[PATCH 04/10] exit: Stop poorly open coding do_task_dead in make_task_dead

Eric W. Biederman
2021-12-08T20:26:29Z

When the kernel detects it is oops or otherwise force killing a task
while it exits the code poorly attempts to permanently stop the task
from scheduling.

I say poorly because it is possible for a task in TASK_UINTERRUPTIBLE
to be woken up.

As it makes no sense for the task to continue call do_task_dead
instead which actually does the work and permanently removes the task
from the scheduler. Guaranteeing the task will never be woken
up again.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
kernel/exit.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index d0ec6f6b41cb..f975cd8a2ed8 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -886,8 +886,7 @@ void __noreturn make_task_dead(int signr)
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_task_dead();
}

do_exit(signr);
--
2.29.2