diff mbox series

[v2,net-next] ipvs: reduce kernel stack usage

Message ID 20190722113009.2704377-1-arnd@arndb.de
State New
Headers show
Series [v2,net-next] ipvs: reduce kernel stack usage | expand

Commit Message

Arnd Bergmann July 22, 2019, 11:29 a.m. UTC 
With the new CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL option, the stack
usage in the ipvs debug output grows because each instance of
IP_VS_DBG_BUF() now has its own buffer of 160 bytes that add up
rather than reusing the stack slots:

net/netfilter/ipvs/ip_vs_core.c: In function 'ip_vs_sched_persist':
net/netfilter/ipvs/ip_vs_core.c:427:1: error: the frame size of 1052 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
net/netfilter/ipvs/ip_vs_core.c: In function 'ip_vs_new_conn_out':
net/netfilter/ipvs/ip_vs_core.c:1231:1: error: the frame size of 1048 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
net/netfilter/ipvs/ip_vs_ftp.c: In function 'ip_vs_ftp_out':
net/netfilter/ipvs/ip_vs_ftp.c:397:1: error: the frame size of 1104 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
net/netfilter/ipvs/ip_vs_ftp.c: In function 'ip_vs_ftp_in':
net/netfilter/ipvs/ip_vs_ftp.c:555:1: error: the frame size of 1200 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

Since printk() already has a way to print IPv4/IPv6 addresses using
the %pISc format string, use that instead, combined with a macro that
creates a local sockaddr structure on the stack. These will still
add up, but the stack frames are now under 200 bytes.

So far I have also only added three files that caused the warning
messages to be reported. There are still a lot of other instances of
IP_VS_DBG_BUF() that could be converted the same way after the
basic idea is confirmed.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
v2:
 - use compressed ipv6 format
 - fix port number endianess
---
 include/net/ip_vs.h             | 59 ++++++++++++++++-----------------
 net/netfilter/ipvs/ip_vs_core.c | 44 ++++++++++++------------
 net/netfilter/ipvs/ip_vs_ftp.c  | 20 +++++------
 3 files changed, 60 insertions(+), 63 deletions(-)

-- 
2.20.0
diff mbox series

Patch

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 3759167f91f5..eace4374e69f 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -227,6 +227,16 @@  static inline const char *ip_vs_dbg_addr(int af, char *buf, size_t buf_len,
 		       sizeof(ip_vs_dbg_buf), addr,			\
 		       &ip_vs_dbg_idx)
 
+#define IP_VS_DBG_SOCKADDR4(fam, addr, port)				\
+	(struct sockaddr*)&(struct sockaddr_in)				\
+	{ .sin_family = (fam), .sin_addr = (addr)->in, .sin_port = (port) }
+#define IP_VS_DBG_SOCKADDR6(fam, addr, port)				\
+	(struct sockaddr*)&(struct sockaddr_in6) \
+	{ .sin6_family = (fam), .sin6_addr = (addr)->in6, .sin6_port = (port) }
+#define IP_VS_DBG_SOCKADDR(fam, addr, port) (fam == AF_INET ?		\
+			IP_VS_DBG_SOCKADDR4(fam, addr, port) :		\
+			IP_VS_DBG_SOCKADDR6(fam, addr, port))
+
 #define IP_VS_DBG(level, msg, ...)					\
 	do {								\
 		if (level <= ip_vs_get_debug_level())			\
@@ -251,6 +261,7 @@  static inline const char *ip_vs_dbg_addr(int af, char *buf, size_t buf_len,
 #else	/* NO DEBUGGING at ALL */
 #define IP_VS_DBG_BUF(level, msg...)  do {} while (0)
 #define IP_VS_ERR_BUF(msg...)  do {} while (0)
+#define IP_VS_DBG_SOCKADDR(fam, addr, port) NULL
 #define IP_VS_DBG(level, msg...)  do {} while (0)
 #define IP_VS_DBG_RL(msg...)  do {} while (0)
 #define IP_VS_DBG_PKT(level, af, pp, skb, ofs, msg)	do {} while (0)
@@ -1244,31 +1255,23 @@  static inline void ip_vs_control_del(struct ip_vs_conn *cp)
 {
 	struct ip_vs_conn *ctl_cp = cp->control;
 	if (!ctl_cp) {
-		IP_VS_ERR_BUF("request control DEL for uncontrolled: "
-			      "%s:%d to %s:%d\n",
-			      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
-			      ntohs(cp->cport),
-			      IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
-			      ntohs(cp->vport));
+		pr_err("request control DEL for uncontrolled: "
+		       "%pISpc to %pISpcn",
+		       IP_VS_DBG_SOCKADDR(cp->af, &cp->caddr, cp->cport),
+		       IP_VS_DBG_SOCKADDR(cp->af, &cp->vaddr, cp->vport));
 
 		return;
 	}
 
-	IP_VS_DBG_BUF(7, "DELeting control for: "
-		      "cp.dst=%s:%d ctl_cp.dst=%s:%d\n",
-		      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
-		      ntohs(cp->cport),
-		      IP_VS_DBG_ADDR(cp->af, &ctl_cp->caddr),
-		      ntohs(ctl_cp->cport));
+	IP_VS_DBG(7, "DELeting control for: cp.dst=%pISpc ctl_cp.dst=%pISpc\n",
+		  IP_VS_DBG_SOCKADDR(cp->af, &cp->caddr, cp->cport),
+		  IP_VS_DBG_SOCKADDR(cp->af, &ctl_cp->caddr, ctl_cp->cport));
 
 	cp->control = NULL;
 	if (atomic_read(&ctl_cp->n_control) == 0) {
-		IP_VS_ERR_BUF("BUG control DEL with n=0 : "
-			      "%s:%d to %s:%d\n",
-			      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
-			      ntohs(cp->cport),
-			      IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
-			      ntohs(cp->vport));
+		pr_err("BUG control DEL with n=0 : %pISpc to %pISpc\n",
+		       IP_VS_DBG_SOCKADDR(cp->af, &cp->caddr, cp->cport),
+		       IP_VS_DBG_SOCKADDR(cp->af, &cp->vaddr, cp->vport));
 
 		return;
 	}
@@ -1279,22 +1282,18 @@  static inline void
 ip_vs_control_add(struct ip_vs_conn *cp, struct ip_vs_conn *ctl_cp)
 {
 	if (cp->control) {
-		IP_VS_ERR_BUF("request control ADD for already controlled: "
-			      "%s:%d to %s:%d\n",
-			      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
-			      ntohs(cp->cport),
-			      IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
-			      ntohs(cp->vport));
+		pr_err("request control ADD for already controlled: "
+		       "%pISpc to %pISpc\n",
+		       IP_VS_DBG_SOCKADDR(cp->af, &cp->caddr, cp->cport),
+		       IP_VS_DBG_SOCKADDR(cp->af, &cp->vaddr, cp->vport));
 
 		ip_vs_control_del(cp);
 	}
 
-	IP_VS_DBG_BUF(7, "ADDing control for: "
-		      "cp.dst=%s:%d ctl_cp.dst=%s:%d\n",
-		      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
-		      ntohs(cp->cport),
-		      IP_VS_DBG_ADDR(cp->af, &ctl_cp->caddr),
-		      ntohs(ctl_cp->cport));
+	IP_VS_DBG(7, "ADDing control for: "
+		  "cp.dst=%pISpc ctl_cp.dst=%pISpc\n",
+		  IP_VS_DBG_SOCKADDR(cp->af, &cp->caddr, cp->cport),
+		  IP_VS_DBG_SOCKADDR(cp->af, &ctl_cp->caddr, ctl_cp->cport));
 
 	cp->control = ctl_cp;
 	atomic_inc(&ctl_cp->n_control);
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index 46f06f92ab8f..06ab0bf9ae08 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -52,7 +52,6 @@ 
 #include <net/ip_vs.h>
 #include <linux/indirect_call_wrapper.h>
 
-
 EXPORT_SYMBOL(register_ip_vs_scheduler);
 EXPORT_SYMBOL(unregister_ip_vs_scheduler);
 EXPORT_SYMBOL(ip_vs_proto_name);
@@ -295,11 +294,11 @@  ip_vs_sched_persist(struct ip_vs_service *svc,
 #endif
 		snet.ip = src_addr->ip & svc->netmask;
 
-	IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
-		      "mnet %s\n",
-		      IP_VS_DBG_ADDR(svc->af, src_addr), ntohs(src_port),
-		      IP_VS_DBG_ADDR(svc->af, dst_addr), ntohs(dst_port),
-		      IP_VS_DBG_ADDR(svc->af, &snet));
+	IP_VS_DBG(6, "p-schedule: src %pISpc dest %pISpc "
+		      "mnet %pIS\n",
+		      IP_VS_DBG_SOCKADDR(svc->af, src_addr, src_port),
+		      IP_VS_DBG_SOCKADDR(svc->af, dst_addr, dst_port),
+		      IP_VS_DBG_SOCKADDR(svc->af, &snet, 0));
 
 	/*
 	 * As far as we know, FTP is a very complicated network protocol, and
@@ -567,12 +566,12 @@  ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
 		}
 	}
 
-	IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
-		      "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
+	IP_VS_DBG(6, "Schedule fwd:%c c:%pISpc v:%pISpc "
+		      "d:%pISp conn->flags:%X conn->refcnt:%d\n",
 		      ip_vs_fwd_tag(cp),
-		      IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
-		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
-		      IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
+		      IP_VS_DBG_SOCKADDR(cp->af, &cp->caddr, cp->cport),
+		      IP_VS_DBG_SOCKADDR(cp->af, &cp->vaddr, cp->vport),
+		      IP_VS_DBG_SOCKADDR(cp->daf, &cp->daddr, cp->dport),
 		      cp->flags, refcount_read(&cp->refcnt));
 
 	ip_vs_conn_stats(cp, svc);
@@ -886,8 +885,8 @@  static int handle_response_icmp(int af, struct sk_buff *skb,
 	/* Ensure the checksum is correct */
 	if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
 		/* Failed checksum! */
-		IP_VS_DBG_BUF(1, "Forward ICMP: failed checksum from %s!\n",
-			      IP_VS_DBG_ADDR(af, snet));
+		IP_VS_DBG(1, "Forward ICMP: failed checksum from %pISc!\n",
+			      IP_VS_DBG_SOCKADDR(af, snet, 0));
 		goto out;
 	}
 
@@ -1220,13 +1219,13 @@  struct ip_vs_conn *ip_vs_new_conn_out(struct ip_vs_service *svc,
 	ip_vs_conn_stats(cp, svc);
 
 	/* return connection (will be used to handle outgoing packet) */
-	IP_VS_DBG_BUF(6, "New connection RS-initiated:%c c:%s:%u v:%s:%u "
-		      "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
-		      ip_vs_fwd_tag(cp),
-		      IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
-		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
-		      IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
-		      cp->flags, refcount_read(&cp->refcnt));
+	IP_VS_DBG(6, "New connection RS-initiated:%c c:%pISpc v:%pISpc "
+		  "d:%pISp conn->flags:%X conn->refcnt:%d\n",
+		  ip_vs_fwd_tag(cp),
+		  IP_VS_DBG_SOCKADDR(cp->af, &cp->caddr, cp->cport),
+		  IP_VS_DBG_SOCKADDR(cp->af, &cp->vaddr, cp->vport),
+		  IP_VS_DBG_SOCKADDR(cp->af, &cp->daddr, cp->dport),
+		  cp->flags, refcount_read(&cp->refcnt));
 	LeaveFunction(12);
 	return cp;
 }
@@ -1969,7 +1968,6 @@  static int ip_vs_in_icmp_v6(struct netns_ipvs *ipvs, struct sk_buff *skb,
 }
 #endif
 
-
 /*
  *	Check if it's for virtual services, look it up,
  *	and send it on its way...
@@ -1998,10 +1996,10 @@  ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int
 		      hooknum != NF_INET_LOCAL_OUT) ||
 		     !skb_dst(skb))) {
 		ip_vs_fill_iph_skb(af, skb, false, &iph);
-		IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s"
+		IP_VS_DBG(12, "packet type=%d proto=%d daddr=%pISc"
 			      " ignored in hook %u\n",
 			      skb->pkt_type, iph.protocol,
-			      IP_VS_DBG_ADDR(af, &iph.daddr), hooknum);
+			      IP_VS_DBG_SOCKADDR(af, &iph.daddr, 0), hooknum);
 		return NF_ACCEPT;
 	}
 	/* ipvs enabled in this netns ? */
diff --git a/net/netfilter/ipvs/ip_vs_ftp.c b/net/netfilter/ipvs/ip_vs_ftp.c
index cf925906f59b..22099c42e184 100644
--- a/net/netfilter/ipvs/ip_vs_ftp.c
+++ b/net/netfilter/ipvs/ip_vs_ftp.c
@@ -306,9 +306,9 @@  static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
 					   &start, &end) != 1)
 			return 1;
 
-		IP_VS_DBG_BUF(7, "EPSV response (%s:%u) -> %s:%u detected\n",
-			      IP_VS_DBG_ADDR(cp->af, &from), ntohs(port),
-			      IP_VS_DBG_ADDR(cp->af, &cp->caddr), 0);
+		IP_VS_DBG(7, "EPSV response (%pISpc) -> %pISc detected\n",
+			  IP_VS_DBG_SOCKADDR(cp->af, &from, port),
+			  IP_VS_DBG_SOCKADDR(cp->af, &cp->caddr, 0));
 	} else {
 		return 1;
 	}
@@ -510,15 +510,15 @@  static int ip_vs_ftp_in(struct ip_vs_app *app, struct ip_vs_conn *cp,
 					  &to, &port, cp->af,
 					  &start, &end) == 1) {
 
-		IP_VS_DBG_BUF(7, "EPRT %s:%u detected\n",
-			      IP_VS_DBG_ADDR(cp->af, &to), ntohs(port));
+		IP_VS_DBG(7, "EPRT %pISpc detected\n",
+			  IP_VS_DBG_SOCKADDR(cp->af, &to, port));
 
 		/* Now update or create a connection entry for it */
-		IP_VS_DBG_BUF(7, "protocol %s %s:%u %s:%u\n",
-			      ip_vs_proto_name(ipvsh->protocol),
-			      IP_VS_DBG_ADDR(cp->af, &to), ntohs(port),
-			      IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
-			      ntohs(cp->vport)-1);
+		IP_VS_DBG(7, "protocol %s %pISpc %pISpc\n",
+			  ip_vs_proto_name(ipvsh->protocol),
+			  IP_VS_DBG_SOCKADDR(cp->af, &to, port),
+			  IP_VS_DBG_SOCKADDR(cp->af, &cp->vaddr,
+					     htons(ntohs(cp->vport)-1)));
 	} else {
 		return 1;
 	}