sch_gred: should not use GFP_KERNEL while holding a spinlock
Eric Dumazet [Sun, 11 Dec 2011 23:42:53 +0000 (23:42 +0000)]
[ Upstream commit 3f1e6d3fd37bd4f25e5b19f1c7ca21850426c33f ]

gred_change_vq() is called under sch_tree_lock(sch).

This means a spinlock is held, and we are not allowed to sleep in this
context.

We might pre-allocate memory using GFP_KERNEL before taking spinlock,
but this is not suitable for stable material.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

net/sched/sch_gred.c

index b9493a0..6cd8ddf 100644 (file)
@@ -385,7 +385,7 @@ static inline int gred_change_vq(struct Qdisc *sch, int dp,
        struct gred_sched_data *q;
 
        if (table->tab[dp] == NULL) {
-               table->tab[dp] = kzalloc(sizeof(*q), GFP_KERNEL);
+               table->tab[dp] = kzalloc(sizeof(*q), GFP_ATOMIC);
                if (table->tab[dp] == NULL)
                        return -ENOMEM;
        }