Re: [PATCH v2] overflow: Introduce overflows_type() and castable_to_type()

Gwan-gyeong Mun
2022-09-27T08:30:24Z

Hi Kees,
Thanks for update it to v2.
I'm leaving a comment because the patches this patch depends on aren't
part of one of the series.
If this patch alone is forwarded to the intel-gfx mailing, it will
report a build issue.
If this patch is only for review, please ignore my comments.

In order to remove overflows_type() from the i915 gpu driver and add the
updated overflows_type() to overflows.h, the following two patches must
be applied first because of dependencies.

"overflow: Allow mixed type arguments" [1][2]
"overflow: Introduce check_assign() and check_assign_user_ptr()" [2]

https://www.spinics.net/lists/kernel/msg4495457.html [1]
https://patchwork.freedesktop.org/patch/504792/?series=109063&rev=1 [2]
https://patchwork.freedesktop.org/patch/504791/?series=109063&rev=1 [3]

br,
G.G

On 9/26/22 10:11 PM, Kees Cook wrote:
> Implement a robust overflows_type() macro to test if a variable or
> constant value would overflow another variable or type. This can be
> used as a constant expression for static_assert() (which requires a
> constant expression[1][2]) when used on constant values. This must be
> constructed manually, since __builtin_add_overflow() does not produce
> a constant expression[3].
>
> Additionally adds castable_to_type(), similar to __same_type(), but for
> checking if a constant value would overflow if cast to a given type.
>
> Add unit tests for overflows_type(), __same_type(), and castable_to_type()
> to the existing KUnit "overflow" test.
>
> [1] https://en.cppreference.com/w/c/language/_Static_assert
> [2] C11 standard (ISO/IEC 9899:2011): 6.7.10 Static assertions
> [3] https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html
> 6.56 Built-in Functions to Perform Arithmetic with Overflow Checking
> Built-in Function: bool __builtin_add_overflow (type1 a, type2 b,
>
> Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
> Cc: Nathan Chancellor <nathan@kernel.org>
> Cc: Nick Desaulniers <ndesaulniers@google.com>
> Cc: Tom Rix <trix@redhat.com>
> Cc: Daniel Latypov <dlatypov@google.com>
> Cc: Vitor Massaru Iha <vitor@massaru.org>
> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> Cc: linux-hardening@vger.kernel.org
> Cc: llvm@lists.linux.dev
> Co-developed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> v2:
> - fix comment typo
> - wrap clang pragma to avoid GCC warnings
> - style nit cleanups
> - rename __castable_to_type() to castable_to_type()
> - remove prior overflows_type() definition
> v1: https://lore.kernel.org/lkml/20220926003743.409911-1-keescook@chromium.org
> ---
> drivers/gpu/drm/i915/i915_utils.h | 4 -
> include/linux/compiler.h | 1 +
> include/linux/overflow.h | 48 ++++
> lib/overflow_kunit.c | 388 +++++++++++++++++++++++++++++-
> 4 files changed, 436 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h
> index c10d68cdc3ca..d14b7faee054 100644
> --- a/drivers/gpu/drm/i915/i915_utils.h
> +++ b/drivers/gpu/drm/i915/i915_utils.h
> @@ -111,10 +111,6 @@ bool i915_error_injected(void);
> #define range_overflows_end_t(type, start, size, max) \
> range_overflows_end((type)(start), (type)(size), (type)(max))
>
> -/* Note we don't consider signbits :| */
> -#define overflows_type(x, T) \
> - (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T))
> -
> #define ptr_mask_bits(ptr, n) ({ \
> unsigned long __v = (unsigned long)(ptr); \
> (typeof(ptr))(__v & -BIT(n)); \
> diff --git a/include/linux/compiler.h b/include/linux/compiler.h
> index 7713d7bcdaea..c631107e93b1 100644
> --- a/include/linux/compiler.h
> +++ b/include/linux/compiler.h
> @@ -244,6 +244,7 @@ static inline void *offset_to_ptr(const int *off)
> * bool and also pointer types.
> */
> #define is_signed_type(type) (((type)(-1)) < (__force type)1)
> +#define is_unsigned_type(type) (!is_signed_type(type))
>
> /*
> * This is needed in functions which generate the stack canary, see
> diff --git a/include/linux/overflow.h b/include/linux/overflow.h
> index 19dfdd74835e..58eb34aa2af9 100644
> --- a/include/linux/overflow.h
> +++ b/include/linux/overflow.h
> @@ -127,6 +127,54 @@ static inline bool __must_check __must_check_overflow(bool overflow)
> (*_d >> _to_shift) != _a); \
> }))
>
> +#define __overflows_type_constexpr(x, T) ( \
> + is_unsigned_type(typeof(x)) ? \
> + (x) > type_max(typeof(T)) ? 1 : 0 \
> + : is_unsigned_type(typeof(T)) ? \
> + (x) < 0 || (x) > type_max(typeof(T)) ? 1 : 0 \
> + : (x) < type_min(typeof(T)) || \
> + (x) > type_max(typeof(T)) ? 1 : 0)
> +
> +#define __overflows_type(x, T) ({ \
> + typeof(T) v = 0; \
> + check_add_overflow((x), v, &v); \
> +})
> +
> +/**
> + * overflows_type - helper for checking the overflows between value, variables,
> + * or data type
> + *
> + * @n: source constant value or variable to be checked
> + * @T: destination variable or data type proposed to store @x
> + *
> + * Compares the @x expression for whether or not it can safely fit in
> + * the storage of the type in @T. @x and @T can have different types.
> + * If @x is a constant expression, this will also resolve to a constant
> + * expression.
> + *
> + * Returns: true if overflow can occur, false otherwise.
> + */
> +#define overflows_type(n, T) \
> + __builtin_choose_expr(__is_constexpr(n), \
> + __overflows_type_constexpr(n, T), \
> + __overflows_type(n, T))
> +
> +/**
> + * castable_to_type - like __same_type(), but also allows for casted literals
> + *
> + * @n: variable or constant value
> + * @T: variable or data type
> + *
> + * Unlike the __same_type() macro, this allows a constant value as the
> + * first argument. If this value would not overflow into an assignment
> + * of the second argument's type, it returns true. Otherwise, this falls
> + * back to __same_type().
> + */
> +#define castable_to_type(n, T) \
> + __builtin_choose_expr(__is_constexpr(n), \
> + !__overflows_type_constexpr(n, T), \
> + __same_type(n, T))
> +
> /**
> * size_mul() - Calculate size_t multiplication with saturation at SIZE_MAX
> *
> diff --git a/lib/overflow_kunit.c b/lib/overflow_kunit.c
> index f385ca652b74..fffc3f86181d 100644
> --- a/lib/overflow_kunit.c
> +++ b/lib/overflow_kunit.c
> @@ -16,6 +16,11 @@
> #include <linux/types.h>
> #include <linux/vmalloc.h>
>
> +/* We're expecting to do a lot of "always true" or "always false" tests. */
> +#ifdef CONFIG_CC_IS_CLANG
> +#pragma clang diagnostic ignored "-Wtautological-constant-out-of-range-compare"
> +#endif
> +
> #define DEFINE_TEST_ARRAY_TYPED(t1, t2, t) \
> static const struct test_ ## t1 ## _ ## t2 ## __ ## t { \
> t1 a; \
> @@ -246,7 +251,7 @@ DEFINE_TEST_ARRAY(s64) = {
>
> #define DEFINE_TEST_FUNC_TYPED(n, t, fmt) \
> static void do_test_ ## n(struct kunit *test, const struct test_ ## n *p) \
> -{ \
> +{ \
> 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); \
> @@ -708,6 +713,384 @@ static void overflow_size_helpers_test(struct kunit *test)
> #undef check_one_size_helper
> }
>
> +static void overflows_type_test(struct kunit *test)
> +{
> + int count = 0;
> + unsigned int var;
> +
> +#define __TEST_OVERFLOWS_TYPE(func, arg1, arg2, of) do { \
> + bool __of = func(arg1, arg2); \
> + KUNIT_EXPECT_EQ_MSG(test, __of, of, \
> + "expected " #func "(" #arg1 ", " #arg2 " to%s overflow\n",\
> + of ? "" : " not"); \
> + count++; \
> +} while (0)
> +
> +/* Args are: first type, second type, value, overflow expected */
> +#define TEST_OVERFLOWS_TYPE(__t1, __t2, v, of) do { \
> + __t1 t1 = (v); \
> + __t2 t2; \
> + __TEST_OVERFLOWS_TYPE(__overflows_type, t1, t2, of); \
> + __TEST_OVERFLOWS_TYPE(__overflows_type, t1, __t2, of); \
> + __TEST_OVERFLOWS_TYPE(__overflows_type_constexpr, t1, t2, of); \
> + __TEST_OVERFLOWS_TYPE(__overflows_type_constexpr, t1, __t2, of);\
> +} while (0)
> +
> + TEST_OVERFLOWS_TYPE(u8, u8, U8_MAX, false);
> + TEST_OVERFLOWS_TYPE(u8, u16, U8_MAX, false);
> + TEST_OVERFLOWS_TYPE(u8, s8, U8_MAX, true);
> + TEST_OVERFLOWS_TYPE(u8, s8, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(u8, s8, (u8)S8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u8, s16, U8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s8, u8, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s8, u8, -1, true);
> + TEST_OVERFLOWS_TYPE(s8, u8, S8_MIN, true);
> + TEST_OVERFLOWS_TYPE(s8, u16, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s8, u16, -1, true);
> + TEST_OVERFLOWS_TYPE(s8, u16, S8_MIN, true);
> + TEST_OVERFLOWS_TYPE(s8, u32, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s8, u32, -1, true);
> + TEST_OVERFLOWS_TYPE(s8, u32, S8_MIN, true);
> +#if BITS_PER_LONG == 64
> + TEST_OVERFLOWS_TYPE(s8, u64, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s8, u64, -1, true);
> + TEST_OVERFLOWS_TYPE(s8, u64, S8_MIN, true);
> +#endif
> + TEST_OVERFLOWS_TYPE(s8, s8, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s8, s8, S8_MIN, false);
> + TEST_OVERFLOWS_TYPE(s8, s16, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s8, s16, S8_MIN, false);
> + TEST_OVERFLOWS_TYPE(u16, u8, U8_MAX, false);
> + TEST_OVERFLOWS_TYPE(u16, u8, (u16)U8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u16, u8, U16_MAX, true);
> + TEST_OVERFLOWS_TYPE(u16, s8, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(u16, s8, (u16)S8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u16, s8, U16_MAX, true);
> + TEST_OVERFLOWS_TYPE(u16, s16, S16_MAX, false);
> + TEST_OVERFLOWS_TYPE(u16, s16, (u16)S16_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u16, s16, U16_MAX, true);
> + TEST_OVERFLOWS_TYPE(u16, u32, U16_MAX, false);
> + TEST_OVERFLOWS_TYPE(u16, s32, U16_MAX, false);
> + TEST_OVERFLOWS_TYPE(s16, u8, U8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s16, u8, (s16)U8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s16, u8, -1, true);
> + TEST_OVERFLOWS_TYPE(s16, u8, S16_MIN, true);
> + TEST_OVERFLOWS_TYPE(s16, u16, S16_MAX, false);
> + TEST_OVERFLOWS_TYPE(s16, u16, -1, true);
> + TEST_OVERFLOWS_TYPE(s16, u16, S16_MIN, true);
> + TEST_OVERFLOWS_TYPE(s16, u32, S16_MAX, false);
> + TEST_OVERFLOWS_TYPE(s16, u32, -1, true);
> + TEST_OVERFLOWS_TYPE(s16, u32, S16_MIN, true);
> +#if BITS_PER_LONG == 64
> + TEST_OVERFLOWS_TYPE(s16, u64, S16_MAX, false);
> + TEST_OVERFLOWS_TYPE(s16, u64, -1, true);
> + TEST_OVERFLOWS_TYPE(s16, u64, S16_MIN, true);
> +#endif
> + TEST_OVERFLOWS_TYPE(s16, s8, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s16, s8, S8_MIN, false);
> + TEST_OVERFLOWS_TYPE(s16, s8, (s16)S8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s16, s8, (s16)S8_MIN - 1, true);
> + TEST_OVERFLOWS_TYPE(s16, s8, S16_MAX, true);
> + TEST_OVERFLOWS_TYPE(s16, s8, S16_MIN, true);
> + TEST_OVERFLOWS_TYPE(s16, s16, S16_MAX, false);
> + TEST_OVERFLOWS_TYPE(s16, s16, S16_MIN, false);
> + TEST_OVERFLOWS_TYPE(s16, s32, S16_MAX, false);
> + TEST_OVERFLOWS_TYPE(s16, s32, S16_MIN, false);
> + TEST_OVERFLOWS_TYPE(u32, u8, U8_MAX, false);
> + TEST_OVERFLOWS_TYPE(u32, u8, (u32)U8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u32, u8, U32_MAX, true);
> + TEST_OVERFLOWS_TYPE(u32, s8, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(u32, s8, (u32)S8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u32, s8, U32_MAX, true);
> + TEST_OVERFLOWS_TYPE(u32, u16, U16_MAX, false);
> + TEST_OVERFLOWS_TYPE(u32, u16, U16_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u32, u16, U32_MAX, true);
> + TEST_OVERFLOWS_TYPE(u32, s16, S16_MAX, false);
> + TEST_OVERFLOWS_TYPE(u32, s16, (u32)S16_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u32, s16, U32_MAX, true);
> + TEST_OVERFLOWS_TYPE(u32, u32, U32_MAX, false);
> + TEST_OVERFLOWS_TYPE(u32, s32, S32_MAX, false);
> + TEST_OVERFLOWS_TYPE(u32, s32, U32_MAX, true);
> + TEST_OVERFLOWS_TYPE(u32, s32, (u32)S32_MAX + 1, true);
> +#if BITS_PER_LONG == 64
> + TEST_OVERFLOWS_TYPE(u32, u64, U32_MAX, false);
> + TEST_OVERFLOWS_TYPE(u32, s64, U32_MAX, false);
> +#endif
> + TEST_OVERFLOWS_TYPE(s32, u8, U8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s32, u8, (s32)U8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s32, u16, S32_MAX, true);
> + TEST_OVERFLOWS_TYPE(s32, u8, -1, true);
> + TEST_OVERFLOWS_TYPE(s32, u8, S32_MIN, true);
> + TEST_OVERFLOWS_TYPE(s32, u16, U16_MAX, false);
> + TEST_OVERFLOWS_TYPE(s32, u16, (s32)U16_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s32, u16, S32_MAX, true);
> + TEST_OVERFLOWS_TYPE(s32, u16, -1, true);
> + TEST_OVERFLOWS_TYPE(s32, u16, S32_MIN, true);
> + TEST_OVERFLOWS_TYPE(s32, u32, S32_MAX, false);
> + TEST_OVERFLOWS_TYPE(s32, u32, -1, true);
> + TEST_OVERFLOWS_TYPE(s32, u32, S32_MIN, true);
> +#if BITS_PER_LONG == 64
> + TEST_OVERFLOWS_TYPE(s32, u64, S32_MAX, false);
> + TEST_OVERFLOWS_TYPE(s32, u64, -1, true);
> + TEST_OVERFLOWS_TYPE(s32, u64, S32_MIN, true);
> +#endif
> + TEST_OVERFLOWS_TYPE(s32, s8, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s32, s8, S8_MIN, false);
> + TEST_OVERFLOWS_TYPE(s32, s8, (s32)S8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s32, s8, (s32)S8_MIN - 1, true);
> + TEST_OVERFLOWS_TYPE(s32, s8, S32_MAX, true);
> + TEST_OVERFLOWS_TYPE(s32, s8, S32_MIN, true);
> + TEST_OVERFLOWS_TYPE(s32, s16, S16_MAX, false);
> + TEST_OVERFLOWS_TYPE(s32, s16, S16_MIN, false);
> + TEST_OVERFLOWS_TYPE(s32, s16, (s32)S16_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s32, s16, (s32)S16_MIN - 1, true);
> + TEST_OVERFLOWS_TYPE(s32, s16, S32_MAX, true);
> + TEST_OVERFLOWS_TYPE(s32, s16, S32_MIN, true);
> + TEST_OVERFLOWS_TYPE(s32, s32, S32_MAX, false);
> + TEST_OVERFLOWS_TYPE(s32, s32, S32_MIN, false);
> +#if BITS_PER_LONG == 64
> + TEST_OVERFLOWS_TYPE(s32, s64, S32_MAX, false);
> + TEST_OVERFLOWS_TYPE(s32, s64, S32_MIN, false);
> + TEST_OVERFLOWS_TYPE(u64, u8, U64_MAX, true);
> + TEST_OVERFLOWS_TYPE(u64, u8, U8_MAX, false);
> + TEST_OVERFLOWS_TYPE(u64, u8, (u64)U8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u64, u16, U64_MAX, true);
> + TEST_OVERFLOWS_TYPE(u64, u16, U16_MAX, false);
> + TEST_OVERFLOWS_TYPE(u64, u16, (u64)U16_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u64, u32, U64_MAX, true);
> + TEST_OVERFLOWS_TYPE(u64, u32, U32_MAX, false);
> + TEST_OVERFLOWS_TYPE(u64, u32, (u64)U32_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u64, u64, U64_MAX, false);
> + TEST_OVERFLOWS_TYPE(u64, s8, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(u64, s8, (u64)S8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u64, s8, U64_MAX, true);
> + TEST_OVERFLOWS_TYPE(u64, s16, S16_MAX, false);
> + TEST_OVERFLOWS_TYPE(u64, s16, (u64)S16_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u64, s16, U64_MAX, true);
> + TEST_OVERFLOWS_TYPE(u64, s32, S32_MAX, false);
> + TEST_OVERFLOWS_TYPE(u64, s32, (u64)S32_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(u64, s32, U64_MAX, true);
> + TEST_OVERFLOWS_TYPE(u64, s64, S64_MAX, false);
> + TEST_OVERFLOWS_TYPE(u64, s64, U64_MAX, true);
> + TEST_OVERFLOWS_TYPE(u64, s64, (u64)S64_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s64, u8, S64_MAX, true);
> + TEST_OVERFLOWS_TYPE(s64, u8, S64_MIN, true);
> + TEST_OVERFLOWS_TYPE(s64, u8, -1, true);
> + TEST_OVERFLOWS_TYPE(s64, u8, U8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s64, u8, (s64)U8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s64, u16, S64_MAX, true);
> + TEST_OVERFLOWS_TYPE(s64, u16, S64_MIN, true);
> + TEST_OVERFLOWS_TYPE(s64, u16, -1, true);
> + TEST_OVERFLOWS_TYPE(s64, u16, U16_MAX, false);
> + TEST_OVERFLOWS_TYPE(s64, u16, (s64)U16_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s64, u32, S64_MAX, true);
> + TEST_OVERFLOWS_TYPE(s64, u32, S64_MIN, true);
> + TEST_OVERFLOWS_TYPE(s64, u32, -1, true);
> + TEST_OVERFLOWS_TYPE(s64, u32, U32_MAX, false);
> + TEST_OVERFLOWS_TYPE(s64, u32, (s64)U32_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s64, u64, S64_MAX, false);
> + TEST_OVERFLOWS_TYPE(s64, u64, S64_MIN, true);
> + TEST_OVERFLOWS_TYPE(s64, u64, -1, true);
> + TEST_OVERFLOWS_TYPE(s64, s8, S8_MAX, false);
> + TEST_OVERFLOWS_TYPE(s64, s8, S8_MIN, false);
> + TEST_OVERFLOWS_TYPE(s64, s8, (s64)S8_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s64, s8, (s64)S8_MIN - 1, true);
> + TEST_OVERFLOWS_TYPE(s64, s8, S64_MAX, true);
> + TEST_OVERFLOWS_TYPE(s64, s16, S16_MAX, false);
> + TEST_OVERFLOWS_TYPE(s64, s16, S16_MIN, false);
> + TEST_OVERFLOWS_TYPE(s64, s16, (s64)S16_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s64, s16, (s64)S16_MIN - 1, true);
> + TEST_OVERFLOWS_TYPE(s64, s16, S64_MAX, true);
> + TEST_OVERFLOWS_TYPE(s64, s32, S32_MAX, false);
> + TEST_OVERFLOWS_TYPE(s64, s32, S32_MIN, false);
> + TEST_OVERFLOWS_TYPE(s64, s32, (s64)S32_MAX + 1, true);
> + TEST_OVERFLOWS_TYPE(s64, s32, (s64)S32_MIN - 1, true);
> + TEST_OVERFLOWS_TYPE(s64, s32, S64_MAX, true);
> + TEST_OVERFLOWS_TYPE(s64, s64, S64_MAX, false);
> + TEST_OVERFLOWS_TYPE(s64, s64, S64_MIN, false);
> +#endif
> +
> + /* Check for macro side-effects. */
> + var = INT_MAX - 1;
> + __TEST_OVERFLOWS_TYPE(__overflows_type, var++, int, false);
> + __TEST_OVERFLOWS_TYPE(__overflows_type, var++, int, false);
> + __TEST_OVERFLOWS_TYPE(__overflows_type, var++, int, true);
> + var = INT_MAX - 1;
> + __TEST_OVERFLOWS_TYPE(overflows_type, var++, int, false);
> + __TEST_OVERFLOWS_TYPE(overflows_type, var++, int, false);
> + __TEST_OVERFLOWS_TYPE(overflows_type, var++, int, true);
> +
> + kunit_info(test, "%d overflows_type() tests finished\n", count);
> +#undef TEST_OVERFLOWS_TYPE
> +#undef __TEST_OVERFLOWS_TYPE
> +}
> +
> +static void same_type_test(struct kunit *test)
> +{
> + int count = 0;
> + int var;
> +
> +#define TEST_SAME_TYPE(t1, t2, same) do { \
> + typeof(t1) __t1h = type_max(t1); \
> + typeof(t1) __t1l = type_min(t1); \
> + typeof(t2) __t2h = type_max(t2); \
> + typeof(t2) __t2l = type_min(t2); \
> + KUNIT_EXPECT_EQ(test, true, __same_type(t1, __t1h)); \
> + KUNIT_EXPECT_EQ(test, true, __same_type(t1, __t1l)); \
> + KUNIT_EXPECT_EQ(test, true, __same_type(__t1h, t1)); \
> + KUNIT_EXPECT_EQ(test, true, __same_type(__t1l, t1)); \
> + KUNIT_EXPECT_EQ(test, true, __same_type(t2, __t2h)); \
> + KUNIT_EXPECT_EQ(test, true, __same_type(t2, __t2l)); \
> + KUNIT_EXPECT_EQ(test, true, __same_type(__t2h, t2)); \
> + KUNIT_EXPECT_EQ(test, true, __same_type(__t2l, t2)); \
> + KUNIT_EXPECT_EQ(test, same, __same_type(t1, t2)); \
> + KUNIT_EXPECT_EQ(test, same, __same_type(t2, __t1h)); \
> + KUNIT_EXPECT_EQ(test, same, __same_type(t2, __t1l)); \
> + KUNIT_EXPECT_EQ(test, same, __same_type(__t1h, t2)); \
> + KUNIT_EXPECT_EQ(test, same, __same_type(__t1l, t2)); \
> + KUNIT_EXPECT_EQ(test, same, __same_type(t1, __t2h)); \
> + KUNIT_EXPECT_EQ(test, same, __same_type(t1, __t2l)); \
> + KUNIT_EXPECT_EQ(test, same, __same_type(__t2h, t1)); \
> + KUNIT_EXPECT_EQ(test, same, __same_type(__t2l, t1)); \
> +} while (0)
> +
> +#if BITS_PER_LONG == 64
> +# define TEST_SAME_TYPE64(base, t, m) TEST_SAME_TYPE(base, t, m)
> +#else
> +# define TEST_SAME_TYPE64(base, t, m) do { } while (0)
> +#endif
> +
> +#define TEST_TYPE_SETS(base, mu8, mu16, mu32, ms8, ms16, ms32, mu64, ms64) \
> +do { \
> + TEST_SAME_TYPE(base, u8, mu8); \
> + TEST_SAME_TYPE(base, u16, mu16); \
> + TEST_SAME_TYPE(base, u32, mu32); \
> + TEST_SAME_TYPE(base, s8, ms8); \
> + TEST_SAME_TYPE(base, s16, ms16); \
> + TEST_SAME_TYPE(base, s32, ms32); \
> + TEST_SAME_TYPE64(base, u64, mu64); \
> + TEST_SAME_TYPE64(base, s64, ms64); \
> +} while (0)
> +
> + TEST_TYPE_SETS(u8, true, false, false, false, false, false, false, false);
> + TEST_TYPE_SETS(u16, false, true, false, false, false, false, false, false);
> + TEST_TYPE_SETS(u32, false, false, true, false, false, false, false, false);
> + TEST_TYPE_SETS(s8, false, false, false, true, false, false, false, false);
> + TEST_TYPE_SETS(s16, false, false, false, false, true, false, false, false);
> + TEST_TYPE_SETS(s32, false, false, false, false, false, true, false, false);
> +#if BITS_PER_LONG == 64
> + TEST_TYPE_SETS(u64, false, false, false, false, false, false, true, false);
> + TEST_TYPE_SETS(s64, false, false, false, false, false, false, false, true);
> +#endif
> +
> + /* Check for macro side-effects. */
> + var = 4;
> + KUNIT_EXPECT_EQ(test, var, 4);
> + KUNIT_EXPECT_TRUE(test, __same_type(var++, int));
> + KUNIT_EXPECT_EQ(test, var, 4);
> + KUNIT_EXPECT_TRUE(test, __same_type(int, var++));
> + KUNIT_EXPECT_EQ(test, var, 4);
> + KUNIT_EXPECT_TRUE(test, __same_type(var++, var++));
> + KUNIT_EXPECT_EQ(test, var, 4);
> +
> + kunit_info(test, "%d __same_type() tests finished\n", count);
> +
> +#undef TEST_TYPE_SETS
> +#undef TEST_SAME_TYPE64
> +#undef TEST_SAME_TYPE
> +}
> +
> +static void castable_to_type_test(struct kunit *test)
> +{
> + int count = 0;
> +
> +#define TEST_CASTABLE_TO_TYPE(arg1, arg2, pass) do { \
> + bool __pass = castable_to_type(arg1, arg2); \
> + KUNIT_EXPECT_EQ_MSG(test, __pass, pass, \
> + "expected castable_to_type(" #arg1 ", " #arg2 ") to%s pass\n",\
> + pass ? "" : " not"); \
> + count++; \
> +} while (0)
> +
> + TEST_CASTABLE_TO_TYPE(16, u8, true);
> + TEST_CASTABLE_TO_TYPE(16, u16, true);
> + TEST_CASTABLE_TO_TYPE(16, u32, true);
> + TEST_CASTABLE_TO_TYPE(16, s8, true);
> + TEST_CASTABLE_TO_TYPE(16, s16, true);
> + TEST_CASTABLE_TO_TYPE(16, s32, true);
> + TEST_CASTABLE_TO_TYPE(-16, s8, true);
> + TEST_CASTABLE_TO_TYPE(-16, s16, true);
> + TEST_CASTABLE_TO_TYPE(-16, s32, true);
> +#if BITS_PER_LONG == 64
> + TEST_CASTABLE_TO_TYPE(16, u64, true);
> + TEST_CASTABLE_TO_TYPE(-16, s64, true);
> +#endif
> +
> +#define TEST_CASTABLE_TO_TYPE_VAR(width) do { \
> + u ## width u ## width ## var = 0; \
> + s ## width s ## width ## var = 0; \
> + \
> + /* Constant expressions that fit types. */ \
> + TEST_CASTABLE_TO_TYPE(type_max(u ## width), u ## width, true); \
> + TEST_CASTABLE_TO_TYPE(type_min(u ## width), u ## width, true); \
> + TEST_CASTABLE_TO_TYPE(type_max(u ## width), u ## width ## var, true); \
> + TEST_CASTABLE_TO_TYPE(type_min(u ## width), u ## width ## var, true); \
> + TEST_CASTABLE_TO_TYPE(type_max(s ## width), s ## width, true); \
> + TEST_CASTABLE_TO_TYPE(type_min(s ## width), s ## width, true); \
> + TEST_CASTABLE_TO_TYPE(type_max(s ## width), s ## width ## var, true); \
> + TEST_CASTABLE_TO_TYPE(type_min(u ## width), s ## width ## var, true); \
> + /* Constant expressions that do not fit types. */ \
> + TEST_CASTABLE_TO_TYPE(type_max(u ## width), s ## width, false); \
> + TEST_CASTABLE_TO_TYPE(type_max(u ## width), s ## width ## var, false); \
> + TEST_CASTABLE_TO_TYPE(type_min(s ## width), u ## width, false); \
> + TEST_CASTABLE_TO_TYPE(type_min(s ## width), u ## width ## var, false); \
> + /* Non-constant expression with mismatched type. */ \
> + TEST_CASTABLE_TO_TYPE(s ## width ## var, u ## width, false); \
> + TEST_CASTABLE_TO_TYPE(u ## width ## var, s ## width, false); \
> +} while (0)
> +
> +#define TEST_CASTABLE_TO_TYPE_RANGE(width) do { \
> + unsigned long big = U ## width ## _MAX; \
> + signed long small = S ## width ## _MIN; \
> + u ## width u ## width ## var = 0; \
> + s ## width s ## width ## var = 0; \
> + \
> + /* Constant expression in range. */ \
> + TEST_CASTABLE_TO_TYPE(U ## width ## _MAX, u ## width, true); \
> + TEST_CASTABLE_TO_TYPE(U ## width ## _MAX, u ## width ## var, true); \
> + TEST_CASTABLE_TO_TYPE(S ## width ## _MIN, s ## width, true); \
> + TEST_CASTABLE_TO_TYPE(S ## width ## _MIN, s ## width ## var, true); \
> + /* Constant expression out of range. */ \
> + TEST_CASTABLE_TO_TYPE((unsigned long)U ## width ## _MAX + 1, u ## width, false); \
> + TEST_CASTABLE_TO_TYPE((unsigned long)U ## width ## _MAX + 1, u ## width ## var, false); \
> + TEST_CASTABLE_TO_TYPE((signed long)S ## width ## _MIN - 1, s ## width, false); \
> + TEST_CASTABLE_TO_TYPE((signed long)S ## width ## _MIN - 1, s ## width ## var, false); \
> + /* Non-constant expression with mismatched type. */ \
> + TEST_CASTABLE_TO_TYPE(big, u ## width, false); \
> + TEST_CASTABLE_TO_TYPE(big, u ## width ## var, false); \
> + TEST_CASTABLE_TO_TYPE(small, s ## width, false); \
> + TEST_CASTABLE_TO_TYPE(small, s ## width ## var, false); \
> +} while (0)
> +
> + TEST_CASTABLE_TO_TYPE_VAR(8);
> + TEST_CASTABLE_TO_TYPE_VAR(16);
> + TEST_CASTABLE_TO_TYPE_VAR(32);
> +#if BITS_PER_LONG == 64
> + TEST_CASTABLE_TO_TYPE_VAR(64);
> +#endif
> +
> + TEST_CASTABLE_TO_TYPE_RANGE(8);
> + TEST_CASTABLE_TO_TYPE_RANGE(16);
> +#if BITS_PER_LONG == 64
> + TEST_CASTABLE_TO_TYPE_RANGE(32);
> +#endif
> + kunit_info(test, "%d castable_to_type() tests finished\n", count);
> +
> +#undef TEST_CASTABLE_TO_TYPE_RANGE
> +#undef TEST_CASTABLE_TO_TYPE_VAR
> +#undef TEST_CASTABLE_TO_TYPE
> +}
> +
> static struct kunit_case overflow_test_cases[] = {
> KUNIT_CASE(u8_u8__u8_overflow_test),
> KUNIT_CASE(s8_s8__s8_overflow_test),
> @@ -730,6 +1113,9 @@ static struct kunit_case overflow_test_cases[] = {
> KUNIT_CASE(shift_nonsense_test),
> KUNIT_CASE(overflow_allocation_test),
> KUNIT_CASE(overflow_size_helpers_test),
> + KUNIT_CASE(overflows_type_test),
> + KUNIT_CASE(same_type_test),
> + KUNIT_CASE(castable_to_type_test),
> {}
> };
>