net: sctp: rework debugging framework to use pr_debug and friends

We should get rid of all own SCTP debug printk macros and use the ones
that the kernel offers anyway instead. This makes the code more readable
and conform to the kernel code, and offers all the features of dynamic
debbuging that pr_debug() et al has, such as only turning on/off portions
of debug messages at runtime through debugfs. The runtime cost of having
CONFIG_DYNAMIC_DEBUG enabled, but none of the debug statements printing,
is negligible [1]. If kernel debugging is completly turned off, then these
statements will also compile into "empty" functions.

While we're at it, we also need to change the Kconfig option as it /now/
only refers to the ifdef'ed code portions in outqueue.c that enable further
debugging/tracing of SCTP transaction fields. Also, since SCTP_ASSERT code
was enabled with this Kconfig option and has now been removed, we
transform those code parts into WARNs resp. where appropriate BUG_ONs so
that those bugs can be more easily detected as probably not many people
have SCTP debugging permanently turned on.

To turn on all SCTP debugging, the following steps are needed:

 # mount -t debugfs none /sys/kernel/debug
 # echo -n 'module sctp +p' > /sys/kernel/debug/dynamic_debug/control

This can be done more fine-grained on a per file, per line basis and others
as described in [2].

 [1] https://www.kernel.org/doc/ols/2009/ols2009-pages-39-46.pdf
 [2] Documentation/dynamic-debug-howto.txt

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

16 files changed, 383 insertions, 409 deletions

diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig
index cf4852814e0..d80bf1aebae 100644
--- a/net/sctp/Kconfig
+++ b/net/sctp/Kconfig
@@ -30,7 +30,8 @@ menuconfig IP_SCTP
 	  homing at either or both ends of an association."
 
 	  To compile this protocol support as a module, choose M here: the
-	  module will be called sctp.
+	  module will be called sctp. Debug messages are handeled by the
+	  kernel's dynamic debugging framework.
 
 	  If in doubt, say N.
 
@@ -48,13 +49,14 @@ config NET_SCTPPROBE
         To compile this code as a module, choose M here: the
         module will be called sctp_probe.
 
-config SCTP_DBG_MSG
-	bool "SCTP: Debug messages"
+config SCTP_DBG_TSNS
+	bool "SCTP: Debug transactions"
 	help
-	  If you say Y, this will enable verbose debugging messages. 
+	  If you say Y, this will enable transaction debugging, visible
+	  from the kernel's dynamic debugging framework.
 
 	  If unsure, say N.  However, if you are running into problems, use 
-	  this option to gather detailed trace information
+	  this option to gather outqueue trace information.
 
 config SCTP_DBG_OBJCNT
 	bool "SCTP: Debug object counts"
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 9a383a8774e..bce5b79662a 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -357,7 +357,8 @@ struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
 		goto fail_init;
 
 	SCTP_DBG_OBJCNT_INC(assoc);
-	SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc);
+
+	pr_debug("Created asoc %p\n", asoc);
 
 	return asoc;
 
@@ -455,7 +456,10 @@ void sctp_association_free(struct sctp_association *asoc)
 /* Cleanup and free up an association. */
 static void sctp_association_destroy(struct sctp_association *asoc)
 {
-	SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
+	if (unlikely(!asoc->base.dead)) {
+		WARN(1, "Attempt to destroy undead association %p!\n", asoc);
+		return;
+	}
 
 	sctp_endpoint_put(asoc->ep);
 	sock_put(asoc->base.sk);
@@ -536,11 +540,8 @@ void sctp_assoc_rm_peer(struct sctp_association *asoc,
 	struct list_head	*pos;
 	struct sctp_transport	*transport;
 
-	SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
-				 " port: %d\n",
-				 asoc,
-				 (&peer->ipaddr),
-				 ntohs(peer->ipaddr.v4.sin_port));
+	pr_debug("%s: association:%p addr:%pISpc\n",
+		 __func__, asoc, &peer->ipaddr.sa);
 
 	/* If we are to remove the current retran_path, update it
 	 * to the next peer before removing this peer from the list.
@@ -636,12 +637,8 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
 	/* AF_INET and AF_INET6 share common port field. */
 	port = ntohs(addr->v4.sin_port);
 
-	SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
-				 " port: %d state:%d\n",
-				 asoc,
-				 addr,
-				 port,
-				 peer_state);
+	pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__,
+		 asoc, &addr->sa, peer_state);
 
 	/* Set the port if it has not been set yet.  */
 	if (0 == asoc->peer.port)
@@ -708,8 +705,9 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
 	else
 		asoc->pathmtu = peer->pathmtu;
 
-	SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
-			  "%d\n", asoc, asoc->pathmtu);
+	pr_debug("%s: association:%p PMTU set to %d\n", __func__, asoc,
+		 asoc->pathmtu);
+
 	peer->pmtu_pending = 0;
 
 	asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
@@ -1349,12 +1347,8 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc)
 	else
 		t = asoc->peer.retran_path;
 
-	SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
-				 " %p addr: ",
-				 " port: %d\n",
-				 asoc,
-				 (&t->ipaddr),
-				 ntohs(t->ipaddr.v4.sin_port));
+	pr_debug("%s: association:%p addr:%pISpc\n", __func__, asoc,
+		 &t->ipaddr.sa);
 }
 
 /* Choose the transport for sending retransmit packet.  */
@@ -1401,8 +1395,8 @@ void sctp_assoc_sync_pmtu(struct sock *sk, struct sctp_association *asoc)
 		asoc->frag_point = sctp_frag_point(asoc, pmtu);
 	}
 
-	SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
-			  __func__, asoc, asoc->pathmtu, asoc->frag_point);
+	pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
+		 asoc->pathmtu, asoc->frag_point);
 }
 
 /* Should we send a SACK to update our peer? */
@@ -1454,9 +1448,9 @@ void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
 		asoc->rwnd_press -= change;
 	}
 
-	SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
-			  "- %u\n", __func__, asoc, len, asoc->rwnd,
-			  asoc->rwnd_over, asoc->a_rwnd);
+	pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
+		 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
+		 asoc->a_rwnd);
 
 	/* Send a window update SACK if the rwnd has increased by at least the
 	 * minimum of the association's PMTU and half of the receive buffer.
@@ -1465,9 +1459,11 @@ void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
 	 */
 	if (sctp_peer_needs_update(asoc)) {
 		asoc->a_rwnd = asoc->rwnd;
-		SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
-				  "rwnd: %u a_rwnd: %u\n", __func__,
-				  asoc, asoc->rwnd, asoc->a_rwnd);
+
+		pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
+			 "a_rwnd:%u\n", __func__, asoc, asoc->rwnd,
+			 asoc->a_rwnd);
+
 		sack = sctp_make_sack(asoc);
 		if (!sack)
 			return;
@@ -1489,8 +1485,10 @@ void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
 	int rx_count;
 	int over = 0;
 
-	SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
-	SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
+	if (unlikely(!asoc->rwnd || asoc->rwnd_over))
+		pr_debug("%s: association:%p has asoc->rwnd:%u, "
+			 "asoc->rwnd_over:%u!\n", __func__, asoc,
+			 asoc->rwnd, asoc->rwnd_over);
 
 	if (asoc->ep->rcvbuf_policy)
 		rx_count = atomic_read(&asoc->rmem_alloc);
@@ -1515,9 +1513,10 @@ void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
 		asoc->rwnd_over = len - asoc->rwnd;
 		asoc->rwnd = 0;
 	}
-	SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u, %u)\n",
-			  __func__, asoc, len, asoc->rwnd,
-			  asoc->rwnd_over, asoc->rwnd_press);
+
+	pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
+		 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
+		 asoc->rwnd_press);
 }
 
 /* Build the bind address list for the association based on info from the
diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
index 7135fc0c087..5780565f5b7 100644
--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -193,8 +193,9 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
 		msg->expires_at = jiffies +
 				    msecs_to_jiffies(sinfo->sinfo_timetolive);
 		msg->can_abandon = 1;
-		SCTP_DEBUG_PRINTK("%s: msg:%p expires_at: %ld jiffies:%ld\n",
-				  __func__, msg, msg->expires_at, jiffies);
+
+		pr_debug("%s: msg:%p expires_at:%ld jiffies:%ld\n", __func__,
+			 msg, msg->expires_at, jiffies);
 	}
 
 	/* This is the biggest possible DATA chunk that can fit into
diff --git a/net/sctp/debug.c b/net/sctp/debug.c
index ec997cfe0a7..f4998780d6d 100644
--- a/net/sctp/debug.c
+++ b/net/sctp/debug.c
@@ -47,10 +47,6 @@
 
 #include <net/sctp/sctp.h>
 
-#if SCTP_DEBUG
-int sctp_debug_flag = 1;	/* Initially enable DEBUG */
-#endif	/* SCTP_DEBUG */
-
 /* These are printable forms of Chunk ID's from section 3.1.  */
 static const char *const sctp_cid_tbl[SCTP_NUM_BASE_CHUNK_TYPES] = {
 	"DATA",
diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
index b26999d508b..9e3d257de0e 100644
--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c
@@ -249,7 +249,10 @@ static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
 {
 	struct sock *sk;
 
-	SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
+	if (unlikely(!ep->base.dead)) {
+		WARN(1, "Attempt to destroy undead endpoint %p!\n", ep);
+		return;
+	}
 
 	/* Free the digest buffer */
 	kfree(ep->digest);
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 4cfc74699a3..3fa4d858c35 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -454,8 +454,6 @@ void sctp_icmp_proto_unreachable(struct sock *sk,
 			   struct sctp_association *asoc,
 			   struct sctp_transport *t)
 {
-	SCTP_DEBUG_PRINTK("%s\n",  __func__);
-
 	if (sock_owned_by_user(sk)) {
 		if (timer_pending(&t->proto_unreach_timer))
 			return;
@@ -464,10 +462,12 @@ void sctp_icmp_proto_unreachable(struct sock *sk,
 						jiffies + (HZ/20)))
 				sctp_association_hold(asoc);
 		}
-			
 	} else {
 		struct net *net = sock_net(sk);
 
+		pr_debug("%s: unrecognized next header type "
+			 "encountered!\n", __func__);
+
 		if (del_timer(&t->proto_unreach_timer))
 			sctp_association_put(asoc);
 
diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c
index 3221d073448..cb25f040fed 100644
--- a/net/sctp/inqueue.c
+++ b/net/sctp/inqueue.c
@@ -219,10 +219,10 @@ struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
 		chunk->end_of_packet = 1;
 	}
 
-	SCTP_DEBUG_PRINTK("+++sctp_inq_pop+++ chunk %p[%s],"
-			  " length %d, skb->len %d\n",chunk,
-			  sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
-			  ntohs(chunk->chunk_hdr->length), chunk->skb->len);
+	pr_debug("+++sctp_inq_pop+++ chunk:%p[%s], length:%d, skb->len:%d\n",
+		 chunk, sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
+		 ntohs(chunk->chunk_hdr->length), chunk->skb->len);
+
 	return chunk;
 }
 
@@ -238,4 +238,3 @@ void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback)
 {
 	INIT_WORK(&q->immediate, callback);
 }
-
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index adeaa0e64f5..09ffcc912d2 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -239,9 +239,8 @@ static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
 		fl6.daddr = *rt0->addr;
 	}
 
-	SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n",
-			  __func__, skb, skb->len,
-			  &fl6.saddr, &fl6.daddr);
+	pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
+		 skb->len, &fl6.saddr, &fl6.daddr);
 
 	SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 
@@ -276,7 +275,7 @@ static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 		fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 
-	SCTP_DEBUG_PRINTK("%s: DST=%pI6 ", __func__, &fl6->daddr);
+	pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 
 	if (asoc)
 		fl6->fl6_sport = htons(asoc->base.bind_addr.port);
@@ -284,7 +283,8 @@ static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 	if (saddr) {
 		fl6->saddr = saddr->v6.sin6_addr;
 		fl6->fl6_sport = saddr->v6.sin6_port;
-		SCTP_DEBUG_PRINTK("SRC=%pI6 - ", &fl6->saddr);
+
+		pr_debug("src=%pI6 - ", &fl6->saddr);
 	}
 
 	dst = ip6_dst_lookup_flow(sk, fl6, NULL, false);
@@ -348,13 +348,16 @@ static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 out:
 	if (!IS_ERR_OR_NULL(dst)) {
 		struct rt6_info *rt;
+
 		rt = (struct rt6_info *)dst;
 		t->dst = dst;
-		SCTP_DEBUG_PRINTK("rt6_dst:%pI6 rt6_src:%pI6\n",
-			&rt->rt6i_dst.addr, &fl6->saddr);
+
+		pr_debug("rt6_dst:%pI6 rt6_src:%pI6\n", &rt->rt6i_dst.addr,
+			 &fl6->saddr);
 	} else {
 		t->dst = NULL;
-		SCTP_DEBUG_PRINTK("NO ROUTE\n");
+
+		pr_debug("no route\n");
 	}
 }
 
@@ -377,7 +380,7 @@ static void sctp_v6_get_saddr(struct sctp_sock *sk,
 	struct flowi6 *fl6 = &fl->u.ip6;
 	union sctp_addr *saddr = &t->saddr;
 
-	SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
+	pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 
 	if (t->dst) {
 		saddr->v6.sin6_family = AF_INET6;
diff --git a/net/sctp/output.c b/net/sctp/output.c
index bbef4a7a9b5..a46d1eb4176 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -93,8 +93,7 @@ struct sctp_packet *sctp_packet_config(struct sctp_packet *packet,
 {
 	struct sctp_chunk *chunk = NULL;
 
-	SCTP_DEBUG_PRINTK("%s: packet:%p vtag:0x%x\n", __func__,
-			  packet, vtag);
+	pr_debug("%s: packet:%p vtag:0x%x\n", __func__, packet, vtag);
 
 	packet->vtag = vtag;
 
@@ -119,8 +118,7 @@ struct sctp_packet *sctp_packet_init(struct sctp_packet *packet,
 	struct sctp_association *asoc = transport->asoc;
 	size_t overhead;
 
-	SCTP_DEBUG_PRINTK("%s: packet:%p transport:%p\n", __func__,
-			  packet, transport);
+	pr_debug("%s: packet:%p transport:%p\n", __func__, packet, transport);
 
 	packet->transport = transport;
 	packet->source_port = sport;
@@ -145,7 +143,7 @@ void sctp_packet_free(struct sctp_packet *packet)
 {
 	struct sctp_chunk *chunk, *tmp;
 
-	SCTP_DEBUG_PRINTK("%s: packet:%p\n", __func__, packet);
+	pr_debug("%s: packet:%p\n", __func__, packet);
 
 	list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) {
 		list_del_init(&chunk->list);
@@ -167,8 +165,7 @@ sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *packet,
 	sctp_xmit_t retval;
 	int error = 0;
 
-	SCTP_DEBUG_PRINTK("%s: packet:%p chunk:%p\n", __func__,
-			  packet, chunk);
+	pr_debug("%s: packet:%p chunk:%p\n", __func__, packet, chunk);
 
 	switch ((retval = (sctp_packet_append_chunk(packet, chunk)))) {
 	case SCTP_XMIT_PMTU_FULL:
@@ -334,8 +331,7 @@ sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *packet,
 {
 	sctp_xmit_t retval = SCTP_XMIT_OK;
 
-	SCTP_DEBUG_PRINTK("%s: packet:%p chunk:%p\n", __func__, packet,
-			  chunk);
+	pr_debug("%s: packet:%p chunk:%p\n", __func__, packet, chunk);
 
 	/* Data chunks are special.  Before seeing what else we can
 	 * bundle into this packet, check to see if we are allowed to
@@ -402,7 +398,7 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 	unsigned char *auth = NULL;	/* pointer to auth in skb data */
 	__u32 cksum_buf_len = sizeof(struct sctphdr);
 
-	SCTP_DEBUG_PRINTK("%s: packet:%p\n", __func__, packet);
+	pr_debug("%s: packet:%p\n", __func__, packet);
 
 	/* Do NOT generate a chunkless packet. */
 	if (list_empty(&packet->chunk_list))
@@ -472,7 +468,9 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 	 *
 	 * [This whole comment explains WORD_ROUND() below.]
 	 */
-	SCTP_DEBUG_PRINTK("***sctp_transmit_packet***\n");
+
+	pr_debug("***sctp_transmit_packet***\n");
+
 	list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) {
 		list_del_init(&chunk->list);
 		if (sctp_chunk_is_data(chunk)) {
@@ -505,16 +503,13 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 		memcpy(skb_put(nskb, chunk->skb->len),
 			       chunk->skb->data, chunk->skb->len);
 
-		SCTP_DEBUG_PRINTK("%s %p[%s] %s 0x%x, %s %d, %s %d, %s %d\n",
-				  "*** Chunk", chunk,
-				  sctp_cname(SCTP_ST_CHUNK(
-					  chunk->chunk_hdr->type)),
-				  chunk->has_tsn ? "TSN" : "No TSN",
-				  chunk->has_tsn ?
-				  ntohl(chunk->subh.data_hdr->tsn) : 0,
-				  "length", ntohs(chunk->chunk_hdr->length),
-				  "chunk->skb->len", chunk->skb->len,
-				  "rtt_in_progress", chunk->rtt_in_progress);
+		pr_debug("*** Chunk:%p[%s] %s 0x%x, length:%d, chunk->skb->len:%d, "
+			 "rtt_in_progress:%d\n", chunk,
+			 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
+			 chunk->has_tsn ? "TSN" : "No TSN",
+			 chunk->has_tsn ? ntohl(chunk->subh.data_hdr->tsn) : 0,
+			 ntohs(chunk->chunk_hdr->length), chunk->skb->len,
+			 chunk->rtt_in_progress);
 
 		/*
 		 * If this is a control chunk, this is our last
@@ -606,8 +601,7 @@ int sctp_packet_transmit(struct sctp_packet *packet)
 		}
 	}
 
-	SCTP_DEBUG_PRINTK("***sctp_transmit_packet*** skb len %d\n",
-			  nskb->len);
+	pr_debug("***sctp_transmit_packet*** skb->len:%d\n", nskb->len);
 
 	nskb->local_df = packet->ipfragok;
 	(*tp->af_specific->sctp_xmit)(nskb, tp);
diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index be35e2dbcc9..511b3b35d60 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -299,10 +299,10 @@ int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
 	struct net *net = sock_net(q->asoc->base.sk);
 	int error = 0;
 
-	SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n",
-			  q, chunk, chunk && chunk->chunk_hdr ?
-			  sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
-			  : "Illegal Chunk");
+	pr_debug("%s: outq:%p, chunk:%p[%s]\n", __func__, q, chunk,
+		 chunk && chunk->chunk_hdr ?
+		 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) :
+		 "illegal chunk");
 
 	/* If it is data, queue it up, otherwise, send it
 	 * immediately.
@@ -328,10 +328,10 @@ int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk)
 			break;
 
 		default:
-			SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n",
-			  q, chunk, chunk && chunk->chunk_hdr ?
-			  sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type))
-			  : "Illegal Chunk");
+			pr_debug("%s: outqueueing: outq:%p, chunk:%p[%s])\n",
+				 __func__, q, chunk, chunk && chunk->chunk_hdr ?
+				 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) :
+				 "illegal chunk");
 
 			sctp_outq_tail_data(q, chunk);
 			if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
@@ -460,14 +460,10 @@ void sctp_retransmit_mark(struct sctp_outq *q,
 		}
 	}
 
-	SCTP_DEBUG_PRINTK("%s: transport: %p, reason: %d, "
-			  "cwnd: %d, ssthresh: %d, flight_size: %d, "
-			  "pba: %d\n", __func__,
-			  transport, reason,
-			  transport->cwnd, transport->ssthresh,
-			  transport->flight_size,
-			  transport->partial_bytes_acked);
-
+	pr_debug("%s: transport:%p, reason:%d, cwnd:%d, ssthresh:%d, "
+		 "flight_size:%d, pba:%d\n", __func__, transport, reason,
+		 transport->cwnd, transport->ssthresh, transport->flight_size,
+		 transport->partial_bytes_acked);
 }
 
 /* Mark all the eligible packets on a transport for retransmission and force
@@ -1014,19 +1010,13 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
 				sctp_transport_burst_limited(transport);
 			}
 
-			SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ",
-					  q, chunk,
-					  chunk && chunk->chunk_hdr ?
-					  sctp_cname(SCTP_ST_CHUNK(
-						  chunk->chunk_hdr->type))
-					  : "Illegal Chunk");
-
-			SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head "
-					"%p skb->users %d.\n",
-					ntohl(chunk->subh.data_hdr->tsn),
-					chunk->skb ?chunk->skb->head : NULL,
-					chunk->skb ?
-					atomic_read(&chunk->skb->users) : -1);
+			pr_debug("%s: outq:%p, chunk:%p[%s], tx-tsn:0x%x skb->head:%p "
+				 "skb->users:%d\n",
+				 __func__, q, chunk, chunk && chunk->chunk_hdr ?
+				 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) :
+				 "illegal chunk", ntohl(chunk->subh.data_hdr->tsn),
+				 chunk->skb ? chunk->skb->head : NULL, chunk->skb ?
+				 atomic_read(&chunk->skb->users) : -1);
 
 			/* Add the chunk to the packet.  */
 			status = sctp_packet_transmit_chunk(packet, chunk, 0);
@@ -1038,10 +1028,10 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
 				/* We could not append this chunk, so put
 				 * the chunk back on the output queue.
 				 */
-				SCTP_DEBUG_PRINTK("sctp_outq_flush: could "
-					"not transmit TSN: 0x%x, status: %d\n",
-					ntohl(chunk->subh.data_hdr->tsn),
-					status);
+				pr_debug("%s: could not transmit tsn:0x%x, status:%d\n",
+					 __func__, ntohl(chunk->subh.data_hdr->tsn),
+					 status);
+
 				sctp_outq_head_data(q, chunk);
 				goto sctp_flush_out;
 				break;
@@ -1284,11 +1274,10 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_chunk *chunk)
 
 	sctp_generate_fwdtsn(q, sack_ctsn);
 
-	SCTP_DEBUG_PRINTK("%s: sack Cumulative TSN Ack is 0x%x.\n",
-			  __func__, sack_ctsn);
-	SCTP_DEBUG_PRINTK("%s: Cumulative TSN Ack of association, "
-			  "%p is 0x%x. Adv peer ack point: 0x%x\n",
-			  __func__, asoc, ctsn, asoc->adv_peer_ack_point);
+	pr_debug("%s: sack cumulative tsn ack:0x%x\n", __func__, sack_ctsn);
+	pr_debug("%s: cumulative tsn ack of assoc:%p is 0x%x, "
+		 "advertised peer ack point:0x%x\n", __func__, asoc, ctsn,
+		 asoc->adv_peer_ack_point);
 
 	/* See if all chunks are acked.
 	 * Make sure the empty queue handler will get run later.
@@ -1304,7 +1293,7 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_chunk *chunk)
 			goto finish;
 	}
 
-	SCTP_DEBUG_PRINTK("sack queue is empty.\n");
+	pr_debug("%s: sack queue is empty\n", __func__);
 finish:
 	return q->empty;
 }
@@ -1348,7 +1337,7 @@ static void sctp_check_transmitted(struct sctp_outq *q,
 
 	/* These state variables are for coherent debug output. --xguo */
 
-#if SCTP_DEBUG
+#ifdef CONFIG_SCTP_DBG_TSNS
 	__u32 dbg_ack_tsn = 0;	/* An ACKed TSN range starts here... */
 	__u32 dbg_last_ack_tsn = 0;  /* ...and finishes here.	     */
 	__u32 dbg_kept_tsn = 0;	/* An un-ACKed range starts here...  */
@@ -1359,7 +1348,7 @@ static void sctp_check_transmitted(struct sctp_outq *q,
 	 * -1: We need to initialize.
 	 */
 	int dbg_prt_state = -1;
-#endif /* SCTP_DEBUG */
+#endif /* CONFIG_SCTP_DBG_TSNS */
 
 	sack_ctsn = ntohl(sack->cum_tsn_ack);
 
@@ -1483,7 +1472,7 @@ static void sctp_check_transmitted(struct sctp_outq *q,
 				list_add_tail(lchunk, &tlist);
 			}
 
-#if SCTP_DEBUG
+#ifdef CONFIG_SCTP_DBG_TSNS
 			switch (dbg_prt_state) {
 			case 0:	/* last TSN was ACKed */
 				if (dbg_last_ack_tsn + 1 == tsn) {
@@ -1497,42 +1486,39 @@ static void sctp_check_transmitted(struct sctp_outq *q,
 					/* Display the end of the
 					 * current range.
 					 */
-					SCTP_DEBUG_PRINTK_CONT("-%08x",
-							       dbg_last_ack_tsn);
+					pr_cont("-%08x", dbg_last_ack_tsn);
 				}
 
 				/* Start a new range.  */
-				SCTP_DEBUG_PRINTK_CONT(",%08x", tsn);
+				pr_cont(",%08x", tsn);
 				dbg_ack_tsn = tsn;
 				break;
 
 			case 1:	/* The last TSN was NOT ACKed. */
 				if (dbg_last_kept_tsn != dbg_kept_tsn) {
 					/* Display the end of current range. */
-					SCTP_DEBUG_PRINTK_CONT("-%08x",
-							       dbg_last_kept_tsn);
+					pr_cont("-%08x", dbg_last_kept_tsn);
 				}
 
-				SCTP_DEBUG_PRINTK_CONT("\n");
-
+				pr_cont("\n");
 				/* FALL THROUGH... */
 			default:
 				/* This is the first-ever TSN we examined.  */
 				/* Start a new range of ACK-ed TSNs.  */
-				SCTP_DEBUG_PRINTK("ACKed: %08x", tsn);
+				pr_debug("ACKed: %08x", tsn);
+
 				dbg_prt_state = 0;
 				dbg_ack_tsn = tsn;
 			}
 
 			dbg_last_ack_tsn = tsn;
-#endif /* SCTP_DEBUG */
+#endif /* CONFIG_SCTP_DBG_TSNS */
 
 		} else {
 			if (tchunk->tsn_gap_acked) {
-				SCTP_DEBUG_PRINTK("%s: Receiver reneged on "
-						  "data TSN: 0x%x\n",
-						  __func__,
-						  tsn);
+				pr_debug("%s: receiver reneged on data TSN:0x%x\n",
+					 __func__, tsn);
+
 				tchunk->tsn_gap_acked = 0;
 
 				if (tchunk->transport)
@@ -1552,7 +1538,7 @@ static void sctp_check_transmitted(struct sctp_outq *q,
 
 			list_add_tail(lchunk, &tlist);
 
-#if SCTP_DEBUG
+#ifdef CONFIG_SCTP_DBG_TSNS
 			/* See the above comments on ACK-ed TSNs. */
 			switch (dbg_prt_state) {
 			case 1:
@@ -1560,50 +1546,47 @@ static void sctp_check_transmitted(struct sctp_outq *q,
 					break;
 
 				if (dbg_last_kept_tsn != dbg_kept_tsn)
-					SCTP_DEBUG_PRINTK_CONT("-%08x",
-							       dbg_last_kept_tsn);
+					pr_cont("-%08x", dbg_last_kept_tsn);
 
-				SCTP_DEBUG_PRINTK_CONT(",%08x", tsn);
+				pr_cont(",%08x", tsn);
 				dbg_kept_tsn = tsn;
 				break;
 
 			case 0:
 				if (dbg_last_ack_tsn != dbg_ack_tsn)
-					SCTP_DEBUG_PRINTK_CONT("-%08x",
-							       dbg_last_ack_tsn);
-				SCTP_DEBUG_PRINTK_CONT("\n");
+					pr_cont("-%08x", dbg_last_ack_tsn);
 
+				pr_cont("\n");
 				/* FALL THROUGH... */
 			default:
-				SCTP_DEBUG_PRINTK("KEPT: %08x",tsn);
+				pr_debug("KEPT: %08x", tsn);
+
 				dbg_prt_state = 1;
 				dbg_kept_tsn = tsn;
 			}
 
 			dbg_last_kept_tsn = tsn;
-#endif /* SCTP_DEBUG */
+#endif /* CONFIG_SCTP_DBG_TSNS */
 		}
 	}
 
-#if SCTP_DEBUG
+#ifdef CONFIG_SCTP_DBG_TSNS
 	/* Finish off the last range, displaying its ending TSN.  */
 	switch (dbg_prt_state) {
 	case 0:
-		if (dbg_last_ack_tsn != dbg_ack_tsn) {
-			SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_ack_tsn);
-		} else {
-			SCTP_DEBUG_PRINTK_CONT("\n");
-		}
-	break;
-
+		if (dbg_last_ack_tsn != dbg_ack_tsn)
+			pr_cont("-%08x\n", dbg_last_ack_tsn);
+		else
+			pr_cont("\n");
+		break;
 	case 1:
-		if (dbg_last_kept_tsn != dbg_kept_tsn) {
-			SCTP_DEBUG_PRINTK_CONT("-%08x\n", dbg_last_kept_tsn);
-		} else {
-			SCTP_DEBUG_PRINTK_CONT("\n");
-		}
+		if (dbg_last_kept_tsn != dbg_kept_tsn)
+			pr_cont("-%08x\n", dbg_last_kept_tsn);
+		else
+			pr_cont("\n");
+		break;
 	}
-#endif /* SCTP_DEBUG */
+#endif /* CONFIG_SCTP_DBG_TSNS */
 	if (transport) {
 		if (bytes_acked) {
 			struct sctp_association *asoc = transport->asoc;
@@ -1676,9 +1659,9 @@ static void sctp_check_transmitted(struct sctp_outq *q,
 			    !list_empty(&tlist) &&
 			    (sack_ctsn+2 == q->asoc->next_tsn) &&
 			    q->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) {
-				SCTP_DEBUG_PRINTK("%s: SACK received for zero "
-						  "window probe: %u\n",
-						  __func__, sack_ctsn);
+				pr_debug("%s: sack received for zero window "
+					 "probe:%u\n", __func__, sack_ctsn);
+
 				q->asoc->overall_error_count = 0;
 				transport->error_count = 0;
 			}
@@ -1739,10 +1722,8 @@ static void sctp_mark_missing(struct sctp_outq *q,
 						count_of_newacks, tsn)) {
 				chunk->tsn_missing_report++;
 
-				SCTP_DEBUG_PRINTK(
-					"%s: TSN 0x%x missing counter: %d\n",
-					__func__, tsn,
-					chunk->tsn_missing_report);
+				pr_debug("%s: tsn:0x%x missing counter:%d\n",
+					 __func__, tsn, chunk->tsn_missing_report);
 			}
 		}
 		/*
@@ -1762,11 +1743,10 @@ static void sctp_mark_missing(struct sctp_outq *q,
 		if (do_fast_retransmit)
 			sctp_retransmit(q, transport, SCTP_RTXR_FAST_RTX);
 
-		SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
-				  "ssthresh: %d, flight_size: %d, pba: %d\n",
-				  __func__, transport, transport->cwnd,
-				  transport->ssthresh, transport->flight_size,
-				  transport->partial_bytes_acked);
+		pr_debug("%s: transport:%p, cwnd:%d, ssthresh:%d, "
+			 "flight_size:%d, pba:%d\n",  __func__, transport,
+			 transport->cwnd, transport->ssthresh,
+			 transport->flight_size, transport->partial_bytes_acked);
 	}
 }
 
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 1de49c802d8..4a17494d736 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -451,8 +451,8 @@ static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 		fl4->fl4_sport = saddr->v4.sin_port;
 	}
 
-	SCTP_DEBUG_PRINTK("%s: DST:%pI4, SRC:%pI4 - ",
-			  __func__, &fl4->daddr, &fl4->saddr);
+	pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
+		 &fl4->saddr);
 
 	rt = ip_route_output_key(sock_net(sk), fl4);
 	if (!IS_ERR(rt))
@@ -513,10 +513,10 @@ out_unlock:
 out:
 	t->dst = dst;
 	if (dst)
-		SCTP_DEBUG_PRINTK("rt_dst:%pI4, rt_src:%pI4\n",
-				  &fl4->daddr, &fl4->saddr);
+		pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
+			 &fl4->daddr, &fl4->saddr);
 	else
-		SCTP_DEBUG_PRINTK("NO ROUTE\n");
+		pr_debug("no route\n");
 }
 
 /* For v4, the source address is cached in the route entry(dst). So no need
@@ -604,9 +604,9 @@ static void sctp_addr_wq_timeout_handler(unsigned long arg)
 	spin_lock_bh(&net->sctp.addr_wq_lock);
 
 	list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
-		SCTP_DEBUG_PRINTK_IPADDR("sctp_addrwq_timo_handler: the first ent in wq %p is ",
-		    " for cmd %d at entry %p\n", &net->sctp.addr_waitq, &addrw->a, addrw->state,
-		    addrw);
+		pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
+			 "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
+			 addrw->state, addrw);
 
 #if IS_ENABLED(CONFIG_IPV6)
 		/* Now we send an ASCONF for each association */
@@ -623,8 +623,10 @@ static void sctp_addr_wq_timeout_handler(unsigned long arg)
 			    addrw->state == SCTP_ADDR_NEW) {
 				unsigned long timeo_val;
 
-				SCTP_DEBUG_PRINTK("sctp_timo_handler: this is on DAD, trying %d sec later\n",
-				    SCTP_ADDRESS_TICK_DELAY);
+				pr_debug("%s: this is on DAD, trying %d sec "
+					 "later\n", __func__,
+					 SCTP_ADDRESS_TICK_DELAY);
+
 				timeo_val = jiffies;
 				timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
 				mod_timer(&net->sctp.addr_wq_timer, timeo_val);
@@ -641,7 +643,7 @@ static void sctp_addr_wq_timeout_handler(unsigned long arg)
 				continue;
 			sctp_bh_lock_sock(sk);
 			if (sctp_asconf_mgmt(sp, addrw) < 0)
-				SCTP_DEBUG_PRINTK("sctp_addrwq_timo_handler: sctp_asconf_mgmt failed\n");
+				pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
 			sctp_bh_unlock_sock(sk);
 		}
 #if IS_ENABLED(CONFIG_IPV6)
@@ -707,9 +709,10 @@ void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cm
 	addrw = sctp_addr_wq_lookup(net, addr);
 	if (addrw) {
 		if (addrw->state != cmd) {
-			SCTP_DEBUG_PRINTK_IPADDR("sctp_addr_wq_mgmt offsets existing entry for %d ",
-			    " in wq %p\n", addrw->state, &addrw->a,
-			    &net->sctp.addr_waitq);
+			pr_debug("%s: offsets existing entry for %d, addr:%pISc "
+				 "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
+				 &net->sctp.addr_waitq);
+
 			list_del(&addrw->list);
 			kfree(addrw);
 		}
@@ -725,8 +728,9 @@ void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cm
 	}
 	addrw->state = cmd;
 	list_add_tail(&addrw->list, &net->sctp.addr_waitq);
-	SCTP_DEBUG_PRINTK_IPADDR("sctp_addr_wq_mgmt add new entry for cmd:%d ",
-	    " in wq %p\n", addrw->state, &addrw->a, &net->sctp.addr_waitq);
+
+	pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
+		 __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
 
 	if (!timer_pending(&net->sctp.addr_wq_timer)) {
 		timeo_val = jiffies;
@@ -952,15 +956,14 @@ static inline int sctp_v4_xmit(struct sk_buff *skb,
 {
 	struct inet_sock *inet = inet_sk(skb->sk);
 
-	SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n",
-			  __func__, skb,