Re: [PATCH RT V2] sched: Prevent task state corruption by spurious lock wakeup

Peter Zijlstra
2017-06-06T16:28:15Z

On Tue, Jun 06, 2017 at 02:20:37PM +0200, Thomas Gleixner wrote:
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -2210,7 +2210,7 @@ EXPORT_SYMBOL(wake_up_process);
> */
> int wake_up_lock_sleeper(struct task_struct *p)
> {
> - return try_to_wake_up(p, TASK_ALL, WF_LOCK_SLEEPER);
> + return try_to_wake_up(p, TASK_UNINTERRUPTIBLE, WF_LOCK_SLEEPER);
> }
>
> int wake_up_state(struct task_struct *p, unsigned int state)

Do we want this?

---
Subject: sched: Remove TASK_ALL

It's unused:

$ git grep "\<TASK_ALL\>" | wc -l
1

And dangerous, kill the bugger.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3dfa5f99d6ee..e88aadbe2071 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -94,7 +94,6 @@ struct task_group;

/* Convenience macros for the sake of wake_up(): */
#define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
-#define TASK_ALL (TASK_NORMAL | __TASK_STOPPED | __TASK_TRACED)

/* get_task_state(): */
#define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \