Messages in this thread | | | From | Chuck Lever III <> | Subject | Re: possible trace_printk() bug in v5.19-rc1 | Date | Sat, 18 Jun 2022 01:28:49 +0000 |
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> On Jun 17, 2022, at 3:50 PM, Steven Rostedt <rostedt@goodmis.org> wrote: > > On Thu, 16 Jun 2022 15:36:43 +0000 > Chuck Lever III <chuck.lever@oracle.com> wrote: > >>> Did you remove any modules before displaying the trace? >> >> I haven't explicitly removed nfsd.ko, and lsmod says it's still there. >> And, trace_printk was working as expected on v5.18. > > Are you sure?
Yes, I'm sure. I just checked out v5.18 and built it with the same CONFIG. trace_printk() on that kernel generates function names as expected.
> I just checkout v5.19-rc2 and added the below patch. Then I did the > following: > > # rmmod bridge > > # trace-cmd start -p function -l :mod:bridge > > # insmod bridge > > # trace-cmd show > # tracer: function > # > # entries-in-buffer/entries-written: 23/23 #P:8 > # > # _-----=> irqs-off/BH-disabled > # / _----=> need-resched > # | / _---=> hardirq/softirq > # || / _--=> preempt-depth > # ||| / _-=> migrate-disable > # |||| / delay > # TASK-PID CPU# ||||| TIMESTAMP FUNCTION > # | | | ||||| | | > modprobe-2155 [005] ...1. 4732.051406: br_init <-do_one_initcall > modprobe-2155 [005] ..... 4732.051408: br_init: here in bridge > modprobe-2155 [005] ...1. 4732.051408: br_fdb_init <-br_init > modprobe-2155 [005] ...1. 4732.051418: br_device_event <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051418: br_device_event: this is an event > modprobe-2155 [005] ...1. 4732.051418: br_device_event <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051418: br_device_event: this is an event > modprobe-2155 [005] ...1. 4732.051418: br_device_event <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051419: br_device_event: this is an event > modprobe-2155 [005] ...1. 4732.051419: br_device_event <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051419: br_device_event: this is an event > modprobe-2155 [005] ...1. 4732.051419: br_device_event <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051419: br_device_event: this is an event > modprobe-2155 [005] ...1. 4732.051419: br_device_event <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051420: br_device_event: this is an event > modprobe-2155 [005] ...1. 4732.051420: br_device_event <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051420: br_device_event: this is an event > modprobe-2155 [005] ...1. 4732.051420: br_device_event <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051420: br_device_event: this is an event > modprobe-2155 [005] ...1. 4732.051420: br_device_event <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051420: br_device_event: this is an event > modprobe-2155 [005] ...1. 4732.051421: br_netlink_init <-br_init > modprobe-2155 [005] ...1. 4732.051421: br_mdb_init <-br_netlink_init > > # rmmod bridge > > # trace-cmd show > # tracer: function > # > # entries-in-buffer/entries-written: 56/56 #P:8 > # > # _-----=> irqs-off/BH-disabled > # / _----=> need-resched > # | / _---=> hardirq/softirq > # || / _--=> preempt-depth > # ||| / _-=> migrate-disable > # |||| / delay > # TASK-PID CPU# ||||| TIMESTAMP FUNCTION > # | | | ||||| | | > modprobe-2155 [005] ...1. 4732.051406: 0xffffffffc0cc7000 <-do_one_initcall > modprobe-2155 [005] ..... 4732.051408: 0xffffffffc0cc702b: here in bridge > modprobe-2155 [005] ...1. 4732.051408: 0xffffffffc0cc7101 <-0xffffffffc0cc7043 > modprobe-2155 [005] ...1. 4732.051418: 0xffffffffc0d81340 <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051418: 0xffffffffc0d81345: this is an event > modprobe-2155 [005] ...1. 4732.051418: 0xffffffffc0d81340 <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051418: 0xffffffffc0d81345: this is an event > modprobe-2155 [005] ...1. 4732.051418: 0xffffffffc0d81340 <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051419: 0xffffffffc0d81345: this is an event > modprobe-2155 [005] ...1. 4732.051419: 0xffffffffc0d81340 <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051419: 0xffffffffc0d81345: this is an event > modprobe-2155 [005] ...1. 4732.051419: 0xffffffffc0d81340 <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051419: 0xffffffffc0d81345: this is an event > modprobe-2155 [005] ...1. 4732.051419: 0xffffffffc0d81340 <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051420: 0xffffffffc0d81345: this is an event > modprobe-2155 [005] ...1. 4732.051420: 0xffffffffc0d81340 <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051420: 0xffffffffc0d81345: this is an event > modprobe-2155 [005] ...1. 4732.051420: 0xffffffffc0d81340 <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051420: 0xffffffffc0d81345: this is an event > modprobe-2155 [005] ...1. 4732.051420: 0xffffffffc0d81340 <-call_netdevice_register_net_notifiers > modprobe-2155 [005] ..... 4732.051420: 0xffffffffc0d81345: this is an event > modprobe-2155 [005] ...1. 4732.051421: 0xffffffffc0cc7132 <-0xffffffffc0cc70a3 > modprobe-2155 [005] ...1. 4732.051421: 0xffffffffc0da1500 <-0xffffffffc0cc713e > kworker/u16:2-2023 [004] ...1. 4737.946576: 0xffffffffc0d81340 <-raw_notifier_call_chain > kworker/u16:2-2023 [004] ..... 4737.946578: 0xffffffffc0d81345: this is an event > kworker/u16:2-2023 [004] ...1. 4737.946634: 0xffffffffc0d8e1a0 <-if_nlmsg_size > kworker/u16:2-2023 [004] ...1. 4737.946735: 0xffffffffc0d81340 <-raw_notifier_call_chain > kworker/u16:2-2023 [004] ..... 4737.946735: 0xffffffffc0d81345: this is an event > kworker/u16:2-2023 [004] ...1. 4737.946833: 0xffffffffc0d81340 <-raw_notifier_call_chain > kworker/u16:2-2023 [004] ..... 4737.946833: 0xffffffffc0d81345: this is an event > kworker/u16:2-2023 [004] ...1. 4737.946834: 0xffffffffc0d8e1a0 <-if_nlmsg_size > kworker/u16:2-2023 [004] ...1. 4737.957648: 0xffffffffc0d81190 <-cleanup_net > rmmod-2206 [000] ...1. 5739.459376: 0xffffffffc0d8f880 <-0xffffffffc0da3d1d > rmmod-2206 [000] ...1. 5739.459378: 0xffffffffc0da1570 <-0xffffffffc0d8f88a > rmmod-2206 [000] ...1. 5739.471367: 0xffffffffc0d81340 <-call_netdevice_unregister_notifiers > rmmod-2206 [000] ..... 5739.471368: 0xffffffffc0d81345: this is an event > rmmod-2206 [000] ...1. 5739.471369: 0xffffffffc0d81340 <-call_netdevice_unregister_notifiers > rmmod-2206 [000] ..... 5739.471369: 0xffffffffc0d81345: this is an event > rmmod-2206 [000] ...1. 5739.471369: 0xffffffffc0d81340 <-call_netdevice_unregister_notifiers > rmmod-2206 [000] ..... 5739.471369: 0xffffffffc0d81345: this is an event > rmmod-2206 [000] ...1. 5739.471370: 0xffffffffc0d81340 <-call_netdevice_unregister_notifiers > rmmod-2206 [000] ..... 5739.471370: 0xffffffffc0d81345: this is an event > rmmod-2206 [000] ...1. 5739.471370: 0xffffffffc0d81340 <-call_netdevice_unregister_notifiers > rmmod-2206 [000] ..... 5739.471370: 0xffffffffc0d81345: this is an event > rmmod-2206 [000] ...1. 5739.471370: 0xffffffffc0d81340 <-call_netdevice_unregister_notifiers > rmmod-2206 [000] ..... 5739.471370: 0xffffffffc0d81345: this is an event > rmmod-2206 [000] ...1. 5739.471371: 0xffffffffc0d81340 <-call_netdevice_unregister_notifiers > rmmod-2206 [000] ..... 5739.471371: 0xffffffffc0d81345: this is an event > rmmod-2206 [000] ...1. 5739.471371: 0xffffffffc0d81340 <-call_netdevice_unregister_notifiers > rmmod-2206 [000] ..... 5739.471371: 0xffffffffc0d81345: this is an event > rmmod-2206 [000] ...1. 5739.471371: 0xffffffffc0d81340 <-call_netdevice_unregister_notifiers > rmmod-2206 [000] ..... 5739.471372: 0xffffffffc0d81345: this is an event > rmmod-2206 [000] ...1. 5739.471372: 0xffffffffc0d81340 <-call_netdevice_unregister_notifiers > rmmod-2206 [000] ..... 5739.471372: 0xffffffffc0d81345: this is an event > rmmod-2206 [000] ...1. 5739.477366: 0xffffffffc0d81190 <-unregister_pernet_operations > rmmod-2206 [000] ...1. 5739.477375: 0xffffffffc0d84910 <-__do_sys_delete_module.constprop.0 > > Before removing the module, the names were all present. Then after I > removed the module, they did not exist. > > Other than that, I cannot reproduce the issue. > > -- Steve > > > diff --git a/net/bridge/br.c b/net/bridge/br.c > index 96e91d69a9a8..4067760d3763 100644 > --- a/net/bridge/br.c > +++ b/net/bridge/br.c > @@ -36,6 +36,7 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v > bool changed_addr; > int err; > > + trace_printk("this is an event\n"); > if (netif_is_bridge_master(dev)) { > err = br_vlan_bridge_event(dev, event, ptr); > if (err) > @@ -385,6 +386,7 @@ static int __init br_init(void) > return err; > } > > + trace_printk("here in bridge\n"); > err = br_fdb_init(); > if (err) > goto err_out;
-- Chuck Lever
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