kernel/linux.git/include/trace/events/net.h, branch v7.1-rc5

net: validate skb->napi_id in RX tracepoints

2026-04-23T03:15:50+00:00

Since commit 2bd82484bb4c ("xps: fix xps for stacked devices"), skb->napi_id shares storage with sender_cpu. RX tracepoints using net_dev_rx_verbose_template read skb->napi_id directly and can therefore report sender_cpu values as if they were NAPI IDs. For example, on the loopback path this can report 1 as napi_id, where 1 comes from raw_smp_processor_id() + 1 in the XPS path: # bpftrace -e 'tracepoint:net:netif_rx_entry{ print(args->napi_id); }' # taskset -c 0 ping -c 1 ::1 Report only valid NAPI IDs in these tracepoints and use 0 otherwise. Fixes: 2bd82484bb4c ("xps: fix xps for stacked devices") Signed-off-by: Kohei Enju Reviewed-by: Simon Horman Reviewed-by: Jiayuan Chen Link: https://patch.msgid.link/20260420105427.162816-1-kohei@enjuk.jp Signed-off-by: Jakub Kicinski

net: add net cookie for net device trace events

2025-11-04T08:59:19+00:00

In a multi-network card or container environment, this is needed in order to differentiate between trace events relating to net devices that exist in different network namespaces and share the same name. for xmit_timeout trace events: [002] ..s1. 1838.311662: net_dev_xmit_timeout: dev=eth0 driver=virtio_net queue=10 net_cookie=3 [007] ..s1. 1839.335650: net_dev_xmit_timeout: dev=eth0 driver=virtio_net queue=10 net_cookie=4100 [007] ..s1. 1844.455659: net_dev_xmit_timeout: dev=eth0 driver=virtio_net queue=10 net_cookie=3 [002] ..s1. 1850.087647: net_dev_xmit_timeout: dev=eth0 driver=virtio_net queue=10 net_cookie=3 Cc: Eran Ben Elisha Cc: Jiri Pirko Cc: Cong Wang Cc: Jakub Kicinski Cc: Eric Dumazet Cc: Simon Horman Cc: Paolo Abeni Suggested-by: Ido Schimmel Signed-off-by: Tonghao Zhang Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20251028043244.82288-1-tonghao@bamaicloud.com Signed-off-by: Paolo Abeni

tracing/treewide: Remove second parameter of __assign_str()

2024-05-23T00:14:47+00:00

With the rework of how the __string() handles dynamic strings where it saves off the source string in field in the helper structure[1], the assignment of that value to the trace event field is stored in the helper value and does not need to be passed in again. This means that with: __string(field, mystring) Which use to be assigned with __assign_str(field, mystring), no longer needs the second parameter and it is unused. With this, __assign_str() will now only get a single parameter. There's over 700 users of __assign_str() and because coccinelle does not handle the TRACE_EVENT() macro I ended up using the following sed script: git grep -l __assign_str | while read a ; do sed -e 's/$__assign_str([^,]*[^ ,]$ *,[^;]*/\1)/' $a > /tmp/test-file; mv /tmp/test-file $a; done I then searched for __assign_str() that did not end with ';' as those were multi line assignments that the sed script above would fail to catch. Note, the same updates will need to be done for: __assign_str_len() __assign_rel_str() __assign_rel_str_len() I tested this with both an allmodconfig and an allyesconfig (build only for both). [1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/ Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Linus Torvalds Cc: Julia Lawall Signed-off-by: Steven Rostedt (Google) Acked-by: Jani Nikula Acked-by: Christian König for the amdgpu parts. Acked-by: Thomas Hellström #for Acked-by: Rafael J. Wysocki # for thermal Acked-by: Takashi Iwai Acked-by: Darrick J. Wong # xfs Tested-by: Guenter Roeck

net: fix net_dev_start_xmit trace event vs skb_transport_offset()

2023-07-03T08:13:23+00:00

After blamed commit, we must be more careful about using skb_transport_offset(), as reminded us by syzbot: WARNING: CPU: 0 PID: 10 at include/linux/skbuff.h:2868 skb_transport_offset include/linux/skbuff.h:2977 [inline] WARNING: CPU: 0 PID: 10 at include/linux/skbuff.h:2868 perf_trace_net_dev_start_xmit+0x89a/0xce0 include/trace/events/net.h:14 Modules linked in: CPU: 0 PID: 10 Comm: kworker/u4:1 Not tainted 6.1.30-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:skb_transport_header include/linux/skbuff.h:2868 [inline] RIP: 0010:skb_transport_offset include/linux/skbuff.h:2977 [inline] RIP: 0010:perf_trace_net_dev_start_xmit+0x89a/0xce0 include/trace/events/net.h:14 Code: 8b 04 25 28 00 00 00 48 3b 84 24 c0 00 00 00 0f 85 4e 04 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc e8 56 22 01 fd <0f> 0b e9 f6 fc ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 86 f9 ff RSP: 0018:ffffc900002bf700 EFLAGS: 00010293 RAX: ffffffff8485d8ca RBX: 000000000000ffff RCX: ffff888100914280 RDX: 0000000000000000 RSI: 000000000000ffff RDI: 000000000000ffff RBP: ffffc900002bf818 R08: ffffffff8485d5b6 R09: fffffbfff0f8fb5e R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff110217d8f67 R13: ffff88810bec7b3a R14: dffffc0000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f96cf6d52f0 CR3: 000000012224c000 CR4: 0000000000350ef0 Call Trace: [] trace_net_dev_start_xmit include/trace/events/net.h:14 [inline] [] xmit_one net/core/dev.c:3643 [inline] [] dev_hard_start_xmit+0x705/0x980 net/core/dev.c:3660 [] __dev_queue_xmit+0x16b2/0x3370 net/core/dev.c:4324 [] dev_queue_xmit include/linux/netdevice.h:3030 [inline] [] batadv_send_skb_packet+0x3f3/0x680 net/batman-adv/send.c:108 [] batadv_send_broadcast_skb+0x24/0x30 net/batman-adv/send.c:127 [] batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:393 [inline] [] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:421 [inline] [] batadv_iv_send_outstanding_bat_ogm_packet+0x69a/0x840 net/batman-adv/bat_iv_ogm.c:1701 [] process_one_work+0x8ac/0x1170 kernel/workqueue.c:2289 [] worker_thread+0xaa8/0x12d0 kernel/workqueue.c:2436 Fixes: 66e4c8d95008 ("net: warn if transport header was not set") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller

net: Print hashed skb addresses for all net and qdisc events

2022-06-27T10:57:06+00:00

The following commits added support for printing the real address- 65875073eddd ("net: use %px to print skb address in trace_netif_receive_skb") 70713dddf3d2 ("net_sched: introduce tracepoint trace_qdisc_enqueue()") 851f36e40962 ("net_sched: use %px to print skb address in trace_qdisc_dequeue()") 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 %p for all the events to have a consistent format of printing the hashed addresses in all cases. Signed-off-by: Sean Tranchetti Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller

net: dev: Makes sure netif_rx() can be invoked in any context.

2022-02-14T13:38:35+00:00

Dave suggested a while ago (eleven years by now) "Let's make netif_rx() work in all contexts and get rid of netif_rx_ni()". Eric agreed and pointed out that modern devices should use netif_receive_skb() to avoid the overhead. In the meantime someone added another variant, netif_rx_any_context(), which behaves as suggested. netif_rx() must be invoked with disabled bottom halves to ensure that pending softirqs, which were raised within the function, are handled. netif_rx_ni() can be invoked only from process context (bottom halves must be enabled) because the function handles pending softirqs without checking if bottom halves were disabled or not. netif_rx_any_context() invokes on the former functions by checking in_interrupts(). netif_rx() could be taught to handle both cases (disabled and enabled bottom halves) by simply disabling bottom halves while invoking netif_rx_internal(). The local_bh_enable() invocation will then invoke pending softirqs only if the BH-disable counter drops to zero. Eric is concerned about the overhead of BH-disable+enable especially in regard to the loopback driver. As critical as this driver is, it will receive a shortcut to avoid the additional overhead which is not needed. Add a local_bh_disable() section in netif_rx() to ensure softirqs are handled if needed. Provide __netif_rx() which does not disable BH and has a lockdep assert to ensure that interrupts are disabled. Use this shortcut in the loopback driver and in drivers/net/*.c. Make netif_rx_ni() and netif_rx_any_context() invoke netif_rx() so they can be removed once they are no more users left. Link: https://lkml.kernel.org/r/20100415.020246.218622820.davem@davemloft.net Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Eric Dumazet Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller

net: use %px to print skb address in trace_netif_receive_skb

2021-07-15T17:28:48+00:00

The print format of skb adress in tracepoint class net_dev_template is changed to %px from %p, because we want to use skb address as a quick way to identify a packet. Note, trace ring buffer is only accessible to privileged users, it is safe to use a real kernel address here. Reviewed-by: Cong Wang Signed-off-by: Qitao Xu Signed-off-by: David S. Miller

net: add a generic tracepoint for TX queue timeout

2019-05-04T04:41:41+00:00

Although devlink health report does a nice job on reporting TX timeout and other NIC errors, unfortunately it requires drivers to support it but currently only mlx5 has implemented it. Before other drivers could catch up, it is useful to have a generic tracepoint to monitor this kind of TX timeout. We have been suffering TX timeout with different drivers, we plan to start to monitor it with rasdaemon which just needs a new tracepoint. Sample output: ksoftirqd/1-16 [001] ..s2 144.043173: net_dev_xmit_timeout: dev=ens3 driver=e1000 queue=0 Cc: Eran Ben Elisha Cc: Jiri Pirko Signed-off-by: Cong Wang Acked-by: Jiri Pirko Reviewed-by: Eran Ben Elisha Signed-off-by: David S. Miller

net: Add trace events for all receive exit points

2018-11-30T21:23:25+00:00

Trace events are already present for the receive entry points, to indicate how the reception entered the stack. This patch adds the corresponding exit trace events that will bound the reception such that all events occurring between the entry and the exit can be considered as part of the reception context. This greatly helps for dependency and root cause analyses. Without this, it is not possible with tracepoint instrumentation to determine whether a sched_wakeup event following a netif_receive_skb event is the result of the packet reception or a simple coincidence after further processing by the thread. It is possible using other mechanisms like kretprobes, but considering the "entry" points are already present, it would be good to add the matching exit events. In addition to linking packets with wakeups, the entry/exit event pair can also be used to perform network stack latency analyses. Signed-off-by: Geneviève Bastien CC: Mathieu Desnoyers CC: Steven Rostedt CC: Ingo Molnar CC: David S. Miller Reviewed-by: Steven Rostedt (VMware) (tracing side) Signed-off-by: David S. Miller

net: core: unwrap skb list receive slightly further

2018-07-04T05:06:19+00:00

Signed-off-by: Edward Cree Signed-off-by: David S. Miller