Ported from i386 (originally from Linus)
clean up ptrace single-stepping, make PT_DTRACE exact.
(This makes the naming of "DTRACE" purely historical, since
on x86 it now means "single step in progress").
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
aa85b9af5b