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>

5 files changed, 20 insertions, 32 deletions

diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 4f224f169524..3ff20b322598 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -146,17 +146,6 @@ int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
                             unsigned long data);
 
 /**
- * task_ptrace - return %PT_* flags that apply to a task
- * @task:       pointer to &task_struct in question
- *
- * Returns the %PT_* flags that apply to @task.
- */
-static inline int task_ptrace(struct task_struct *task)
-{
-        return task->ptrace;
-}
-
-/**
  * ptrace_event - possibly stop for a ptrace event notification
  * @mask:       %PT_* bit to check in @current->ptrace
  * @event:      %PTRACE_EVENT_* value to report if @mask is set
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index 15745cdd32ce..a3e838784f43 100644
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -63,7 +63,7 @@ struct linux_binprm;
  */
 static inline int tracehook_expect_breakpoints(struct task_struct *task)
 {
-        return (task_ptrace(task) & PT_PTRACED) != 0;
+        return (task->ptrace & PT_PTRACED) != 0;
 }
 
 /*
@@ -71,7 +71,7 @@ static inline int tracehook_expect_breakpoints(struct task_struct *task)
  */
 static inline void ptrace_report_syscall(struct pt_regs *regs)
 {
-        int ptrace = task_ptrace(current);
+        int ptrace = current->ptrace;
 
         if (!(ptrace & PT_PTRACED))
                 return;
@@ -155,7 +155,7 @@ static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
 static inline int tracehook_unsafe_exec(struct task_struct *task)
 {
         int unsafe = 0;
-        int ptrace = task_ptrace(task);
+        int ptrace = task->ptrace;
         if (ptrace & PT_PTRACED) {
                 if (ptrace & PT_PTRACE_CAP)
                         unsafe |= LSM_UNSAFE_PTRACE_CAP;
@@ -178,7 +178,7 @@ static inline int tracehook_unsafe_exec(struct task_struct *task)
  */
 static inline struct task_struct *tracehook_tracer_task(struct task_struct *tsk)
 {
-        if (task_ptrace(tsk) & PT_PTRACED)
+        if (tsk->ptrace & PT_PTRACED)
                 return rcu_dereference(tsk->parent);
         return NULL;
 }
@@ -202,7 +202,7 @@ static inline void tracehook_report_exec(struct linux_binfmt *fmt,
                                          struct pt_regs *regs)
 {
         if (!ptrace_event(PT_TRACE_EXEC, PTRACE_EVENT_EXEC, 0) &&
-            unlikely(task_ptrace(current) & PT_PTRACED))
+            unlikely(current->ptrace & PT_PTRACED))
                 send_sig(SIGTRAP, current, 0);
 }
 
@@ -285,7 +285,7 @@ static inline void tracehook_report_clone(struct pt_regs *regs,
                                           unsigned long clone_flags,
                                           pid_t pid, struct task_struct *child)
 {
-        if (unlikely(task_ptrace(child))) {
+        if (unlikely(child->ptrace)) {
                 /*
                  * It doesn't matter who attached/attaching to this
                  * task, the pending SIGSTOP is right in any case.
@@ -403,7 +403,7 @@ static inline void tracehook_signal_handler(int sig, siginfo_t *info,
 static inline int tracehook_consider_ignored_signal(struct task_struct *task,
                                                     int sig)
 {
-        return (task_ptrace(task) & PT_PTRACED) != 0;
+        return (task->ptrace & PT_PTRACED) != 0;
 }
 
 /**
@@ -422,7 +422,7 @@ static inline int tracehook_consider_ignored_signal(struct task_struct *task,
 static inline int tracehook_consider_fatal_signal(struct task_struct *task,
                                                   int sig)
 {
-        return (task_ptrace(task) & PT_PTRACED) != 0;
+        return (task->ptrace & PT_PTRACED) != 0;
 }
 
 #define DEATH_REAP                      -1
diff --git a/kernel/exit.c b/kernel/exit.c
index 289f59d686bf..e5cc05644609 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -765,7 +765,7 @@ static void reparent_leader(struct task_struct *father, struct task_struct *p,
         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 @@ static void forget_original_parent(struct task_struct *father)
                 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 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
                  * 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 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
                  * 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;
 
diff --git a/kernel/signal.c b/kernel/signal.c
index 97e575a3387e..0f3370872506 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1592,7 +1592,7 @@ int do_notify_parent(struct task_struct *tsk, int sig)
         /* 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 @@ int do_notify_parent(struct task_struct *tsk, int sig)
 
         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 void do_notify_parent_cldstop(struct task_struct *tsk,
 
 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 @@ static bool do_signal_stop(int signr)
                 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 @@ static bool do_signal_stop(int signr)
                 }
         }
 
-        if (likely(!task_ptrace(current))) {
+        if (likely(!current->ptrace)) {
                 int notify = 0;
 
                 /*
@@ -2093,7 +2093,7 @@ static void do_jobctl_trap(void)
 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 @@ relock:
                 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);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index e4b0991ca351..b0be989d4365 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -339,8 +339,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
                                  * then wait for it to finish before killing
                                  * some other task unnecessarily.
                                  */
-                                if (!(task_ptrace(p->group_leader) &
-                                                        PT_TRACE_EXIT))
+                                if (!(p->group_leader->ptrace & PT_TRACE_EXIT))
                                         return ERR_PTR(-1UL);
                         }
                 }