shift "ptrace implies WUNTRACED" from ptrace_do_wait() to wait_task_stopped()

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 6 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 94a9992e6fd..fd781b56401 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1330,7 +1330,10 @@ static int wait_task_stopped(int ptrace, struct task_struct *p,
         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_struct *tsk, int *notask_error,
 {
         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,