ptrace: kill __ptrace_detach(), fix ->exit_state check

Move the code from __ptrace_detach() to its single caller and kill this
helper.

Also, fix the ->exit_state check, we shouldn't wake up EXIT_DEAD tasks.
Actually, I think task_is_stopped_or_traced() makes more sense, but this
needs another patch.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 13 deletions

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index c9cf48b21f05..f62a568e84ec 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -235,16 +235,6 @@ out:
         return retval;
 }
 
-static inline void __ptrace_detach(struct task_struct *child, unsigned int data)
-{
-        child->exit_code = data;
-        /* .. re-parent .. */
-        __ptrace_unlink(child);
-        /* .. and wake it up. */
-        if (child->exit_state != EXIT_ZOMBIE)
-                wake_up_process(child);
-}
-
 int ptrace_detach(struct task_struct *child, unsigned int data)
 {
         if (!valid_signal(data))
@@ -254,10 +244,16 @@ int ptrace_detach(struct task_struct *child, unsigned int data)
         ptrace_disable(child);
         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 
-        write_lock_irq(&tasklist_lock);
         /* protect against de_thread()->release_task() */
-        if (child->ptrace)
-                __ptrace_detach(child, data);
+        write_lock_irq(&tasklist_lock);
+        if (child->ptrace) {
+                child->exit_code = data;
+
+                __ptrace_unlink(child);
+
+                if (!child->exit_state)
+                        wake_up_process(child);
+        }
         write_unlock_irq(&tasklist_lock);
 
         return 0;