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| author |   Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-08-23 10:46:45 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2022-08-24 13:46:57 +0100 |
| commit | bf955b5ab8f6f7b0632cdef8e36b14e4f6e77829 (patch) | |
| tree | 45d85660cd5cbaa68bdd7e11b9290fdf6d98fc9e /net/core | |
| parent | net: Fix data-races around sysctl_[rw]mem_(max|default). (diff) | |
| download | linux-dev-bf955b5ab8f6f7b0632cdef8e36b14e4f6e77829.tar.xz linux-dev-bf955b5ab8f6f7b0632cdef8e36b14e4f6e77829.zip | |
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/core')
| -rw-r--r-- | net/core/dev.c | 2 | ||||
| -rw-r--r-- | net/core/sysctl_net_core.c | 15 |
2 files changed, 10 insertions, 7 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; } |