Commit f25c0515 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Jakub Kicinski
Browse files

net: sched: gred: dynamically allocate tc_gred_qopt_offload 



The tc_gred_qopt_offload structure has grown too big to be on the
stack for 32-bit architectures after recent changes.

net/sched/sch_gred.c:903:13: error: stack frame size (1180) exceeds limit (1024) in 'gred_destroy' [-Werror,-Wframe-larger-than]
net/sched/sch_gred.c:310:13: error: stack frame size (1212) exceeds limit (1024) in 'gred_offload' [-Werror,-Wframe-larger-than]

Use dynamic allocation per qdisc to avoid this.

Fixes: 50dc9a85 ("net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data types")
Fixes: 67c9e627 ("net: sched: Protect Qdisc::bstats with u64_stats")
Suggested-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20211026100711.nalhttf6mbe6sudx@linutronix.de


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 4796e251

net/sched/sch_gred.c

+30 −20
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ struct gred_sched { 
	u32 		DPs;

	u32 		def;

	struct red_vars wred_set;

	struct tc_gred_qopt_offload *opt;

};



static inline int gred_wred_mode(struct gred_sched *table)
@@ -311,42 +312,43 @@ static void gred_offload(struct Qdisc *sch, enum tc_gred_command command) 
{

	struct gred_sched *table = qdisc_priv(sch);

	struct net_device *dev = qdisc_dev(sch);

	struct tc_gred_qopt_offload opt = {

		.command	= command,

		.handle		= sch->handle,

		.parent		= sch->parent,

	};

	struct tc_gred_qopt_offload *opt = table->opt;



	if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)

		return;



	memset(opt, 0, sizeof(*opt));

	opt->command = command;

	opt->handle = sch->handle;

	opt->parent = sch->parent;



	if (command == TC_GRED_REPLACE) {

		unsigned int i;



		opt.set.grio_on = gred_rio_mode(table);

		opt.set.wred_on = gred_wred_mode(table);

		opt.set.dp_cnt = table->DPs;

		opt.set.dp_def = table->def;

		opt->set.grio_on = gred_rio_mode(table);

		opt->set.wred_on = gred_wred_mode(table);

		opt->set.dp_cnt = table->DPs;

		opt->set.dp_def = table->def;



		for (i = 0; i < table->DPs; i++) {

			struct gred_sched_data *q = table->tab[i];



			if (!q)

				continue;

			opt.set.tab[i].present = true;

			opt.set.tab[i].limit = q->limit;

			opt.set.tab[i].prio = q->prio;

			opt.set.tab[i].min = q->parms.qth_min >> q->parms.Wlog;

			opt.set.tab[i].max = q->parms.qth_max >> q->parms.Wlog;

			opt.set.tab[i].is_ecn = gred_use_ecn(q);

			opt.set.tab[i].is_harddrop = gred_use_harddrop(q);

			opt.set.tab[i].probability = q->parms.max_P;

			opt.set.tab[i].backlog = &q->backlog;

			opt->set.tab[i].present = true;

			opt->set.tab[i].limit = q->limit;

			opt->set.tab[i].prio = q->prio;

			opt->set.tab[i].min = q->parms.qth_min >> q->parms.Wlog;

			opt->set.tab[i].max = q->parms.qth_max >> q->parms.Wlog;

			opt->set.tab[i].is_ecn = gred_use_ecn(q);

			opt->set.tab[i].is_harddrop = gred_use_harddrop(q);

			opt->set.tab[i].probability = q->parms.max_P;

			opt->set.tab[i].backlog = &q->backlog;

		}

		opt.set.qstats = &sch->qstats;

		opt->set.qstats = &sch->qstats;

	}



	dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_GRED, &opt);

	dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_GRED, opt);

}



static int gred_offload_dump_stats(struct Qdisc *sch)
@@ -731,6 +733,7 @@ static int gred_change(struct Qdisc *sch, struct nlattr *opt, 
static int gred_init(struct Qdisc *sch, struct nlattr *opt,

		     struct netlink_ext_ack *extack)

{

	struct gred_sched *table = qdisc_priv(sch);

	struct nlattr *tb[TCA_GRED_MAX + 1];

	int err;
@@ -754,6 +757,12 @@ static int gred_init(struct Qdisc *sch, struct nlattr *opt, 
		sch->limit = qdisc_dev(sch)->tx_queue_len

		             * psched_mtu(qdisc_dev(sch));



	if (qdisc_dev(sch)->netdev_ops->ndo_setup_tc) {

		table->opt = kzalloc(sizeof(*table->opt), GFP_KERNEL);

		if (!table->opt)

			return -ENOMEM;

	}



	return gred_change_table_def(sch, tb[TCA_GRED_DPS], extack);

}
@@ -910,6 +919,7 @@ static void gred_destroy(struct Qdisc *sch) 
			gred_destroy_vq(table->tab[i]);

	}

	gred_offload(sch, TC_GRED_DESTROY);

	kfree(table->opt);

}



static struct Qdisc_ops gred_qdisc_ops __read_mostly = {