[ANNOUNCE] 4.19.152-rt66

[Tom Zanussi]

Hello RT Folks!

I'm pleased to announce the 4.19.152-rt66 stable release.

You can get this release via the git tree at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

  branch: v4.19-rt
  Head SHA1: 3b515711216822e708490d1c686813c819e237b1

Or to build 4.19.152-rt66 directly, the following patches should be applied:

  https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.19.tar.xz

  https://www.kernel.org/pub/linux/kernel/v4.x/patch-4.19.152.xz

  https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/patch-4.19.152-rt66.patch.xz


You can also build from 4.19.152-rt65 by applying the incremental patch:

  https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/incr/patch-4.19.152-rt65-rt66.patch.xz

Enjoy!

   Tom

Changes from v4.19.152-rt65:
---

Oleg Nesterov (1):
      ptrace: fix ptrace_unfreeze_traced() race with rt-lock

Sebastian Andrzej Siewior (1):
      mm/memcontrol: Disable preemption in __mod_memcg_lruvec_state()

Tom Zanussi (1):
      Linux 4.19.152-rt66
---
include/linux/memcontrol.h |  2 ++
 kernel/ptrace.c            | 23 +++++++++++++++--------
 localversion-rt            |  2 +-
 3 files changed, 18 insertions(+), 9 deletions(-)
---
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index cc6b6532eb56..dbb2c4e27277 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -665,6 +665,7 @@ static inline void __mod_lruvec_state(struct lruvec *lruvec,
 
 	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
 
+	preempt_disable_rt();
 	/* Update memcg */
 	__mod_memcg_state(pn->memcg, idx, val);
 
@@ -675,6 +676,7 @@ static inline void __mod_lruvec_state(struct lruvec *lruvec,
 		x = 0;
 	}
 	__this_cpu_write(pn->lruvec_stat_cpu->count[idx], x);
+	preempt_enable_rt();
 }
 
 static inline void mod_lruvec_state(struct lruvec *lruvec,
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index a38b304fb9fd..cbefb0234be3 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -191,8 +191,8 @@ static bool ptrace_freeze_traced(struct task_struct *task)
 
 static void ptrace_unfreeze_traced(struct task_struct *task)
 {
-	if (task->state != __TASK_TRACED)
-		return;
+	unsigned long flags;
+	bool frozen = true;
 
 	WARN_ON(!task->ptrace || task->parent != current);
 
@@ -201,12 +201,19 @@ static void ptrace_unfreeze_traced(struct task_struct *task)
 	 * Recheck state under the lock to close this race.
 	 */
 	spin_lock_irq(&task->sighand->siglock);
-	if (task->state == __TASK_TRACED) {
-		if (__fatal_signal_pending(task))
-			wake_up_state(task, __TASK_TRACED);
-		else
-			task->state = TASK_TRACED;
-	}
+
+	raw_spin_lock_irqsave(&task->pi_lock, flags);
+	if (task->state == __TASK_TRACED)
+		task->state = TASK_TRACED;
+	else if (task->saved_state == __TASK_TRACED)
+		task->saved_state = TASK_TRACED;
+	else
+		frozen = false;
+	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+
+	if (frozen && __fatal_signal_pending(task))
+		wake_up_state(task, __TASK_TRACED);
+
 	spin_unlock_irq(&task->sighand->siglock);
 }
 
diff --git a/localversion-rt b/localversion-rt
index e2eb19782d4c..d42c0971b041 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt65
+-rt66