Merge branch 'sysctl-data-races'

Kuniyuki Iwashima says:

====================
net: sysctl: Fix data-races around net.core.XXX

This series fixes data-races around all knobs in net_core_table and
netns_core_table except for bpf stuff.

These knobs are skipped:

  - 4 bpf knobs
  - netdev_rss_key: Written only once by net_get_random_once() and
                    read-only knob
  - rps_sock_flow_entries: Protected with sock_flow_mutex
  - flow_limit_cpu_bitmap: Protected with flow_limit_update_mutex
  - flow_limit_table_len: Protected with flow_limit_update_mutex
  - default_qdisc: Protected with qdisc_mod_lock
  - warnings: Unused
  - high_order_alloc_disable: Protected with static_key_mutex
  - skb_defer_max: Already using READ_ONCE()
  - sysctl_txrehash: Already using READ_ONCE()

Note 5th patch fixes net.core.message_cost and net.core.message_burst,
and lib/ratelimit.c does not have an explicit maintainer.

Changes:
  v3:
    * Fix build failures of CONFIG_SYSCTL=n case in 13th & 14th patches

  v2: https://lore.kernel.org/netdev/20220818035227.81567-1-kuniyu@amazon.com/
    * Remove 4 bpf knobs and added 6 knobs

  v1: https://lore.kernel.org/netdev/20220816052347.70042-1-kuniyu@amazon.com/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 19 insertions, 5 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 1a3cb93c3dcc..05d6f3facd5a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -640,9 +640,23 @@ extern int sysctl_devconf_inherit_init_net;
  */
 static inline bool net_has_fallback_tunnels(const struct net *net)
 {
-	return !IS_ENABLED(CONFIG_SYSCTL) ||
-	       !sysctl_fb_tunnels_only_for_init_net ||
-	       (net == &init_net && sysctl_fb_tunnels_only_for_init_net == 1);
+#if IS_ENABLED(CONFIG_SYSCTL)
+	int fb_tunnels_only_for_init_net = READ_ONCE(sysctl_fb_tunnels_only_for_init_net);
+
+	return !fb_tunnels_only_for_init_net ||
+		(net_eq(net, &init_net) && fb_tunnels_only_for_init_net == 1);
+#else
+	return true;
+#endif
+}
+
+static inline int net_inherit_devconf(void)
+{
+#if IS_ENABLED(CONFIG_SYSCTL)
+	return READ_ONCE(sysctl_devconf_inherit_init_net);
+#else
+	return 0;
+#endif
 }
 
 static inline int netdev_queue_numa_node_read(const struct netdev_queue *q)
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index c4898fcbf923..f90f0021f5f2 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -33,7 +33,7 @@ extern unsigned int sysctl_net_busy_poll __read_mostly;
 
 static inline bool net_busy_loop_on(void)
 {
-	return sysctl_net_busy_poll;
+	return READ_ONCE(sysctl_net_busy_poll);
 }
 
 static inline bool sk_can_busy_loop(const struct sock *sk)
diff --git a/include/net/gro.h b/include/net/gro.h
index 867656b0739c..24003dea8fa4 100644
--- a/include/net/gro.h
+++ b/include/net/gro.h
@@ -439,7 +439,7 @@ static inline void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb,
 {
 	list_add_tail(&skb->list, &napi->rx_list);
 	napi->rx_count += segs;
-	if (napi->rx_count >= gro_normal_batch)
+	if (napi->rx_count >= READ_ONCE(gro_normal_batch))
 		gro_normal_list(napi);
 }