[PATCH] ptrace: make pid of child process available for PTRACE_EVENT_VFORK_DONE

When delivering PTRACE_EVENT_VFORK_DONE, provide pid of the child process
when tracer calls ptrace(PTRACE_GETEVENTMSG).  This is already
(accidentally) available when the tracer is tracing VFORK in addition to
VFORK_DONE.
Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com>
Cc: Daniel Jacobowitz <dan@debian.org>
Cc: Albert Cahalan <acahalan@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kernel/fork.c

@@ -1387,9 +1387,11 @@ long do_fork(unsigned long clone_flags,
 
 		if (clone_flags & CLONE_VFORK) {
 			wait_for_completion(&vfork);
-			if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE))
+			if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE)) {
+				current->ptrace_message = nr;
 				ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
 			}
+		}
 	} else {
 		free_pid(pid);
 		nr = PTR_ERR(p);