[PATCH v2 7/7] kunit, slub: add test_kfree_rcu() and test_leak_destroy()

Vlastimil Babka
2024-08-07T10:31:45Z

Add a test that will create cache, allocate one object, kfree_rcu() it
and attempt to destroy it. As long as the usage of kvfree_rcu_barrier()
in kmem_cache_destroy() works correctly, there should be no warnings in
dmesg and the test should pass.

Additionally add a test_leak_destroy() test that leaks an object on
purpose and verifies that kmem_cache_destroy() catches it.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
lib/slub_kunit.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)

diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c
index e6667a28c014..6e3a1e5a7142 100644
--- a/lib/slub_kunit.c
+++ b/lib/slub_kunit.c
@@ -5,6 +5,7 @@
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kernel.h>
+#include <linux/rcupdate.h>
#include "../mm/slab.h"

static struct kunit_resource resource;
@@ -157,6 +158,34 @@ static void test_kmalloc_redzone_access(struct kunit *test)
kmem_cache_destroy(s);
}

+struct test_kfree_rcu_struct {
+ struct rcu_head rcu;
+};
+
+static void test_kfree_rcu(struct kunit *test)
+{
+ struct kmem_cache *s = test_kmem_cache_create("TestSlub_kfree_rcu",
+ sizeof(struct test_kfree_rcu_struct),
+ SLAB_NO_MERGE);
+ struct test_kfree_rcu_struct *p = kmem_cache_alloc(s, GFP_KERNEL);
+
+ kfree_rcu(p, rcu);
+ kmem_cache_destroy(s);
+
+ KUNIT_EXPECT_EQ(test, 0, slab_errors);
+}
+
+static void test_leak_destroy(struct kunit *test)
+{
+ struct kmem_cache *s = test_kmem_cache_create("TestSlub_kfree_rcu",
+ 64, SLAB_NO_MERGE);
+ kmem_cache_alloc(s, GFP_KERNEL);
+
+ kmem_cache_destroy(s);
+
+ KUNIT_EXPECT_EQ(test, 1, slab_errors);
+}
+
static int test_init(struct kunit *test)
{
slab_errors = 0;
@@ -177,6 +206,8 @@ static struct kunit_case test_cases[] = {

KUNIT_CASE(test_clobber_redzone_free),
KUNIT_CASE(test_kmalloc_redzone_access),
+ KUNIT_CASE(test_kfree_rcu),
+ KUNIT_CASE(test_leak_destroy),
{}
};

--
2.46.0