Re: [RFC PATCH v2 3/3] KASAN: Port KASAN Tests to KUnit

[Dmitry Vyukov]

On Thu, Mar 19, 2020 at 5:42 PM 'Patricia Alfonso' via kasan-dev
<kasan-dev@xxxxxxxxxxxxxxxx> wrote:
>
> Transfer all previous tests for KASAN to KUnit so they can be run
> more easily. Using kunit_tool, developers can run these tests with their
> other KUnit tests and see "pass" or "fail" with the appropriate KASAN
> report instead of needing to parse each KASAN report to test KASAN
> functionalities. All KASAN reports are still printed to dmesg.
>
> Stack tests do not work in UML so those tests are protected inside an
> "#if IS_ENABLED(CONFIG_KASAN_STACK)" so this only runs if stack
> instrumentation is enabled.
>
> copy_user_test cannot be run in KUnit so there is a separate test file
> for those tests, which can be run as before as a module.

Hi Patricia,

FWIW I've got some conflicts applying this patch on latest linux-next
next-20200324. There are some changes to the tests in mm tree I think.

Which tree will this go through? I would be nice to resolve these
conflicts somehow, but I am not sure how. Maybe the kasan tests
changes are merged upstream next windows, and then rebase this?

Also, how can I apply this for testing? I assume this is based on some
kunit branch? which one?

Why the copy_from_user tests can't be converted?
It would be very nice to get rid of the modules entirely, rather than
having 2 different test procedures because of 2 tests.
Or, alternatively can there be other tests in future that can't be
converted? Naming it "KASAN_USER" looks somewhat overspecialized. Say
tomorrow we have another test that can't run under Kunit, but is not
related to copt_from_user, should we create yet another module for it?
I think the crux of that is that's a module, so a better name may be
"KASAN_TEST_MODULE". Currently all tests that need to run as module
are related to copy_from_user, but that's just an implementation
detail.


> Signed-off-by: Patricia Alfonso <trishalfonso@xxxxxxxxxx>
> ---
>  lib/Kconfig.kasan          |  13 +-
>  lib/Makefile               |   1 +
>  lib/test_kasan.c           | 606 ++++++++++++++-----------------------
>  lib/test_kasan_copy_user.c |  75 +++++
>  4 files changed, 309 insertions(+), 386 deletions(-)
>  create mode 100644 lib/test_kasan_copy_user.c
>
> diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
> index 5b54f3c9a741..f026c2e62b1d 100644
> --- a/lib/Kconfig.kasan
> +++ b/lib/Kconfig.kasan
> @@ -159,9 +159,16 @@ config KASAN_VMALLOC
>           stacks), but at the cost of higher memory usage.
>
>  config TEST_KASAN
> -       tristate "Module for testing KASAN for bug detection"
> -       depends on m && KASAN
> +       tristate "KUnit testing KASAN for bug detection"
> +       depends on KASAN && KUNIT=y
>         help
> -         This is a test module doing various nasty things like
> +         This is a test suite doing various nasty things like
>           out of bounds accesses, use after free. It is useful for testing
>           kernel debugging features like KASAN.
> +
> +config TEST_KASAN_USER
> +       tristate "Module testing KASAN for bug detection on copy user tests"
> +       depends on m && KASAN
> +       help
> +         This is a test module for copy_user_tests because these functions
> +         cannot be tested by KUnit so they must be their own module.
> diff --git a/lib/Makefile b/lib/Makefile
> index 5d64890d6b6a..e0dc4430e405 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -62,6 +62,7 @@ obj-$(CONFIG_TEST_IDA) += test_ida.o
>  obj-$(CONFIG_TEST_KASAN) += test_kasan.o
>  CFLAGS_test_kasan.o += -fno-builtin
>  CFLAGS_test_kasan.o += $(call cc-disable-warning, vla)
> +obj-$(CONFIG_TEST_KASAN_USER) += test_kasan_copy_user.o
>  obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o
>  CFLAGS_test_ubsan.o += $(call cc-disable-warning, vla)
>  UBSAN_SANITIZE_test_ubsan.o := y
> diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> index cf73c6bee81b..c255495e6ce3 100644
> --- a/lib/test_kasan.c
> +++ b/lib/test_kasan.c
> @@ -5,8 +5,6 @@
>   * Author: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
>   */
>
> -#define pr_fmt(fmt) "kasan test: %s " fmt, __func__
> -
>  #include <linux/bitops.h>
>  #include <linux/delay.h>
>  #include <linux/kasan.h>
> @@ -25,8 +23,26 @@
>
>  #include <kunit/test.h>
>
> +#if IS_BUILTIN(CONFIG_KUNIT)
> +
>  struct kunit_resource resource;
>  struct kunit_kasan_expectation fail_data;
> +bool multishot;
> +
> +int kasan_multi_shot_init(struct kunit *test)
> +{
> +       /*
> +        * Temporarily enable multi-shot mode. Otherwise, we'd only get a
> +        * report for the first case.
> +        */
> +       multishot = kasan_save_enable_multi_shot();
> +       return 0;
> +}
> +
> +void kasan_multi_shot_exit(struct kunit *test)
> +{
> +       kasan_restore_multi_shot(multishot);
> +}
>
>  #define KUNIT_SET_KASAN_DATA(test) do { \
>         fail_data.report_expected = true; \
> @@ -60,61 +76,44 @@ struct kunit_kasan_expectation fail_data;
>         KUNIT_DO_EXPECT_KASAN_FAIL(test, condition); \
>  } while (0)
>
> -/*
> - * Note: test functions are marked noinline so that their names appear in
> - * reports.
> - */
> -
> -static noinline void __init kmalloc_oob_right(void)
> +static void kmalloc_oob_right(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 123;
>
> -       pr_info("out-of-bounds to right\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       ptr[size] = 'x';
> +       KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'x');
>         kfree(ptr);
>  }
>
> -static noinline void __init kmalloc_oob_left(void)
> +static void kmalloc_oob_left(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 15;
>
> -       pr_info("out-of-bounds to left\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       *ptr = *(ptr - 1);
> +       KUNIT_EXPECT_KASAN_FAIL(test, *ptr = *(ptr - 1));
>         kfree(ptr);
>  }
>
> -static noinline void __init kmalloc_node_oob_right(void)
> +static void kmalloc_node_oob_right(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 4096;
>
> -       pr_info("kmalloc_node(): out-of-bounds to right\n");
>         ptr = kmalloc_node(size, GFP_KERNEL, 0);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       ptr[size] = 0;
> +       KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
>         kfree(ptr);
>  }
>
>  #ifdef CONFIG_SLUB
> -static noinline void __init kmalloc_pagealloc_oob_right(void)
> +static void kmalloc_pagealloc_oob_right(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
> @@ -122,324 +121,253 @@ static noinline void __init kmalloc_pagealloc_oob_right(void)
>         /* Allocate a chunk that does not fit into a SLUB cache to trigger
>          * the page allocator fallback.
>          */
> -       pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       ptr[size] = 0;
> +       KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
>         kfree(ptr);
>  }
>
> -static noinline void __init kmalloc_pagealloc_uaf(void)
> +static void kmalloc_pagealloc_uaf(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
>
> -       pr_info("kmalloc pagealloc allocation: use-after-free\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
>         kfree(ptr);
> -       ptr[0] = 0;
> +       KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = 0);
>  }
>
> -static noinline void __init kmalloc_pagealloc_invalid_free(void)
> +static void kmalloc_pagealloc_invalid_free(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
>
> -       pr_info("kmalloc pagealloc allocation: invalid-free\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       kfree(ptr + 1);
> +       KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1));
>  }
> -#endif
> +#endif /* CONFIG_SLUB */
>
> -static noinline void __init kmalloc_large_oob_right(void)
> +static void kmalloc_large_oob_right(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
>         /* Allocate a chunk that is large enough, but still fits into a slab
>          * and does not trigger the page allocator fallback in SLUB.
>          */
> -       pr_info("kmalloc large allocation: out-of-bounds to right\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       ptr[size] = 0;
> +       KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
>         kfree(ptr);
>  }
>
> -static noinline void __init kmalloc_oob_krealloc_more(void)
> +static void kmalloc_oob_krealloc_more(struct kunit *test)
>  {
>         char *ptr1, *ptr2;
>         size_t size1 = 17;
>         size_t size2 = 19;
>
> -       pr_info("out-of-bounds after krealloc more\n");
>         ptr1 = kmalloc(size1, GFP_KERNEL);
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
> +
>         ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
> -       if (!ptr1 || !ptr2) {
> -               pr_err("Allocation failed\n");
> -               kfree(ptr1);
> -               kfree(ptr2);
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
>
> -       ptr2[size2] = 'x';
> +       KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');
>         kfree(ptr2);
>  }
>
> -static noinline void __init kmalloc_oob_krealloc_less(void)
> +static void kmalloc_oob_krealloc_less(struct kunit *test)
>  {
>         char *ptr1, *ptr2;
>         size_t size1 = 17;
>         size_t size2 = 15;
>
> -       pr_info("out-of-bounds after krealloc less\n");
>         ptr1 = kmalloc(size1, GFP_KERNEL);
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
> +
>         ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
> -       if (!ptr1 || !ptr2) {
> -               pr_err("Allocation failed\n");
> -               kfree(ptr1);
> -               return;
> -       }
> -       ptr2[size2] = 'x';
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
> +
> +       KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');
>         kfree(ptr2);
>  }
>
> -static noinline void __init kmalloc_oob_16(void)
> +static void kmalloc_oob_16(struct kunit *test)
>  {
>         struct {
>                 u64 words[2];
>         } *ptr1, *ptr2;
>
> -       pr_info("kmalloc out-of-bounds for 16-bytes access\n");
>         ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
> +
>         ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
> -       if (!ptr1 || !ptr2) {
> -               pr_err("Allocation failed\n");
> -               kfree(ptr1);
> -               kfree(ptr2);
> -               return;
> -       }
> -       *ptr1 = *ptr2;
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
> +
> +       KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
>         kfree(ptr1);
>         kfree(ptr2);
>  }
>
> -static noinline void __init kmalloc_oob_memset_2(void)
> +static void kmalloc_oob_memset_2(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 8;
>
> -       pr_info("out-of-bounds in memset2\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       memset(ptr+7, 0, 2);
> +       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr+7, 0, 2));
>         kfree(ptr);
>  }
>
> -static noinline void __init kmalloc_oob_memset_4(void)
> +static void kmalloc_oob_memset_4(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 8;
>
> -       pr_info("out-of-bounds in memset4\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       memset(ptr+5, 0, 4);
> +       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr+5, 0, 4));
>         kfree(ptr);
>  }
>
>
> -static noinline void __init kmalloc_oob_memset_8(void)
> +static void kmalloc_oob_memset_8(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 8;
>
> -       pr_info("out-of-bounds in memset8\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       memset(ptr+1, 0, 8);
> +       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr+1, 0, 8));
>         kfree(ptr);
>  }
>
> -static noinline void __init kmalloc_oob_memset_16(void)
> +static void kmalloc_oob_memset_16(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 16;
>
> -       pr_info("out-of-bounds in memset16\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       memset(ptr+1, 0, 16);
> +       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr+1, 0, 16));
>         kfree(ptr);
>  }
>
> -static noinline void __init kmalloc_oob_in_memset(void)
> +static void kmalloc_oob_in_memset(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 666;
>
> -       pr_info("out-of-bounds in memset\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       memset(ptr, 0, size+5);
> +       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size+5));
>         kfree(ptr);
>  }
>
> -static noinline void __init kmalloc_uaf(void)
> +static void kmalloc_uaf(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 10;
>
> -       pr_info("use-after-free\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
>         kfree(ptr);
> -       *(ptr + 8) = 'x';
> +       KUNIT_EXPECT_KASAN_FAIL(test, *(ptr + 8) = 'x');
>  }
>
> -static noinline void __init kmalloc_uaf_memset(void)
> +static void kmalloc_uaf_memset(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 33;
>
> -       pr_info("use-after-free in memset\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
>         kfree(ptr);
> -       memset(ptr, 0, size);
> +       KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size));
>  }
>
> -static noinline void __init kmalloc_uaf2(void)
> +static void kmalloc_uaf2(struct kunit *test)
>  {
>         char *ptr1, *ptr2;
>         size_t size = 43;
>
> -       pr_info("use-after-free after another kmalloc\n");
>         ptr1 = kmalloc(size, GFP_KERNEL);
> -       if (!ptr1) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
>
>         kfree(ptr1);
> +
>         ptr2 = kmalloc(size, GFP_KERNEL);
> -       if (!ptr2) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
> +
> +       KUNIT_EXPECT_KASAN_FAIL(test, ptr1[40] = 'x');
> +       KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2);
>
> -       ptr1[40] = 'x';
> -       if (ptr1 == ptr2)
> -               pr_err("Could not detect use-after-free: ptr1 == ptr2\n");
>         kfree(ptr2);
>  }
>
> -static noinline void __init kfree_via_page(void)
> +static void kfree_via_page(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 8;
>         struct page *page;
>         unsigned long offset;
>
> -       pr_info("invalid-free false positive (via page)\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
>         page = virt_to_page(ptr);
>         offset = offset_in_page(ptr);
>         kfree(page_address(page) + offset);
>  }
>
> -static noinline void __init kfree_via_phys(void)
> +static void kfree_via_phys(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 8;
>         phys_addr_t phys;
>
> -       pr_info("invalid-free false positive (via phys)\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
>         phys = virt_to_phys(ptr);
>         kfree(phys_to_virt(phys));
>  }
>
> -static noinline void __init kmem_cache_oob(void)
> +static void kmem_cache_oob(struct kunit *test)
>  {
>         char *p;
>         size_t size = 200;
>         struct kmem_cache *cache = kmem_cache_create("test_cache",
>                                                 size, 0,
>                                                 0, NULL);
> -       if (!cache) {
> -               pr_err("Cache allocation failed\n");
> -               return;
> -       }
> -       pr_info("out-of-bounds in kmem_cache_alloc\n");
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
>         p = kmem_cache_alloc(cache, GFP_KERNEL);
>         if (!p) {
> -               pr_err("Allocation failed\n");
> +               kunit_err(test, "Allocation failed: %s\n", __func__);
>                 kmem_cache_destroy(cache);
>                 return;
>         }
>
> -       *p = p[size];
> +       KUNIT_EXPECT_KASAN_FAIL(test, *p = p[size]);
>         kmem_cache_free(cache, p);
>         kmem_cache_destroy(cache);
>  }
>
> -static noinline void __init memcg_accounted_kmem_cache(void)
> +static void memcg_accounted_kmem_cache(struct kunit *test)
>  {
>         int i;
>         char *p;
> @@ -447,12 +375,8 @@ static noinline void __init memcg_accounted_kmem_cache(void)
>         struct kmem_cache *cache;
>
>         cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL);
> -       if (!cache) {
> -               pr_err("Cache allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
>
> -       pr_info("allocate memcg accounted object\n");
>         /*
>          * Several allocations with a delay to allow for lazy per memcg kmem
>          * cache creation.
> @@ -472,134 +396,80 @@ static noinline void __init memcg_accounted_kmem_cache(void)
>
>  static char global_array[10];
>
> -static noinline void __init kasan_global_oob(void)
> +static void kasan_global_oob(struct kunit *test)
>  {
>         volatile int i = 3;
>         char *p = &global_array[ARRAY_SIZE(global_array) + i];
>
> -       pr_info("out-of-bounds global variable\n");
> -       *(volatile char *)p;
> -}
> -
> -static noinline void __init kasan_stack_oob(void)
> -{
> -       char stack_array[10];
> -       volatile int i = 0;
> -       char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
> -
> -       pr_info("out-of-bounds on stack\n");
> -       *(volatile char *)p;
> +       KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
>  }
>
> -static noinline void __init ksize_unpoisons_memory(void)
> +static void ksize_unpoisons_memory(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 123, real_size;
>
> -       pr_info("ksize() unpoisons the whole allocated chunk\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>         real_size = ksize(ptr);
>         /* This access doesn't trigger an error. */
>         ptr[size] = 'x';
>         /* This one does. */
> -       ptr[real_size] = 'y';
> +       KUNIT_EXPECT_KASAN_FAIL(test, ptr[real_size] = 'y');
>         kfree(ptr);
>  }
>
> -static noinline void __init copy_user_test(void)
> +#if (IS_ENABLED(CONFIG_KASAN_STACK))
> +static void kasan_stack_oob(struct kunit *test)
>  {
> -       char *kmem;
> -       char __user *usermem;
> -       size_t size = 10;
> -       int unused;
> -
> -       kmem = kmalloc(size, GFP_KERNEL);
> -       if (!kmem)
> -               return;
> -
> -       usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
> -                           PROT_READ | PROT_WRITE | PROT_EXEC,
> -                           MAP_ANONYMOUS | MAP_PRIVATE, 0);
> -       if (IS_ERR(usermem)) {
> -               pr_err("Failed to allocate user memory\n");
> -               kfree(kmem);
> -               return;
> -       }
> -
> -       pr_info("out-of-bounds in copy_from_user()\n");
> -       unused = copy_from_user(kmem, usermem, size + 1);
> -
> -       pr_info("out-of-bounds in copy_to_user()\n");
> -       unused = copy_to_user(usermem, kmem, size + 1);
> -
> -       pr_info("out-of-bounds in __copy_from_user()\n");
> -       unused = __copy_from_user(kmem, usermem, size + 1);
> -
> -       pr_info("out-of-bounds in __copy_to_user()\n");
> -       unused = __copy_to_user(usermem, kmem, size + 1);
> -
> -       pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
> -       unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
> -
> -       pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
> -       unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
> -
> -       pr_info("out-of-bounds in strncpy_from_user()\n");
> -       unused = strncpy_from_user(kmem, usermem, size + 1);
> +       char stack_array[10];
> +       volatile int i = 0;
> +       char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
>
> -       vm_munmap((unsigned long)usermem, PAGE_SIZE);
> -       kfree(kmem);
> +       KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
>  }
>
> -static noinline void __init kasan_alloca_oob_left(void)
> +static void kasan_alloca_oob_left(struct kunit *test)
>  {
>         volatile int i = 10;
>         char alloca_array[i];
>         char *p = alloca_array - 1;
>
> -       pr_info("out-of-bounds to left on alloca\n");
> -       *(volatile char *)p;
> +       KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
>  }
>
> -static noinline void __init kasan_alloca_oob_right(void)
> +static void kasan_alloca_oob_right(struct kunit *test)
>  {
>         volatile int i = 10;
>         char alloca_array[i];
>         char *p = alloca_array + i;
>
> -       pr_info("out-of-bounds to right on alloca\n");
> -       *(volatile char *)p;
> +       KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
>  }
> +#endif /* CONFIG_KASAN_STACK */
>
> -static noinline void __init kmem_cache_double_free(void)
> +static void kmem_cache_double_free(struct kunit *test)
>  {
>         char *p;
>         size_t size = 200;
>         struct kmem_cache *cache;
>
>         cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
> -       if (!cache) {
> -               pr_err("Cache allocation failed\n");
> -               return;
> -       }
> -       pr_info("double-free on heap object\n");
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
> +
>         p = kmem_cache_alloc(cache, GFP_KERNEL);
>         if (!p) {
> -               pr_err("Allocation failed\n");
> +               kunit_err(test, "Allocation failed: %s\n", __func__);
>                 kmem_cache_destroy(cache);
>                 return;
>         }
>
>         kmem_cache_free(cache, p);
> -       kmem_cache_free(cache, p);
> +       KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p));
>         kmem_cache_destroy(cache);
>  }
>
> -static noinline void __init kmem_cache_invalid_free(void)
> +static void kmem_cache_invalid_free(struct kunit *test)
>  {
>         char *p;
>         size_t size = 200;
> @@ -607,20 +477,17 @@ static noinline void __init kmem_cache_invalid_free(void)
>
>         cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
>                                   NULL);
> -       if (!cache) {
> -               pr_err("Cache allocation failed\n");
> -               return;
> -       }
> -       pr_info("invalid-free of heap object\n");
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
> +
>         p = kmem_cache_alloc(cache, GFP_KERNEL);
>         if (!p) {
> -               pr_err("Allocation failed\n");
> +               kunit_err(test, "Allocation failed: %s\n", __func__);
>                 kmem_cache_destroy(cache);
>                 return;
>         }
>
>         /* Trigger invalid free, the object doesn't get freed */
> -       kmem_cache_free(cache, p + 1);
> +       KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1));
>
>         /*
>          * Properly free the object to prevent the "Objects remaining in
> @@ -631,45 +498,39 @@ static noinline void __init kmem_cache_invalid_free(void)
>         kmem_cache_destroy(cache);
>  }
>
> -static noinline void __init kasan_memchr(void)
> +static void kasan_memchr(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 24;
>
> -       pr_info("out-of-bounds in memchr\n");
>         ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> -       if (!ptr)
> -               return;
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       memchr(ptr, '1', size + 1);
> +       KUNIT_EXPECT_KASAN_FAIL(test, memchr(ptr, '1', size + 1));
>         kfree(ptr);
>  }
>
> -static noinline void __init kasan_memcmp(void)
> +static void kasan_memcmp(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 24;
>         int arr[9];
>
> -       pr_info("out-of-bounds in memcmp\n");
>         ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> -       if (!ptr)
> -               return;
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
>         memset(arr, 0, sizeof(arr));
> -       memcmp(ptr, arr, size+1);
> +       KUNIT_EXPECT_KASAN_FAIL(test, memcmp(ptr, arr, size+1));
>         kfree(ptr);
>  }
>
> -static noinline void __init kasan_strings(void)
> +static void kasan_strings(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 24;
>
> -       pr_info("use-after-free in strchr\n");
>         ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> -       if (!ptr)
> -               return;
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
>         kfree(ptr);
>
> @@ -680,188 +541,167 @@ static noinline void __init kasan_strings(void)
>          * will likely point to zeroed byte.
>          */
>         ptr += 16;
> -       strchr(ptr, '1');
> +       KUNIT_EXPECT_KASAN_FAIL(test, strchr(ptr, '1'));
>
> -       pr_info("use-after-free in strrchr\n");
> -       strrchr(ptr, '1');
> +       KUNIT_EXPECT_KASAN_FAIL(test, strrchr(ptr, '1'));
>
> -       pr_info("use-after-free in strcmp\n");
> -       strcmp(ptr, "2");
> +       KUNIT_EXPECT_KASAN_FAIL(test, strcmp(ptr, "2"));
>
> -       pr_info("use-after-free in strncmp\n");
> -       strncmp(ptr, "2", 1);
> +       KUNIT_EXPECT_KASAN_FAIL(test, strncmp(ptr, "2", 1));
>
> -       pr_info("use-after-free in strlen\n");
> -       strlen(ptr);
> +       KUNIT_EXPECT_KASAN_FAIL(test, strlen(ptr));
>
> -       pr_info("use-after-free in strnlen\n");
> -       strnlen(ptr, 1);
> +       KUNIT_EXPECT_KASAN_FAIL(test, strnlen(ptr, 1));
>  }
>
> -static noinline void __init kasan_bitops(void)
> +static void kasan_bitops(struct kunit *test)
>  {
>         /*
>          * Allocate 1 more byte, which causes kzalloc to round up to 16-bytes;
>          * this way we do not actually corrupt other memory.
>          */
>         long *bits = kzalloc(sizeof(*bits) + 1, GFP_KERNEL);
> -       if (!bits)
> -               return;
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);
>
>         /*
>          * Below calls try to access bit within allocated memory; however, the
>          * below accesses are still out-of-bounds, since bitops are defined to
>          * operate on the whole long the bit is in.
>          */
> -       pr_info("out-of-bounds in set_bit\n");
> -       set_bit(BITS_PER_LONG, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test, set_bit(BITS_PER_LONG, bits));
>
> -       pr_info("out-of-bounds in __set_bit\n");
> -       __set_bit(BITS_PER_LONG, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test, __set_bit(BITS_PER_LONG, bits));
>
> -       pr_info("out-of-bounds in clear_bit\n");
> -       clear_bit(BITS_PER_LONG, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test, clear_bit(BITS_PER_LONG, bits));
>
> -       pr_info("out-of-bounds in __clear_bit\n");
> -       __clear_bit(BITS_PER_LONG, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit(BITS_PER_LONG, bits));
>
> -       pr_info("out-of-bounds in clear_bit_unlock\n");
> -       clear_bit_unlock(BITS_PER_LONG, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test, clear_bit_unlock(BITS_PER_LONG, bits));
>
> -       pr_info("out-of-bounds in __clear_bit_unlock\n");
> -       __clear_bit_unlock(BITS_PER_LONG, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit_unlock(BITS_PER_LONG, bits));
>
> -       pr_info("out-of-bounds in change_bit\n");
> -       change_bit(BITS_PER_LONG, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test, change_bit(BITS_PER_LONG, bits));
>
> -       pr_info("out-of-bounds in __change_bit\n");
> -       __change_bit(BITS_PER_LONG, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test, __change_bit(BITS_PER_LONG, bits));
>
>         /*
>          * Below calls try to access bit beyond allocated memory.
>          */
> -       pr_info("out-of-bounds in test_and_set_bit\n");
> -       test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test,
> +               test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> -       pr_info("out-of-bounds in __test_and_set_bit\n");
> -       __test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test,
> +               __test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> -       pr_info("out-of-bounds in test_and_set_bit_lock\n");
> -       test_and_set_bit_lock(BITS_PER_LONG + BITS_PER_BYTE, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test,
> +               test_and_set_bit_lock(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> -       pr_info("out-of-bounds in test_and_clear_bit\n");
> -       test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test,
> +               test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> -       pr_info("out-of-bounds in __test_and_clear_bit\n");
> -       __test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test,
> +               __test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> -       pr_info("out-of-bounds in test_and_change_bit\n");
> -       test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test,
> +               test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> -       pr_info("out-of-bounds in __test_and_change_bit\n");
> -       __test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test,
> +               __test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> -       pr_info("out-of-bounds in test_bit\n");
> -       (void)test_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test,
> +               (void)test_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
>  #if defined(clear_bit_unlock_is_negative_byte)
> -       pr_info("out-of-bounds in clear_bit_unlock_is_negative_byte\n");
> -       clear_bit_unlock_is_negative_byte(BITS_PER_LONG + BITS_PER_BYTE, bits);
> +       KUNIT_EXPECT_KASAN_FAIL(test,
> +               clear_bit_unlock_is_negative_byte(BITS_PER_LONG + BITS_PER_BYTE,
> +                                               bits));
>  #endif
>         kfree(bits);
>  }
>
> -static noinline void __init kmalloc_double_kzfree(void)
> +static void kmalloc_double_kzfree(struct kunit *test)
>  {
>         char *ptr;
>         size_t size = 16;
>
> -       pr_info("double-free (kzfree)\n");
>         ptr = kmalloc(size, GFP_KERNEL);
> -       if (!ptr) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
>         kzfree(ptr);
> -       kzfree(ptr);
> +       KUNIT_EXPECT_KASAN_FAIL(test, kzfree(ptr));
>  }
>
>  #ifdef CONFIG_KASAN_VMALLOC
> -static noinline void __init vmalloc_oob(void)
> +static void vmalloc_oob(struct kunit *test)
>  {
>         void *area;
>
> -       pr_info("vmalloc out-of-bounds\n");
> -
>         /*
>          * We have to be careful not to hit the guard page.
>          * The MMU will catch that and crash us.
>          */
>         area = vmalloc(3000);
> -       if (!area) {
> -               pr_err("Allocation failed\n");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, area);
>
> -       ((volatile char *)area)[3100];
> +       KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)area)[3100]);
>         vfree(area);
>  }
>  #else
> -static void __init vmalloc_oob(void) {}
> +static void vmalloc_oob(struct kunit *test) {}
>  #endif
>
> -static int __init kmalloc_tests_init(void)
> -{
> -       /*
> -        * Temporarily enable multi-shot mode. Otherwise, we'd only get a
> -        * report for the first case.
> -        */
> -       bool multishot = kasan_save_enable_multi_shot();
> -
> -       kmalloc_oob_right();
> -       kmalloc_oob_left();
> -       kmalloc_node_oob_right();
> +static struct kunit_case kasan_kunit_test_cases[] = {
> +       KUNIT_CASE(kmalloc_oob_right),
> +       KUNIT_CASE(kmalloc_oob_left),
> +       KUNIT_CASE(kmalloc_node_oob_right),
>  #ifdef CONFIG_SLUB
> -       kmalloc_pagealloc_oob_right();
> -       kmalloc_pagealloc_uaf();
> -       kmalloc_pagealloc_invalid_free();
> -#endif
> -       kmalloc_large_oob_right();
> -       kmalloc_oob_krealloc_more();
> -       kmalloc_oob_krealloc_less();
> -       kmalloc_oob_16();
> -       kmalloc_oob_in_memset();
> -       kmalloc_oob_memset_2();
> -       kmalloc_oob_memset_4();
> -       kmalloc_oob_memset_8();
> -       kmalloc_oob_memset_16();
> -       kmalloc_uaf();
> -       kmalloc_uaf_memset();
> -       kmalloc_uaf2();
> -       kfree_via_page();
> -       kfree_via_phys();
> -       kmem_cache_oob();
> -       memcg_accounted_kmem_cache();
> -       kasan_stack_oob();
> -       kasan_global_oob();
> -       kasan_alloca_oob_left();
> -       kasan_alloca_oob_right();
> -       ksize_unpoisons_memory();
> -       copy_user_test();
> -       kmem_cache_double_free();
> -       kmem_cache_invalid_free();
> -       kasan_memchr();
> -       kasan_memcmp();
> -       kasan_strings();
> -       kasan_bitops();
> -       kmalloc_double_kzfree();
> -       vmalloc_oob();
> -
> -       kasan_restore_multi_shot(multishot);
> -
> -       return -EAGAIN;
> -}
> +       KUNIT_CASE(kmalloc_pagealloc_oob_right),
> +       KUNIT_CASE(kmalloc_pagealloc_uaf),
> +       KUNIT_CASE(kmalloc_pagealloc_invalid_free),
> +#endif /* CONFIG_SLUB */
> +       KUNIT_CASE(kmalloc_large_oob_right),
> +       KUNIT_CASE(kmalloc_oob_krealloc_more),
> +       KUNIT_CASE(kmalloc_oob_krealloc_less),
> +       KUNIT_CASE(kmalloc_oob_16),
> +       KUNIT_CASE(kmalloc_oob_in_memset),
> +       KUNIT_CASE(kmalloc_oob_memset_2),
> +       KUNIT_CASE(kmalloc_oob_memset_4),
> +       KUNIT_CASE(kmalloc_oob_memset_8),
> +       KUNIT_CASE(kmalloc_oob_memset_16),
> +       KUNIT_CASE(kmalloc_uaf),
> +       KUNIT_CASE(kmalloc_uaf_memset),
> +       KUNIT_CASE(kmalloc_uaf2),
> +       KUNIT_CASE(kfree_via_page),
> +       KUNIT_CASE(kfree_via_phys),
> +       KUNIT_CASE(kmem_cache_oob),
> +       KUNIT_CASE(memcg_accounted_kmem_cache),
> +       KUNIT_CASE(kasan_global_oob),
> +#if (IS_ENABLED(CONFIG_KASAN_STACK))
> +       KUNIT_CASE(kasan_stack_oob), // need stack protection
> +       KUNIT_CASE(kasan_alloca_oob_left),
> +       KUNIT_CASE(kasan_alloca_oob_right),
> +#endif /*CONFIG_KASAN_STACK*/
> +       KUNIT_CASE(ksize_unpoisons_memory),
> +       KUNIT_CASE(kmem_cache_double_free),
> +       KUNIT_CASE(kmem_cache_invalid_free),
> +       KUNIT_CASE(kasan_memchr),
> +       KUNIT_CASE(kasan_memcmp),
> +       KUNIT_CASE(kasan_strings),
> +       KUNIT_CASE(kasan_bitops),
> +       KUNIT_CASE(kmalloc_double_kzfree),
> +       KUNIT_CASE(vmalloc_oob),
> +       {}
> +};
> +
> +static struct kunit_suite kasan_kunit_test_suite = {
> +       .name = "kasan_kunit_test",
> +       .init = kasan_multi_shot_init,
> +       .test_cases = kasan_kunit_test_cases,
> +       .exit = kasan_multi_shot_exit,
> +};
> +
> +kunit_test_suite(kasan_kunit_test_suite);
> +
> +#endif /* BUILTIN(CONFIG_KUNIT) */
>
> -module_init(kmalloc_tests_init);
>  MODULE_LICENSE("GPL");
> diff --git a/lib/test_kasan_copy_user.c b/lib/test_kasan_copy_user.c
> new file mode 100644
> index 000000000000..9523cbc332ec
> --- /dev/null
> +++ b/lib/test_kasan_copy_user.c
> @@ -0,0 +1,75 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + *
> + * Copyright (c) 2014 Samsung Electronics Co., Ltd.
> + * Author: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
> + */
> +
> +#define pr_fmt(fmt) "kasan test: %s " fmt, __func__
> +
> +#include <linux/mman.h>
> +#include <linux/module.h>
> +#include <linux/printk.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +
> +static noinline void __init copy_user_test(void)
> +{
> +       char *kmem;
> +       char __user *usermem;
> +       size_t size = 10;
> +       int unused;
> +
> +       kmem = kmalloc(size, GFP_KERNEL);
> +       if (!kmem)
> +               return;
> +
> +       usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
> +                           PROT_READ | PROT_WRITE | PROT_EXEC,
> +                           MAP_ANONYMOUS | MAP_PRIVATE, 0);
> +       if (IS_ERR(usermem)) {
> +               pr_err("Failed to allocate user memory\n");
> +               kfree(kmem);
> +               return;
> +       }
> +
> +       pr_info("out-of-bounds in copy_from_user()\n");
> +       unused = copy_from_user(kmem, usermem, size + 1);
> +
> +       pr_info("out-of-bounds in copy_to_user()\n");
> +       unused = copy_to_user(usermem, kmem, size + 1);
> +
> +       pr_info("out-of-bounds in __copy_from_user()\n");
> +       unused = __copy_from_user(kmem, usermem, size + 1);
> +
> +       pr_info("out-of-bounds in __copy_to_user()\n");
> +       unused = __copy_to_user(usermem, kmem, size + 1);
> +
> +       pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
> +       unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
> +
> +       pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
> +       unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
> +
> +       pr_info("out-of-bounds in strncpy_from_user()\n");
> +       unused = strncpy_from_user(kmem, usermem, size + 1);
> +
> +       vm_munmap((unsigned long)usermem, PAGE_SIZE);
> +       kfree(kmem);
> +}
> +
> +static int __init copy_user_tests_init(void)
> +{
> +       /*
> +        * Temporarily enable multi-shot mode. Otherwise, we'd only get a
> +        * report for the first case.
> +        */
> +       bool multishot = kasan_save_enable_multi_shot();
> +
> +       copy_user_test();
> +       kasan_restore_multi_shot(multishot);
> +       return -EAGAIN;
> +}
> +
> +module_init(copy_user_tests_init);
> +MODULE_LICENSE("GPL");
> --
> 2.25.1.696.g5e7596f4ac-goog
>
> --
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