This is a note to let you know that I've just added the patch titled
net: Fix a data-race around netdev_budget_usecs.
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-fix-a-data-race-around-netdev_budget_usecs.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 89fc07d8955ef4c8aaf68edefd1f6b0f08cbb4ac
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Tue Aug 23 10:46:55 2022 -0700
net: Fix a data-race around netdev_budget_usecs.
[ Upstream commit fa45d484c52c73f79db2c23b0cdfc6c6455093ad ]
While reading netdev_budget_usecs, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: 7acf8a1e8a28 ("Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/core/dev.c b/net/core/dev.c
index f6d3cbc57425c..4741c239af170 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5648,7 +5648,7 @@ 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);
+ usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
int budget = READ_ONCE(netdev_budget);
LIST_HEAD(list);
LIST_HEAD(repoll);
