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authorKuniyuki Iwashima <kuniyu@amazon.com>2022-08-23 10:46:45 -0700
committerDavid S. Miller <davem@davemloft.net>2022-08-24 13:46:57 +0100
commitbf955b5ab8f6f7b0632cdef8e36b14e4f6e77829 (patch)
tree45d85660cd5cbaa68bdd7e11b9290fdf6d98fc9e /net
parent1227c1771dd2ad44318aa3ab9e3a293b3f34ff2a (diff)
net: Fix data-races around weight_p and dev_weight_[rt]x_bias.
While reading weight_p, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Also, dev_[rt]x_weight can be read/written at the same time. So, we need to use READ_ONCE() and WRITE_ONCE() for its access. Moreover, to use the same weight_p while changing dev_[rt]x_weight, we add a mutex in proc_do_dev_weight(). Fixes: 3d48b53fb2ae ("net: dev_weight: TX/RX orthogonality") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/dev.c2
-rw-r--r--net/core/sysctl_net_core.c15
-rw-r--r--net/sched/sch_generic.c2
3 files changed, 11 insertions, 8 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 716df64fcfa5..b5b92dcd5eea 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5918,7 +5918,7 @@ static int process_backlog(struct napi_struct *napi, int quota)
net_rps_action_and_irq_enable(sd);
}
- napi->weight = dev_rx_weight;
+ napi->weight = READ_ONCE(dev_rx_weight);
while (again) {
struct sk_buff *skb;
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index 71a13596ea2b..725891527814 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -234,14 +234,17 @@ static int set_default_qdisc(struct ctl_table *table, int write,
static int proc_do_dev_weight(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
- int ret;
+ static DEFINE_MUTEX(dev_weight_mutex);
+ int ret, weight;
+ mutex_lock(&dev_weight_mutex);
ret = proc_dointvec(table, write, buffer, lenp, ppos);
- if (ret != 0)
- return ret;
-
- dev_rx_weight = weight_p * dev_weight_rx_bias;
- dev_tx_weight = weight_p * dev_weight_tx_bias;
+ if (!ret && write) {
+ weight = READ_ONCE(weight_p);
+ WRITE_ONCE(dev_rx_weight, weight * dev_weight_rx_bias);
+ WRITE_ONCE(dev_tx_weight, weight * dev_weight_tx_bias);
+ }
+ mutex_unlock(&dev_weight_mutex);
return ret;
}
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index d47b9689eba6..99b697ad2b98 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -409,7 +409,7 @@ static inline bool qdisc_restart(struct Qdisc *q, int *packets)
void __qdisc_run(struct Qdisc *q)
{
- int quota = dev_tx_weight;
+ int quota = READ_ONCE(dev_tx_weight);
int packets;
while (qdisc_restart(q, &packets)) {