New syscons bugs: shutdown -r doesn't execute rc.d sequence and others

On 29.03.2017 0:46, Ngie Cooper (yaneurabeya) wrote:
> 
>> On Mar 28, 2017, at 14:27, Andrey Chernov <ache_at_freebsd.org> wrote:
> 
> …
> 
>>> Using rc_debug=yes I see that it is the kernel problem, not rc problem.
>>> Sometimes rc backward sequence executed even fully, sometimes only
>>> partly, but in unpredictable moment inside rc sequence the kernel decide
>>> to reboot quickly (or even deadly hang in rare cases). Always without
>>> any "Syncing buffers..." leaving FS dirty. No zfs etc. just normal UFS,
>>> no EFI, no GPT.
>>> I change GELI swap to normal one, but it does not help. The same
>>> untouched config works for years, I see this bug for the first time in
>>> FreeBSD.
>>>
>>
>> I forget to mention that typescript and dmesg does not survive after
>> this reboot (or rare hang).
> 
> Good to note.
> The simple explanation to the problem might be r307755, depending on when you last synced/built ^/head.
> 
> I have a few more questions (if reverting that doesn't pan out):

I just found the cause, it is new syscons bug (bde_at_ cc'ed). I never
compile vt driver into kernel, i.e. I don't have this lines in the
kernel config:

device	vt
device	vt_vga
device	vt_efifb

When I add them, the bug described is gone. It seems syscons goes off to
early, provoking reboot.

I also find some lines of the kernel messages strange colored instead of
white in the syscons only mode. Even in vt mode vidcontrol errors have
invisible escapes prepended (although visible through /var/log/messages).

Moreover, I can't enter KDB via Ctrl-Alt-ESC in the syscons only mode
anymore - nothing happens. In the vt mode I can, but can't exit via "c"
properly, all chars typed after "c" produce beep unless I switch to
another screen and back.

All it means that syscons becomes very broken now by itself and even
damages the kernel operations.