Commit 26c6cb7c authored by Vlastimil Babka's avatar Vlastimil Babka Committed by Linus Torvalds
Browse files

kunit: make test->lock irq safe 

The upcoming SLUB kunit test will be calling kunit_find_named_resource()
from a context with disabled interrupts.  That means kunit's test->lock
needs to be IRQ safe to avoid potential deadlocks and lockdep splats.

This patch therefore changes the test->lock usage to spin_lock_irqsave()
and spin_unlock_irqrestore().

Link: https://lkml.kernel.org/r/20210511150734.3492-1-glittao@gmail.com


Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarOliver Glitta <glittao@gmail.com>
Reviewed-by: default avatarBrendan Higgins <brendanhiggins@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Marco Elver <elver@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4acaa7d5

include/kunit/test.h

+3 −2
Original line number Diff line number Diff line
@@ -515,8 +515,9 @@ kunit_find_resource(struct kunit *test, 
		    void *match_data)

{

	struct kunit_resource *res, *found = NULL;

	unsigned long flags;



	spin_lock(&test->lock);

	spin_lock_irqsave(&test->lock, flags);



	list_for_each_entry_reverse(res, &test->resources, node) {

		if (match(test, res, (void *)match_data)) {
@@ -526,7 +527,7 @@ kunit_find_resource(struct kunit *test, 
		}

	}



	spin_unlock(&test->lock);

	spin_unlock_irqrestore(&test->lock, flags);



	return found;

}

lib/kunit/test.c

+11 −7
Original line number Diff line number Diff line
@@ -475,6 +475,7 @@ int kunit_add_resource(struct kunit *test, 
		       void *data)

{

	int ret = 0;

	unsigned long flags;



	res->free = free;

	kref_init(&res->refcount);
@@ -487,10 +488,10 @@ int kunit_add_resource(struct kunit *test, 
		res->data = data;

	}



	spin_lock(&test->lock);

	spin_lock_irqsave(&test->lock, flags);

	list_add_tail(&res->node, &test->resources);

	/* refcount for list is established by kref_init() */

	spin_unlock(&test->lock);

	spin_unlock_irqrestore(&test->lock, flags);



	return ret;

}
@@ -548,9 +549,11 @@ EXPORT_SYMBOL_GPL(kunit_alloc_and_get_resource); 


void kunit_remove_resource(struct kunit *test, struct kunit_resource *res)

{

	spin_lock(&test->lock);

	unsigned long flags;



	spin_lock_irqsave(&test->lock, flags);

	list_del(&res->node);

	spin_unlock(&test->lock);

	spin_unlock_irqrestore(&test->lock, flags);

	kunit_put_resource(res);

}

EXPORT_SYMBOL_GPL(kunit_remove_resource);
@@ -630,6 +633,7 @@ EXPORT_SYMBOL_GPL(kunit_kfree); 
void kunit_cleanup(struct kunit *test)

{

	struct kunit_resource *res;

	unsigned long flags;



	/*

	 * test->resources is a stack - each allocation must be freed in the
@@ -641,9 +645,9 @@ void kunit_cleanup(struct kunit *test) 
	 * protect against the current node being deleted, not the next.

	 */

	while (true) {

		spin_lock(&test->lock);

		spin_lock_irqsave(&test->lock, flags);

		if (list_empty(&test->resources)) {

			spin_unlock(&test->lock);

			spin_unlock_irqrestore(&test->lock, flags);

			break;

		}

		res = list_last_entry(&test->resources,
@@ -654,7 +658,7 @@ void kunit_cleanup(struct kunit *test) 
		 * resource, and this can't happen if the test->lock

		 * is held.

		 */

		spin_unlock(&test->lock);

		spin_unlock_irqrestore(&test->lock, flags);

		kunit_remove_resource(test, res);

	}

	current->kunit_test = NULL;