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// SPDX-License-Identifier: GPL-2.0
#include <kunit/test.h>
#include <kunit/test-bug.h>
#include <linux/mm.h>
#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;
static int slab_errors;
/*
* Wrapper function for kmem_cache_create(), which reduces 2 parameters:
* 'align' and 'ctor', and sets SLAB_SKIP_KFENCE flag to avoid getting an
* object from kfence pool, where the operation could be caught by both
* our test and kfence sanity check.
*/
static struct kmem_cache *test_kmem_cache_create(const char *name,
unsigned int size, slab_flags_t flags)
{
struct kmem_cache *s = kmem_cache_create(name, size, 0,
(flags | SLAB_NO_USER_FLAGS), NULL);
s->flags |= SLAB_SKIP_KFENCE;
return s;
}
static void test_clobber_zone(struct kunit *test)
{
struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_alloc", 64,
SLAB_RED_ZONE);
u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
kasan_disable_current();
p[64] = 0x12;
validate_slab_cache(s);
KUNIT_EXPECT_EQ(test, 2, slab_errors);
kasan_enable_current();
kmem_cache_free(s, p);
kmem_cache_destroy(s);
}
#ifndef CONFIG_KASAN
static void test_next_pointer(struct kunit *test)
{
struct kmem_cache *s = test_kmem_cache_create("TestSlub_next_ptr_free",
64, SLAB_POISON);
u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
unsigned long tmp;
unsigned long *ptr_addr;
kmem_cache_free(s, p);
ptr_addr = (unsigned long *)(p + s->offset);
tmp = *ptr_addr;
p[s->offset] = ~p[s->offset];
/*
* Expecting three errors.
* One for the corrupted freechain and the other one for the wrong
* count of objects in use. The third error is fixing broken cache.
*/
validate_slab_cache(s);
KUNIT_EXPECT_EQ(test, 3, slab_errors);
/*
* Try to repair corrupted freepointer.
* Still expecting two errors. The first for the wrong count
* of objects in use.
* The second error is for fixing broken cache.
*/
*ptr_addr = tmp;
slab_errors = 0;
validate_slab_cache(s);
KUNIT_EXPECT_EQ(test, 2, slab_errors);
/*
* Previous validation repaired the count of objects in use.
* Now expecting no error.
*/
slab_errors = 0;
validate_slab_cache(s);
KUNIT_EXPECT_EQ(test, 0, slab_errors);
kmem_cache_destroy(s);
}
static void test_first_word(struct kunit *test)
{
struct kmem_cache *s = test_kmem_cache_create("TestSlub_1th_word_free",
64, SLAB_POISON);
u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
kmem_cache_free(s, p);
*p = 0x78;
validate_slab_cache(s);
KUNIT_EXPECT_EQ(test, 2, slab_errors);
kmem_cache_destroy(s);
}
static void test_clobber_50th_byte(struct kunit *test)
{
struct kmem_cache *s = test_kmem_cache_create("TestSlub_50th_word_free",
64, SLAB_POISON);
u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
kmem_cache_free(s, p);
p[50] = 0x9a;
validate_slab_cache(s);
KUNIT_EXPECT_EQ(test, 2, slab_errors);
kmem_cache_destroy(s);
}
#endif
static void test_clobber_redzone_free(struct kunit *test)
{
struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_free", 64,
SLAB_RED_ZONE);
u8 *p = kmem_cache_alloc(s, GFP_KERNEL);
kasan_disable_current();
kmem_cache_free(s, p);
p[64] = 0xab;
validate_slab_cache(s);
KUNIT_EXPECT_EQ(test, 2, slab_errors);
kasan_enable_current();
kmem_cache_destroy(s);
}
static void test_kmalloc_redzone_access(struct kunit *test)
{
struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32,
SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
u8 *p = __kmalloc_cache_noprof(s, GFP_KERNEL, 18);
kasan_disable_current();
/* Suppress the -Warray-bounds warning */
OPTIMIZER_HIDE_VAR(p);
p[18] = 0xab;
p[19] = 0xab;
validate_slab_cache(s);
KUNIT_EXPECT_EQ(test, 2, slab_errors);
kasan_enable_current();
kmem_cache_free(s, p);
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;
kunit_add_named_resource(test, NULL, NULL, &resource,
"slab_errors", &slab_errors);
return 0;
}
static struct kunit_case test_cases[] = {
KUNIT_CASE(test_clobber_zone),
#ifndef CONFIG_KASAN
KUNIT_CASE(test_next_pointer),
KUNIT_CASE(test_first_word),
KUNIT_CASE(test_clobber_50th_byte),
#endif
KUNIT_CASE(test_clobber_redzone_free),
KUNIT_CASE(test_kmalloc_redzone_access),
KUNIT_CASE(test_kfree_rcu),
KUNIT_CASE(test_leak_destroy),
{}
};
static struct kunit_suite test_suite = {
.name = "slub_test",
.init = test_init,
.test_cases = test_cases,
};
kunit_test_suite(test_suite);
MODULE_LICENSE("GPL");
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