In ia32 emulation, the amd64 kernel refuses the ioctls TIOCSBRK and
TIOCCBRK with EINVAL.  I've attached a patch that adds them to the
compatibility list.

Since all architectures have these ioctls ("m68knommu" inherits them from
"m68k", "um" from its host) and use the same code, I think adding them to
compat_ioctl.h is the correct choice (as opposed to adding them to
arch/x86_64/ia32/ia32_ioctl.c).
Signed-off-by: Werner Almesberger <werner@almesberger.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>