ptrace: kill real_parent_is_ptracer() in in favor of ptrace_reparented()

Kill real_parent_is_ptracer() and update the callers to use
ptrace_reparented(), after the previous patch they do the same.

Remove the unnecessary ->ptrace != 0 check in get_signal_to_deliver(),
if ptrace_reparented() == T then the task must be ptraced.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/signal.c b/kernel/signal.c
index 4c4ad34caf77cbe52d6f22935485621efc3156cf..0a1bf2c8bdcd108ac730194b7ccbbca5377f5566 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1759,15 +1759,6 @@ static int sigkill_pending(struct task_struct *tsk)
                sigismember(&tsk->signal->shared_pending.signal, SIGKILL);
 }
 
-/*
- * Test whether the target task of the usual cldstop notification - the
- * real_parent of @child - is in the same group as the ptracer.
- */
-static bool real_parent_is_ptracer(struct task_struct *child)
-{
-       return same_thread_group(child->parent, child->real_parent);
-}
-
 /*
  * This must be called with current->sighand->siglock held.
  *
@@ -1848,7 +1839,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info)
                 * separately unless they're gonna be duplicates.
                 */
                do_notify_parent_cldstop(current, true, why);
-               if (gstop_done && !real_parent_is_ptracer(current))
+               if (gstop_done && ptrace_reparented(current))
                        do_notify_parent_cldstop(current, false, why);
 
                /*
@@ -2154,7 +2145,6 @@ relock:
         * the CLD_ si_code into SIGNAL_CLD_MASK bits.
         */
        if (unlikely(signal->flags & SIGNAL_CLD_MASK)) {
-               struct task_struct *leader;
                int why;
 
                if (signal->flags & SIGNAL_CLD_CONTINUED)
@@ -2175,13 +2165,11 @@ relock:
                 * a duplicate.
                 */
                read_lock(&tasklist_lock);
-
                do_notify_parent_cldstop(current, false, why);
 
-               leader = current->group_leader;
-               if (leader->ptrace && !real_parent_is_ptracer(leader))
-                       do_notify_parent_cldstop(leader, true, why);
-
+               if (ptrace_reparented(current->group_leader))
+                       do_notify_parent_cldstop(current->group_leader,
+                                               true, why);
                read_unlock(&tasklist_lock);
 
                goto relock;