From f25c0515c521375154c62c72447869f40218c861 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 26 Oct 2021 12:07:11 +0200 Subject: [PATCH] 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: 50dc9a8572aa ("net: sched: Merge Qdisc::bstats and Qdisc::cpu_bstats data types") Fixes: 67c9e6270f30 ("net: sched: Protect Qdisc::bstats with u64_stats") Suggested-by: Jakub Kicinski Signed-off-by: Arnd Bergmann Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20211026100711.nalhttf6mbe6sudx@linutronix.de Signed-off-by: Jakub Kicinski --- net/sched/sch_gred.c | 50 ++++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 20 deletions(-) diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c index 72de08ef8335..1073c76d05c4 100644 --- a/net/sched/sch_gred.c +++ b/net/sched/sch_gred.c @@ -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 @@ err_unlock_free: 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 = {