Commit bb52c7ac authored Dec 23, 2011 by Eric Dumazet Committed by David S. Miller Dec 24, 2011

netem: dont call vfree() under spinlock and BH disabled



commit 6373a9a2 (netem: use vmalloc for distribution table) added a
regression, since vfree() is called while holding a spinlock and BH
being disabled.

Fix this by doing the pointers swap in critical section, and freeing
after spinlock release.

Also add __GFP_NOWARN to the kmalloc() try, since we fallback to
vmalloc().

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 5f0a6e2d

net/sched/sch_netem.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -488,7 +488,7 @@ static int get_dist_table(struct Qdisc sch, const struct nlattr attr)
		return -EINVAL;

		s = sizeof(struct disttable) + n * sizeof(s16);
		d = kmalloc(s, GFP_KERNEL);
		d = kmalloc(s, GFP_KERNEL \| __GFP_NOWARN);
		if (!d)
		d = vmalloc(s);
		if (!d)
		@@ -501,9 +501,10 @@ static int get_dist_table(struct Qdisc sch, const struct nlattr attr)
		root_lock = qdisc_root_sleeping_lock(sch);

		spin_lock_bh(root_lock);
		dist_free(q->delay_dist);
		q->delay_dist = d;
		swap(q->delay_dist, d);
		spin_unlock_bh(root_lock);

		dist_free(d);
		return 0;
		}

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