ipvs: fix overflow on dest weight multiply

Schedulers such as lblc and lblcr require the weight to be as high as the
maximum number of active connections. In commit b552f7e3a9524abcbcdf
("ipvs: unify the formula to estimate the overhead of processing
connections"), the consideration of inactconns and activeconns was cleaned
up to always count activeconns as 256 times more important than inactconns.
In cases where 3000 or more connections are expected, a weight of 3000 *
256 * 3000 connections overflows the 32-bit signed result used to determine
if rescheduling is required.

On amd64, this merely changes the multiply and comparison instructions to
64-bit. On x86, a 64-bit result is already present from imull, so only
a few more comparison instructions are emitted.

Signed-off-by: Simon Kirby <sim@hostway.ca>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index f0d70f066f3ddc59a0c1c7bb5e58daf1c4b3c3a4..fe782ed2fe720d9d9464a2643e76b86b5619543f 100644 (file)
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -1649,7 +1649,7 @@ static inline void ip_vs_conn_drop_conntrack(struct ip_vs_conn *cp)
 /* CONFIG_IP_VS_NFCT */
 #endif
 
-static inline unsigned int
+static inline int
 ip_vs_dest_conn_overhead(struct ip_vs_dest *dest)
 {
        /*

diff --git a/net/netfilter/ipvs/ip_vs_lblc.c b/net/netfilter/ipvs/ip_vs_lblc.c
index 1383b0eadc0e777d5ff6dbce2a2ded451a3ae296..eb814bf74e64385186efa9c2ac740112bb76f1f2 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_lblc.c
+++ b/net/netfilter/ipvs/ip_vs_lblc.c
@@ -443,8 +443,8 @@ __ip_vs_lblc_schedule(struct ip_vs_service *svc)
                        continue;
 
                doh = ip_vs_dest_conn_overhead(dest);
-               if (loh * atomic_read(&dest->weight) >
-                   doh * atomic_read(&least->weight)) {
+               if ((__s64)loh * atomic_read(&dest->weight) >
+                   (__s64)doh * atomic_read(&least->weight)) {
                        least = dest;
                        loh = doh;
                }

diff --git a/net/netfilter/ipvs/ip_vs_lblcr.c b/net/netfilter/ipvs/ip_vs_lblcr.c
index 5199448697f64fcf0da0e35dbc38903477a92861..e65f7c573090ead9a8d664bda1ca9edccb095480 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_lblcr.c
+++ b/net/netfilter/ipvs/ip_vs_lblcr.c
@@ -200,8 +200,8 @@ static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set)
                        continue;
 
                doh = ip_vs_dest_conn_overhead(dest);
-               if ((loh * atomic_read(&dest->weight) >
-                    doh * atomic_read(&least->weight))
+               if (((__s64)loh * atomic_read(&dest->weight) >
+                    (__s64)doh * atomic_read(&least->weight))
                    && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
                        least = dest;
                        loh = doh;
@@ -246,8 +246,8 @@ static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set)
                dest = rcu_dereference_protected(e->dest, 1);
                doh = ip_vs_dest_conn_overhead(dest);
                /* moh/mw < doh/dw ==> moh*dw < doh*mw, where mw,dw>0 */
-               if ((moh * atomic_read(&dest->weight) <
-                    doh * atomic_read(&most->weight))
+               if (((__s64)moh * atomic_read(&dest->weight) <
+                    (__s64)doh * atomic_read(&most->weight))
                    && (atomic_read(&dest->weight) > 0)) {
                        most = dest;
                        moh = doh;
@@ -611,8 +611,8 @@ __ip_vs_lblcr_schedule(struct ip_vs_service *svc)
                        continue;
 
                doh = ip_vs_dest_conn_overhead(dest);
-               if (loh * atomic_read(&dest->weight) >
-                   doh * atomic_read(&least->weight)) {
+               if ((__s64)loh * atomic_read(&dest->weight) >
+                   (__s64)doh * atomic_read(&least->weight)) {
                        least = dest;
                        loh = doh;
                }

diff --git a/net/netfilter/ipvs/ip_vs_nq.c b/net/netfilter/ipvs/ip_vs_nq.c
index d8d9860934fee1e7f59505eeefa094307b2d58c3..961a6de9bb29035458945185f488a5fc1209ba00 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_nq.c
+++ b/net/netfilter/ipvs/ip_vs_nq.c
@@ -40,7 +40,7 @@
 #include <net/ip_vs.h>
 
 
-static inline unsigned int
+static inline int
 ip_vs_nq_dest_overhead(struct ip_vs_dest *dest)
 {
        /*
@@ -59,7 +59,7 @@ ip_vs_nq_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
                  struct ip_vs_iphdr *iph)
 {
        struct ip_vs_dest *dest, *least = NULL;
-       unsigned int loh = 0, doh;
+       int loh = 0, doh;
 
        IP_VS_DBG(6, "%s(): Scheduling...\n", __func__);
 
@@ -92,8 +92,8 @@ ip_vs_nq_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
                }
 
                if (!least ||
-                   (loh * atomic_read(&dest->weight) >
-                    doh * atomic_read(&least->weight))) {
+                   ((__s64)loh * atomic_read(&dest->weight) >
+                    (__s64)doh * atomic_read(&least->weight))) {
                        least = dest;
                        loh = doh;
                }

diff --git a/net/netfilter/ipvs/ip_vs_sed.c b/net/netfilter/ipvs/ip_vs_sed.c
index a5284cc3d88279923b6a28b1f8a8f87bfc2a6a0f..e446b9fa7424c6382cb65433447f3febe2b17eeb 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_sed.c
+++ b/net/netfilter/ipvs/ip_vs_sed.c
@@ -44,7 +44,7 @@
 #include <net/ip_vs.h>
 
 
-static inline unsigned int
+static inline int
 ip_vs_sed_dest_overhead(struct ip_vs_dest *dest)
 {
        /*
@@ -63,7 +63,7 @@ ip_vs_sed_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
                   struct ip_vs_iphdr *iph)
 {
        struct ip_vs_dest *dest, *least;
-       unsigned int loh, doh;
+       int loh, doh;
 
        IP_VS_DBG(6, "%s(): Scheduling...\n", __func__);
 
@@ -99,8 +99,8 @@ ip_vs_sed_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
                if (dest->flags & IP_VS_DEST_F_OVERLOAD)
                        continue;
                doh = ip_vs_sed_dest_overhead(dest);
-               if (loh * atomic_read(&dest->weight) >
-                   doh * atomic_read(&least->weight)) {
+               if ((__s64)loh * atomic_read(&dest->weight) >
+                   (__s64)doh * atomic_read(&least->weight)) {
                        least = dest;
                        loh = doh;
                }

diff --git a/net/netfilter/ipvs/ip_vs_wlc.c b/net/netfilter/ipvs/ip_vs_wlc.c
index 6dc1fa1288409067de8a19f53a32e174caa9adc9..b5b4650d50a9180f211e6cce82e3393ece2fc11c 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_wlc.c
+++ b/net/netfilter/ipvs/ip_vs_wlc.c
@@ -35,7 +35,7 @@ ip_vs_wlc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
                   struct ip_vs_iphdr *iph)
 {
        struct ip_vs_dest *dest, *least;
-       unsigned int loh, doh;
+       int loh, doh;
 
        IP_VS_DBG(6, "ip_vs_wlc_schedule(): Scheduling...\n");
 
@@ -71,8 +71,8 @@ ip_vs_wlc_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
                if (dest->flags & IP_VS_DEST_F_OVERLOAD)
                        continue;
                doh = ip_vs_dest_conn_overhead(dest);
-               if (loh * atomic_read(&dest->weight) >
-                   doh * atomic_read(&least->weight)) {
+               if ((__s64)loh * atomic_read(&dest->weight) >
+                   (__s64)doh * atomic_read(&least->weight)) {
                        least = dest;
                        loh = doh;
                }