2 files changed, 216 insertions, 142 deletions

diff --git a/include/net/tc_act/tc_pedit.h b/include/net/tc_act/tc_pedit.h
index 3e02709a1df6..83fe39931781 100644
--- a/include/net/tc_act/tc_pedit.h
+++ b/include/net/tc_act/tc_pedit.h
@@ -4,22 +4,29 @@
 
 #include <net/act_api.h>
 #include <linux/tc_act/tc_pedit.h>
+#include <linux/types.h>
 
 struct tcf_pedit_key_ex {
 	enum pedit_header_type htype;
 	enum pedit_cmd cmd;
 };
 
-struct tcf_pedit {
-	struct tc_action	common;
-	unsigned char		tcfp_nkeys;
-	unsigned char		tcfp_flags;
-	u32			tcfp_off_max_hint;
+struct tcf_pedit_parms {
 	struct tc_pedit_key	*tcfp_keys;
 	struct tcf_pedit_key_ex	*tcfp_keys_ex;
+	u32 tcfp_off_max_hint;
+	unsigned char tcfp_nkeys;
+	unsigned char tcfp_flags;
+	struct rcu_head rcu;
+};
+
+struct tcf_pedit {
+	struct tc_action common;
+	struct tcf_pedit_parms __rcu *parms;
 };
 
 #define to_pedit(a) ((struct tcf_pedit *)a)
+#define to_pedit_parms(a) (rcu_dereference(to_pedit(a)->parms))
 
 static inline bool is_tcf_pedit(const struct tc_action *a)
 {
@@ -32,37 +39,81 @@ static inline bool is_tcf_pedit(const struct tc_action *a)
 
 static inline int tcf_pedit_nkeys(const struct tc_action *a)
 {
-	return to_pedit(a)->tcfp_nkeys;
+	struct tcf_pedit_parms *parms;
+	int nkeys;
+
+	rcu_read_lock();
+	parms = to_pedit_parms(a);
+	nkeys = parms->tcfp_nkeys;
+	rcu_read_unlock();
+
+	return nkeys;
 }
 
 static inline u32 tcf_pedit_htype(const struct tc_action *a, int index)
 {
-	if (to_pedit(a)->tcfp_keys_ex)
-		return to_pedit(a)->tcfp_keys_ex[index].htype;
+	u32 htype = TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
+	struct tcf_pedit_parms *parms;
+
+	rcu_read_lock();
+	parms = to_pedit_parms(a);
+	if (parms->tcfp_keys_ex)
+		htype = parms->tcfp_keys_ex[index].htype;
+	rcu_read_unlock();
 
-	return TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
+	return htype;
 }
 
 static inline u32 tcf_pedit_cmd(const struct tc_action *a, int index)
 {
-	if (to_pedit(a)->tcfp_keys_ex)
-		return to_pedit(a)->tcfp_keys_ex[index].cmd;
+	struct tcf_pedit_parms *parms;
+	u32 cmd = __PEDIT_CMD_MAX;
 
-	return __PEDIT_CMD_MAX;
+	rcu_read_lock();
+	parms = to_pedit_parms(a);
+	if (parms->tcfp_keys_ex)
+		cmd = parms->tcfp_keys_ex[index].cmd;
+	rcu_read_unlock();
+
+	return cmd;
 }
 
 static inline u32 tcf_pedit_mask(const struct tc_action *a, int index)
 {
-	return to_pedit(a)->tcfp_keys[index].mask;
+	struct tcf_pedit_parms *parms;
+	u32 mask;
+
+	rcu_read_lock();
+	parms = to_pedit_parms(a);
+	mask = parms->tcfp_keys[index].mask;
+	rcu_read_unlock();
+
+	return mask;
 }
 
 static inline u32 tcf_pedit_val(const struct tc_action *a, int index)
 {
-	return to_pedit(a)->tcfp_keys[index].val;
+	struct tcf_pedit_parms *parms;
+	u32 val;
+
+	rcu_read_lock();
+	parms = to_pedit_parms(a);
+	val = parms->tcfp_keys[index].val;
+	rcu_read_unlock();
+
+	return val;
 }
 
 static inline u32 tcf_pedit_offset(const struct tc_action *a, int index)
 {
-	return to_pedit(a)->tcfp_keys[index].off;
+	struct tcf_pedit_parms *parms;
+	u32 off;
+
+	rcu_read_lock();
+	parms = to_pedit_parms(a);
+	off = parms->tcfp_keys[index].off;
+	rcu_read_unlock();
+
+	return off;
 }
 #endif /* __NET_TC_PED_H */
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index a0378e9f0121..c42fcc47dd6d 100644
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -134,6 +134,17 @@ nla_failure:
 	return -EINVAL;
 }
 
+static void tcf_pedit_cleanup_rcu(struct rcu_head *head)
+{
+	struct tcf_pedit_parms *parms =
+		container_of(head, struct tcf_pedit_parms, rcu);
+
+	kfree(parms->tcfp_keys_ex);
+	kfree(parms->tcfp_keys);
+
+	kfree(parms);
+}
+
 static int tcf_pedit_init(struct net *net, struct nlattr *nla,
 			  struct nlattr *est, struct tc_action **a,
 			  struct tcf_proto *tp, u32 flags,
@@ -141,10 +152,9 @@ static int tcf_pedit_init(struct net *net, struct nlattr *nla,
 {
 	struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id);
 	bool bind = flags & TCA_ACT_FLAGS_BIND;
-	struct nlattr *tb[TCA_PEDIT_MAX + 1];
 	struct tcf_chain *goto_ch = NULL;
-	struct tc_pedit_key *keys = NULL;
-	struct tcf_pedit_key_ex *keys_ex;
+	struct tcf_pedit_parms *oparms, *nparms;
+	struct nlattr *tb[TCA_PEDIT_MAX + 1];
 	struct tc_pedit *parm;
 	struct nlattr *pattr;
 	struct tcf_pedit *p;
@@ -181,18 +191,25 @@ static int tcf_pedit_init(struct net *net, struct nlattr *nla,
 		return -EINVAL;
 	}
 
-	keys_ex = tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys);
-	if (IS_ERR(keys_ex))
-		return PTR_ERR(keys_ex);
+	nparms = kzalloc(sizeof(*nparms), GFP_KERNEL);
+	if (!nparms)
+		return -ENOMEM;
+
+	nparms->tcfp_keys_ex =
+		tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys);
+	if (IS_ERR(nparms->tcfp_keys_ex)) {
+		ret = PTR_ERR(nparms->tcfp_keys_ex);
+		goto out_free;
+	}
 
 	index = parm->index;
 	err = tcf_idr_check_alloc(tn, &index, a, bind);
 	if (!err) {
-		ret = tcf_idr_create(tn, index, est, a,
-				     &act_pedit_ops, bind, false, flags);
+		ret = tcf_idr_create_from_flags(tn, index, est, a,
+						&act_pedit_ops, bind, flags);
 		if (ret) {
 			tcf_idr_cleanup(tn, index);
-			goto out_free;
+			goto out_free_ex;
 		}
 		ret = ACT_P_CREATED;
 	} else if (err > 0) {
@@ -204,7 +221,7 @@ static int tcf_pedit_init(struct net *net, struct nlattr *nla,
 		}
 	} else {
 		ret = err;
-		goto out_free;
+		goto out_free_ex;
 	}
 
 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
@@ -212,48 +229,50 @@ static int tcf_pedit_init(struct net *net, struct nlattr *nla,
 		ret = err;
 		goto out_release;
 	}
-	p = to_pedit(*a);
-	spin_lock_bh(&p->tcf_lock);
 
-	if (ret == ACT_P_CREATED ||
-	    (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys)) {
-		keys = kmalloc(ksize, GFP_ATOMIC);
-		if (!keys) {
-			spin_unlock_bh(&p->tcf_lock);
-			ret = -ENOMEM;
-			goto put_chain;
-		}
-		kfree(p->tcfp_keys);
-		p->tcfp_keys = keys;
-		p->tcfp_nkeys = parm->nkeys;
+	nparms->tcfp_off_max_hint = 0;
+	nparms->tcfp_flags = parm->flags;
+	nparms->tcfp_nkeys = parm->nkeys;
+
+	nparms->tcfp_keys = kmalloc(ksize, GFP_KERNEL);
+	if (!nparms->tcfp_keys) {
+		ret = -ENOMEM;
+		goto put_chain;
 	}
-	memcpy(p->tcfp_keys, parm->keys, ksize);
-	p->tcfp_off_max_hint = 0;
-	for (i = 0; i < p->tcfp_nkeys; ++i) {
-		u32 cur = p->tcfp_keys[i].off;
+
+	memcpy(nparms->tcfp_keys, parm->keys, ksize);
+
+	for (i = 0; i < nparms->tcfp_nkeys; ++i) {
+		u32 cur = nparms->tcfp_keys[i].off;
 
 		/* sanitize the shift value for any later use */
-		p->tcfp_keys[i].shift = min_t(size_t, BITS_PER_TYPE(int) - 1,
-					      p->tcfp_keys[i].shift);
+		nparms->tcfp_keys[i].shift = min_t(size_t,
+						   BITS_PER_TYPE(int) - 1,
+						   nparms->tcfp_keys[i].shift);
 
 		/* The AT option can read a single byte, we can bound the actual
 		 * value with uchar max.
 		 */
-		cur += (0xff & p->tcfp_keys[i].offmask) >> p->tcfp_keys[i].shift;
+		cur += (0xff & nparms->tcfp_keys[i].offmask) >> nparms->tcfp_keys[i].shift;
 
 		/* Each key touches 4 bytes starting from the computed offset */
-		p->tcfp_off_max_hint = max(p->tcfp_off_max_hint, cur + 4);
+		nparms->tcfp_off_max_hint =
+			max(nparms->tcfp_off_max_hint, cur + 4);
 	}
 
-	p->tcfp_flags = parm->flags;
+	p = to_pedit(*a);
+
+	spin_lock_bh(&p->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
+	oparms = rcu_replace_pointer(p->parms, nparms, 1);
+	spin_unlock_bh(&p->tcf_lock);
 
-	kfree(p->tcfp_keys_ex);
-	p->tcfp_keys_ex = keys_ex;
+	if (oparms)
+		call_rcu(&oparms->rcu, tcf_pedit_cleanup_rcu);
 
-	spin_unlock_bh(&p->tcf_lock);
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);
+
 	return ret;
 
 put_chain:
@@ -261,19 +280,22 @@ put_chain:
 		tcf_chain_put_by_act(goto_ch);
 out_release:
 	tcf_idr_release(*a, bind);
+out_free_ex:
+	kfree(nparms->tcfp_keys_ex);
 out_free:
-	kfree(keys_ex);
+	kfree(nparms);
 	return ret;
-
 }
 
 static void tcf_pedit_cleanup(struct tc_action *a)
 {
 	struct tcf_pedit *p = to_pedit(a);
-	struct tc_pedit_key *keys = p->tcfp_keys;
+	struct tcf_pedit_parms *parms;
+
+	parms = rcu_dereference_protected(p->parms, 1);
 
-	kfree(keys);
-	kfree(p->tcfp_keys_ex);
+	if (parms)
+		call_rcu(&parms->rcu, tcf_pedit_cleanup_rcu);
 }
 
 static bool offset_valid(struct sk_buff *skb, int offset)
@@ -324,109 +346,107 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 				    const struct tc_action *a,
 				    struct tcf_result *res)
 {
+	enum pedit_header_type htype = TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
+	enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET;
 	struct tcf_pedit *p = to_pedit(a);
+	struct tcf_pedit_key_ex *tkey_ex;
+	struct tcf_pedit_parms *parms;
+	struct tc_pedit_key *tkey;
 	u32 max_offset;
 	int i;
 
-	spin_lock(&p->tcf_lock);
+	parms = rcu_dereference_bh(p->parms);
 
 	max_offset = (skb_transport_header_was_set(skb) ?
 		      skb_transport_offset(skb) :
 		      skb_network_offset(skb)) +
-		     p->tcfp_off_max_hint;
+		     parms->tcfp_off_max_hint;
 	if (skb_ensure_writable(skb, min(skb->len, max_offset)))
-		goto unlock;
+		goto done;
 
 	tcf_lastuse_update(&p->tcf_tm);
+	tcf_action_update_bstats(&p->common, skb);
 
-	if (p->tcfp_nkeys > 0) {
-		struct tc_pedit_key *tkey = p->tcfp_keys;
-		struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex;
-		enum pedit_header_type htype =
-			TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
-		enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET;
-
-		for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
-			u32 *ptr, hdata;
-			int offset = tkey->off;
-			int hoffset;
-			u32 val;
-			int rc;
-
-			if (tkey_ex) {
-				htype = tkey_ex->htype;
-				cmd = tkey_ex->cmd;
-
-				tkey_ex++;
-			}
+	tkey = parms->tcfp_keys;
+	tkey_ex = parms->tcfp_keys_ex;
 
-			rc = pedit_skb_hdr_offset(skb, htype, &hoffset);
-			if (rc) {
-				pr_info("tc action pedit bad header type specified (0x%x)\n",
-					htype);
-				goto bad;
-			}
+	for (i = parms->tcfp_nkeys; i > 0; i--, tkey++) {
+		int offset = tkey->off;
+		u32 *ptr, hdata;
+		int hoffset;
+		u32 val;
+		int rc;
 
-			if (tkey->offmask) {
-				u8 *d, _d;
-
-				if (!offset_valid(skb, hoffset + tkey->at)) {
-					pr_info("tc action pedit 'at' offset %d out of bounds\n",
-						hoffset + tkey->at);
-					goto bad;
-				}
-				d = skb_header_pointer(skb, hoffset + tkey->at,
-						       sizeof(_d), &_d);
-				if (!d)
-					goto bad;
-				offset += (*d & tkey->offmask) >> tkey->shift;
-			}
+		if (tkey_ex) {
+			htype = tkey_ex->htype;
+			cmd = tkey_ex->cmd;
 
-			if (offset % 4) {
-				pr_info("tc action pedit offset must be on 32 bit boundaries\n");
-				goto bad;
-			}
+			tkey_ex++;
+		}
 
-			if (!offset_valid(skb, hoffset + offset)) {
-				pr_info("tc action pedit offset %d out of bounds\n",
-					hoffset + offset);
-				goto bad;
-			}
+		rc = pedit_skb_hdr_offset(skb, htype, &hoffset);
+		if (rc) {
+			pr_info("tc action pedit bad header type specified (0x%x)\n",
+				htype);
+			goto bad;
+		}
 
-			ptr = skb_header_pointer(skb, hoffset + offset,
-						 sizeof(hdata), &hdata);
-			if (!ptr)
-				goto bad;
-			/* just do it, baby */
-			switch (cmd) {
-			case TCA_PEDIT_KEY_EX_CMD_SET:
-				val = tkey->val;
-				break;
-			case TCA_PEDIT_KEY_EX_CMD_ADD:
-				val = (*ptr + tkey->val) & ~tkey->mask;
-				break;
-			default:
-				pr_info("tc action pedit bad command (%d)\n",
-					cmd);
+		if (tkey->offmask) {
+			u8 *d, _d;
+
+			if (!offset_valid(skb, hoffset + tkey->at)) {
+				pr_info("tc action pedit 'at' offset %d out of bounds\n",
+					hoffset + tkey->at);
 				goto bad;
 			}
+			d = skb_header_pointer(skb, hoffset + tkey->at,
+					       sizeof(_d), &_d);
+			if (!d)
+				goto bad;
+			offset += (*d & tkey->offmask) >> tkey->shift;
+		}
 
-			*ptr = ((*ptr & tkey->mask) ^ val);
-			if (ptr == &hdata)
-				skb_store_bits(skb, hoffset + offset, ptr, 4);
+		if (offset % 4) {
+			pr_info("tc action pedit offset must be on 32 bit boundaries\n");
+			goto bad;
 		}
 
-		goto done;
-	} else {
-		WARN(1, "pedit BUG: index %d\n", p->tcf_index);
+		if (!offset_valid(skb, hoffset + offset)) {
+			pr_info("tc action pedit offset %d out of bounds\n",
+				hoffset + offset);
+			goto bad;
+		}
+
+		ptr = skb_header_pointer(skb, hoffset + offset,
+					 sizeof(hdata), &hdata);
+		if (!ptr)
+			goto bad;
+		/* just do it, baby */
+		switch (cmd) {
+		case TCA_PEDIT_KEY_EX_CMD_SET:
+			val = tkey->val;
+			break;
+		case TCA_PEDIT_KEY_EX_CMD_ADD:
+			val = (*ptr + tkey->val) & ~tkey->mask;
+			break;
+		default:
+			pr_info("tc action pedit bad command (%d)\n",
+				cmd);
+			goto bad;
+		}
+
+		*ptr = ((*ptr & tkey->mask) ^ val);
+		if (ptr == &hdata)
+			skb_store_bits(skb, hoffset + offset, ptr, 4);
 	}
 
+	goto done;
+
 bad:
+	spin_lock(&p->tcf_lock);
 	p->tcf_qstats.overlimits++;
-done:
-	bstats_update(&p->tcf_bstats, skb);
-unlock:
 	spin_unlock(&p->tcf_lock);
+done:
 	return p->tcf_action;
 }
 
@@ -445,30 +465,33 @@ static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
 {
 	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_pedit *p = to_pedit(a);
+	struct tcf_pedit_parms *parms;
 	struct tc_pedit *opt;
 	struct tcf_t t;
 	int s;
 
-	s = struct_size(opt, keys, p->tcfp_nkeys);
+	spin_lock_bh(&p->tcf_lock);
+	parms = rcu_dereference_protected(p->parms, 1);
+	s = struct_size(opt, keys, parms->tcfp_nkeys);
 
-	/* netlink spinlocks held above us - must use ATOMIC */
 	opt = kzalloc(s, GFP_ATOMIC);
-	if (unlikely(!opt))
+	if (unlikely(!opt)) {
+		spin_unlock_bh(&p->tcf_lock);
 		return -ENOBUFS;
+	}
 
-	spin_lock_bh(&p->tcf_lock);
-	memcpy(opt->keys, p->tcfp_keys, flex_array_size(opt, keys, p->tcfp_nkeys));
+	memcpy(opt->keys, parms->tcfp_keys,
+	       flex_array_size(opt, keys, parms->tcfp_nkeys));
 	opt->index = p->tcf_index;
-	opt->nkeys = p->tcfp_nkeys;
-	opt->flags = p->tcfp_flags;
+	opt->nkeys = parms->tcfp_nkeys;
+	opt->flags = parms->tcfp_flags;
 	opt->action = p->tcf_action;
 	opt->refcnt = refcount_read(&p->tcf_refcnt) - ref;
 	opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind;
 
-	if (p->tcfp_keys_ex) {
-		if (tcf_pedit_key_ex_dump(skb,
-					  p->tcfp_keys_ex,
-					  p->tcfp_nkeys))
+	if (parms->tcfp_keys_ex) {
+		if (tcf_pedit_key_ex_dump(skb, parms->tcfp_keys_ex,
+					  parms->tcfp_nkeys))
 			goto nla_put_failure;
 
 		if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt))