Panic while building perl on sheevaplug/armv5 freebsd 10.

[Warner Losh]

On Sep 13, 2013, at 8:03 AM, Ian Lepore wrote:

> On Fri, 2013-09-13 at 15:11 +0200, Ronald Klop wrote:
>> Hello,
>> 
>> I have a repeatable panic while building perl on my Sheevaplug ARMv5  
>> running FreeBSD 10-CURRENT.
>> Kernel is loaded from NAND.
>> / is mounted from USB /dev/da0s2 (UFS2)
>> /usr/ports is mounted over NFS from a 9-STABLE/amd64 box.
>> Swap from 512MB file in /data/swap.
>> 
>> ---- console output
>> login: panic: vm_fault: fault on nofault entry, addr: ddf9d000
>> KDB: enter: panic
>> [ thread pid 659 tid 100057 ]
>> Stopped at      kdb_enter+0x4c: ldrb    r15, [r15, r15, ror r15]!
>> db> bt
>> Tracing pid 659 tid 100057 td 0xc3f86000
> [...]
>> exception_exit() at exception_exit
>>          pc = 0xc0bba3fc  lr = 0xc0a60c88 (tc_setclock+0x458)
>>          sp = 0xddf9d008  fp = 0xddf9e038
>>          r0 = 0xc0bba324  r1 = 0xc0d00000
>>          r2 = 0xddf9d00c  r3 = 0x20000093
>>          r4 = 0x00000000  r5 = 0xc0ccd630
>>          r6 = 0x00000000  r7 = 0x00000000
>>          r8 = 0xc0caece0  r9 = 0x00000001
>>         r10 = 0xc0caec88 r12 = 0x00000000
>> data_abort_entry() at data_abort_entry+0x30
>>          pc = 0xc0bba324  lr = 0xc0a60c88 (tc_setclock+0x458)
>>          sp = 0xddf9d008  fp = 0xddf9e038
>> Unwind failure (no registers changed)
> 
> That's the second time in the past few months I've seen a backtrace that
> makes it look like we ran out of kernel stack, but the default is 8k
> which should be plenty.  Still, try adding "option KSTACK_PAGES=3" to
> your kernel config and see if the problem goes away.  If it does, we may
> need to figure out why we're using so much stack.  If it doesn't, we've
> probably got a bad recursion loop happening somewhere.

FreeBSD/mips runs out of kernel stack on ports builds as well, but there's a number of special conditions that seem to be needed before that happens...

Warner