genirq/test: Resolve irq lock inversion warnings

irq_shutdown_and_deactivate() is normally called with the descriptor lock
held, and interrupts disabled. Nested a few levels down, it grabs the
global irq_resend_lock. Lockdep rightfully complains when interrupts are
not disabled:

       CPU0                    CPU1
       ----                    ----
  lock(irq_resend_lock);
                               local_irq_disable();
                               lock(&irq_desc_lock_class);
                               lock(irq_resend_lock);
  <Interrupt>
    lock(&irq_desc_lock_class);

...
   _raw_spin_lock+0x2b/0x40
   clear_irq_resend+0x14/0x70
   irq_shutdown_and_deactivate+0x29/0x80
   irq_shutdown_depth_test+0x1ce/0x600
   kunit_try_run_case+0x90/0x120

Grab the descriptor lock and disable interrupts, to resolve the
problem.

Fixes: 66067c3c8a1e ("genirq: Add kunit tests for depth counts")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/all/aJJONEIoIiTSDMqc@google.com
Closes: https://lore.kernel.org/lkml/31a761e4-8f81-40cf-aaf5-d220ba11911c@roeck-us.net/

diff --git a/kernel/irq/irq_test.c b/kernel/irq/irq_test.c
index 5161b56a12f9318742ccd587ed55fa34abe558b5..a75abebed7f248c5a7bf62158a99c91eb6d70263 100644 (file)
--- a/kernel/irq/irq_test.c
+++ b/kernel/irq/irq_test.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: LGPL-2.1+
 
+#include <linux/cleanup.h>
 #include <linux/cpu.h>
 #include <linux/cpumask.h>
 #include <linux/interrupt.h>
@@ -134,7 +135,8 @@ static void irq_shutdown_depth_test(struct kunit *test)
        disable_irq(virq);
        KUNIT_EXPECT_EQ(test, desc->depth, 1);
 
-       irq_shutdown_and_deactivate(desc);
+       scoped_guard(raw_spinlock_irqsave, &desc->lock)
+               irq_shutdown_and_deactivate(desc);
 
        KUNIT_EXPECT_FALSE(test, irqd_is_activated(data));
        KUNIT_EXPECT_FALSE(test, irqd_is_started(data));