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Message-ID: <20240306155144.870421-2-edumazet@google.com>
Date: Wed, 6 Mar 2024 15:51:41 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>
Cc: David Ahern <dsahern@...nel.org>, netdev@...r.kernel.org, eric.dumazet@...il.com,
Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH net-next 1/4] ipv6: make inet6_fill_ifaddr() lockless
Make inet6_fill_ifaddr() lockless, and add approriate annotations
on ifa->tstamp, ifa->valid_lft, ifa->preferred_lft, ifa->ifa_proto
and ifa->rt_priority.
Also constify 2nd argument of inet6_fill_ifaddr(), inet6_fill_ifmcaddr()
and inet6_fill_ifacaddr().
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
net/ipv6/addrconf.c | 66 +++++++++++++++++++++++++--------------------
1 file changed, 37 insertions(+), 29 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 2f84e6ecf19f48602cadb47bc378c9b5a1cdbf65..480a1f9492b590bb13008cede5ea7dc9c422af67 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2730,7 +2730,7 @@ int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev,
if (update_lft) {
ifp->valid_lft = valid_lft;
ifp->prefered_lft = prefered_lft;
- ifp->tstamp = now;
+ WRITE_ONCE(ifp->tstamp, now);
flags = ifp->flags;
ifp->flags &= ~IFA_F_DEPRECATED;
spin_unlock_bh(&ifp->lock);
@@ -4898,13 +4898,13 @@ static int inet6_addr_modify(struct net *net, struct inet6_ifaddr *ifp,
IFA_F_HOMEADDRESS | IFA_F_MANAGETEMPADDR |
IFA_F_NOPREFIXROUTE);
ifp->flags |= cfg->ifa_flags;
- ifp->tstamp = jiffies;
- ifp->valid_lft = cfg->valid_lft;
- ifp->prefered_lft = cfg->preferred_lft;
- ifp->ifa_proto = cfg->ifa_proto;
+ WRITE_ONCE(ifp->tstamp, jiffies);
+ WRITE_ONCE(ifp->valid_lft, cfg->valid_lft);
+ WRITE_ONCE(ifp->prefered_lft, cfg->preferred_lft);
+ WRITE_ONCE(ifp->ifa_proto, cfg->ifa_proto);
if (cfg->rt_priority && cfg->rt_priority != ifp->rt_priority)
- ifp->rt_priority = cfg->rt_priority;
+ WRITE_ONCE(ifp->rt_priority, cfg->rt_priority);
if (new_peer)
ifp->peer_addr = *cfg->peer_pfx;
@@ -5125,17 +5125,21 @@ struct inet6_fill_args {
enum addr_type_t type;
};
-static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
+static int inet6_fill_ifaddr(struct sk_buff *skb,
+ const struct inet6_ifaddr *ifa,
struct inet6_fill_args *args)
{
- struct nlmsghdr *nlh;
+ struct nlmsghdr *nlh;
u32 preferred, valid;
+ u32 flags, priority;
+ u8 proto;
nlh = nlmsg_put(skb, args->portid, args->seq, args->event,
sizeof(struct ifaddrmsg), args->flags);
if (!nlh)
return -EMSGSIZE;
+ flags = READ_ONCE(ifa->flags);
put_ifaddrmsg(nlh, ifa->prefix_len, ifa->flags, rt_scope(ifa->scope),
ifa->idev->dev->ifindex);
@@ -5143,13 +5147,14 @@ static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
nla_put_s32(skb, IFA_TARGET_NETNSID, args->netnsid))
goto error;
- spin_lock_bh(&ifa->lock);
- if (!((ifa->flags&IFA_F_PERMANENT) &&
- (ifa->prefered_lft == INFINITY_LIFE_TIME))) {
- preferred = ifa->prefered_lft;
- valid = ifa->valid_lft;
+ preferred = READ_ONCE(ifa->prefered_lft);
+ valid = READ_ONCE(ifa->valid_lft);
+
+ if (!((flags & IFA_F_PERMANENT) &&
+ (preferred == INFINITY_LIFE_TIME))) {
if (preferred != INFINITY_LIFE_TIME) {
- long tval = (jiffies - ifa->tstamp)/HZ;
+ long tval = (jiffies - READ_ONCE(ifa->tstamp)) / HZ;
+
if (preferred > tval)
preferred -= tval;
else
@@ -5165,28 +5170,29 @@ static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
preferred = INFINITY_LIFE_TIME;
valid = INFINITY_LIFE_TIME;
}
- spin_unlock_bh(&ifa->lock);
if (!ipv6_addr_any(&ifa->peer_addr)) {
if (nla_put_in6_addr(skb, IFA_LOCAL, &ifa->addr) < 0 ||
nla_put_in6_addr(skb, IFA_ADDRESS, &ifa->peer_addr) < 0)
goto error;
- } else
+ } else {
if (nla_put_in6_addr(skb, IFA_ADDRESS, &ifa->addr) < 0)
goto error;
+ }
- if (ifa->rt_priority &&
- nla_put_u32(skb, IFA_RT_PRIORITY, ifa->rt_priority))
+ priority = READ_ONCE(ifa->rt_priority);
+ if (priority && nla_put_u32(skb, IFA_RT_PRIORITY, priority))
goto error;
- if (put_cacheinfo(skb, ifa->cstamp, ifa->tstamp, preferred, valid) < 0)
+ if (put_cacheinfo(skb, ifa->cstamp, READ_ONCE(ifa->tstamp),
+ preferred, valid) < 0)
goto error;
- if (nla_put_u32(skb, IFA_FLAGS, ifa->flags) < 0)
+ if (nla_put_u32(skb, IFA_FLAGS, flags) < 0)
goto error;
- if (ifa->ifa_proto &&
- nla_put_u8(skb, IFA_PROTO, ifa->ifa_proto))
+ proto = READ_ONCE(ifa->ifa_proto);
+ if (proto && nla_put_u8(skb, IFA_PROTO, proto))
goto error;
nlmsg_end(skb, nlh);
@@ -5197,12 +5203,13 @@ static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
return -EMSGSIZE;
}
-static int inet6_fill_ifmcaddr(struct sk_buff *skb, struct ifmcaddr6 *ifmca,
+static int inet6_fill_ifmcaddr(struct sk_buff *skb,
+ const struct ifmcaddr6 *ifmca,
struct inet6_fill_args *args)
{
- struct nlmsghdr *nlh;
- u8 scope = RT_SCOPE_UNIVERSE;
int ifindex = ifmca->idev->dev->ifindex;
+ u8 scope = RT_SCOPE_UNIVERSE;
+ struct nlmsghdr *nlh;
if (ipv6_addr_scope(&ifmca->mca_addr) & IFA_SITE)
scope = RT_SCOPE_SITE;
@@ -5220,7 +5227,7 @@ static int inet6_fill_ifmcaddr(struct sk_buff *skb, struct ifmcaddr6 *ifmca,
put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
if (nla_put_in6_addr(skb, IFA_MULTICAST, &ifmca->mca_addr) < 0 ||
- put_cacheinfo(skb, ifmca->mca_cstamp, ifmca->mca_tstamp,
+ put_cacheinfo(skb, ifmca->mca_cstamp, READ_ONCE(ifmca->mca_tstamp),
INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0) {
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
@@ -5230,13 +5237,14 @@ static int inet6_fill_ifmcaddr(struct sk_buff *skb, struct ifmcaddr6 *ifmca,
return 0;
}
-static int inet6_fill_ifacaddr(struct sk_buff *skb, struct ifacaddr6 *ifaca,
+static int inet6_fill_ifacaddr(struct sk_buff *skb,
+ const struct ifacaddr6 *ifaca,
struct inet6_fill_args *args)
{
struct net_device *dev = fib6_info_nh_dev(ifaca->aca_rt);
int ifindex = dev ? dev->ifindex : 1;
- struct nlmsghdr *nlh;
u8 scope = RT_SCOPE_UNIVERSE;
+ struct nlmsghdr *nlh;
if (ipv6_addr_scope(&ifaca->aca_addr) & IFA_SITE)
scope = RT_SCOPE_SITE;
@@ -5254,7 +5262,7 @@ static int inet6_fill_ifacaddr(struct sk_buff *skb, struct ifacaddr6 *ifaca,
put_ifaddrmsg(nlh, 128, IFA_F_PERMANENT, scope, ifindex);
if (nla_put_in6_addr(skb, IFA_ANYCAST, &ifaca->aca_addr) < 0 ||
- put_cacheinfo(skb, ifaca->aca_cstamp, ifaca->aca_tstamp,
+ put_cacheinfo(skb, ifaca->aca_cstamp, READ_ONCE(ifaca->aca_tstamp),
INFINITY_LIFE_TIME, INFINITY_LIFE_TIME) < 0) {
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
--
2.44.0.278.ge034bb2e1d-goog
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