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net: mpls: Remove rcu protection from nh_dev

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Following the previous commit, nh_dev can no longer be accessed and
modified concurrently.

Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Benjamin Poirier 2021-11-29 15:15:06 +09:00 committed by David S. Miller
parent 7d4741eacd
commit 189168181b
2 changed files with 16 additions and 25 deletions
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39
net/mpls/af_mpls.c
View File

@ -409,7 +409,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
goto err;
/* Find the output device */
out_dev = rcu_dereference(nh->nh_dev);
out_dev = nh->nh_dev;
if (!mpls_output_possible(out_dev))
goto tx_err;
@ -698,7 +698,7 @@ static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
(dev->addr_len != nh->nh_via_alen))
goto errout;
RCU_INIT_POINTER(nh->nh_dev, dev);
nh->nh_dev = dev;
if (!(dev->flags & IFF_UP)) {
nh->nh_flags |= RTNH_F_DEAD;
@ -1510,12 +1510,9 @@ static int mpls_ifdown(struct net_device *dev, int event)
u8 deleted = 0;
for_nexthops(rt) {
struct net_device *nh_dev =
rtnl_dereference(nh->nh_dev);
if (!nh_dev || nh_dev == dev)
if (!nh->nh_dev || nh->nh_dev == dev)
deleted++;
if (nh_dev == dev)
if (nh->nh_dev == dev)
nh_del = true;
} endfor_nexthops(rt);
@ -1540,7 +1537,7 @@ static int mpls_ifdown(struct net_device *dev, int event)
change_nexthops(rt) {
unsigned int nh_flags = nh->nh_flags;
if (rtnl_dereference(nh->nh_dev) != dev)
if (nh->nh_dev != dev)
goto next;
switch (event) {
@ -1553,7 +1550,7 @@ static int mpls_ifdown(struct net_device *dev, int event)
break;
}
if (event == NETDEV_UNREGISTER)
RCU_INIT_POINTER(nh->nh_dev, NULL);
nh->nh_dev = NULL;
if (nh->nh_flags != nh_flags)
WRITE_ONCE(nh->nh_flags, nh_flags);
@ -1588,14 +1585,12 @@ static void mpls_ifup(struct net_device *dev, unsigned int flags)
alive = 0;
change_nexthops(rt) {
unsigned int nh_flags = nh->nh_flags;
struct net_device *nh_dev =
rtnl_dereference(nh->nh_dev);
if (!(nh_flags & flags)) {
alive++;
continue;
}
if (nh_dev != dev)
if (nh->nh_dev != dev)
continue;
alive++;
nh_flags &= ~flags;
@ -2030,7 +2025,7 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
nh->nh_via_alen))
goto nla_put_failure;
dev = rtnl_dereference(nh->nh_dev);
dev = nh->nh_dev;
if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
goto nla_put_failure;
if (nh->nh_flags & RTNH_F_LINKDOWN)
@ -2048,7 +2043,7 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
goto nla_put_failure;
for_nexthops(rt) {
dev = rtnl_dereference(nh->nh_dev);
dev = nh->nh_dev;
if (!dev)
continue;
@ -2159,18 +2154,14 @@ static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
static bool mpls_rt_uses_dev(struct mpls_route *rt,
const struct net_device *dev)
{
struct net_device *nh_dev;
if (rt->rt_nhn == 1) {
struct mpls_nh *nh = rt->rt_nh;
nh_dev = rtnl_dereference(nh->nh_dev);
if (dev == nh_dev)
if (nh->nh_dev == dev)
return true;
} else {
for_nexthops(rt) {
nh_dev = rtnl_dereference(nh->nh_dev);
if (nh_dev == dev)
if (nh->nh_dev == dev)
return true;
} endfor_nexthops(rt);
}
@ -2258,7 +2249,7 @@ static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
size_t nhsize = 0;
for_nexthops(rt) {
if (!rtnl_dereference(nh->nh_dev))
if (!nh->nh_dev)
continue;
nhsize += nla_total_size(sizeof(struct rtnexthop));
/* RTA_VIA */
@ -2504,7 +2495,7 @@ static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
nh->nh_via_alen))
goto nla_put_failure;
dev = rtnl_dereference(nh->nh_dev);
dev = nh->nh_dev;
if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
goto nla_put_failure;
@ -2543,7 +2534,7 @@ static int resize_platform_label_table(struct net *net, size_t limit)
rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
if (IS_ERR(rt0))
goto nort0;
RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
rt0->rt_nh->nh_dev = lo;
rt0->rt_protocol = RTPROT_KERNEL;
rt0->rt_payload_type = MPT_IPV4;
rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
@ -2557,7 +2548,7 @@ static int resize_platform_label_table(struct net *net, size_t limit)
rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
if (IS_ERR(rt2))
goto nort2;
RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
rt2->rt_nh->nh_dev = lo;
rt2->rt_protocol = RTPROT_KERNEL;
rt2->rt_payload_type = MPT_IPV6;
rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;

2
net/mpls/internal.h
View File

@ -87,7 +87,7 @@ enum mpls_payload_type {
};
struct mpls_nh { /* next hop label forwarding entry */
struct net_device __rcu *nh_dev;
struct net_device *nh_dev;
/* nh_flags is accessed under RCU in the packet path; it is
* modified handling netdev events with rtnl lock held