ppp triggers GPF panic

[Lawrence Stewart]

Stefan Bethke wrote:
> Yesterday's -current, amd64, C2D, 4 GB RAM. Full dmesg below.
> 
> 
> Fatal trap 9: general protection fault while in kernel mode
> cpuid = 0; apic id = 00
> instruction pointer    = 0x20:0xffffffff802fc2ce
> stack pointer            = 0x28:0xffffff8000037b10
> frame pointer            = 0x28:0xffffff8000037b30
> 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 (swi1: netisr 0)
> [thread pid 12 tid 100007 ]
> Stopped at      _mtx_lock_sleep+0x4e:   movl    0x288(%rcx),%esi
> 
> Didn't capture anything else there.  This happened when my ADSL link was 
> forced down (24h connection reset).
> 
> After fixing the file system (UFS2 + softupdates on /), I got another 
> "panic: spin lock held too long" on rebooting.
> 
> Then, the GPF panic happened again as ppp was trying to establish the 
> connection:

1. Do you have a crash dump?

2. Can you try find a sequence of events to deterministically reproduce 
this?

Cheers,
Lawrence