🚀 go-pugleaf

Files:
	/usr/src/sys/sys/tty.c

O/S: 4.3bsd (vax release, but probably all)

Priority: low (unless of course it affects -you-)

Description:
	The 4.3bsd tty driver contains some code that assumes that
	a structure is contained within another structure, but there
	are no physical bindings between the two structures.

	ie: the code that handles the 4 ioctls:  TIOCGETC, TIOCSETC,
	TIOCGLTC, TIOCSLTC assume that the structure that they copy
	in or out (ie: struct tchars or struct ltchars) aligns exactly
	with a component of struct ttychars (ie: t_intrc or t_suspc,
	respectively).

	Whilst this probably will work on most byte addressable
	machines, it is clearly unportable and a dangerous practise.

Implications:
	somebody changes struct ttychars without knowing what
	the kernel expects of the order/adjacency of components
	and the kernel may fall over

Fix:
	Easy. Copy each component to/from user space using individual
	assignments rather than a single bcopy().

	Either that, or make struct ttychars consist of struct tchars
	and struct ltchars plus other goodies.

	(well I would do the former, since all these extra structs
	are really pointless and should be chucked out of the kernel anyway)

Ian Donaldson