Re: [Linux-fbdev-devel] [PATCH] add mutex to fbdev for fb_mmap locking

[Alan C. <al...@lx...>]

> ie the fact that the TTY layer does user-mode copies while holding some 
> tty lock. So now the tty layer introduces that chain from some random lock 
> to the mmap_sem.

Its basically holding the termios lock to copy from the struct termios to
user space which means its trivial to do copy to a stack buffer first. I
can fix that pretty easily if you want.

Alan