Re: [RFC] tty/sysrq: Add alternative SysRq key

From: Maciej W. Rozycki
Date: Thu Nov 04 2021 - 09:07:56 EST


On Thu, 4 Nov 2021, Andrzej Pietrasiewicz wrote:

> > Is F10 sensible default? Would it make sense to use something like
> > alt-shift-esc so that this can be enabled by default?
>
> Why "alt-shift-esc" could be enabled by default? Do you mean to enable it for
> all systems regardless of whether they declare or don't declare KEY_SYSRQ
> in their 'keybit' bitmap?

FWIW from my perspective it'll work better as a replacement rather than
additional key combination.

The reason for this is with their more recent laptops Lenovo in their
infinite wisdom have placed the <PrintScreen> key (which in a traditional
PS/2-keyboard manner produces <SysRq> when combined with <Alt>) in their
keyboards between the right <Alt> and <Ctrl> keys. With thumbs not being
as accurate as other fingers (and the overall misdesign of the keyboard
and touchpad interface) you can imagine how often I have inadvertently hit
<SysRq> combined with a letter key, wreaking havoc to my system (and of
course I want to keep the key enabled for times when I do need it).

Also Documentation/admin-guide/sysrq.rst mentions that you can set an
alternative keycode sequence for KEY_SYSRQ with `setkeycodes <sequence>
99' already, but I find this pretty limiting as this only works for single
keypresses rather than combinations of keys, because <sequence> actually
refers to a single scancode (possibly 0xe0-prefixed).

Maciej