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author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2018-05-08 00:36:28 +0200 |
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committer | Kees Cook <keescook@chromium.org> | 2018-06-05 21:16:51 +0200 |
commit | 455a35a6cdb6f53fe9294e23301eb056f2908bd9 (patch) | |
tree | d100b0647b858d100609b4115680e1349cc912aa /lib | |
parent | compiler.h: enable builtin overflow checkers and add fallback code (diff) | |
download | linux-455a35a6cdb6f53fe9294e23301eb056f2908bd9.tar.xz linux-455a35a6cdb6f53fe9294e23301eb056f2908bd9.zip |
lib: add runtime test of check_*_overflow functions
This adds a small module for testing that the check_*_overflow
functions work as expected, whether implemented in C or using gcc
builtins.
Example output:
test_overflow: u8 : 18 tests
test_overflow: s8 : 19 tests
test_overflow: u16: 17 tests
test_overflow: s16: 17 tests
test_overflow: u32: 17 tests
test_overflow: s32: 17 tests
test_overflow: u64: 17 tests
test_overflow: s64: 21 tests
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
[kees: add output to commit log, drop u64 tests on 32-bit]
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Kconfig.debug | 3 | ||||
-rw-r--r-- | lib/Makefile | 1 | ||||
-rw-r--r-- | lib/test_overflow.c | 287 |
3 files changed, 291 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c40c7b734cd1..d9fe912afed5 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1785,6 +1785,9 @@ 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 ce20696d5a92..eb762ad52ccf 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -59,6 +59,7 @@ 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..af01e46500be --- /dev/null +++ b/lib/test_overflow.c @@ -0,0 +1,287 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Test cases for arithmetic overflow checks. + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/overflow.h> +#include <linux/types.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 DEFINE_TEST_FUNC(t, fmt) \ +static void __init do_test_ ## t(const struct test_ ## t *p) \ +{ \ + t r; \ + bool of; \ + \ + of = check_add_overflow(p->a, p->b, &r); \ + if (of != p->s_of) \ + pr_warn("expected "fmt" + "fmt" to%s overflow (type %s)\n", \ + p->a, p->b, p->s_of ? "" : " not", #t); \ + if (r != p->sum) \ + pr_warn("expected "fmt" + "fmt" == "fmt", got "fmt" (type %s)\n", \ + p->a, p->b, p->sum, r, #t); \ + \ + of = check_sub_overflow(p->a, p->b, &r); \ + if (of != p->d_of) \ + pr_warn("expected "fmt" - "fmt" to%s overflow (type %s)\n", \ + p->a, p->b, p->s_of ? "" : " not", #t); \ + if (r != p->diff) \ + pr_warn("expected "fmt" - "fmt" == "fmt", got "fmt" (type %s)\n", \ + p->a, p->b, p->diff, r, #t); \ + \ + of = check_mul_overflow(p->a, p->b, &r); \ + if (of != p->p_of) \ + pr_warn("expected "fmt" * "fmt" to%s overflow (type %s)\n", \ + p->a, p->b, p->p_of ? "" : " not", #t); \ + if (r != p->prod) \ + pr_warn("expected "fmt" * "fmt" == "fmt", got "fmt" (type %s)\n", \ + p->a, p->b, p->prod, r, #t); \ +} \ + \ +static void __init test_ ## t ## _overflow(void) { \ + unsigned i; \ + \ + pr_info("%-3s: %zu tests\n", #t, ARRAY_SIZE(t ## _tests)); \ + for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i) \ + do_test_ ## t(&t ## _tests[i]); \ +} + +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(void) +{ + test_u8_overflow(); + test_s8_overflow(); + test_u16_overflow(); + test_s16_overflow(); + test_u32_overflow(); + test_s32_overflow(); +#if BITS_PER_LONG == 64 + test_u64_overflow(); + test_s64_overflow(); +#endif + + pr_info("done\n"); + + return 0; +} + +static void __exit test_module_exit(void) +{ } + +module_init(test_overflow); +module_exit(test_module_exit); +MODULE_LICENSE("Dual MIT/GPL"); |