head -r325997: Fatal trap 12: page fault while in kernel mode (during a buildworld, virtualbox guest context) [2nd example]

[Mark Millard]

[I got another of these. By the way: amd64 context.
Again: buildworld was running.]

On 2017-Nov-19, at 5:52 PM, Mark Millard <markmi at dsl-only.net> wrote:

> 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

New one:                  0x806b49010

> fault code            = supervisor read data, page not present

New one:                  supervisor write data, page not present

> instruction pointer   = 0x20:0xffffffff80f2b11e

New one:                  0x20:0xffffffff80f2b21b

> stack pointer         = 0x0:0xfffffe01aeb28970

New one:                  0x28:0xfffffe01aeb28970

> frame pointer         = 0x0:0xfffffe01aeb289f0

New one:                  0x28:0xfffffe01aeb289f0

> 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

New one: pmap_ts_referenced+0x82b: movq %rcx,0x10(%rax)

> bd > bt
> Tracing pid 20 tid 100089 td 0xfffff80003eb3560

New one:                    td 0xfffff80003df6000

> pmap_ts_referenced() at pmap_ts_referenced_0x72e/frame 0xfffffe01aeb289f0
New one:
pmap_ts_referenced() at pmap_ts_referenced_0x82b/frame 0xfffffe01aeb289f0

> vm_pageout() at vm_pageout+0xdeb/frame 0xfffffe01aeb28ab0

Correction to original:            frame 0xfffffe01aeb28a70
(new is the same)

> 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