These changes are the raw update to linux-4.4.6-rt14. Kernel sources

are taken from kernel.org, and rt patch from the rt wiki download page.

During the rebasing, the following patch collided:

Force tick interrupt and get rid of softirq magic(I70131fb85).

Collisions have been removed because its logic was found on the
source already.

Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

1 files changed, 25 insertions, 19 deletions

diff --git a/kernel/net/sched/act_gact.c b/kernel/net/sched/act_gact.c
index 7fffc2272..5c1b05170 100644
--- a/kernel/net/sched/act_gact.c
+++ b/kernel/net/sched/act_gact.c
@@ -28,14 +28,18 @@
 #ifdef CONFIG_GACT_PROB
 static int gact_net_rand(struct tcf_gact *gact)
 {
-	if (!gact->tcfg_pval || prandom_u32() % gact->tcfg_pval)
+	smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
+	if (prandom_u32() % gact->tcfg_pval)
 		return gact->tcf_action;
 	return gact->tcfg_paction;
 }
 
 static int gact_determ(struct tcf_gact *gact)
 {
-	if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval)
+	u32 pack = atomic_inc_return(&gact->packets);
+
+	smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
+	if (pack % gact->tcfg_pval)
 		return gact->tcf_action;
 	return gact->tcfg_paction;
 }
@@ -85,7 +89,8 @@ static int tcf_gact_init(struct net *net, struct nlattr *nla,
 #endif
 
 	if (!tcf_hash_check(parm->index, a, bind)) {
-		ret = tcf_hash_create(parm->index, est, a, sizeof(*gact), bind);
+		ret = tcf_hash_create(parm->index, est, a, sizeof(*gact),
+				      bind, true);
 		if (ret)
 			return ret;
 		ret = ACT_P_CREATED;
@@ -99,16 +104,19 @@ static int tcf_gact_init(struct net *net, struct nlattr *nla,
 
 	gact = to_gact(a);
 
-	spin_lock_bh(&gact->tcf_lock);
+	ASSERT_RTNL();
 	gact->tcf_action = parm->action;
 #ifdef CONFIG_GACT_PROB
 	if (p_parm) {
 		gact->tcfg_paction = p_parm->paction;
-		gact->tcfg_pval    = p_parm->pval;
+		gact->tcfg_pval    = max_t(u16, 1, p_parm->pval);
+		/* Make sure tcfg_pval is written before tcfg_ptype
+		 * coupled with smp_rmb() in gact_net_rand() & gact_determ()
+		 */
+		smp_wmb();
 		gact->tcfg_ptype   = p_parm->ptype;
 	}
 #endif
-	spin_unlock_bh(&gact->tcf_lock);
 	if (ret == ACT_P_CREATED)
 		tcf_hash_insert(a);
 	return ret;
@@ -118,23 +126,21 @@ static int tcf_gact(struct sk_buff *skb, const struct tc_action *a,
 		    struct tcf_result *res)
 {
 	struct tcf_gact *gact = a->priv;
-	int action = TC_ACT_SHOT;
+	int action = READ_ONCE(gact->tcf_action);
 
-	spin_lock(&gact->tcf_lock);
 #ifdef CONFIG_GACT_PROB
-	if (gact->tcfg_ptype)
-		action = gact_rand[gact->tcfg_ptype](gact);
-	else
-		action = gact->tcf_action;
-#else
-	action = gact->tcf_action;
+	{
+	u32 ptype = READ_ONCE(gact->tcfg_ptype);
+
+	if (ptype)
+		action = gact_rand[ptype](gact);
+	}
 #endif
-	gact->tcf_bstats.bytes += qdisc_pkt_len(skb);
-	gact->tcf_bstats.packets++;
+	bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb);
 	if (action == TC_ACT_SHOT)
-		gact->tcf_qstats.drops++;
-	gact->tcf_tm.lastuse = jiffies;
-	spin_unlock(&gact->tcf_lock);
+		qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats));
+
+	tcf_lastuse_update(&gact->tcf_tm);
 
 	return action;
 }