pkt_sched: Add BH protection for qdisc_stab_lock.

Since qdisc_stab_lock is used in qdisc_put_stab(), which is called in
BH context from __qdisc_destroy() RCU callback, softirq safe locking
is needed.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index bbf149dd7818b192c0aad9b8693a3790e115a26e..c25465e5607aeb32cf39fb8c784514a64ebedcbf 100644 (file)
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -331,7 +331,7 @@ static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
        if (!s || tsize != s->tsize || (!tab && tsize > 0))
                return ERR_PTR(-EINVAL);
 
-       spin_lock(&qdisc_stab_lock);
+       spin_lock_bh(&qdisc_stab_lock);
 
        list_for_each_entry(stab, &qdisc_stab_list, list) {
                if (memcmp(&stab->szopts, s, sizeof(*s)))
@@ -339,11 +339,11 @@ static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
                if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
                        continue;
                stab->refcnt++;
-               spin_unlock(&qdisc_stab_lock);
+               spin_unlock_bh(&qdisc_stab_lock);
                return stab;
        }
 
-       spin_unlock(&qdisc_stab_lock);
+       spin_unlock_bh(&qdisc_stab_lock);
 
        stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
        if (!stab)
@@ -354,9 +354,9 @@ static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
        if (tsize > 0)
                memcpy(stab->data, tab, tsize * sizeof(u16));
 
-       spin_lock(&qdisc_stab_lock);
+       spin_lock_bh(&qdisc_stab_lock);
        list_add_tail(&stab->list, &qdisc_stab_list);
-       spin_unlock(&qdisc_stab_lock);
+       spin_unlock_bh(&qdisc_stab_lock);
 
        return stab;
 }
@@ -366,14 +366,14 @@ void qdisc_put_stab(struct qdisc_size_table *tab)
        if (!tab)
                return;
 
-       spin_lock(&qdisc_stab_lock);
+       spin_lock_bh(&qdisc_stab_lock);
 
        if (--tab->refcnt == 0) {
                list_del(&tab->list);
                kfree(tab);
        }
 
-       spin_unlock(&qdisc_stab_lock);
+       spin_unlock_bh(&qdisc_stab_lock);
 }
 EXPORT_SYMBOL(qdisc_put_stab);