ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up()

Cleanup and preparation for the next change.

signal_wake_up(resume => true) is overused. None of ptrace/jctl callers
actually want to wakeup a TASK_WAKEKILL task, but they can't specify the
necessary mask.

Turn signal_wake_up() into signal_wake_up_state(state), reintroduce
signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up()
which adds __TASK_TRACED.

This way ptrace_signal_wake_up() can work "inside" ptrace_request()
even if the tracee doesn't have the TASK_WAKEKILL bit set.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 10 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 53cd5c4d1172..6e97aa6fa32c 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -680,23 +680,17 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
  * No need to set need_resched since signal event passing
  * goes through ->blocked
  */
-void signal_wake_up(struct task_struct *t, int resume)
+void signal_wake_up_state(struct task_struct *t, unsigned int state)
 {
-        unsigned int mask;
-
         set_tsk_thread_flag(t, TIF_SIGPENDING);
-
         /*
-         * For SIGKILL, we want to wake it up in the stopped/traced/killable
+         * TASK_WAKEKILL also means wake it up in the stopped/traced/killable
          * case. We don't check t->state here because there is a race with it
          * executing another processor and just now entering stopped state.
          * By using wake_up_state, we ensure the process will wake up and
          * handle its death signal.
          */
-        mask = TASK_INTERRUPTIBLE;
-        if (resume)
-                mask |= TASK_WAKEKILL;
-        if (!wake_up_state(t, mask))
+        if (!wake_up_state(t, state | TASK_INTERRUPTIBLE))
                 kick_process(t);
 }
 
@@ -844,7 +838,7 @@ static void ptrace_trap_notify(struct task_struct *t)
         assert_spin_locked(&t->sighand->siglock);
 
         task_set_jobctl_pending(t, JOBCTL_TRAP_NOTIFY);
-        signal_wake_up(t, t->jobctl & JOBCTL_LISTENING);
+        ptrace_signal_wake_up(t, t->jobctl & JOBCTL_LISTENING);
 }
 
 /*