dcbnl : Disable software interrupts before taking dcb_lock
Solves possible lockup issues that can be seen from firmware DCB agents calling
into the DCB app api.
DCB firmware event queues can be tied in with NAPI so that dcb events are
generated in softIRQ context. This can results in calls to dcb_*app()
functions which try to take the dcb_lock.
If the the event triggers while we also have the dcb_lock because lldpad or
some other agent happened to be issuing a get/set command we could see a cpu
lockup.
This code was not originally written with firmware agents in mind, hence
grabbing dcb_lock from softIRQ context was not considered.
Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index ca11d28..93ea801 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -1080,13 +1080,13 @@
if (!app)
return -EMSGSIZE;
- spin_lock(&dcb_lock);
+ spin_lock_bh(&dcb_lock);
list_for_each_entry(itr, &dcb_app_list, list) {
if (itr->ifindex == netdev->ifindex) {
err = nla_put(skb, DCB_ATTR_IEEE_APP, sizeof(itr->app),
&itr->app);
if (err) {
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
return -EMSGSIZE;
}
}
@@ -1097,7 +1097,7 @@
else
dcbx = -EOPNOTSUPP;
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
nla_nest_end(skb, app);
/* get peer info if available */
@@ -1234,7 +1234,7 @@
}
/* local app */
- spin_lock(&dcb_lock);
+ spin_lock_bh(&dcb_lock);
app = nla_nest_start(skb, DCB_ATTR_CEE_APP_TABLE);
if (!app)
goto dcb_unlock;
@@ -1271,7 +1271,7 @@
else
dcbx = -EOPNOTSUPP;
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
/* features flags */
if (ops->getfeatcfg) {
@@ -1326,7 +1326,7 @@
return 0;
dcb_unlock:
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
nla_put_failure:
return err;
}
@@ -1762,10 +1762,10 @@
struct dcb_app_type *itr;
u8 prio = 0;
- spin_lock(&dcb_lock);
+ spin_lock_bh(&dcb_lock);
if ((itr = dcb_app_lookup(app, dev->ifindex, 0)))
prio = itr->app.priority;
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
return prio;
}
@@ -1789,7 +1789,7 @@
if (dev->dcbnl_ops->getdcbx)
event.dcbx = dev->dcbnl_ops->getdcbx(dev);
- spin_lock(&dcb_lock);
+ spin_lock_bh(&dcb_lock);
/* Search for existing match and replace */
if ((itr = dcb_app_lookup(new, dev->ifindex, 0))) {
if (new->priority)
@@ -1804,7 +1804,7 @@
if (new->priority)
err = dcb_app_add(new, dev->ifindex);
out:
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
if (!err)
call_dcbevent_notifiers(DCB_APP_EVENT, &event);
return err;
@@ -1823,10 +1823,10 @@
struct dcb_app_type *itr;
u8 prio = 0;
- spin_lock(&dcb_lock);
+ spin_lock_bh(&dcb_lock);
if ((itr = dcb_app_lookup(app, dev->ifindex, 0)))
prio |= 1 << itr->app.priority;
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
return prio;
}
@@ -1850,7 +1850,7 @@
if (dev->dcbnl_ops->getdcbx)
event.dcbx = dev->dcbnl_ops->getdcbx(dev);
- spin_lock(&dcb_lock);
+ spin_lock_bh(&dcb_lock);
/* Search for existing match and abort if found */
if (dcb_app_lookup(new, dev->ifindex, new->priority)) {
err = -EEXIST;
@@ -1859,7 +1859,7 @@
err = dcb_app_add(new, dev->ifindex);
out:
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
if (!err)
call_dcbevent_notifiers(DCB_APP_EVENT, &event);
return err;
@@ -1882,7 +1882,7 @@
if (dev->dcbnl_ops->getdcbx)
event.dcbx = dev->dcbnl_ops->getdcbx(dev);
- spin_lock(&dcb_lock);
+ spin_lock_bh(&dcb_lock);
/* Search for existing match and remove it. */
if ((itr = dcb_app_lookup(del, dev->ifindex, del->priority))) {
list_del(&itr->list);
@@ -1890,7 +1890,7 @@
err = 0;
}
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
if (!err)
call_dcbevent_notifiers(DCB_APP_EVENT, &event);
return err;
@@ -1902,12 +1902,12 @@
struct dcb_app_type *app;
struct dcb_app_type *tmp;
- spin_lock(&dcb_lock);
+ spin_lock_bh(&dcb_lock);
list_for_each_entry_safe(app, tmp, &dcb_app_list, list) {
list_del(&app->list);
kfree(app);
}
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
}
static int __init dcbnl_init(void)