Merge tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull overflow updates from Kees Cook:
 "This adds the new overflow checking helpers and adds them to the
  2-factor argument allocators. And this adds the saturating size
  helpers and does a treewide replacement for the struct_size() usage.
  Additionally this adds the overflow testing modules to make sure
  everything works.

  I'm still working on the treewide replacements for allocators with
  "simple" multiplied arguments:

     *alloc(a * b, ...) -> *alloc_array(a, b, ...)

  and

     *zalloc(a * b, ...) -> *calloc(a, b, ...)

  as well as the more complex cases, but that's separable from this
  portion of the series. I expect to have the rest sent before -rc1
  closes; there are a lot of messy cases to clean up.

  Summary:

   - Introduce arithmetic overflow test helper functions (Rasmus)

   - Use overflow helpers in 2-factor allocators (Kees, Rasmus)

   - Introduce overflow test module (Rasmus, Kees)

   - Introduce saturating size helper functions (Matthew, Kees)

   - Treewide use of struct_size() for allocators (Kees)"

* tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  treewide: Use struct_size() for devm_kmalloc() and friends
  treewide: Use struct_size() for vmalloc()-family
  treewide: Use struct_size() for kmalloc()-family
  device: Use overflow helpers for devm_kmalloc()
  mm: Use overflow helpers in kvmalloc()
  mm: Use overflow helpers in kmalloc_array*()
  test_overflow: Add memory allocation overflow tests
  overflow.h: Add allocation size calculation helpers
  test_overflow: Report test failures
  test_overflow: macrofy some more, do more tests for free
  lib: add runtime test of check_*_overflow functions
  compiler.h: enable builtin overflow checkers and add fallback code

3 files changed, 421 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 76555479ae36..eb885942eb0f 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1802,6 +1802,9 @@ config TEST_BITMAP
 config TEST_UUID
 	tristate "Test functions located in the uuid module at runtime"
 
+config TEST_OVERFLOW
+	tristate "Test check_*_overflow() functions at runtime"
+
 config TEST_RHASHTABLE
 	tristate "Perform selftest on resizable hash table"
 	default n
diff --git a/lib/Makefile b/lib/Makefile
index 9f18c8152281..84c6dcb31fbb 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -60,6 +60,7 @@ UBSAN_SANITIZE_test_ubsan.o := y
 obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
 obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o
 obj-$(CONFIG_TEST_LKM) += test_module.o
+obj-$(CONFIG_TEST_OVERFLOW) += test_overflow.o
 obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
 obj-$(CONFIG_TEST_SORT) += test_sort.o
 obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
diff --git a/lib/test_overflow.c b/lib/test_overflow.c
new file mode 100644
index 000000000000..aecbbb217305
--- /dev/null
+++ b/lib/test_overflow.c
@@ -0,0 +1,417 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Test cases for arithmetic overflow checks.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/overflow.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+
+#define DEFINE_TEST_ARRAY(t)			\
+	static const struct test_ ## t {	\
+		t a, b;				\
+		t sum, diff, prod;		\
+		bool s_of, d_of, p_of;		\
+	} t ## _tests[] __initconst
+
+DEFINE_TEST_ARRAY(u8) = {
+	{0, 0, 0, 0, 0, false, false, false},
+	{1, 1, 2, 0, 1, false, false, false},
+	{0, 1, 1, U8_MAX, 0, false, true, false},
+	{1, 0, 1, 1, 0, false, false, false},
+	{0, U8_MAX, U8_MAX, 1, 0, false, true, false},
+	{U8_MAX, 0, U8_MAX, U8_MAX, 0, false, false, false},
+	{1, U8_MAX, 0, 2, U8_MAX, true, true, false},
+	{U8_MAX, 1, 0, U8_MAX-1, U8_MAX, true, false, false},
+	{U8_MAX, U8_MAX, U8_MAX-1, 0, 1, true, false, true},
+
+	{U8_MAX, U8_MAX-1, U8_MAX-2, 1, 2, true, false, true},
+	{U8_MAX-1, U8_MAX, U8_MAX-2, U8_MAX, 2, true, true, true},
+
+	{1U << 3, 1U << 3, 1U << 4, 0, 1U << 6, false, false, false},
+	{1U << 4, 1U << 4, 1U << 5, 0, 0, false, false, true},
+	{1U << 4, 1U << 3, 3*(1U << 3), 1U << 3, 1U << 7, false, false, false},
+	{1U << 7, 1U << 7, 0, 0, 0, true, false, true},
+
+	{48, 32, 80, 16, 0, false, false, true},
+	{128, 128, 0, 0, 0, true, false, true},
+	{123, 234, 101, 145, 110, true, true, true},
+};
+DEFINE_TEST_ARRAY(u16) = {
+	{0, 0, 0, 0, 0, false, false, false},
+	{1, 1, 2, 0, 1, false, false, false},
+	{0, 1, 1, U16_MAX, 0, false, true, false},
+	{1, 0, 1, 1, 0, false, false, false},
+	{0, U16_MAX, U16_MAX, 1, 0, false, true, false},
+	{U16_MAX, 0, U16_MAX, U16_MAX, 0, false, false, false},
+	{1, U16_MAX, 0, 2, U16_MAX, true, true, false},
+	{U16_MAX, 1, 0, U16_MAX-1, U16_MAX, true, false, false},
+	{U16_MAX, U16_MAX, U16_MAX-1, 0, 1, true, false, true},
+
+	{U16_MAX, U16_MAX-1, U16_MAX-2, 1, 2, true, false, true},
+	{U16_MAX-1, U16_MAX, U16_MAX-2, U16_MAX, 2, true, true, true},
+
+	{1U << 7, 1U << 7, 1U << 8, 0, 1U << 14, false, false, false},
+	{1U << 8, 1U << 8, 1U << 9, 0, 0, false, false, true},
+	{1U << 8, 1U << 7, 3*(1U << 7), 1U << 7, 1U << 15, false, false, false},
+	{1U << 15, 1U << 15, 0, 0, 0, true, false, true},
+
+	{123, 234, 357, 65425, 28782, false, true, false},
+	{1234, 2345, 3579, 64425, 10146, false, true, true},
+};
+DEFINE_TEST_ARRAY(u32) = {
+	{0, 0, 0, 0, 0, false, false, false},
+	{1, 1, 2, 0, 1, false, false, false},
+	{0, 1, 1, U32_MAX, 0, false, true, false},
+	{1, 0, 1, 1, 0, false, false, false},
+	{0, U32_MAX, U32_MAX, 1, 0, false, true, false},
+	{U32_MAX, 0, U32_MAX, U32_MAX, 0, false, false, false},
+	{1, U32_MAX, 0, 2, U32_MAX, true, true, false},
+	{U32_MAX, 1, 0, U32_MAX-1, U32_MAX, true, false, false},
+	{U32_MAX, U32_MAX, U32_MAX-1, 0, 1, true, false, true},
+
+	{U32_MAX, U32_MAX-1, U32_MAX-2, 1, 2, true, false, true},
+	{U32_MAX-1, U32_MAX, U32_MAX-2, U32_MAX, 2, true, true, true},
+
+	{1U << 15, 1U << 15, 1U << 16, 0, 1U << 30, false, false, false},
+	{1U << 16, 1U << 16, 1U << 17, 0, 0, false, false, true},
+	{1U << 16, 1U << 15, 3*(1U << 15), 1U << 15, 1U << 31, false, false, false},
+	{1U << 31, 1U << 31, 0, 0, 0, true, false, true},
+
+	{-2U, 1U, -1U, -3U, -2U, false, false, false},
+	{-4U, 5U, 1U, -9U, -20U, true, false, true},
+};
+
+DEFINE_TEST_ARRAY(u64) = {
+	{0, 0, 0, 0, 0, false, false, false},
+	{1, 1, 2, 0, 1, false, false, false},
+	{0, 1, 1, U64_MAX, 0, false, true, false},
+	{1, 0, 1, 1, 0, false, false, false},
+	{0, U64_MAX, U64_MAX, 1, 0, false, true, false},
+	{U64_MAX, 0, U64_MAX, U64_MAX, 0, false, false, false},
+	{1, U64_MAX, 0, 2, U64_MAX, true, true, false},
+	{U64_MAX, 1, 0, U64_MAX-1, U64_MAX, true, false, false},
+	{U64_MAX, U64_MAX, U64_MAX-1, 0, 1, true, false, true},
+
+	{U64_MAX, U64_MAX-1, U64_MAX-2, 1, 2, true, false, true},
+	{U64_MAX-1, U64_MAX, U64_MAX-2, U64_MAX, 2, true, true, true},
+
+	{1ULL << 31, 1ULL << 31, 1ULL << 32, 0, 1ULL << 62, false, false, false},
+	{1ULL << 32, 1ULL << 32, 1ULL << 33, 0, 0, false, false, true},
+	{1ULL << 32, 1ULL << 31, 3*(1ULL << 31), 1ULL << 31, 1ULL << 63, false, false, false},
+	{1ULL << 63, 1ULL << 63, 0, 0, 0, true, false, true},
+	{1000000000ULL /* 10^9 */, 10000000000ULL /* 10^10 */,
+	 11000000000ULL, 18446744064709551616ULL, 10000000000000000000ULL,
+	 false, true, false},
+	{-15ULL, 10ULL, -5ULL, -25ULL, -150ULL, false, false, true},
+};
+
+DEFINE_TEST_ARRAY(s8) = {
+	{0, 0, 0, 0, 0, false, false, false},
+
+	{0, S8_MAX, S8_MAX, -S8_MAX, 0, false, false, false},
+	{S8_MAX, 0, S8_MAX, S8_MAX, 0, false, false, false},
+	{0, S8_MIN, S8_MIN, S8_MIN, 0, false, true, false},
+	{S8_MIN, 0, S8_MIN, S8_MIN, 0, false, false, false},
+
+	{-1, S8_MIN, S8_MAX, S8_MAX, S8_MIN, true, false, true},
+	{S8_MIN, -1, S8_MAX, -S8_MAX, S8_MIN, true, false, true},
+	{-1, S8_MAX, S8_MAX-1, S8_MIN, -S8_MAX, false, false, false},
+	{S8_MAX, -1, S8_MAX-1, S8_MIN, -S8_MAX, false, true, false},
+	{-1, -S8_MAX, S8_MIN, S8_MAX-1, S8_MAX, false, false, false},
+	{-S8_MAX, -1, S8_MIN, S8_MIN+2, S8_MAX, false, false, false},
+
+	{1, S8_MIN, -S8_MAX, -S8_MAX, S8_MIN, false, true, false},
+	{S8_MIN, 1, -S8_MAX, S8_MAX, S8_MIN, false, true, false},
+	{1, S8_MAX, S8_MIN, S8_MIN+2, S8_MAX, true, false, false},
+	{S8_MAX, 1, S8_MIN, S8_MAX-1, S8_MAX, true, false, false},
+
+	{S8_MIN, S8_MIN, 0, 0, 0, true, false, true},
+	{S8_MAX, S8_MAX, -2, 0, 1, true, false, true},
+
+	{-4, -32, -36, 28, -128, false, false, true},
+	{-4, 32, 28, -36, -128, false, false, false},
+};
+
+DEFINE_TEST_ARRAY(s16) = {
+	{0, 0, 0, 0, 0, false, false, false},
+
+	{0, S16_MAX, S16_MAX, -S16_MAX, 0, false, false, false},
+	{S16_MAX, 0, S16_MAX, S16_MAX, 0, false, false, false},
+	{0, S16_MIN, S16_MIN, S16_MIN, 0, false, true, false},
+	{S16_MIN, 0, S16_MIN, S16_MIN, 0, false, false, false},
+
+	{-1, S16_MIN, S16_MAX, S16_MAX, S16_MIN, true, false, true},
+	{S16_MIN, -1, S16_MAX, -S16_MAX, S16_MIN, true, false, true},
+	{-1, S16_MAX, S16_MAX-1, S16_MIN, -S16_MAX, false, false, false},
+	{S16_MAX, -1, S16_MAX-1, S16_MIN, -S16_MAX, false, true, false},
+	{-1, -S16_MAX, S16_MIN, S16_MAX-1, S16_MAX, false, false, false},
+	{-S16_MAX, -1, S16_MIN, S16_MIN+2, S16_MAX, false, false, false},
+
+	{1, S16_MIN, -S16_MAX, -S16_MAX, S16_MIN, false, true, false},
+	{S16_MIN, 1, -S16_MAX, S16_MAX, S16_MIN, false, true, false},
+	{1, S16_MAX, S16_MIN, S16_MIN+2, S16_MAX, true, false, false},
+	{S16_MAX, 1, S16_MIN, S16_MAX-1, S16_MAX, true, false, false},
+
+	{S16_MIN, S16_MIN, 0, 0, 0, true, false, true},
+	{S16_MAX, S16_MAX, -2, 0, 1, true, false, true},
+};
+DEFINE_TEST_ARRAY(s32) = {
+	{0, 0, 0, 0, 0, false, false, false},
+
+	{0, S32_MAX, S32_MAX, -S32_MAX, 0, false, false, false},
+	{S32_MAX, 0, S32_MAX, S32_MAX, 0, false, false, false},
+	{0, S32_MIN, S32_MIN, S32_MIN, 0, false, true, false},
+	{S32_MIN, 0, S32_MIN, S32_MIN, 0, false, false, false},
+
+	{-1, S32_MIN, S32_MAX, S32_MAX, S32_MIN, true, false, true},
+	{S32_MIN, -1, S32_MAX, -S32_MAX, S32_MIN, true, false, true},
+	{-1, S32_MAX, S32_MAX-1, S32_MIN, -S32_MAX, false, false, false},
+	{S32_MAX, -1, S32_MAX-1, S32_MIN, -S32_MAX, false, true, false},
+	{-1, -S32_MAX, S32_MIN, S32_MAX-1, S32_MAX, false, false, false},
+	{-S32_MAX, -1, S32_MIN, S32_MIN+2, S32_MAX, false, false, false},
+
+	{1, S32_MIN, -S32_MAX, -S32_MAX, S32_MIN, false, true, false},
+	{S32_MIN, 1, -S32_MAX, S32_MAX, S32_MIN, false, true, false},
+	{1, S32_MAX, S32_MIN, S32_MIN+2, S32_MAX, true, false, false},
+	{S32_MAX, 1, S32_MIN, S32_MAX-1, S32_MAX, true, false, false},
+
+	{S32_MIN, S32_MIN, 0, 0, 0, true, false, true},
+	{S32_MAX, S32_MAX, -2, 0, 1, true, false, true},
+};
+DEFINE_TEST_ARRAY(s64) = {
+	{0, 0, 0, 0, 0, false, false, false},
+
+	{0, S64_MAX, S64_MAX, -S64_MAX, 0, false, false, false},
+	{S64_MAX, 0, S64_MAX, S64_MAX, 0, false, false, false},
+	{0, S64_MIN, S64_MIN, S64_MIN, 0, false, true, false},
+	{S64_MIN, 0, S64_MIN, S64_MIN, 0, false, false, false},
+
+	{-1, S64_MIN, S64_MAX, S64_MAX, S64_MIN, true, false, true},
+	{S64_MIN, -1, S64_MAX, -S64_MAX, S64_MIN, true, false, true},
+	{-1, S64_MAX, S64_MAX-1, S64_MIN, -S64_MAX, false, false, false},
+	{S64_MAX, -1, S64_MAX-1, S64_MIN, -S64_MAX, false, true, false},
+	{-1, -S64_MAX, S64_MIN, S64_MAX-1, S64_MAX, false, false, false},
+	{-S64_MAX, -1, S64_MIN, S64_MIN+2, S64_MAX, false, false, false},
+
+	{1, S64_MIN, -S64_MAX, -S64_MAX, S64_MIN, false, true, false},
+	{S64_MIN, 1, -S64_MAX, S64_MAX, S64_MIN, false, true, false},
+	{1, S64_MAX, S64_MIN, S64_MIN+2, S64_MAX, true, false, false},
+	{S64_MAX, 1, S64_MIN, S64_MAX-1, S64_MAX, true, false, false},
+
+	{S64_MIN, S64_MIN, 0, 0, 0, true, false, true},
+	{S64_MAX, S64_MAX, -2, 0, 1, true, false, true},
+
+	{-1, -1, -2, 0, 1, false, false, false},
+	{-1, -128, -129, 127, 128, false, false, false},
+	{-128, -1, -129, -127, 128, false, false, false},
+	{0, -S64_MAX, -S64_MAX, S64_MAX, 0, false, false, false},
+};
+
+#define check_one_op(t, fmt, op, sym, a, b, r, of) do {		\
+	t _r;							\
+	bool _of;						\
+								\
+	_of = check_ ## op ## _overflow(a, b, &_r);		\
+	if (_of != of) {					\
+		pr_warn("expected "fmt" "sym" "fmt		\
+			" to%s overflow (type %s)\n",		\
+			a, b, of ? "" : " not", #t);		\
+		err = 1;					\
+	}							\
+	if (_r != r) {						\
+		pr_warn("expected "fmt" "sym" "fmt" == "	\
+			fmt", got "fmt" (type %s)\n",		\
+			a, b, r, _r, #t);			\
+		err = 1;					\
+	}							\
+} while (0)
+
+#define DEFINE_TEST_FUNC(t, fmt)					\
+static int __init do_test_ ## t(const struct test_ ## t *p)		\
+{							   		\
+	int err = 0;							\
+									\
+	check_one_op(t, fmt, add, "+", p->a, p->b, p->sum, p->s_of);	\
+	check_one_op(t, fmt, add, "+", p->b, p->a, p->sum, p->s_of);	\
+	check_one_op(t, fmt, sub, "-", p->a, p->b, p->diff, p->d_of);	\
+	check_one_op(t, fmt, mul, "*", p->a, p->b, p->prod, p->p_of);	\
+	check_one_op(t, fmt, mul, "*", p->b, p->a, p->prod, p->p_of);	\
+									\
+	return err;							\
+}									\
+									\
+static int __init test_ ## t ## _overflow(void) {			\
+	int err = 0;							\
+	unsigned i;							\
+									\
+	pr_info("%-3s: %zu tests\n", #t, ARRAY_SIZE(t ## _tests));	\
+	for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i)			\
+		err |= do_test_ ## t(&t ## _tests[i]);			\
+	return err;							\
+}
+
+DEFINE_TEST_FUNC(u8, "%d");
+DEFINE_TEST_FUNC(s8, "%d");
+DEFINE_TEST_FUNC(u16, "%d");
+DEFINE_TEST_FUNC(s16, "%d");
+DEFINE_TEST_FUNC(u32, "%u");
+DEFINE_TEST_FUNC(s32, "%d");
+#if BITS_PER_LONG == 64
+DEFINE_TEST_FUNC(u64, "%llu");
+DEFINE_TEST_FUNC(s64, "%lld");
+#endif
+
+static int __init test_overflow_calculation(void)
+{
+	int err = 0;
+
+	err |= test_u8_overflow();
+	err |= test_s8_overflow();
+	err |= test_u16_overflow();
+	err |= test_s16_overflow();
+	err |= test_u32_overflow();
+	err |= test_s32_overflow();
+#if BITS_PER_LONG == 64
+	err |= test_u64_overflow();
+	err |= test_s64_overflow();
+#endif
+
+	return err;
+}
+
+/*
+ * Deal with the various forms of allocator arguments. See comments above
+ * the DEFINE_TEST_ALLOC() instances for mapping of the "bits".
+ */
+#define alloc010(alloc, arg, sz) alloc(sz, GFP_KERNEL)
+#define alloc011(alloc, arg, sz) alloc(sz, GFP_KERNEL, NUMA_NO_NODE)
+#define alloc000(alloc, arg, sz) alloc(sz)
+#define alloc001(alloc, arg, sz) alloc(sz, NUMA_NO_NODE)
+#define alloc110(alloc, arg, sz) alloc(arg, sz, GFP_KERNEL)
+#define free0(free, arg, ptr)	 free(ptr)
+#define free1(free, arg, ptr)	 free(arg, ptr)
+
+/* Wrap around to 8K */
+#define TEST_SIZE		(9 << PAGE_SHIFT)
+
+#define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\
+static int __init test_ ## func (void *arg)				\
+{									\
+	volatile size_t a = TEST_SIZE;					\
+	volatile size_t b = (SIZE_MAX / TEST_SIZE) + 1;			\
+	void *ptr;							\
+									\
+	/* Tiny allocation test. */					\
+	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, 1);\
+	if (!ptr) {							\
+		pr_warn(#func " failed regular allocation?!\n");	\
+		return 1;						\
+	}								\
+	free ## want_arg (free_func, arg, ptr);				\
+									\
+	/* Wrapped allocation test. */					\
+	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,	\
+							  a * b);	\
+	if (!ptr) {							\
+		pr_warn(#func " unexpectedly failed bad wrapping?!\n");	\
+		return 1;						\
+	}								\
+	free ## want_arg (free_func, arg, ptr);				\
+									\
+	/* Saturated allocation test. */				\
+	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,	\
+						   array_size(a, b));	\
+	if (ptr) {							\
+		pr_warn(#func " missed saturation!\n");			\
+		free ## want_arg (free_func, arg, ptr);			\
+		return 1;						\
+	}								\
+	pr_info(#func " detected saturation\n");			\
+	return 0;							\
+}
+
+/*
+ * Allocator uses a trailing node argument --------+  (e.g. kmalloc_node())
+ * Allocator uses the gfp_t argument -----------+  |  (e.g. kmalloc())
+ * Allocator uses a special leading argument +  |  |  (e.g. devm_kmalloc())
+ *                                           |  |  |
+ */
+DEFINE_TEST_ALLOC(kmalloc,	 kfree,	     0, 1, 0);
+DEFINE_TEST_ALLOC(kmalloc_node,	 kfree,	     0, 1, 1);
+DEFINE_TEST_ALLOC(kzalloc,	 kfree,	     0, 1, 0);
+DEFINE_TEST_ALLOC(kzalloc_node,  kfree,	     0, 1, 1);
+DEFINE_TEST_ALLOC(vmalloc,	 vfree,	     0, 0, 0);
+DEFINE_TEST_ALLOC(vmalloc_node,  vfree,	     0, 0, 1);
+DEFINE_TEST_ALLOC(vzalloc,	 vfree,	     0, 0, 0);
+DEFINE_TEST_ALLOC(vzalloc_node,  vfree,	     0, 0, 1);
+DEFINE_TEST_ALLOC(kvmalloc,	 kvfree,     0, 1, 0);
+DEFINE_TEST_ALLOC(kvmalloc_node, kvfree,     0, 1, 1);
+DEFINE_TEST_ALLOC(kvzalloc,	 kvfree,     0, 1, 0);
+DEFINE_TEST_ALLOC(kvzalloc_node, kvfree,     0, 1, 1);
+DEFINE_TEST_ALLOC(devm_kmalloc,  devm_kfree, 1, 1, 0);
+DEFINE_TEST_ALLOC(devm_kzalloc,  devm_kfree, 1, 1, 0);
+
+static int __init test_overflow_allocation(void)
+{
+	const char device_name[] = "overflow-test";
+	struct device *dev;
+	int err = 0;
+
+	/* Create dummy device for devm_kmalloc()-family tests. */
+	dev = root_device_register(device_name);
+	if (!dev) {
+		pr_warn("Cannot register test device\n");
+		return 1;
+	}
+
+	err |= test_kmalloc(NULL);
+	err |= test_kmalloc_node(NULL);
+	err |= test_kzalloc(NULL);
+	err |= test_kzalloc_node(NULL);
+	err |= test_kvmalloc(NULL);
+	err |= test_kvmalloc_node(NULL);
+	err |= test_kvzalloc(NULL);
+	err |= test_kvzalloc_node(NULL);
+	err |= test_vmalloc(NULL);
+	err |= test_vmalloc_node(NULL);
+	err |= test_vzalloc(NULL);
+	err |= test_vzalloc_node(NULL);
+	err |= test_devm_kmalloc(dev);
+	err |= test_devm_kzalloc(dev);
+
+	device_unregister(dev);
+
+	return err;
+}
+
+static int __init test_module_init(void)
+{
+	int err = 0;
+
+	err |= test_overflow_calculation();
+	err |= test_overflow_allocation();
+
+	if (err) {
+		pr_warn("FAIL!\n");
+		err = -EINVAL;
+	} else {
+		pr_info("all tests passed\n");
+	}
+
+	return err;
+}
+
+static void __exit test_module_exit(void)
+{ }
+
+module_init(test_module_init);
+module_exit(test_module_exit);
+MODULE_LICENSE("Dual MIT/GPL");