head -r325997: Fatal trap 12: page fault while in kernel mode (during a buildworld, virtualbox guest context)

[Mark Millard]

Attempting a dump failed. I'm afraid all for
information is the below. The kernel was a
non-debug kernel (with debug information).

The following is hand typed from a screen shot:

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address = 0xffffff53f000e2b0
fault code            = supervisor read data, page not present
instruction pointer   = 0x20:0xffffffff80f2b11e
stack pointer         = 0x0:0xfffffe01aeb28970
frame pointer         = 0x0:0xfffffe01aeb289f0
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       = 20 (pagedaemon)
[ thread pid 20 tid 100089 ]
Stopped at pmap_ts_referenced+0x72e: movq (%rcx,rdi,8),%rbx
bd > bt
Tracing pid 20 tid 100089 td 0xfffff80003eb3560
pmap_ts_referenced() at pmap_ts_referenced_0x72e/frame 0xfffffe01aeb289f0
vm_pageout() at vm_pageout+0xdeb/frame 0xfffffe01aeb28ab0
fork_exit() at fork_exit+0x82/frame 0xfffffe01aeb28ab0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe01aeb28ab0
--- trap 0, rip = 0, rsp = 0, rpb = 0 ---
db>

The prior (cross) buildworld buildkernel had completed fine.

Until yesterday, I'd been running -r325700 or before and had not
seen such an issue ever before. I'd been using the virtualbox
version for a while before this as well.

===
Mark Millard
markmi at dsl-only.net