signal: remove three noop tracehooks

Remove the following three noop tracehooks in signals.c.

* tracehook_force_sigpending()
* tracehook_get_signal()
* tracehook_finish_jctl()

The code area is about to be updated and these hooks don't do anything
other than obfuscating the logic.

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

diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index e95f523..15745cd 100644 (file)
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -425,58 +425,6 @@ static inline int tracehook_consider_fatal_signal(struct task_struct *task,
        return (task_ptrace(task) & PT_PTRACED) != 0;
 }
 
-/**
- * tracehook_force_sigpending - let tracing force signal_pending(current) on
- *
- * Called when recomputing our signal_pending() flag.  Return nonzero
- * to force the signal_pending() flag on, so that tracehook_get_signal()
- * will be called before the next return to user mode.
- *
- * Called with @current->sighand->siglock held.
- */
-static inline int tracehook_force_sigpending(void)
-{
-       return 0;
-}
-
-/**
- * tracehook_get_signal - deliver synthetic signal to traced task
- * @task:              @current
- * @regs:              task_pt_regs(@current)
- * @info:              details of synthetic signal
- * @return_ka:         sigaction for synthetic signal
- *
- * Return zero to check for a real pending signal normally.
- * Return -1 after releasing the siglock to repeat the check.
- * Return a signal number to induce an artificial signal delivery,
- * setting *@info and *@return_ka to specify its details and behavior.
- *
- * The @return_ka->sa_handler value controls the disposition of the
- * signal, no matter the signal number.  For %SIG_DFL, the return value
- * is a representative signal to indicate the behavior (e.g. %SIGTERM
- * for death, %SIGQUIT for core dump, %SIGSTOP for job control stop,
- * %SIGTSTP for stop unless in an orphaned pgrp), but the signal number
- * reported will be @info->si_signo instead.
- *
- * Called with @task->sighand->siglock held, before dequeuing pending signals.
- */
-static inline int tracehook_get_signal(struct task_struct *task,
-                                      struct pt_regs *regs,
-                                      siginfo_t *info,
-                                      struct k_sigaction *return_ka)
-{
-       return 0;
-}
-
-/**
- * tracehook_finish_jctl - report about return from job control stop
- *
- * This is called by do_signal_stop() after wakeup.
- */
-static inline void tracehook_finish_jctl(void)
-{
-}
-
 #define DEATH_REAP                     -1
 #define DEATH_DELAYED_GROUP_LEADER     -2
 

diff --git a/kernel/signal.c b/kernel/signal.c
index 172a4c7..c99b8b5 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -150,9 +150,7 @@ void recalc_sigpending_and_wake(struct task_struct *t)
 
 void recalc_sigpending(void)
 {
-       if (unlikely(tracehook_force_sigpending()))
-               set_thread_flag(TIF_SIGPENDING);
-       else if (!recalc_sigpending_tsk(current) && !freezing(current))
+       if (!recalc_sigpending_tsk(current) && !freezing(current))
                clear_thread_flag(TIF_SIGPENDING);
 
 }
@@ -2005,8 +2003,6 @@ retry:
 
        spin_unlock_irq(&current->sighand->siglock);
 
-       tracehook_finish_jctl();
-
        return 1;
 }
 
@@ -2109,37 +2105,25 @@ relock:
 
        for (;;) {
                struct k_sigaction *ka;
-               /*
-                * Tracing can induce an artificial signal and choose sigaction.
-                * The return value in @signr determines the default action,
-                * but @info->si_signo is the signal number we will report.
-                */
-               signr = tracehook_get_signal(current, regs, info, return_ka);
-               if (unlikely(signr < 0))
+
+               if (unlikely(current->jobctl & JOBCTL_STOP_PENDING) &&
+                   do_signal_stop(0))
                        goto relock;
-               if (unlikely(signr != 0))
-                       ka = return_ka;
-               else {
-                       if (unlikely(current->jobctl & JOBCTL_STOP_PENDING) &&
-                           do_signal_stop(0))
-                               goto relock;
 
-                       signr = dequeue_signal(current, &current->blocked,
-                                              info);
+               signr = dequeue_signal(current, &current->blocked, info);
 
-                       if (!signr)
-                               break; /* will return 0 */
+               if (!signr)
+                       break; /* will return 0 */
 
-                       if (signr != SIGKILL) {
-                               signr = ptrace_signal(signr, info,
-                                                     regs, cookie);
-                               if (!signr)
-                                       continue;
-                       }
-
-                       ka = &sighand->action[signr-1];
+               if (signr != SIGKILL) {
+                       signr = ptrace_signal(signr, info,
+                                             regs, cookie);
+                       if (!signr)
+                               continue;
                }
 
+               ka = &sighand->action[signr-1];
+
                /* Trace actually delivered signals. */
                trace_signal_deliver(signr, info, ka);