net: Fix a data-race around netdev_budget.

While reading netdev_budget, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.

Fixes: 983507ab3bc6 ("[NET]: Separate two usages of netdev_max_backlog.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index 4705e6630efa3e46f51a1f90b73405e448b2e654..c83e23cfc57d7ff8b60efc1891601230a9997a11 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6666,7 +6666,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h)
        struct softnet_data *sd = this_cpu_ptr(&softnet_data);
        unsigned long time_limit = jiffies +
                usecs_to_jiffies(netdev_budget_usecs);
-       int budget = netdev_budget;
+       int budget = READ_ONCE(netdev_budget);
        LIST_HEAD(list);
        LIST_HEAD(repoll);