diff options
| -rw-r--r-- | Documentation/core-api/kernel-api.rst | 6 | ||||
| -rw-r--r-- | Documentation/driver-api/basics.rst | 3 | ||||
| -rw-r--r-- | include/linux/overflow.h | 38 | ||||
| -rw-r--r-- | lib/overflow_kunit.c | 47 |
4 files changed, 58 insertions, 36 deletions
diff --git a/Documentation/core-api/kernel-api.rst b/Documentation/core-api/kernel-api.rst index 0793c400d4b0..06f4ab122697 100644 --- a/Documentation/core-api/kernel-api.rst +++ b/Documentation/core-api/kernel-api.rst @@ -118,6 +118,12 @@ Text Searching CRC and Math Functions in Linux =============================== +Arithmetic Overflow Checking +---------------------------- + +.. kernel-doc:: include/linux/overflow.h + :internal: + CRC Functions ------------- diff --git a/Documentation/driver-api/basics.rst b/Documentation/driver-api/basics.rst index 3e2dae954898..4b4d8e28d3be 100644 --- a/Documentation/driver-api/basics.rst +++ b/Documentation/driver-api/basics.rst @@ -107,9 +107,6 @@ Kernel utility functions .. kernel-doc:: kernel/panic.c :export: -.. kernel-doc:: include/linux/overflow.h - :internal: - Device Resource Management -------------------------- diff --git a/include/linux/overflow.h b/include/linux/overflow.h index 19dfdd74835e..1d3be1a2204c 100644 --- a/include/linux/overflow.h +++ b/include/linux/overflow.h @@ -51,8 +51,8 @@ static inline bool __must_check __must_check_overflow(bool overflow) return unlikely(overflow); } -/** check_add_overflow() - Calculate addition with overflow checking - * +/** + * check_add_overflow() - Calculate addition with overflow checking * @a: first addend * @b: second addend * @d: pointer to store sum @@ -66,8 +66,8 @@ static inline bool __must_check __must_check_overflow(bool overflow) #define check_add_overflow(a, b, d) \ __must_check_overflow(__builtin_add_overflow(a, b, d)) -/** check_sub_overflow() - Calculate subtraction with overflow checking - * +/** + * check_sub_overflow() - Calculate subtraction with overflow checking * @a: minuend; value to subtract from * @b: subtrahend; value to subtract from @a * @d: pointer to store difference @@ -81,8 +81,8 @@ static inline bool __must_check __must_check_overflow(bool overflow) #define check_sub_overflow(a, b, d) \ __must_check_overflow(__builtin_sub_overflow(a, b, d)) -/** check_mul_overflow() - Calculate multiplication with overflow checking - * +/** + * check_mul_overflow() - Calculate multiplication with overflow checking * @a: first factor * @b: second factor * @d: pointer to store product @@ -96,23 +96,24 @@ static inline bool __must_check __must_check_overflow(bool overflow) #define check_mul_overflow(a, b, d) \ __must_check_overflow(__builtin_mul_overflow(a, b, d)) -/** check_shl_overflow() - Calculate a left-shifted value and check overflow - * +/** + * check_shl_overflow() - Calculate a left-shifted value and check overflow * @a: Value to be shifted * @s: How many bits left to shift * @d: Pointer to where to store the result * * Computes *@d = (@a << @s) * - * Returns true if '*d' cannot hold the result or when 'a << s' doesn't + * Returns true if '*@d' cannot hold the result or when '@a << @s' doesn't * make sense. Example conditions: - * - 'a << s' causes bits to be lost when stored in *d. - * - 's' is garbage (e.g. negative) or so large that the result of - * 'a << s' is guaranteed to be 0. - * - 'a' is negative. - * - 'a << s' sets the sign bit, if any, in '*d'. * - * '*d' will hold the results of the attempted shift, but is not + * - '@a << @s' causes bits to be lost when stored in *@d. + * - '@s' is garbage (e.g. negative) or so large that the result of + * '@a << @s' is guaranteed to be 0. + * - '@a' is negative. + * - '@a << @s' sets the sign bit, if any, in '*@d'. + * + * '*@d' will hold the results of the attempted shift, but is not * considered "safe for use" if true is returned. */ #define check_shl_overflow(a, s, d) __must_check_overflow(({ \ @@ -129,7 +130,6 @@ static inline bool __must_check __must_check_overflow(bool overflow) /** * size_mul() - Calculate size_t multiplication with saturation at SIZE_MAX - * * @factor1: first factor * @factor2: second factor * @@ -149,7 +149,6 @@ static inline size_t __must_check size_mul(size_t factor1, size_t factor2) /** * size_add() - Calculate size_t addition with saturation at SIZE_MAX - * * @addend1: first addend * @addend2: second addend * @@ -169,7 +168,6 @@ static inline size_t __must_check size_add(size_t addend1, size_t addend2) /** * size_sub() - Calculate size_t subtraction with saturation at SIZE_MAX - * * @minuend: value to subtract from * @subtrahend: value to subtract from @minuend * @@ -192,7 +190,6 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend) /** * array_size() - Calculate size of 2-dimensional array. - * * @a: dimension one * @b: dimension two * @@ -205,7 +202,6 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend) /** * array3_size() - Calculate size of 3-dimensional array. - * * @a: dimension one * @b: dimension two * @c: dimension three @@ -220,7 +216,6 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend) /** * flex_array_size() - Calculate size of a flexible array member * within an enclosing structure. - * * @p: Pointer to the structure. * @member: Name of the flexible array member. * @count: Number of elements in the array. @@ -237,7 +232,6 @@ static inline size_t __must_check size_sub(size_t minuend, size_t subtrahend) /** * struct_size() - Calculate size of structure with trailing flexible array. - * * @p: Pointer to the structure. * @member: Name of the array member. * @count: Number of elements in the array. diff --git a/lib/overflow_kunit.c b/lib/overflow_kunit.c index 5369634701fa..b8556a2e7bb1 100644 --- a/lib/overflow_kunit.c +++ b/lib/overflow_kunit.c @@ -16,6 +16,34 @@ #include <linux/types.h> #include <linux/vmalloc.h> +#define SKIP(cond, reason) do { \ + if (cond) { \ + kunit_skip(test, reason); \ + return; \ + } \ +} while (0) + +/* + * Clang 11 and earlier generate unwanted libcalls for signed output + * on unsigned input. + */ +#if defined(CONFIG_CC_IS_CLANG) && __clang_major__ <= 11 +# define SKIP_SIGN_MISMATCH(t) SKIP(t, "Clang 11 unwanted libcalls") +#else +# define SKIP_SIGN_MISMATCH(t) do { } while (0) +#endif + +/* + * Clang 13 and earlier generate unwanted libcalls for 64-bit tests on + * 32-bit hosts. + */ +#if defined(CONFIG_CC_IS_CLANG) && __clang_major__ <= 13 && \ + BITS_PER_LONG != 64 +# define SKIP_64_ON_32(t) SKIP(t, "Clang 13 unwanted libcalls") +#else +# define SKIP_64_ON_32(t) do { } while (0) +#endif + #define DEFINE_TEST_ARRAY_TYPED(t1, t2, t) \ static const struct test_ ## t1 ## _ ## t2 ## __ ## t { \ t1 a; \ @@ -94,7 +122,6 @@ DEFINE_TEST_ARRAY(u32) = { {-4U, 5U, 1U, -9U, -20U, true, false, true}, }; -#if BITS_PER_LONG == 64 DEFINE_TEST_ARRAY(u64) = { {0, 0, 0, 0, 0, false, false, false}, {1, 1, 2, 0, 1, false, false, false}, @@ -118,7 +145,6 @@ DEFINE_TEST_ARRAY(u64) = { false, true, false}, {-15ULL, 10ULL, -5ULL, -25ULL, -150ULL, false, false, true}, }; -#endif DEFINE_TEST_ARRAY(s8) = { {0, 0, 0, 0, 0, false, false, false}, @@ -194,7 +220,6 @@ DEFINE_TEST_ARRAY(s32) = { {S32_MAX, S32_MAX, -2, 0, 1, true, false, true}, }; -#if BITS_PER_LONG == 64 DEFINE_TEST_ARRAY(s64) = { {0, 0, 0, 0, 0, false, false, false}, @@ -223,7 +248,6 @@ DEFINE_TEST_ARRAY(s64) = { {-128, -1, -129, -127, 128, false, false, false}, {0, -S64_MAX, -S64_MAX, S64_MAX, 0, false, false, false}, }; -#endif #define check_one_op(t, fmt, op, sym, a, b, r, of) do { \ int _a_orig = a, _a_bump = a + 1; \ @@ -246,7 +270,7 @@ 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); \ @@ -257,6 +281,12 @@ static void do_test_ ## n(struct kunit *test, const struct test_ ## n *p) \ static void n ## _overflow_test(struct kunit *test) { \ unsigned i; \ \ + SKIP_64_ON_32(__same_type(t, u64)); \ + SKIP_64_ON_32(__same_type(t, s64)); \ + SKIP_SIGN_MISMATCH(__same_type(n ## _tests[0].a, u32) && \ + __same_type(n ## _tests[0].b, u32) && \ + __same_type(n ## _tests[0].sum, int)); \ + \ for (i = 0; i < ARRAY_SIZE(n ## _tests); ++i) \ do_test_ ## n(test, &n ## _tests[i]); \ kunit_info(test, "%zu %s arithmetic tests finished\n", \ @@ -272,10 +302,8 @@ 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 DEFINE_TEST_ARRAY_TYPED(u32, u32, u8) = { {0, 0, 0, 0, 0, false, false, false}, @@ -715,13 +743,10 @@ static struct kunit_case overflow_test_cases[] = { KUNIT_CASE(s16_s16__s16_overflow_test), KUNIT_CASE(u32_u32__u32_overflow_test), KUNIT_CASE(s32_s32__s32_overflow_test), -/* Clang 13 and earlier generate unwanted libcalls on 32-bit. */ -#if BITS_PER_LONG == 64 KUNIT_CASE(u64_u64__u64_overflow_test), KUNIT_CASE(s64_s64__s64_overflow_test), -#endif - KUNIT_CASE(u32_u32__u8_overflow_test), KUNIT_CASE(u32_u32__int_overflow_test), + KUNIT_CASE(u32_u32__u8_overflow_test), KUNIT_CASE(u8_u8__int_overflow_test), KUNIT_CASE(int_int__u8_overflow_test), KUNIT_CASE(shift_sane_test), |