[bpf-next V4 PATCH 7/8] xdp/trace: extend tracepoint in devmap with an err

Jesper Dangaard Brouer
2018-05-18T13:35:08Z

Extending tracepoint xdp:xdp_devmap_xmit in devmap with an err code
allow people to easier identify the reason behind the ndo_xdp_xmit
call to a given driver is failing.
---
include/trace/events/xdp.h | 10 ++++++----
kernel/bpf/devmap.c | 2 +-
2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index 2e9ef0650144..1ecf4c67fcf7 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -234,9 +234,9 @@ TRACE_EVENT(xdp_devmap_xmit,
TP_PROTO(const struct bpf_map *map, u32 map_index,
int sent, int drops,
const struct net_device *from_dev,
- const struct net_device *to_dev),
+ const struct net_device *to_dev, int err),

- TP_ARGS(map, map_index, sent, drops, from_dev, to_dev),
+ TP_ARGS(map, map_index, sent, drops, from_dev, to_dev, err),

TP_STRUCT__entry(
__field(int, map_id)
@@ -246,6 +246,7 @@ TRACE_EVENT(xdp_devmap_xmit,
__field(int, sent)
__field(int, from_ifindex)
__field(int, to_ifindex)
+ __field(int, err)
),

TP_fast_assign(
@@ -256,16 +257,17 @@ TRACE_EVENT(xdp_devmap_xmit,
__entry->sent = sent;
__entry->from_ifindex = from_dev->ifindex;
__entry->to_ifindex = to_dev->ifindex;
+ __entry->err = err;
),

TP_printk("ndo_xdp_xmit"
" map_id=%d map_index=%d action=%s"
" sent=%d drops=%d"
- " from_ifindex=%d to_ifindex=%d",
+ " from_ifindex=%d to_ifindex=%d err=%d",
__entry->map_id, __entry->map_index,
__print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
__entry->sent, __entry->drops,
- __entry->from_ifindex, __entry->to_ifindex)
+ __entry->from_ifindex, __entry->to_ifindex, __entry->err)
);

#endif /* _TRACE_XDP_H */
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 1317629662ae..4dd8f0e3a8d9 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -245,7 +245,7 @@ static int bq_xmit_all(struct bpf_dtab_netdev *obj,
bq->count = 0;

trace_xdp_devmap_xmit(&obj->dtab->map, obj->bit,
- sent, drops, bq->dev_rx, dev);
+ sent, drops, bq->dev_rx, dev, err);
bq->dev_rx = NULL;
return 0;