4.19-stable patches

added patches:
	rtmutex-drop-rt_mutex-wait_lock-before-scheduling.patch

diff --git a/queue-4.19/rtmutex-drop-rt_mutex-wait_lock-before-scheduling.patch b/queue-4.19/rtmutex-drop-rt_mutex-wait_lock-before-scheduling.patch
new file mode 100644 (file)
index 0000000..fc063c4
--- /dev/null
+++ b/queue-4.19/rtmutex-drop-rt_mutex-wait_lock-before-scheduling.patch
@@ -0,0 +1,57 @@
+From d33d26036a0274b472299d7dcdaa5fb34329f91b Mon Sep 17 00:00:00 2001
+From: Roland Xu <mu001999@outlook.com>
+Date: Thu, 15 Aug 2024 10:58:13 +0800
+Subject: rtmutex: Drop rt_mutex::wait_lock before scheduling
+
+From: Roland Xu <mu001999@outlook.com>
+
+commit d33d26036a0274b472299d7dcdaa5fb34329f91b upstream.
+
+rt_mutex_handle_deadlock() is called with rt_mutex::wait_lock held.  In the
+good case it returns with the lock held and in the deadlock case it emits a
+warning and goes into an endless scheduling loop with the lock held, which
+triggers the 'scheduling in atomic' warning.
+
+Unlock rt_mutex::wait_lock in the dead lock case before issuing the warning
+and dropping into the schedule for ever loop.
+
+[ tglx: Moved unlock before the WARN(), removed the pointless comment,
+       massaged changelog, added Fixes tag ]
+
+Fixes: 3d5c9340d194 ("rtmutex: Handle deadlock detection smarter")
+Signed-off-by: Roland Xu <mu001999@outlook.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Cc: stable@vger.kernel.org
+Link: https://lore.kernel.org/all/ME0P300MB063599BEF0743B8FA339C2CECC802@ME0P300MB0635.AUSP300.PROD.OUTLOOK.COM
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/locking/rtmutex.c |    4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+--- a/kernel/locking/rtmutex.c
++++ b/kernel/locking/rtmutex.c
+@@ -1205,6 +1205,7 @@ __rt_mutex_slowlock(struct rt_mutex *loc
+ }
+ 
+ static void rt_mutex_handle_deadlock(int res, int detect_deadlock,
++                                   struct rt_mutex *lock,
+                                    struct rt_mutex_waiter *w)
+ {
+       /*
+@@ -1214,6 +1215,7 @@ static void rt_mutex_handle_deadlock(int
+       if (res != -EDEADLOCK || detect_deadlock)
+               return;
+ 
++      raw_spin_unlock_irq(&lock->wait_lock);
+       /*
+        * Yell lowdly and stop the task right here.
+        */
+@@ -1269,7 +1271,7 @@ rt_mutex_slowlock(struct rt_mutex *lock,
+       if (unlikely(ret)) {
+               __set_current_state(TASK_RUNNING);
+               remove_waiter(lock, &waiter);
+-              rt_mutex_handle_deadlock(ret, chwalk, &waiter);
++              rt_mutex_handle_deadlock(ret, chwalk, lock, &waiter);
+       }
+ 
+       /*

diff --git a/queue-4.19/series b/queue-4.19/series
index 85ac27934fb72cc2756044cb4fb97ccfe854009f..80847d694665fbc4e30cd67124e5e773f5373cf7 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -89,3 +89,4 @@ acpi-processor-return-an-error-if-acpi_processor_get.patch
 acpi-processor-fix-memory-leaks-in-error-paths-of-pr.patch
 drm-i915-fence-mark-debug_fence_init_onstack-with-__.patch
 drm-i915-fence-mark-debug_fence_free-with-__maybe_un.patch
+rtmutex-drop-rt_mutex-wait_lock-before-scheduling.patch