thread-unsafety problems as spl*() ones are NOP

[Slawa Olhovchenkov]

On Sat, Jan 30, 2016 at 09:42:13PM +0330, mokhi wrote:

> i currently only wanna do patch on kbd.c (because i'm sure there is a
> thread-unsafety)
> and i don't want to add anything to spltty() nor splx(), i just wanna
> add things under where they've been used.
> isn't problem with using mutex/spin/lock/unlock etc there?

yes.
currenly spltty act as mutex_lock(&spltty_mutex), like global lock for
all used files. this is also inter-files lock, not only lock inside
only kbd.c.
you need patch all files. all using spltty need to remove
simultaneously.