Kernel access of bad area on kernel 4.1.6

[Ilia Mirkin]

I've recently come into the possession of a PowerMac7,3 and have been
cross-compiling a chroot for it on my (x86_64) desktop. However
elfutils doesn't cross-compile for ppc64 due to its biarch m4 script
which tries to execute a built program, so I kicked off a build
locally and left for a few minutes. When I came back, I saw the below
through netconsole, the fans were going full blast, and the machine
was unresponsive.

Is this a kernel issue? Hardware issue? What do I need to do in order
for the instruction dump to not be XXX's and have a call trace? (Is
this the annoying security stuff in action? I started with the
g5_defconfig, perhaps that was a mistake.) Sorry for the newbie
questions, but I'm very new to ppc.

In case it matters, it's booted on an nfsroot, no swap.

Thanks for any help,

  -ilia

[ 8419.415061] Oops: Kernel access of bad area, sig: 11 [#1]
[ 8419.416338] SMP NR_CPUS=4 PowerMac
[ 8419.417623] Modules linked in: snd_aoa_codec_tas snd_aoa snd
nouveau soundcore btusb btbcm btintel ttm bluetooth drm_kms_helper drm
uninorth_agp agpgart
[ 8419.419138] CPU: 0 PID: 12927 Comm: as Not tainted 4.1.6 #4
[ 8419.420539] task: c0000000573f3520 ti: c000000057698000 task.ti:
c000000057698000
[ 8419.421963] NIP: c00000005769bca8 LR: c00000005769bca8 CTR: c00000000008a710
[ 8419.423400] REGS: c00000005769b7e0 TRAP: 0400   Not tainted  (4.1.6)
[ 8419.424850] MSR: 9000000010001032 <SF,HV,ME,IR,DR,RI>  CR: 001048fc
 XER: 00000000
[ 8419.426407] SOFTE: 0
GPR00: 00000000ffffffff c00000005769ba60 c000000000b9ac00 c0000000590bb520
GPR04: c0000000573f3ab0 c0000000573f3588 c0000000001048fc c00000005769bca8
GPR08: c00000005769b890 c000000050000000 0000000000000001 c00000005ee0a290
GPR12: 0000000024044048 c00000000ffff000 c00000005769ba20 0000000000000600
GPR16: 0000000000000001 0000000000000000 c00000005bbd8e00 c000000058ccbcb0
GPR20: c00000005769ba50 0000000000000000 c000000000103d60 c00000005bbd8e00
GPR24: c00000005769ba40 0000000000000000 0000000000000001 0000000000000001
GPR28: 000000001007d630 0000000010049d08 c00000005769bc80 c000000058ccbcb0
[ 8419.440558] NIP [c00000005769bca8] 0xc00000005769bca8
[ 8419.442170] LR [c00000005769bca8] 0xc00000005769bca8
[ 8419.443774] Call Trace:
[ 8419.445351] Instruction dump:
[ 8419.446946] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX
[ 8419.448659] XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX
[ 8419.456445] ---[ end trace ad7c77d8920840ff ]---
[ 8419.456511]
[ 8419.456565] Fixing recursive fault but reboot is needed!