Re: [PATCH net-next] net: Print real skb addresses for all net events
From: Eric Dumazet <edumazet@google.com>
Date: 2022-06-24 06:27:53
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
On Fri, Jun 24, 2022 at 8:09 AM Subash Abhinov Kasiviswanathan [off-list ref] wrote:
Commit 65875073eddd ("net: use %px to print skb address in trace_netif_receive_skb")
added support for printing the real addresses for the events using
net_dev_template.It is not clear why the 'real address' is needed in trace events. I would rather do the opposite.
diff --git a/include/trace/events/net.h b/include/trace/events/net.h
index 032b431b987b63b5fab1d3c763643d6192f2c325..da611a7aaf970f541949cdd87ac9203c4c7e81b1100644
--- a/include/trace/events/net.h
+++ b/include/trace/events/net.h@@ -136,7 +136,7 @@ DECLARE_EVENT_CLASS(net_dev_template, __assign_str(name, skb->dev->name); ), - TP_printk("dev=%s skbaddr=%px len=%u", + TP_printk("dev=%s skbaddr=%p len=%u", __get_str(name), __entry->skbaddr, __entry->len) )
diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h
index 59c945b66f9c7469bc071e2a27efb8bfa9eb19f7..a3995925cb057021dc779344d19f7e3724f6df3c100644
--- a/include/trace/events/qdisc.h
+++ b/include/trace/events/qdisc.h@@ -41,7 +41,7 @@ TRACE_EVENT(qdisc_dequeue, __entry->txq_state = txq->state; ), - TP_printk("dequeue ifindex=%d qdisc handle=0x%X parent=0x%X
txq_state=0x%lX packets=%d skbaddr=%px",
+ TP_printk("dequeue ifindex=%d qdisc handle=0x%X parent=0x%X
txq_state=0x%lX packets=%d skbaddr=%p",
__entry->ifindex, __entry->handle, __entry->parent,
__entry->txq_state, __entry->packets, __entry->skbaddr )
);@@ -70,7 +70,7 @@ TRACE_EVENT(qdisc_enqueue, __entry->parent = qdisc->parent; ), - TP_printk("enqueue ifindex=%d qdisc handle=0x%X parent=0x%X
skbaddr=%px",
+ TP_printk("enqueue ifindex=%d qdisc handle=0x%X parent=0x%X skbaddr=%p",
__entry->ifindex, __entry->handle, __entry->parent,
__entry->skbaddr)
);
quoted hunk ↗ jump to hunk
However, tracing the packet traversal shows a mix of hashes and real addresses. Pasting a sample trace for reference- ping-14249 [002] ..... 3424.046612: netif_rx_entry: dev=lo napi_id=0x3 queue_mapping=0 skbaddr=00000000dcbed83e vlan_tagged=0 vlan_proto=0x0000 vlan_tci=0x0000 protocol=0x0800 ip_summed=0 hash=0x00000000 l4_hash=0 len=84 data_len=0 truesize=768 mac_header_valid=1 mac_header=-14 nr_frags=0 gso_size=0 gso_type=0x0 ping-14249 [002] ..... 3424.046615: netif_rx: dev=lo skbaddr=ffffff888e5d1000 len=84 Switch the trace print formats to %px for all the events to have a consistent format of printing the real addresses in all cases. Signed-off-by: Sean Tranchetti <redacted> Signed-off-by: Subash Abhinov Kasiviswanathan <redacted> --- include/trace/events/net.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)diff --git a/include/trace/events/net.h b/include/trace/events/net.h index 032b431..2651350 100644 --- a/include/trace/events/net.h +++ b/include/trace/events/net.h@@ -58,7 +58,7 @@ TRACE_EVENT(net_dev_start_xmit, __entry->gso_type = skb_shinfo(skb)->gso_type; ), - TP_printk("dev=%s queue_mapping=%u skbaddr=%p vlan_tagged=%d vlan_proto=0x%04x vlan_tci=0x%04x protocol=0x%04x ip_summed=%d len=%u data_len=%u network_offset=%d transport_offset_valid=%d transport_offset=%d tx_flags=%d gso_size=%d gso_segs=%d gso_type=%#x", + TP_printk("dev=%s queue_mapping=%u skbaddr=%px vlan_tagged=%d vlan_proto=0x%04x vlan_tci=0x%04x protocol=0x%04x ip_summed=%d len=%u data_len=%u network_offset=%d transport_offset_valid=%d transport_offset=%d tx_flags=%d gso_size=%d gso_segs=%d gso_type=%#x", __get_str(name), __entry->queue_mapping, __entry->skbaddr, __entry->vlan_tagged, __entry->vlan_proto, __entry->vlan_tci, __entry->protocol, __entry->ip_summed, __entry->len,@@ -91,7 +91,7 @@ TRACE_EVENT(net_dev_xmit, __assign_str(name, dev->name); ), - TP_printk("dev=%s skbaddr=%p len=%u rc=%d", + TP_printk("dev=%s skbaddr=%px len=%u rc=%d", __get_str(name), __entry->skbaddr, __entry->len, __entry->rc) );@@ -215,7 +215,7 @@ DECLARE_EVENT_CLASS(net_dev_rx_verbose_template, __entry->gso_type = skb_shinfo(skb)->gso_type; ), - TP_printk("dev=%s napi_id=%#x queue_mapping=%u skbaddr=%p vlan_tagged=%d vlan_proto=0x%04x vlan_tci=0x%04x protocol=0x%04x ip_summed=%d hash=0x%08x l4_hash=%d len=%u data_len=%u truesize=%u mac_header_valid=%d mac_header=%d nr_frags=%d gso_size=%d gso_type=%#x", + TP_printk("dev=%s napi_id=%#x queue_mapping=%u skbaddr=%px vlan_tagged=%d vlan_proto=0x%04x vlan_tci=0x%04x protocol=0x%04x ip_summed=%d hash=0x%08x l4_hash=%d len=%u data_len=%u truesize=%u mac_header_valid=%d mac_header=%d nr_frags=%d gso_size=%d gso_type=%#x", __get_str(name), __entry->napi_id, __entry->queue_mapping, __entry->skbaddr, __entry->vlan_tagged, __entry->vlan_proto, __entry->vlan_tci, __entry->protocol, __entry->ip_summed, --2.7.4