Running `sysctl -a` causes crash (Hyper-V)

[Pavel Timofeev]

root at bsdtest:~ # kgdb /boot/kernel/kernel ./vmcore.1
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This GDB was configured as "amd64-marcel-freebsd"...

Unread portion of the kernel message buffer:


Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 01
fault virtual address   = 0x0
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff8095d79b
stack pointer           = 0x28:0xfffffe003d31c8f0
frame pointer           = 0x28:0xfffffe003d31c900
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         = 777 (sysctl)
trap number             = 12
panic: page fault
cpuid = 1
KDB: stack backtrace:
#0 0xffffffff808e7a90 at kdb_backtrace+0x60
#1 0xffffffff808af575 at panic+0x155
#2 0xffffffff80c8e272 at trap_fatal+0x3a2
#3 0xffffffff80c8e549 at trap_pfault+0x2c9
#4 0xffffffff80c8dcd6 at trap+0x5e6
#5 0xffffffff80c74f72 at calltrap+0x8
#6 0xffffffff808ea529 at sysctl_kern_vm_guest+0x29
#7 0xffffffff808baacf at sysctl_root+0x24f
#8 0xffffffff808bb088 at userland_sysctl+0x1d8
#9 0xffffffff808bae74 at sys___sysctl+0x74
#10 0xffffffff80c8eb67 at amd64_syscall+0x357
#11 0xffffffff80c7525b at Xfast_syscall+0xfb
Uptime: 30s
Dumping 89 out of 1001 MB:..18%..36%..54%..72%..89%

Reading symbols from /boot/kernel/fuse.ko.symbols...done.
Loaded symbols for /boot/kernel/fuse.ko.symbols
Reading symbols from /boot/kernel/fdescfs.ko.symbols...done.
Loaded symbols for /boot/kernel/fdescfs.ko.symbols
#0  doadump (textdump=<value optimized out>) at pcpu.h:219
219     pcpu.h: No such file or directory.
        in pcpu.h
(kgdb) p vm_guest
$1 = 3
Current language:  auto; currently minimal
(kgdb)




2013/11/11 Sergey Kandaurov <pluknet at gmail.com>:
> [Please, don't top-post.]
> On 11 November 2013 17:06, Pavel Timofeev <timp87 at gmail.com> wrote:
>> I'm sorry, could you explain how to do it? Which one is the 'core
>> file', vmcore or core.txt?
>>
>
> It's vmcore.
> kgdb /path/to/kernel /path/to/vmcore
>
>> 2013/11/11 Sergey Kandaurov <pluknet at gmail.com>:
>>> On 11 November 2013 16:38, Pavel Timofeev <timp87 at gmail.com> wrote:
>>>> Hi! Can anybody confirm the subject?
>>>> Every time when I run `sysctl -a` get this
>>>>
>>>> http://pastebin.com/Chf9qQTD
>>>
>>> Can you show 'p vm_guest' from core file?
>
> --
> wbr,
> pluknet