Re: udp6: Page fault panics

On 9/15/18 8:04 PM, Larry Rosenman wrote:
> I've got 2 of these:
> 
> Fatal trap 12: page fault while in kernel mode
> cpuid = 4; apic id = 04
> fault virtual address   = 0x7c
> fault code              = supervisor read data, page not present
> instruction pointer     = 0x20:0xffffffff80631428
> stack pointer           = 0x28:0xfffffe00ca17c440
> frame pointer           = 0x28:0xfffffe00ca17c480
> 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         = 1225 (isc-worker0003)
> trap number             = 12
> panic: page fault
> cpuid = 4
> time = 1537050918
> KDB: stack backtrace:
> db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00ca17c0f0
> vpanic() at vpanic+0x1a3/frame 0xfffffe00ca17c150
> panic() at panic+0x43/frame 0xfffffe00ca17c1b0
> trap_fatal() at trap_fatal+0x35f/frame 0xfffffe00ca17c200
> trap_pfault() at trap_pfault+0x49/frame 0xfffffe00ca17c260
> trap() at trap+0x2ba/frame 0xfffffe00ca17c370
> calltrap() at calltrap+0x8/frame 0xfffffe00ca17c370
> --- trap 0xc, rip = 0xffffffff80631428, rsp = 0xfffffe00ca17c440, rbp = 0xfffffe00ca17c480 ---
> selectroute() at selectroute+0x198/frame 0xfffffe00ca17c480
> in6_selectroute_fib() at in6_selectroute_fib+0xf/frame 0xfffffe00ca17c4a0
> ip6_output() at ip6_output+0xfd7/frame 0xfffffe00ca17c710
> udp6_send() at udp6_send+0x720/frame 0xfffffe00ca17c8d0
> sosend_dgram() at sosend_dgram+0x346/frame 0xfffffe00ca17c930
> kern_sendit() at kern_sendit+0x201/frame 0xfffffe00ca17c9d0
> sendit() at sendit+0x19e/frame 0xfffffe00ca17ca20
> sys_sendmsg() at sys_sendmsg+0x61/frame 0xfffffe00ca17ca80
> amd64_syscall() at amd64_syscall+0x272/frame 0xfffffe00ca17cbb0
> fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe00ca17cbb0
> --- syscall (28, FreeBSD ELF64, sys_sendmsg), rip = 0x800be5a9a, rsp = 0x7fffdf9fa468, rbp = 0x7fffdf9fa4a0 --
> -
> Uptime: 35s

 [ .. snip .. ]

This is likely another instance of
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=230950

I had similar, seemingly random panics on a nameserver I run and the
only workaround I have so far is to revert SVNs r338257 and r338306 :-(

	imb