diff options
Diffstat (limited to 'kernel/bpf/devmap.c')
| -rw-r--r-- | kernel/bpf/devmap.c | 47 |
1 files changed, 38 insertions, 9 deletions
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 2625601de76e..3d619d01088e 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -45,6 +45,7 @@ * types of devmap; only the lookup and insertion is different. */ #include <linux/bpf.h> +#include <linux/local_lock.h> #include <net/xdp.h> #include <linux/filter.h> #include <trace/events/xdp.h> @@ -60,6 +61,7 @@ struct xdp_dev_bulk_queue { struct net_device *dev_rx; struct bpf_prog *xdp_prog; unsigned int count; + local_lock_t bq_lock; }; struct bpf_dtab_netdev { @@ -381,6 +383,8 @@ static void bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags) int to_send = cnt; int i; + lockdep_assert_held(&bq->bq_lock); + if (unlikely(!cnt)) return; @@ -425,10 +429,12 @@ void __dev_flush(struct list_head *flush_list) struct xdp_dev_bulk_queue *bq, *tmp; list_for_each_entry_safe(bq, tmp, flush_list, flush_node) { + local_lock_nested_bh(&bq->dev->xdp_bulkq->bq_lock); bq_xmit_all(bq, XDP_XMIT_FLUSH); bq->dev_rx = NULL; bq->xdp_prog = NULL; __list_del_clearprev(&bq->flush_node); + local_unlock_nested_bh(&bq->dev->xdp_bulkq->bq_lock); } } @@ -451,12 +457,16 @@ static void *__dev_map_lookup_elem(struct bpf_map *map, u32 key) /* Runs in NAPI, i.e., softirq under local_bh_disable(). Thus, safe percpu * variable access, and map elements stick around. See comment above - * xdp_do_flush() in filter.c. + * xdp_do_flush() in filter.c. PREEMPT_RT relies on local_lock_nested_bh() + * to serialise access to the per-CPU bq. */ static void bq_enqueue(struct net_device *dev, struct xdp_frame *xdpf, struct net_device *dev_rx, struct bpf_prog *xdp_prog) { - struct xdp_dev_bulk_queue *bq = this_cpu_ptr(dev->xdp_bulkq); + struct xdp_dev_bulk_queue *bq; + + local_lock_nested_bh(&dev->xdp_bulkq->bq_lock); + bq = this_cpu_ptr(dev->xdp_bulkq); if (unlikely(bq->count == DEV_MAP_BULK_SIZE)) bq_xmit_all(bq, 0); @@ -477,6 +487,8 @@ static void bq_enqueue(struct net_device *dev, struct xdp_frame *xdpf, } bq->q[bq->count++] = xdpf; + + local_unlock_nested_bh(&dev->xdp_bulkq->bq_lock); } static inline int __xdp_enqueue(struct net_device *dev, struct xdp_frame *xdpf, @@ -588,18 +600,22 @@ static inline bool is_ifindex_excluded(int *excluded, int num_excluded, int ifin } /* Get ifindex of each upper device. 'indexes' must be able to hold at - * least MAX_NEST_DEV elements. - * Returns the number of ifindexes added. + * least 'max' elements. + * Returns the number of ifindexes added, or -EOVERFLOW if there are too + * many upper devices. */ -static int get_upper_ifindexes(struct net_device *dev, int *indexes) +static int get_upper_ifindexes(struct net_device *dev, int *indexes, int max) { struct net_device *upper; struct list_head *iter; int n = 0; netdev_for_each_upper_dev_rcu(dev, upper, iter) { + if (n >= max) + return -EOVERFLOW; indexes[n++] = upper->ifindex; } + return n; } @@ -615,7 +631,11 @@ int dev_map_enqueue_multi(struct xdp_frame *xdpf, struct net_device *dev_rx, int err; if (exclude_ingress) { - num_excluded = get_upper_ifindexes(dev_rx, excluded_devices); + num_excluded = get_upper_ifindexes(dev_rx, excluded_devices, + ARRAY_SIZE(excluded_devices) - 1); + if (num_excluded < 0) + return num_excluded; + excluded_devices[num_excluded++] = dev_rx->ifindex; } @@ -733,7 +753,11 @@ int dev_map_redirect_multi(struct net_device *dev, struct sk_buff *skb, int err; if (exclude_ingress) { - num_excluded = get_upper_ifindexes(dev, excluded_devices); + num_excluded = get_upper_ifindexes(dev, excluded_devices, + ARRAY_SIZE(excluded_devices) - 1); + if (num_excluded < 0) + return num_excluded; + excluded_devices[num_excluded++] = dev->ifindex; } @@ -1115,8 +1139,13 @@ static int dev_map_notification(struct notifier_block *notifier, if (!netdev->xdp_bulkq) return NOTIFY_BAD; - for_each_possible_cpu(cpu) - per_cpu_ptr(netdev->xdp_bulkq, cpu)->dev = netdev; + for_each_possible_cpu(cpu) { + struct xdp_dev_bulk_queue *bq; + + bq = per_cpu_ptr(netdev->xdp_bulkq, cpu); + bq->dev = netdev; + local_lock_init(&bq->bq_lock); + } break; case NETDEV_UNREGISTER: /* This rcu_read_lock/unlock pair is needed because |