lkml.org 
[lkml]   [2021]   [Oct]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH net-next v3] net: sched: gred: dynamically allocate tc_gred_qopt_offload
From: Arnd Bergmann <arnd@arndb.de>

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 <kuba@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
v2…v3:
- drop not needed return statement in gred_offload() (Jakub)
- use kzalloc(sizeof(*table->opt) in gred_init() (Eric)
- Make the allocation conditional on ->ndo_setup_tc (Jakub).

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 72de08ef8335e..1073c76d05c45 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 @@ 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 = {
--
2.33.1
\
 
 \ /
  Last update: 2021-10-26 12:07    [W:0.049 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site