql_g_slave_cfg() and eql_s_slave_cfg() are
protected under rtnl_lock. So if we use __dev_get_by_name() instead
of dev_get_by_name() to find interface handlers in them, this would
help us avoid to change interface reference counters.
dev_ioctl()
rtnl_lock()
dev_ifsioc()
eql_ioctl()
eql_enslave()
eql_emancipate()
eql_g_slave_cfg()
eql_s_slave_cfg()
rtnl_unlock()
Additionally we also change their return values from -EINVAL to
-ENODEV in case that interfaces are no found.
Signed-off-by: Ying Xue <[email protected]>
---
drivers/net/eql.c | 95 +++++++++++++++++++++++------------------------------
1 file changed, 42 insertions(+), 53 deletions(-)
diff --git a/drivers/net/eql.c b/drivers/net/eql.c
index f219d38..7a79b60 100644
--- a/drivers/net/eql.c
+++ b/drivers/net/eql.c
@@ -395,6 +395,7 @@ static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
if (duplicate_slave)
eql_kill_one_slave(queue, duplicate_slave);
+ dev_hold(slave->dev);
list_add(&slave->list, &queue->all_slaves);
queue->num_slaves++;
slave->dev->flags |= IFF_SLAVE;
@@ -413,39 +414,35 @@ static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *
if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
return -EFAULT;
- slave_dev = dev_get_by_name(&init_net, srq.slave_name);
- if (slave_dev) {
- if ((master_dev->flags & IFF_UP) == IFF_UP) {
- /* slave is not a master & not already a slave: */
- if (!eql_is_master(slave_dev) &&
- !eql_is_slave(slave_dev)) {
- slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
- equalizer_t *eql = netdev_priv(master_dev);
- int ret;
-
- if (!s) {
- dev_put(slave_dev);
- return -ENOMEM;
- }
-
- memset(s, 0, sizeof(*s));
- s->dev = slave_dev;
- s->priority = srq.priority;
- s->priority_bps = srq.priority;
- s->priority_Bps = srq.priority / 8;
-
- spin_lock_bh(&eql->queue.lock);
- ret = __eql_insert_slave(&eql->queue, s);
- if (ret) {
- dev_put(slave_dev);
- kfree(s);
- }
- spin_unlock_bh(&eql->queue.lock);
-
- return ret;
- }
+ slave_dev = __dev_get_by_name(&init_net, srq.slave_name);
+ if (!slave_dev)
+ return -ENODEV;
+
+ if ((master_dev->flags & IFF_UP) == IFF_UP) {
+ /* slave is not a master & not already a slave: */
+ if (!eql_is_master(slave_dev) && !eql_is_slave(slave_dev)) {
+ slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
+ equalizer_t *eql = netdev_priv(master_dev);
+ int ret;
+
+ if (!s)
+ return -ENOMEM;
+
+ memset(s, 0, sizeof(*s));
+ s->dev = slave_dev;
+ s->priority = srq.priority;
+ s->priority_bps = srq.priority;
+ s->priority_Bps = srq.priority / 8;
+
+ spin_lock_bh(&eql->queue.lock);
+ ret = __eql_insert_slave(&eql->queue, s);
+ if (ret)
+ kfree(s);
+
+ spin_unlock_bh(&eql->queue.lock);
+
+ return ret;
}
- dev_put(slave_dev);
}
return -EINVAL;
@@ -461,24 +458,20 @@ static int eql_emancipate(struct net_device *master_dev, slaving_request_t __use
if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
return -EFAULT;
- slave_dev = dev_get_by_name(&init_net, srq.slave_name);
- ret = -EINVAL;
- if (slave_dev) {
- spin_lock_bh(&eql->queue.lock);
-
- if (eql_is_slave(slave_dev)) {
- slave_t *slave = __eql_find_slave_dev(&eql->queue,
- slave_dev);
+ slave_dev = __dev_get_by_name(&init_net, srq.slave_name);
+ if (!slave_dev)
+ return -ENODEV;
- if (slave) {
- eql_kill_one_slave(&eql->queue, slave);
- ret = 0;
- }
+ ret = -EINVAL;
+ spin_lock_bh(&eql->queue.lock);
+ if (eql_is_slave(slave_dev)) {
+ slave_t *slave = __eql_find_slave_dev(&eql->queue, slave_dev);
+ if (slave) {
+ eql_kill_one_slave(&eql->queue, slave);
+ ret = 0;
}
- dev_put(slave_dev);
-
- spin_unlock_bh(&eql->queue.lock);
}
+ spin_unlock_bh(&eql->queue.lock);
return ret;
}
@@ -494,7 +487,7 @@ static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
return -EFAULT;
- slave_dev = dev_get_by_name(&init_net, sc.slave_name);
+ slave_dev = __dev_get_by_name(&init_net, sc.slave_name);
if (!slave_dev)
return -ENODEV;
@@ -510,8 +503,6 @@ static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
}
spin_unlock_bh(&eql->queue.lock);
- dev_put(slave_dev);
-
if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
ret = -EFAULT;
@@ -529,7 +520,7 @@ static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
return -EFAULT;
- slave_dev = dev_get_by_name(&init_net, sc.slave_name);
+ slave_dev = __dev_get_by_name(&init_net, sc.slave_name);
if (!slave_dev)
return -ENODEV;
@@ -548,8 +539,6 @@ static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
}
spin_unlock_bh(&eql->queue.lock);
- dev_put(slave_dev);
-
return ret;
}
--
1.7.9.5
As __cfg80211_rdev_from_attrs(), nl80211_dump_wiphy_parse() and
nl80211_set_wiphy() are all under rtnl_lock protection,
__dev_get_by_index() instead of dev_get_by_index() should be used
to find interface handler in them allowing us to avoid to change
interface reference counter.
Cc: Johannes Berg <[email protected]>
Signed-off-by: Ying Xue <[email protected]>
---
net/wireless/nl80211.c | 100 +++++++++++++++++-------------------------------
1 file changed, 36 insertions(+), 64 deletions(-)
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b4f40fe..0d4d7fd 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -165,7 +165,7 @@ __cfg80211_rdev_from_attrs(struct net *netns, struct nlattr **attrs)
if (attrs[NL80211_ATTR_IFINDEX]) {
int ifindex = nla_get_u32(attrs[NL80211_ATTR_IFINDEX]);
- netdev = dev_get_by_index(netns, ifindex);
+ netdev = __dev_get_by_index(netns, ifindex);
if (netdev) {
if (netdev->ieee80211_ptr)
tmp = wiphy_to_dev(
@@ -173,8 +173,6 @@ __cfg80211_rdev_from_attrs(struct net *netns, struct nlattr **attrs)
else
tmp = NULL;
- dev_put(netdev);
-
/* not wireless device -- return error */
if (!tmp)
return ERR_PTR(-EINVAL);
@@ -1656,7 +1654,7 @@ static int nl80211_dump_wiphy_parse(struct sk_buff *skb,
struct cfg80211_registered_device *rdev;
int ifidx = nla_get_u32(tb[NL80211_ATTR_IFINDEX]);
- netdev = dev_get_by_index(sock_net(skb->sk), ifidx);
+ netdev = __dev_get_by_index(sock_net(skb->sk), ifidx);
if (!netdev)
return -ENODEV;
if (netdev->ieee80211_ptr) {
@@ -1664,7 +1662,6 @@ static int nl80211_dump_wiphy_parse(struct sk_buff *skb,
netdev->ieee80211_ptr->wiphy);
state->filter_wiphy = rdev->wiphy_idx;
}
- dev_put(netdev);
}
return 0;
@@ -1987,7 +1984,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
if (info->attrs[NL80211_ATTR_IFINDEX]) {
int ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
- netdev = dev_get_by_index(genl_info_net(info), ifindex);
+ netdev = __dev_get_by_index(genl_info_net(info), ifindex);
if (netdev && netdev->ieee80211_ptr)
rdev = wiphy_to_dev(netdev->ieee80211_ptr->wiphy);
else
@@ -2015,32 +2012,24 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
rdev, nla_data(info->attrs[NL80211_ATTR_WIPHY_NAME]));
if (result)
- goto bad_res;
+ return result;
if (info->attrs[NL80211_ATTR_WIPHY_TXQ_PARAMS]) {
struct ieee80211_txq_params txq_params;
struct nlattr *tb[NL80211_TXQ_ATTR_MAX + 1];
- if (!rdev->ops->set_txq_params) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
+ if (!rdev->ops->set_txq_params)
+ return -EOPNOTSUPP;
- if (!netdev) {
- result = -EINVAL;
- goto bad_res;
- }
+ if (!netdev)
+ return -EINVAL;
if (netdev->ieee80211_ptr->iftype != NL80211_IFTYPE_AP &&
- netdev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO) {
- result = -EINVAL;
- goto bad_res;
- }
+ netdev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
+ return -EINVAL;
- if (!netif_running(netdev)) {
- result = -ENETDOWN;
- goto bad_res;
- }
+ if (!netif_running(netdev))
+ return -ENETDOWN;
nla_for_each_nested(nl_txq_params,
info->attrs[NL80211_ATTR_WIPHY_TXQ_PARAMS],
@@ -2051,12 +2040,12 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
txq_params_policy);
result = parse_txq_params(tb, &txq_params);
if (result)
- goto bad_res;
+ return result;
result = rdev_set_txq_params(rdev, netdev,
&txq_params);
if (result)
- goto bad_res;
+ return result;
}
}
@@ -2065,7 +2054,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
nl80211_can_set_dev_channel(wdev) ? wdev : NULL,
info);
if (result)
- goto bad_res;
+ return result;
}
if (info->attrs[NL80211_ATTR_WIPHY_TX_POWER_SETTING]) {
@@ -2076,19 +2065,15 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
if (!(rdev->wiphy.features & NL80211_FEATURE_VIF_TXPOWER))
txp_wdev = NULL;
- if (!rdev->ops->set_tx_power) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
+ if (!rdev->ops->set_tx_power)
+ return -EOPNOTSUPP;
idx = NL80211_ATTR_WIPHY_TX_POWER_SETTING;
type = nla_get_u32(info->attrs[idx]);
if (!info->attrs[NL80211_ATTR_WIPHY_TX_POWER_LEVEL] &&
- (type != NL80211_TX_POWER_AUTOMATIC)) {
- result = -EINVAL;
- goto bad_res;
- }
+ (type != NL80211_TX_POWER_AUTOMATIC))
+ return -EINVAL;
if (type != NL80211_TX_POWER_AUTOMATIC) {
idx = NL80211_ATTR_WIPHY_TX_POWER_LEVEL;
@@ -2097,7 +2082,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
result = rdev_set_tx_power(rdev, txp_wdev, type, mbm);
if (result)
- goto bad_res;
+ return result;
}
if (info->attrs[NL80211_ATTR_WIPHY_ANTENNA_TX] &&
@@ -2105,10 +2090,8 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
u32 tx_ant, rx_ant;
if ((!rdev->wiphy.available_antennas_tx &&
!rdev->wiphy.available_antennas_rx) ||
- !rdev->ops->set_antenna) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
+ !rdev->ops->set_antenna)
+ return -EOPNOTSUPP;
tx_ant = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_ANTENNA_TX]);
rx_ant = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_ANTENNA_RX]);
@@ -2116,17 +2099,15 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
/* reject antenna configurations which don't match the
* available antenna masks, except for the "all" mask */
if ((~tx_ant && (tx_ant & ~rdev->wiphy.available_antennas_tx)) ||
- (~rx_ant && (rx_ant & ~rdev->wiphy.available_antennas_rx))) {
- result = -EINVAL;
- goto bad_res;
- }
+ (~rx_ant && (rx_ant & ~rdev->wiphy.available_antennas_rx)))
+ return -EINVAL;
tx_ant = tx_ant & rdev->wiphy.available_antennas_tx;
rx_ant = rx_ant & rdev->wiphy.available_antennas_rx;
result = rdev_set_antenna(rdev, tx_ant, rx_ant);
if (result)
- goto bad_res;
+ return result;
}
changed = 0;
@@ -2134,30 +2115,27 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
if (info->attrs[NL80211_ATTR_WIPHY_RETRY_SHORT]) {
retry_short = nla_get_u8(
info->attrs[NL80211_ATTR_WIPHY_RETRY_SHORT]);
- if (retry_short == 0) {
- result = -EINVAL;
- goto bad_res;
- }
+ if (retry_short == 0)
+ return -EINVAL;
+
changed |= WIPHY_PARAM_RETRY_SHORT;
}
if (info->attrs[NL80211_ATTR_WIPHY_RETRY_LONG]) {
retry_long = nla_get_u8(
info->attrs[NL80211_ATTR_WIPHY_RETRY_LONG]);
- if (retry_long == 0) {
- result = -EINVAL;
- goto bad_res;
- }
+ if (retry_long == 0)
+ return -EINVAL;
+
changed |= WIPHY_PARAM_RETRY_LONG;
}
if (info->attrs[NL80211_ATTR_WIPHY_FRAG_THRESHOLD]) {
frag_threshold = nla_get_u32(
info->attrs[NL80211_ATTR_WIPHY_FRAG_THRESHOLD]);
- if (frag_threshold < 256) {
- result = -EINVAL;
- goto bad_res;
- }
+ if (frag_threshold < 256)
+ return -EINVAL;
+
if (frag_threshold != (u32) -1) {
/*
* Fragments (apart from the last one) are required to
@@ -2187,10 +2165,8 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
u32 old_frag_threshold, old_rts_threshold;
u8 old_coverage_class;
- if (!rdev->ops->set_wiphy_params) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
+ if (!rdev->ops->set_wiphy_params)
+ return -EOPNOTSUPP;
old_retry_short = rdev->wiphy.retry_short;
old_retry_long = rdev->wiphy.retry_long;
@@ -2218,10 +2194,6 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
rdev->wiphy.coverage_class = old_coverage_class;
}
}
-
- bad_res:
- if (netdev)
- dev_put(netdev);
return result;
}
--
1.7.9.5
As cgw_create_job() is always under rtnl_lock protection,
__dev_get_by_index() instead of dev_get_by_index() should be used to
find interface handler in it having us avoid to change interface
reference counter.
Cc: Oliver Hartkopp <[email protected]>
Signed-off-by: Ying Xue <[email protected]>
---
net/can/gw.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/net/can/gw.c b/net/can/gw.c
index 88c8a39..ac31891 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -839,21 +839,21 @@ static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh)
if (!gwj->ccgw.src_idx || !gwj->ccgw.dst_idx)
goto out;
- gwj->src.dev = dev_get_by_index(&init_net, gwj->ccgw.src_idx);
+ gwj->src.dev = __dev_get_by_index(&init_net, gwj->ccgw.src_idx);
if (!gwj->src.dev)
goto out;
if (gwj->src.dev->type != ARPHRD_CAN)
- goto put_src_out;
+ goto out;
- gwj->dst.dev = dev_get_by_index(&init_net, gwj->ccgw.dst_idx);
+ gwj->dst.dev = __dev_get_by_index(&init_net, gwj->ccgw.dst_idx);
if (!gwj->dst.dev)
- goto put_src_out;
+ goto out;
if (gwj->dst.dev->type != ARPHRD_CAN)
- goto put_src_dst_out;
+ goto out;
gwj->limit_hops = limhops;
@@ -862,11 +862,6 @@ static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh)
err = cgw_register_filter(gwj);
if (!err)
hlist_add_head_rcu(&gwj->list, &cgw_list);
-
-put_src_dst_out:
- dev_put(gwj->dst.dev);
-put_src_out:
- dev_put(gwj->src.dev);
out:
if (err)
kmem_cache_free(cgw_cache, gwj);
--
1.7.9.5
The following call chains indicate that chnl_net_open() is under
rtnl_lock protection as __dev_open() is protected by rtnl_lock.
So if __dev_get_by_index() instead of dev_get_by_index() is used
to find interface handler in it, this would help us avoid to change
interface reference counter.
__dev_open()
chnl_net_open()
Cc: Dmitry Tarnyagin <[email protected]>
Signed-off-by: Ying Xue <[email protected]>
---
net/caif/chnl_net.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/caif/chnl_net.c b/net/caif/chnl_net.c
index 7344a8f..4589ff67 100644
--- a/net/caif/chnl_net.c
+++ b/net/caif/chnl_net.c
@@ -285,7 +285,7 @@ static int chnl_net_open(struct net_device *dev)
goto error;
}
- lldev = dev_get_by_index(dev_net(dev), llifindex);
+ lldev = __dev_get_by_index(dev_net(dev), llifindex);
if (lldev == NULL) {
pr_debug("no interface?\n");
@@ -307,7 +307,6 @@ static int chnl_net_open(struct net_device *dev)
mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
mtu = min_t(int, GPRS_PDP_MTU, mtu);
dev_set_mtu(dev, mtu);
- dev_put(lldev);
if (mtu < 100) {
pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
--
1.7.9.5
The following call chains indicate that batadv_is_on_batman_iface()
is always under rtnl_lock protection as call_netdevice_notifier()
is protected by rtnl_lock. So if __dev_get_by_index() rather than
dev_get_by_index() is used to find interface handler in it, this
would help us avoid to change interface reference counter.
call_netdevice_notifier()
batadv_hard_if_event()
batadv_hardif_add_interface()
batadv_is_valid_iface()
batadv_is_on_batman_iface()
Cc: Antonio Quartulli <[email protected]>
Signed-off-by: Ying Xue <[email protected]>
---
net/batman-adv/hard-interface.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index bebd46c..115d14e 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -86,15 +86,13 @@ static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
return false;
/* recurse over the parent device */
- parent_dev = dev_get_by_index(&init_net, net_dev->iflink);
+ parent_dev = __dev_get_by_index(&init_net, net_dev->iflink);
/* if we got a NULL parent_dev there is something broken.. */
if (WARN(!parent_dev, "Cannot find parent device"))
return false;
ret = batadv_is_on_batman_iface(parent_dev);
- if (parent_dev)
- dev_put(parent_dev);
return ret;
}
--
1.7.9.5
The following call chain indicates that dcb_doit() is protected
under rtnl_lock. So if we use __dev_get_by_name() instead of
dev_get_by_name() to find interface handlers in it, this would
help us avoid to change interface reference counter.
rtnetlink_rcv()
rtnl_lock()
netlink_rcv_skb()
dcb_doit()
rtnl_unlock()
Cc: John Fastabend <[email protected]>
Signed-off-by: Ying Xue <[email protected]>
---
net/dcb/dcbnl.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 66fbe19..5536444 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -1688,21 +1688,17 @@ static int dcb_doit(struct sk_buff *skb, struct nlmsghdr *nlh)
if (!tb[DCB_ATTR_IFNAME])
return -EINVAL;
- netdev = dev_get_by_name(net, nla_data(tb[DCB_ATTR_IFNAME]));
+ netdev = __dev_get_by_name(net, nla_data(tb[DCB_ATTR_IFNAME]));
if (!netdev)
return -ENODEV;
- if (!netdev->dcbnl_ops) {
- ret = -EOPNOTSUPP;
- goto out;
- }
+ if (!netdev->dcbnl_ops)
+ return -EOPNOTSUPP;
reply_skb = dcbnl_newmsg(fn->type, dcb->cmd, portid, nlh->nlmsg_seq,
nlh->nlmsg_flags, &reply_nlh);
- if (!reply_skb) {
- ret = -ENOBUFS;
- goto out;
- }
+ if (!reply_skb)
+ return -ENOBUFS;
ret = fn->cb(netdev, nlh, nlh->nlmsg_seq, tb, reply_skb);
if (ret < 0) {
@@ -1714,7 +1710,6 @@ static int dcb_doit(struct sk_buff *skb, struct nlmsghdr *nlh)
ret = rtnl_unicast(reply_skb, net, portid);
out:
- dev_put(netdev);
return ret;
}
--
1.7.9.5
The following call chains indicate that vxlan_fdb_parse() is
under rtnl_lock protection. So if we use __dev_get_by_index()
instead of dev_get_by_index() to find interface handler in it,
this would help us avoid to change interface reference counter.
rtnetlink_rcv()
rtnl_lock()
netlink_rcv_skb()
rtnl_fdb_add()
vxlan_fdb_add()
vxlan_fdb_parse()
rtnl_unlock()
rtnetlink_rcv()
rtnl_lock()
netlink_rcv_skb()
rtnl_fdb_del()
vxlan_fdb_del()
vxlan_fdb_parse()
rtnl_unlock()
Cc: Stephen Hemminger <[email protected]>
Signed-off-by: Ying Xue <[email protected]>
---
drivers/net/vxlan.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 481f85d..8c40802 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -741,10 +741,9 @@ static int vxlan_fdb_parse(struct nlattr *tb[], struct vxlan_dev *vxlan,
if (nla_len(tb[NDA_IFINDEX]) != sizeof(u32))
return -EINVAL;
*ifindex = nla_get_u32(tb[NDA_IFINDEX]);
- tdev = dev_get_by_index(net, *ifindex);
+ tdev = __dev_get_by_index(net, *ifindex);
if (!tdev)
return -EADDRNOTAVAIL;
- dev_put(tdev);
} else {
*ifindex = 0;
}
--
1.7.9.5
The following call chain we can identify that dn_cache_getroute() is
protected under rtnl_lock. So if we use __dev_get_by_index() instead
of dev_get_by_index() to find interface handlers in it, this would help
us avoid to change interface reference counter.
rtnetlink_rcv()
rtnl_lock()
netlink_rcv_skb()
dn_cache_getroute()
rtnl_unlock()
Signed-off-by: Ying Xue <[email protected]>
---
net/decnet/dn_route.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index ad2efa5..22390e4 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -1666,12 +1666,12 @@ static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
if (fld.flowidn_iif) {
struct net_device *dev;
- if ((dev = dev_get_by_index(&init_net, fld.flowidn_iif)) == NULL) {
+ dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
+ if (!dev) {
kfree_skb(skb);
return -ENODEV;
}
if (!dev->dn_ptr) {
- dev_put(dev);
kfree_skb(skb);
return -ENODEV;
}
@@ -1693,8 +1693,6 @@ static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
}
- if (skb->dev)
- dev_put(skb->dev);
skb->dev = NULL;
if (err)
goto out_free;
--
1.7.9.5
The following call chain denotes that both do_reset() and do_del_chan()
are protected under rtnl_lock. If we use __dev_get_by_name() instead of
dev_get_by_name() to find interface handlers in them, this would help
us avoid to change interface reference counter.
dev_ioctl()
rtnl_lock()
dev_ifsioc()
c4_ioctl()
do_reset()
do_del_chan()
Signed-off-by: Ying Xue <[email protected]>
---
drivers/staging/cxt1e1/linux.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/drivers/staging/cxt1e1/linux.c b/drivers/staging/cxt1e1/linux.c
index 9b48373..4a08e16 100644
--- a/drivers/staging/cxt1e1/linux.c
+++ b/drivers/staging/cxt1e1/linux.c
@@ -770,9 +770,9 @@ do_del_chan (struct net_device *musycc_dev, void *data)
if (cp.channum > 999)
return -EINVAL;
snprintf (buf, sizeof(buf), CHANNAME "%d", cp.channum);
- if (!(dev = dev_get_by_name (&init_net, buf)))
- return -ENOENT;
- dev_put (dev);
+ dev = __dev_get_by_name(&init_net, buf);
+ if (!dev)
+ return -ENODEV;
ret = do_deluser (dev, 1);
if (ret)
return ret;
@@ -792,19 +792,18 @@ do_reset (struct net_device *musycc_dev, void *data)
char buf[sizeof (CHANNAME) + 3];
sprintf (buf, CHANNAME "%d", i);
- if (!(ndev = dev_get_by_name(&init_net, buf)))
- continue;
+ ndev = __dev_get_by_name(&init_net, buf);
+ if (!ndev)
+ continue;
priv = dev_to_hdlc (ndev)->priv;
if ((unsigned long) (priv->ci) ==
(unsigned long) (netdev_priv(musycc_dev)))
{
ndev->flags &= ~IFF_UP;
- dev_put (ndev);
netif_stop_queue (ndev);
do_deluser (ndev, 1);
- } else
- dev_put (ndev);
+ }
}
return 0;
}
--
1.7.9.5
On Tue, Jan 14, 2014 at 03:41:01PM +0800, Ying Xue wrote:
>The following call chain indicates that bond_do_ioctl() is protected
>under rtnl_lock. If we use __dev_get_by_name() instead of
>dev_get_by_name() to find interface handler in it, this would
>help us avoid to change reference counter of interface once.
>
>dev_ioctl()
> rtnl_lock()
> dev_ifsioc()
> bond_do_ioctl()
> rtnl_unlock()
>
>Additionally we also change the coding style in bond_do_ioctl(),
>letting it more readable for us.
>
>Cc: Jay Vosburgh <[email protected]>
>Cc: Veaceslav Falico <[email protected]>
Acked-by: Veaceslav Falico <[email protected]>
>Signed-off-by: Ying Xue <[email protected]>
>---
> drivers/net/bonding/bond_main.c | 49 ++++++++++++++++++---------------------
> 1 file changed, 23 insertions(+), 26 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index e06c445..a69afbf 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -3213,37 +3213,34 @@ static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd
> if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
> return -EPERM;
>
>- slave_dev = dev_get_by_name(net, ifr->ifr_slave);
>+ slave_dev = __dev_get_by_name(net, ifr->ifr_slave);
>
> pr_debug("slave_dev=%p:\n", slave_dev);
>
> if (!slave_dev)
>- res = -ENODEV;
>- else {
>- pr_debug("slave_dev->name=%s:\n", slave_dev->name);
>- switch (cmd) {
>- case BOND_ENSLAVE_OLD:
>- case SIOCBONDENSLAVE:
>- res = bond_enslave(bond_dev, slave_dev);
>- break;
>- case BOND_RELEASE_OLD:
>- case SIOCBONDRELEASE:
>- res = bond_release(bond_dev, slave_dev);
>- break;
>- case BOND_SETHWADDR_OLD:
>- case SIOCBONDSETHWADDR:
>- bond_set_dev_addr(bond_dev, slave_dev);
>- res = 0;
>- break;
>- case BOND_CHANGE_ACTIVE_OLD:
>- case SIOCBONDCHANGEACTIVE:
>- res = bond_option_active_slave_set(bond, slave_dev);
>- break;
>- default:
>- res = -EOPNOTSUPP;
>- }
>+ return -ENODEV;
>
>- dev_put(slave_dev);
>+ pr_debug("slave_dev->name=%s:\n", slave_dev->name);
>+ switch (cmd) {
>+ case BOND_ENSLAVE_OLD:
>+ case SIOCBONDENSLAVE:
>+ res = bond_enslave(bond_dev, slave_dev);
>+ break;
>+ case BOND_RELEASE_OLD:
>+ case SIOCBONDRELEASE:
>+ res = bond_release(bond_dev, slave_dev);
>+ break;
>+ case BOND_SETHWADDR_OLD:
>+ case SIOCBONDSETHWADDR:
>+ bond_set_dev_addr(bond_dev, slave_dev);
>+ res = 0;
>+ break;
>+ case BOND_CHANGE_ACTIVE_OLD:
>+ case SIOCBONDCHANGEACTIVE:
>+ res = bond_option_active_slave_set(bond, slave_dev);
>+ break;
>+ default:
>+ res = -EOPNOTSUPP;
> }
>
> return res;
>--
>1.7.9.5
>
On Tue, 2014-01-14 at 15:41 +0800, Ying Xue wrote:
> @@ -2218,10 +2194,6 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
> rdev->wiphy.coverage_class = old_coverage_class;
> }
> }
> -
> - bad_res:
> - if (netdev)
> - dev_put(netdev);
> return result;
I believe that could be "return 0;" now, which would make the code
easier to read.
johannes
On 14.01.2014 08:41, Ying Xue wrote:
> As cgw_create_job() is always under rtnl_lock protection,
> __dev_get_by_index() instead of dev_get_by_index() should be used to
> find interface handler in it having us avoid to change interface
> reference counter.
>
> Cc: Oliver Hartkopp <[email protected]>
> Signed-off-by: Ying Xue <[email protected]>
Thanks for the simplification!
Acked-by: Oliver Hartkopp <[email protected]>
> ---
> net/can/gw.c | 15 +++++----------
> 1 file changed, 5 insertions(+), 10 deletions(-)
>
> diff --git a/net/can/gw.c b/net/can/gw.c
> index 88c8a39..ac31891 100644
> --- a/net/can/gw.c
> +++ b/net/can/gw.c
> @@ -839,21 +839,21 @@ static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh)
> if (!gwj->ccgw.src_idx || !gwj->ccgw.dst_idx)
> goto out;
>
> - gwj->src.dev = dev_get_by_index(&init_net, gwj->ccgw.src_idx);
> + gwj->src.dev = __dev_get_by_index(&init_net, gwj->ccgw.src_idx);
>
> if (!gwj->src.dev)
> goto out;
>
> if (gwj->src.dev->type != ARPHRD_CAN)
> - goto put_src_out;
> + goto out;
>
> - gwj->dst.dev = dev_get_by_index(&init_net, gwj->ccgw.dst_idx);
> + gwj->dst.dev = __dev_get_by_index(&init_net, gwj->ccgw.dst_idx);
>
> if (!gwj->dst.dev)
> - goto put_src_out;
> + goto out;
>
> if (gwj->dst.dev->type != ARPHRD_CAN)
> - goto put_src_dst_out;
> + goto out;
>
> gwj->limit_hops = limhops;
>
> @@ -862,11 +862,6 @@ static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh)
> err = cgw_register_filter(gwj);
> if (!err)
> hlist_add_head_rcu(&gwj->list, &cgw_list);
> -
> -put_src_dst_out:
> - dev_put(gwj->dst.dev);
> -put_src_out:
> - dev_put(gwj->src.dev);
> out:
> if (err)
> kmem_cache_free(cgw_cache, gwj);
>
On Tue, 14 Jan 2014 15:41:05 +0800
Ying Xue <[email protected]> wrote:
> The following call chains indicate that vxlan_fdb_parse() is
> under rtnl_lock protection. So if we use __dev_get_by_index()
> instead of dev_get_by_index() to find interface handler in it,
> this would help us avoid to change interface reference counter.
>
> rtnetlink_rcv()
> rtnl_lock()
> netlink_rcv_skb()
> rtnl_fdb_add()
> vxlan_fdb_add()
> vxlan_fdb_parse()
> rtnl_unlock()
>
> rtnetlink_rcv()
> rtnl_lock()
> netlink_rcv_skb()
> rtnl_fdb_del()
> vxlan_fdb_del()
> vxlan_fdb_parse()
> rtnl_unlock()
>
> Cc: Stephen Hemminger <[email protected]>
> Signed-off-by: Ying Xue <[email protected]>
Acked-by: Stephen Hemminger <[email protected]>
On 01/14/2014 08:11 PM, Johannes Berg wrote:
> On Tue, 2014-01-14 at 15:41 +0800, Ying Xue wrote:
>
>> @@ -2218,10 +2194,6 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
>> rdev->wiphy.coverage_class = old_coverage_class;
>> }
>> }
>> -
>> - bad_res:
>> - if (netdev)
>> - dev_put(netdev);
>> return result;
>
> I believe that could be "return 0;" now, which would make the code
> easier to read.
>
Yes, I will change it in next version.
Thanks,
Ying
> johannes
>
>
>