Adding debian version 4.19.249-2.debian/4.19.249-2debian

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 70 insertions, 0 deletions

diff --git a/debian/patches-rt/0060-futex-workaround-migrate_disable-enable-in-different.patch b/debian/patches-rt/0060-futex-workaround-migrate_disable-enable-in-different.patch
new file mode 100644
index 000000000..373f02a64
--- /dev/null
+++ b/debian/patches-rt/0060-futex-workaround-migrate_disable-enable-in-different.patch
@@ -0,0 +1,70 @@
+From d142001fdbdd8cc5fb558e9c3fa110f575875355 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Wed, 8 Mar 2017 14:23:35 +0100
+Subject: [PATCH 060/347] futex: workaround migrate_disable/enable in different
+ context
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz
+
+migrate_disable()/migrate_enable() takes a different path in atomic() vs
+!atomic() context. These little hacks ensure that we don't underflow / overflow
+the migrate code counts properly while we lock the hb lockwith interrupts
+enabled and unlock it with interrupts disabled.
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ kernel/futex.c | 19 +++++++++++++++++++
+ 1 file changed, 19 insertions(+)
+
+diff --git a/kernel/futex.c b/kernel/futex.c
+index 3c67da9b8408..fac994367189 100644
+--- a/kernel/futex.c
++++ b/kernel/futex.c
+@@ -2998,6 +2998,14 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags,
+ 	 * before __rt_mutex_start_proxy_lock() is done.
+ 	 */
+ 	raw_spin_lock_irq(&q.pi_state->pi_mutex.wait_lock);
++	/*
++	 * the migrate_disable() here disables migration in the in_atomic() fast
++	 * path which is enabled again in the following spin_unlock(). We have
++	 * one migrate_disable() pending in the slow-path which is reversed
++	 * after the raw_spin_unlock_irq() where we leave the atomic context.
++	 */
++	migrate_disable();
++
+ 	spin_unlock(q.lock_ptr);
+ 	/*
+ 	 * __rt_mutex_start_proxy_lock() unconditionally enqueues the @rt_waiter
+@@ -3006,6 +3014,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags,
+ 	 */
+ 	ret = __rt_mutex_start_proxy_lock(&q.pi_state->pi_mutex, &rt_waiter, current);
+ 	raw_spin_unlock_irq(&q.pi_state->pi_mutex.wait_lock);
++	migrate_enable();
+ 
+ 	if (ret) {
+ 		if (ret == 1)
+@@ -3140,11 +3149,21 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
+ 		 * rt_waiter. Also see the WARN in wake_futex_pi().
+ 		 */
+ 		raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
++		/*
++		 * Magic trickery for now to make the RT migrate disable
++		 * logic happy. The following spin_unlock() happens with
++		 * interrupts disabled so the internal migrate_enable()
++		 * won't undo the migrate_disable() which was issued when
++		 * locking hb->lock.
++		 */
++		migrate_disable();
+ 		spin_unlock(&hb->lock);
+ 
+ 		/* drops pi_state->pi_mutex.wait_lock */
+ 		ret = wake_futex_pi(uaddr, uval, pi_state);
+ 
++		migrate_enable();
++
+ 		put_pi_state(pi_state);
+ 
+ 		/*
+-- 
+2.36.1
+