@@ -377,6 +377,7 @@ static int veth_xdp_xmit(struct net_device *dev, int n,
unsigned int max_len;
struct veth_rq *rq;
+ rcu_read_lock();
if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
ret = -EINVAL;
goto drop;
@@ -418,11 +419,14 @@ static int veth_xdp_xmit(struct net_device *dev, int n,
if (flags & XDP_XMIT_FLUSH)
__veth_xdp_flush(rq);
- if (likely(!drops))
+ if (likely(!drops)) {
+ rcu_read_unlock();
return n;
+ }
ret = n - drops;
drop:
+ rcu_read_unlock();
atomic64_add(drops, &priv->dropped);
return ret;
@@ -372,16 +372,17 @@ static int bq_xmit_all(struct xdp_bulk_queue *bq, u32 flags)
* from NET_RX_SOFTIRQ. Either way the poll routine must complete before the
* net device can be torn down. On devmap tear down we ensure the flush list
* is empty before completing to ensure all flush operations have completed.
+ * When drivers update the bpf program they may need to ensure any flush ops
+ * are also complete. Using synchronize_rcu or call_rcu will suffice for this
+ * because both wait for napi context to exit.
*/
void __dev_map_flush(void)
{
struct list_head *flush_list = this_cpu_ptr(&dev_map_flush_list);
struct xdp_bulk_queue *bq, *tmp;
- rcu_read_lock();
list_for_each_entry_safe(bq, tmp, flush_list, flush_node)
bq_xmit_all(bq, XDP_XMIT_FLUSH);
- rcu_read_unlock();
}
/* rcu_read_lock (from syscall and BPF contexts) ensures that if a delete and/or