exit: Move oops specific logic from do_exit into make_task_dead

The beginning of do_exit has become cluttered and difficult to read as
it is filled with checks to handle things that can only happen when
the kernel is operating improperly.

Now that we have a dedicated function for cleaning up a task when the
kernel is operating improperly move the checks there.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

1 files changed, 39 insertions, 39 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index bfa513c5b227..d0ec6f6b41cb 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -735,36 +735,8 @@ void __noreturn do_exit(long code)
 	struct task_struct *tsk = current;
 	int group_dead;
 
-	/*
-	 * We can get here from a kernel oops, sometimes with preemption off.
-	 * Start by checking for critical errors.
-	 * Then fix up important state like USER_DS and preemption.
-	 * Then do everything else.
-	 */
-
 	WARN_ON(blk_needs_flush_plug(tsk));
 
-	if (unlikely(in_interrupt()))
-		panic("Aiee, killing interrupt handler!");
-	if (unlikely(!tsk->pid))
-		panic("Attempted to kill the idle task!");
-
-	/*
-	 * If do_exit is called because this processes oopsed, it's possible
-	 * that get_fs() was left as KERNEL_DS, so reset it to USER_DS before
-	 * continuing. Amongst other possible reasons, this is to prevent
-	 * mm_release()->clear_child_tid() from writing to a user-controlled
-	 * kernel address.
-	 */
-	force_uaccess_begin();
-
-	if (unlikely(in_atomic())) {
-		pr_info("note: %s[%d] exited with preempt_count %d\n",
-			current->comm, task_pid_nr(current),
-			preempt_count());
-		preempt_count_set(PREEMPT_ENABLED);
-	}
-
 	profile_task_exit(tsk);
 	kcov_task_exit(tsk);
 
@@ -773,17 +745,6 @@ void __noreturn do_exit(long code)
 
 	validate_creds_for_do_exit(tsk);
 
-	/*
-	 * We're taking recursive faults here in do_exit. Safest is to just
-	 * leave this task alone and wait for reboot.
-	 */
-	if (unlikely(tsk->flags & PF_EXITING)) {
-		pr_alert("Fixing recursive fault but reboot is needed!\n");
-		futex_exit_recursive(tsk);
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		schedule();
-	}
-
 	io_uring_files_cancel();
 	exit_signals(tsk);  /* sets PF_EXITING */
 
@@ -889,7 +850,46 @@ void __noreturn make_task_dead(int signr)
 	/*
 	 * Take the task off the cpu after something catastrophic has
 	 * happened.
+	 *
+	 * We can get here from a kernel oops, sometimes with preemption off.
+	 * Start by checking for critical errors.
+	 * Then fix up important state like USER_DS and preemption.
+	 * Then do everything else.
 	 */
+	struct task_struct *tsk = current;
+
+	if (unlikely(in_interrupt()))
+		panic("Aiee, killing interrupt handler!");
+	if (unlikely(!tsk->pid))
+		panic("Attempted to kill the idle task!");
+
+	/*
+	 * If make_task_dead is called because this processes oopsed, it's possible
+	 * that get_fs() was left as KERNEL_DS, so reset it to USER_DS before
+	 * continuing. Amongst other possible reasons, this is to prevent
+	 * mm_release()->clear_child_tid() from writing to a user-controlled
+	 * kernel address.
+	 */
+	force_uaccess_begin();
+
+	if (unlikely(in_atomic())) {
+		pr_info("note: %s[%d] exited with preempt_count %d\n",
+			current->comm, task_pid_nr(current),
+			preempt_count());
+		preempt_count_set(PREEMPT_ENABLED);
+	}
+
+	/*
+	 * We're taking recursive faults here in make_task_dead. Safest is to just
+	 * leave this task alone and wait for reboot.
+	 */
+	if (unlikely(tsk->flags & PF_EXITING)) {
+		pr_alert("Fixing recursive fault but reboot is needed!\n");
+		futex_exit_recursive(tsk);
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule();
+	}
+
 	do_exit(signr);
 }