summaryrefslogtreecommitdiffstats
path: root/debian/patches-rt/0069-genirq-Move-prio-assignment-into-the-newly-created-t.patch
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--debian/patches-rt/0069-genirq-Move-prio-assignment-into-the-newly-created-t.patch63
1 files changed, 63 insertions, 0 deletions
diff --git a/debian/patches-rt/0069-genirq-Move-prio-assignment-into-the-newly-created-t.patch b/debian/patches-rt/0069-genirq-Move-prio-assignment-into-the-newly-created-t.patch
new file mode 100644
index 000000000..f09b701ab
--- /dev/null
+++ b/debian/patches-rt/0069-genirq-Move-prio-assignment-into-the-newly-created-t.patch
@@ -0,0 +1,63 @@
+From 617294b2f33cec584f48c12d914fcc982f317be5 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Mon, 9 Nov 2020 23:32:39 +0100
+Subject: [PATCH 069/323] genirq: Move prio assignment into the newly created
+ thread
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz
+
+With enabled threaded interrupts the nouveau driver reported the
+following:
+| Chain exists of:
+| &mm->mmap_lock#2 --> &device->mutex --> &cpuset_rwsem
+|
+| Possible unsafe locking scenario:
+|
+| CPU0 CPU1
+| ---- ----
+| lock(&cpuset_rwsem);
+| lock(&device->mutex);
+| lock(&cpuset_rwsem);
+| lock(&mm->mmap_lock#2);
+
+The device->mutex is nvkm_device::mutex.
+
+Unblocking the lockchain at `cpuset_rwsem' is probably the easiest thing
+to do.
+Move the priority assignment to the start of the newly created thread.
+
+Fixes: 710da3c8ea7df ("sched/core: Prevent race condition between cpuset and __sched_setscheduler()")
+Reported-by: Mike Galbraith <efault@gmx.de>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+[bigeasy: Patch description]
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Link: https://lkml.kernel.org/r/a23a826af7c108ea5651e73b8fbae5e653f16e86.camel@gmx.de
+Signed-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
+---
+ kernel/irq/manage.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
+index 0159925054fa..5ec167fb77b9 100644
+--- a/kernel/irq/manage.c
++++ b/kernel/irq/manage.c
+@@ -1201,6 +1201,8 @@ static int irq_thread(void *data)
+
+ irq_thread_set_ready(desc, action);
+
++ sched_set_fifo(current);
++
+ if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
+ &action->thread_flags))
+ handler_fn = irq_forced_thread_fn;
+@@ -1366,8 +1368,6 @@ setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
+ if (IS_ERR(t))
+ return PTR_ERR(t);
+
+- sched_set_fifo(t);
+-
+ /*
+ * We keep the reference to the task struct even if
+ * the thread dies to avoid that the interrupt code
+--
+2.43.0
+