ptrace: kill task_ptrace()

task_ptrace(task) simply dereferences task->ptrace and isn't even used
consistently only adding confusion.  Kill it and directly access
->ptrace instead.

This doesn't introduce any behavior change.

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

kernel/exit.c

diff --git a/kernel/exit.c b/kernel/exit.c
index 289f59d..e5cc056 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -765,7 +765,7 @@
 	p->exit_signal = SIGCHLD;
 
 	/* If it has exited notify the new parent about this child's death. */
-	if (!task_ptrace(p) &&
+	if (!p->ptrace &&
 	    p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) {
 		do_notify_parent(p, p->exit_signal);
 		if (task_detached(p)) {
@@ -795,7 +795,7 @@
 		do {
 			t->real_parent = reaper;
 			if (t->parent == father) {
-				BUG_ON(task_ptrace(t));
+				BUG_ON(t->ptrace);
 				t->parent = t->real_parent;
 			}
 			if (t->pdeath_signal)
@@ -1565,7 +1565,7 @@
 		 * Notification and reaping will be cascaded to the real
 		 * parent when the ptracer detaches.
 		 */
-		if (likely(!ptrace) && unlikely(task_ptrace(p))) {
+		if (likely(!ptrace) && unlikely(p->ptrace)) {
 			/* it will become visible, clear notask_error */
 			wo->notask_error = 0;
 			return 0;
@@ -1608,7 +1608,7 @@
 		 * own children, it should create a separate process which
 		 * takes the role of real parent.
 		 */
-		if (likely(!ptrace) && task_ptrace(p) &&
+		if (likely(!ptrace) && p->ptrace &&
 		    same_thread_group(p->parent, p->real_parent))
 			return 0;
 

kernel/signal.c

diff --git a/kernel/signal.c b/kernel/signal.c
index 97e575a..0f33708 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1592,7 +1592,7 @@
  	/* do_notify_parent_cldstop should have been called instead.  */
  	BUG_ON(task_is_stopped_or_traced(tsk));
 
-	BUG_ON(!task_ptrace(tsk) &&
+	BUG_ON(!tsk->ptrace &&
 	       (tsk->group_leader != tsk || !thread_group_empty(tsk)));
 
 	info.si_signo = sig;
@@ -1631,7 +1631,7 @@
 
 	psig = tsk->parent->sighand;
 	spin_lock_irqsave(&psig->siglock, flags);
-	if (!task_ptrace(tsk) && sig == SIGCHLD &&
+	if (!tsk->ptrace && sig == SIGCHLD &&
 	    (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN ||
 	     (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) {
 		/*
@@ -1731,7 +1731,7 @@
 
 static inline int may_ptrace_stop(void)
 {
-	if (!likely(task_ptrace(current)))
+	if (!likely(current->ptrace))
 		return 0;
 	/*
 	 * Are we in the middle of do_coredump?
@@ -1989,7 +1989,7 @@
 		if (!(sig->flags & SIGNAL_STOP_STOPPED))
 			sig->group_exit_code = signr;
 		else
-			WARN_ON_ONCE(!task_ptrace(current));
+			WARN_ON_ONCE(!current->ptrace);
 
 		sig->group_stop_count = 0;
 
@@ -2014,7 +2014,7 @@
 		}
 	}
 
-	if (likely(!task_ptrace(current))) {
+	if (likely(!current->ptrace)) {
 		int notify = 0;
 
 		/*
@@ -2093,7 +2093,7 @@
 static int ptrace_signal(int signr, siginfo_t *info,
 			 struct pt_regs *regs, void *cookie)
 {
-	if (!task_ptrace(current))
+	if (!current->ptrace)
 		return signr;
 
 	ptrace_signal_deliver(regs, cookie);
@@ -2179,7 +2179,7 @@
 		do_notify_parent_cldstop(current, false, why);
 
 		leader = current->group_leader;
-		if (task_ptrace(leader) && !real_parent_is_ptracer(leader))
+		if (leader->ptrace && !real_parent_is_ptracer(leader))
 			do_notify_parent_cldstop(leader, true, why);
 
 		read_unlock(&tasklist_lock);