Panic during reboot involving softclock_call_cc(), nd6_timer() and nd6_dad_start()

[Trond Endrestøl]

On Wed, 17 Apr 2019 12:05+0200, Trond Endrestøl wrote:

> On Wed, 17 Apr 2019 12:41+0300, Andrey V. Elsukov wrote:
> 
> > On 15.04.2019 16:31, Trond Endrestøl wrote:
> > > Has anyone else witnessed a panic during reboot involving 
> > > softclock_call_cc(), nd6_timer(), and nd6_dad_start()?
> > > 
> > > The stack trace goes more or less like this:
> > > 
> > > db_trace_self_wrapper()
> > > vpanic()
> > > panic()
> > > trap_fatal()
> > > trap()
> > > calltrap()
> > > nd6_dad_start()
> > > nd6_timer()
> > > softclock_call_cc()
> > > softclock()
> > > ithread_loop()
> > > fork_exit()
> > > fork_trampoline()
> > > 
> > > This was last seen while transitioning from r345628 to r346220 on 
> > > amd64 stable/12.
> > 
> > Hi,
> > 
> > do you have exact panic message and/or backtrace from core dump?
> 
> Here's another system I had to shut down recently:
> 
> root at HOSTNAME:/var/crash # kgdb /boot/kernel/kernel vmcore.0
> [...]
> Fatal trap 12: page fault while in kernel mode
> cpuid = 0; apic id = 00
> fault virtual address   = 0x410
> fault code              = supervisor read data  , page not present
> instruction pointer     = 0x20:0xffffffff807ea33d
> stack pointer           = 0x28:0xfffffe005ad3c8d0
> frame pointer           = 0x28:0xfffffe005ad3c960
> code segment            = base 0x0, limit 0xfffff, type 0x1b
>                         = DPL 0, pres 1, long 1, def32 0, gran 1
> processor eflags        = interrupt enabled, resume, IOPL = 0
> current process         = 12 (swi4: clock (0))
> trap number             = 12
> panic: page fault
> cpuid = 0
> time = 1555402802
> KDB: stack backtrace:
> db_trace_self_wrapper() at 0xffffffff8054125b = db_trace_self_wrapper+0x2b/frame 0xfffffe005ad3c570
> vpanic() at 0xffffffff8080aae4 = vpanic+0x1b4/frame 0xfffffe005ad3c5d0
> panic() at 0xffffffff8080a923 = panic+0x43/frame 0xfffffe005ad3c630
> trap_fatal() at 0xffffffff80b76244 = trap_fatal+0x394/frame 0xfffffe005ad3c690
> trap_pfault() at 0xffffffff80b762a9 = trap_pfault+0x49/frame 0xfffffe005ad3c6f0
> trap() at 0xffffffff80b7588f = trap+0x29f/frame 0xfffffe005ad3c800
> calltrap() at 0xffffffff80b514c5 = calltrap+0x8/frame 0xfffffe005ad3c800
> --- trap 0xc, rip = 0xffffffff807ea33d, rsp = 0xfffffe005ad3c8d0, rbp = 0xfffffe005ad3c960 ---
> __mtx_lock_sleep() at 0xffffffff807ea33d = __mtx_lock_sleep+0xbd/frame 0xfffffe005ad3c960
> mld_fasttimo() at 0xffffffff80a3ae32 = mld_fasttimo+0x492/frame 0xfffffe005ad3ca50
> pffasttimo() at 0xffffffff80899fa4 = pffasttimo+0x54/frame 0xfffffe005ad3ca80
> softclock_call_cc() at 0xffffffff80824e0e = softclock_call_cc+0x12e/frame 0xfffffe005ad3cb30
> softclock() at 0xffffffff808252f9 = softclock+0x79/frame 0xfffffe005ad3cb50
> ithread_loop() at 0xffffffff807cd824 = ithread_loop+0x1d4/frame 0xfffffe005ad3cbb0
> fork_exit() at 0xffffffff807ca2d3 = fork_exit+0x83/frame 0xfffffe005ad3cbf0
> fork_trampoline() at 0xffffffff80b524be = fork_trampoline+0xe/frame 0xfffffe005ad3cbf0
> --- trap 0, rip = 0, rsp = 0, rbp = 0 ---
> Uptime: 34d16h8m2s
> Dumping 4593 out of 12258 
> MB:..1%..11%..21%..31%..41%..51%..61%..71%..81%..91%
> 
> This particular system uses lagg0 comprised of bce0, bce1, em0, and 
> em1. Also, it runs a custom kernel.
> 
> > It would be good to submit PR about such problems.
> 
> I'll submit the details in a PR.

PR is 237329.
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=237329

-- 
Trond.