netem: use vmalloc for distribution table

The netem probability table can be large (up to 64K bytes)
which may be too large to allocate in one contiguous chunk.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index d367783..86dad1e 100644 (file)
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -308,6 +308,16 @@ static void netem_reset(struct Qdisc *sch)
        qdisc_watchdog_cancel(&q->watchdog);
 }
 
+static void dist_free(struct disttable *d)
+{
+       if (d) {
+               if (is_vmalloc_addr(d))
+                       vfree(d);
+               else
+                       kfree(d);
+       }
+}
+
 /*
  * Distribution data is a variable size payload containing
  * signed 16 bit values.
@@ -315,16 +325,20 @@ static void netem_reset(struct Qdisc *sch)
 static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr)
 {
        struct netem_sched_data *q = qdisc_priv(sch);
-       unsigned long n = nla_len(attr)/sizeof(__s16);
+       size_t n = nla_len(attr)/sizeof(__s16);
        const __s16 *data = nla_data(attr);
        spinlock_t *root_lock;
        struct disttable *d;
        int i;
+       size_t s;
 
        if (n > 65536)
                return -EINVAL;
 
-       d = kmalloc(sizeof(*d) + n*sizeof(d->table[0]), GFP_KERNEL);
+       s = sizeof(struct disttable) + n * sizeof(s16);
+       d = kmalloc(s, GFP_KERNEL);
+       if (!d)
+               d = vmalloc(s);
        if (!d)
                return -ENOMEM;
 
@@ -335,7 +349,7 @@ static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr)
        root_lock = qdisc_root_sleeping_lock(sch);
 
        spin_lock_bh(root_lock);
-       kfree(q->delay_dist);
+       dist_free(q->delay_dist);
        q->delay_dist = d;
        spin_unlock_bh(root_lock);
        return 0;
@@ -556,7 +570,7 @@ static void netem_destroy(struct Qdisc *sch)
 
        qdisc_watchdog_cancel(&q->watchdog);
        qdisc_destroy(q->qdisc);
-       kfree(q->delay_dist);
+       dist_free(q->delay_dist);
 }
 
 static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)