{
struct netdev_adjacent *lower;
- WARN_ON_ONCE(!rcu_read_lock_held());
+ WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
return dev->xdp_state[mode].prog;
}
-static u8 dev_xdp_prog_count(struct net_device *dev)
+u8 dev_xdp_prog_count(struct net_device *dev)
{
u8 count = 0;
int i;
count++;
return count;
}
+EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
{
{
unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
struct bpf_prog *cur_prog;
+ struct net_device *upper;
+ struct list_head *iter;
enum bpf_xdp_mode mode;
bpf_op_t bpf_op;
int err;
return -EBUSY;
}
+ /* don't allow if an upper device already has a program */
+ netdev_for_each_upper_dev_rcu(dev, upper, iter) {
+ if (dev_xdp_prog_count(upper) > 0) {
+ NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
+ return -EEXIST;
+ }
+ }
+
cur_prog = dev_xdp_prog(dev, mode);
/* can't replace attached prog with link */
if (link && cur_prog) {