[PATCH 1/5] shift "ptrace implies WUNTRACED" from ptrace_do_wait() to wait_task_stopped()

[Oleg Nesterov <oleg@redhat.com>]

No functional changes, preparation for the next patch.

ptrace_do_wait() adds WUNTRACED to options for wait_task_stopped()
which should always accept the stopped tracee, even if do_wait() was
called without WUNTRACED.

Change wait_task_stopped() to check "ptrace || WUNTRACED" instead.
This makes the code more explicit, and "int options" argument becomes
const in do_wait() pathes.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
---

 kernel/exit.c |   10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

--- PTRACE/kernel/exit.c~1_WUNTRACED	2009-05-03 23:24:14.000000000 +0200
+++ PTRACE/kernel/exit.c	2009-05-07 04:32:08.000000000 +0200
@@ -1330,7 +1330,10 @@ static int wait_task_stopped(int ptrace,
 	uid_t uid = 0; /* unneeded, required by compiler */
 	pid_t pid;
 
-	if (!(options & WUNTRACED))
+	/*
+	 * Traditionally we see ptrace'd stopped tasks regardless of options.
+	 */
+	if (!ptrace && !(options & WUNTRACED))
 		return 0;
 
 	exit_code = 0;
@@ -1548,11 +1551,6 @@ static int ptrace_do_wait(struct task_st
 {
 	struct task_struct *p;
 
-	/*
-	 * Traditionally we see ptrace'd stopped tasks regardless of options.
-	 */
-	options |= WUNTRACED;
-
 	list_for_each_entry(p, &tsk->ptraced, ptrace_entry) {
 		int ret = wait_consider_task(tsk, 1, p, notask_error,
 					     type, pid, options,