On 01/15/2018 09:33 PM, Daniel Borkmann via iovisor-dev wrote:
> On 01/15/2018 09:13 PM, David Miller wrote:
>> From: Daniel Borkmann via iovisor-dev <[email protected]>
>> Date: Mon, 15 Jan 2018 21:11:06 +0100
>>
>>> On 01/15/2018 06:24 PM, Daniel Borkmann via iovisor-dev wrote:
>>>> On 01/11/2018 07:05 AM, Sandipan Das via iovisor-dev wrote:
>>>> [...]
>>>>> Any ideas about why this is happening? Also, it would be really helpful
>>>>> if someone can translate the Pyroute2 calls in the test script to the
>>>>> corresponding tc commands.
>>>>
>>>> I can trigger it as well, so I should have something very soon; currently
>>>> looking into it.
>>>
>>> Here's the fix for your panic ... cooking up proper patch with commit
>>> description for netdev now:
>>>
>>> From 126dd0c1ecb7c207f79976c6c3ef13be08afe6b5 Mon Sep 17 00:00:00 2001
>>> From: Daniel Borkmann <[email protected]>
>>> Date: Mon, 15 Jan 2018 19:48:28 +0000
>>> Subject: [PATCH net] net, sched: fix miniq {b,q}stats handling
>>>
>>> Signed-off-by: Daniel Borkmann <[email protected]>
>>
>> Is this related to:
>>
>> http://patchwork.ozlabs.org/patch/860647/
>>
>> ?
>
> Ahh, yes, I didn't see that one. The fix is needed in net tree however, since
> it's broken there already (v4.15-rc1 onwards). I was using an arm64 machine
> with simple clsact and some filter attached to it, so as soon as this hits
> traffic, we get the panic since {b,q}stats are allocated /after/ setting them
> up in miniq init.
>
> We could use some form of d59f5ffa59d8 ("net: sched: a dflt qdisc may be
> used with per cpu stats") for net and get rid of the per-cpu alloc from
> qdisc_create(), since it's not needed there anymore.
Basically like this for net to reduce merge churn later on:
include/net/sch_generic.h | 2 ++
net/sched/sch_api.c | 15 +--------------
net/sched/sch_generic.c | 18 +++++++++++++++++-
net/sched/sch_ingress.c | 19 ++++---------------
4 files changed, 24 insertions(+), 30 deletions(-)
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 83a3e47..becf86a 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -179,6 +179,7 @@ struct Qdisc_ops {
const struct Qdisc_class_ops *cl_ops;
char id[IFNAMSIZ];
int priv_size;
+ unsigned int static_flags;
int (*enqueue)(struct sk_buff *skb,
struct Qdisc *sch,
@@ -444,6 +445,7 @@ void qdisc_tree_reduce_backlog(struct Qdisc *qdisc,
unsigned int n,
unsigned int len);
struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
const struct Qdisc_ops *ops);
+void qdisc_free(struct Qdisc *qdisc);
struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
const struct Qdisc_ops *ops, u32 parentid);
void __qdisc_calculate_pkt_len(struct sk_buff *skb,
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 0f1eab9..52529b7 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1063,17 +1063,6 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
}
if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
- if (qdisc_is_percpu_stats(sch)) {
- sch->cpu_bstats =
- netdev_alloc_pcpu_stats(struct
gnet_stats_basic_cpu);
- if (!sch->cpu_bstats)
- goto err_out4;
-
- sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
- if (!sch->cpu_qstats)
- goto err_out4;
- }
-
if (tca[TCA_STAB]) {
stab = qdisc_get_stab(tca[TCA_STAB]);
if (IS_ERR(stab)) {
@@ -1115,7 +1104,7 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
ops->destroy(sch);
err_out3:
dev_put(dev);
- kfree((char *) sch - sch->padded);
+ qdisc_free(sch);
err_out2:
module_put(ops->owner);
err_out:
@@ -1123,8 +1112,6 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
return NULL;
err_out4:
- free_percpu(sch->cpu_bstats);
- free_percpu(sch->cpu_qstats);
/*
* Any broken qdiscs that would require a ops->reset() here?
* The qdisc was never in action so it shouldn't be necessary.
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 661c714..cac003f 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -633,6 +633,19 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
qdisc_skb_head_init(&sch->q);
spin_lock_init(&sch->q.lock);
+ if (ops->static_flags & TCQ_F_CPUSTATS) {
+ sch->cpu_bstats =
+ netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
+ if (!sch->cpu_bstats)
+ goto errout1;
+
+ sch->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
+ if (!sch->cpu_qstats) {
+ free_percpu(sch->cpu_bstats);
+ goto errout1;
+ }
+ }
+
spin_lock_init(&sch->busylock);
lockdep_set_class(&sch->busylock,
dev->qdisc_tx_busylock ?: &qdisc_tx_busylock);
@@ -642,6 +655,7 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
dev->qdisc_running_key ?: &qdisc_running_key);
sch->ops = ops;
+ sch->flags = ops->static_flags;
sch->enqueue = ops->enqueue;
sch->dequeue = ops->dequeue;
sch->dev_queue = dev_queue;
@@ -649,6 +663,8 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
refcount_set(&sch->refcnt, 1);
return sch;
+errout1:
+ kfree(p);
errout:
return ERR_PTR(err);
}
@@ -698,7 +714,7 @@ void qdisc_reset(struct Qdisc *qdisc)
}
EXPORT_SYMBOL(qdisc_reset);
-static void qdisc_free(struct Qdisc *qdisc)
+void qdisc_free(struct Qdisc *qdisc)
{
if (qdisc_is_percpu_stats(qdisc)) {
free_percpu(qdisc->cpu_bstats);
diff --git a/net/sched/sch_ingress.c b/net/sched/sch_ingress.c
index fc1286f..003e1b0 100644
--- a/net/sched/sch_ingress.c
+++ b/net/sched/sch_ingress.c
@@ -66,7 +66,6 @@ static int ingress_init(struct Qdisc *sch, struct nlattr *opt)
{
struct ingress_sched_data *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
- int err;
net_inc_ingress_queue();
@@ -76,13 +75,7 @@ static int ingress_init(struct Qdisc *sch, struct nlattr
*opt)
q->block_info.chain_head_change = clsact_chain_head_change;
q->block_info.chain_head_change_priv = &q->miniqp;
- err = tcf_block_get_ext(&q->block, sch, &q->block_info);
- if (err)
- return err;
-
- sch->flags |= TCQ_F_CPUSTATS;
-
- return 0;
+ return tcf_block_get_ext(&q->block, sch, &q->block_info);
}
static void ingress_destroy(struct Qdisc *sch)
@@ -121,6 +114,7 @@ static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
.cl_ops = &ingress_class_ops,
.id = "ingress",
.priv_size = sizeof(struct ingress_sched_data),
+ .static_flags = TCQ_F_CPUSTATS,
.init = ingress_init,
.destroy = ingress_destroy,
.dump = ingress_dump,
@@ -192,13 +186,7 @@ static int clsact_init(struct Qdisc *sch, struct nlattr
*opt)
q->egress_block_info.chain_head_change = clsact_chain_head_change;
q->egress_block_info.chain_head_change_priv = &q->miniqp_egress;
- err = tcf_block_get_ext(&q->egress_block, sch, &q->egress_block_info);
- if (err)
- return err;
-
- sch->flags |= TCQ_F_CPUSTATS;
-
- return 0;
+ return tcf_block_get_ext(&q->egress_block, sch, &q->egress_block_info);
}
static void clsact_destroy(struct Qdisc *sch)
@@ -225,6 +213,7 @@ static struct Qdisc_ops clsact_qdisc_ops __read_mostly = {
.cl_ops = &clsact_class_ops,
.id = "clsact",
.priv_size = sizeof(struct clsact_sched_data),
+ .static_flags = TCQ_F_CPUSTATS,
.init = clsact_init,
.destroy = clsact_destroy,
.dump = ingress_dump,
--
2.9.5
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