diff options
Diffstat (limited to 'lib/test_overflow.c')
| -rw-r--r-- | lib/test_overflow.c | 198 |
1 files changed, 197 insertions, 1 deletions
diff --git a/lib/test_overflow.c b/lib/test_overflow.c index 2278fe05a1b0..fc680562d8b6 100644 --- a/lib/test_overflow.c +++ b/lib/test_overflow.c @@ -252,7 +252,8 @@ static int __init test_ ## t ## _overflow(void) { \ int err = 0; \ unsigned i; \ \ - pr_info("%-3s: %zu tests\n", #t, ARRAY_SIZE(t ## _tests)); \ + pr_info("%-3s: %zu arithmetic 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; \ @@ -287,6 +288,200 @@ static int __init test_overflow_calculation(void) return err; } +static int __init test_overflow_shift(void) +{ + int err = 0; + +/* Args are: value, shift, type, expected result, overflow expected */ +#define TEST_ONE_SHIFT(a, s, t, expect, of) ({ \ + int __failed = 0; \ + typeof(a) __a = (a); \ + typeof(s) __s = (s); \ + t __e = (expect); \ + t __d; \ + bool __of = check_shl_overflow(__a, __s, &__d); \ + if (__of != of) { \ + pr_warn("expected (%s)(%s << %s) to%s overflow\n", \ + #t, #a, #s, of ? "" : " not"); \ + __failed = 1; \ + } else if (!__of && __d != __e) { \ + pr_warn("expected (%s)(%s << %s) == %s\n", \ + #t, #a, #s, #expect); \ + if ((t)-1 < 0) \ + pr_warn("got %lld\n", (s64)__d); \ + else \ + pr_warn("got %llu\n", (u64)__d); \ + __failed = 1; \ + } \ + if (!__failed) \ + pr_info("ok: (%s)(%s << %s) == %s\n", #t, #a, #s, \ + of ? "overflow" : #expect); \ + __failed; \ +}) + + /* Sane shifts. */ + err |= TEST_ONE_SHIFT(1, 0, u8, 1 << 0, false); + err |= TEST_ONE_SHIFT(1, 4, u8, 1 << 4, false); + err |= TEST_ONE_SHIFT(1, 7, u8, 1 << 7, false); + err |= TEST_ONE_SHIFT(0xF, 4, u8, 0xF << 4, false); + err |= TEST_ONE_SHIFT(1, 0, u16, 1 << 0, false); + err |= TEST_ONE_SHIFT(1, 10, u16, 1 << 10, false); + err |= TEST_ONE_SHIFT(1, 15, u16, 1 << 15, false); + err |= TEST_ONE_SHIFT(0xFF, 8, u16, 0xFF << 8, false); + err |= TEST_ONE_SHIFT(1, 0, int, 1 << 0, false); + err |= TEST_ONE_SHIFT(1, 16, int, 1 << 16, false); + err |= TEST_ONE_SHIFT(1, 30, int, 1 << 30, false); + err |= TEST_ONE_SHIFT(1, 0, s32, 1 << 0, false); + err |= TEST_ONE_SHIFT(1, 16, s32, 1 << 16, false); + err |= TEST_ONE_SHIFT(1, 30, s32, 1 << 30, false); + err |= TEST_ONE_SHIFT(1, 0, unsigned int, 1U << 0, false); + err |= TEST_ONE_SHIFT(1, 20, unsigned int, 1U << 20, false); + err |= TEST_ONE_SHIFT(1, 31, unsigned int, 1U << 31, false); + err |= TEST_ONE_SHIFT(0xFFFFU, 16, unsigned int, 0xFFFFU << 16, false); + err |= TEST_ONE_SHIFT(1, 0, u32, 1U << 0, false); + err |= TEST_ONE_SHIFT(1, 20, u32, 1U << 20, false); + err |= TEST_ONE_SHIFT(1, 31, u32, 1U << 31, false); + err |= TEST_ONE_SHIFT(0xFFFFU, 16, u32, 0xFFFFU << 16, false); + err |= TEST_ONE_SHIFT(1, 0, u64, 1ULL << 0, false); + err |= TEST_ONE_SHIFT(1, 40, u64, 1ULL << 40, false); + err |= TEST_ONE_SHIFT(1, 63, u64, 1ULL << 63, false); + err |= TEST_ONE_SHIFT(0xFFFFFFFFULL, 32, u64, + 0xFFFFFFFFULL << 32, false); + + /* Sane shift: start and end with 0, without a too-wide shift. */ + err |= TEST_ONE_SHIFT(0, 7, u8, 0, false); + err |= TEST_ONE_SHIFT(0, 15, u16, 0, false); + err |= TEST_ONE_SHIFT(0, 31, unsigned int, 0, false); + err |= TEST_ONE_SHIFT(0, 31, u32, 0, false); + err |= TEST_ONE_SHIFT(0, 63, u64, 0, false); + + /* Sane shift: start and end with 0, without reaching signed bit. */ + err |= TEST_ONE_SHIFT(0, 6, s8, 0, false); + err |= TEST_ONE_SHIFT(0, 14, s16, 0, false); + err |= TEST_ONE_SHIFT(0, 30, int, 0, false); + err |= TEST_ONE_SHIFT(0, 30, s32, 0, false); + err |= TEST_ONE_SHIFT(0, 62, s64, 0, false); + + /* Overflow: shifted the bit off the end. */ + err |= TEST_ONE_SHIFT(1, 8, u8, 0, true); + err |= TEST_ONE_SHIFT(1, 16, u16, 0, true); + err |= TEST_ONE_SHIFT(1, 32, unsigned int, 0, true); + err |= TEST_ONE_SHIFT(1, 32, u32, 0, true); + err |= TEST_ONE_SHIFT(1, 64, u64, 0, true); + + /* Overflow: shifted into the signed bit. */ + err |= TEST_ONE_SHIFT(1, 7, s8, 0, true); + err |= TEST_ONE_SHIFT(1, 15, s16, 0, true); + err |= TEST_ONE_SHIFT(1, 31, int, 0, true); + err |= TEST_ONE_SHIFT(1, 31, s32, 0, true); + err |= TEST_ONE_SHIFT(1, 63, s64, 0, true); + + /* Overflow: high bit falls off unsigned types. */ + /* 10010110 */ + err |= TEST_ONE_SHIFT(150, 1, u8, 0, true); + /* 1000100010010110 */ + err |= TEST_ONE_SHIFT(34966, 1, u16, 0, true); + /* 10000100000010001000100010010110 */ + err |= TEST_ONE_SHIFT(2215151766U, 1, u32, 0, true); + err |= TEST_ONE_SHIFT(2215151766U, 1, unsigned int, 0, true); + /* 1000001000010000010000000100000010000100000010001000100010010110 */ + err |= TEST_ONE_SHIFT(9372061470395238550ULL, 1, u64, 0, true); + + /* Overflow: bit shifted into signed bit on signed types. */ + /* 01001011 */ + err |= TEST_ONE_SHIFT(75, 1, s8, 0, true); + /* 0100010001001011 */ + err |= TEST_ONE_SHIFT(17483, 1, s16, 0, true); + /* 01000010000001000100010001001011 */ + err |= TEST_ONE_SHIFT(1107575883, 1, s32, 0, true); + err |= TEST_ONE_SHIFT(1107575883, 1, int, 0, true); + /* 0100000100001000001000000010000001000010000001000100010001001011 */ + err |= TEST_ONE_SHIFT(4686030735197619275LL, 1, s64, 0, true); + + /* Overflow: bit shifted past signed bit on signed types. */ + /* 01001011 */ + err |= TEST_ONE_SHIFT(75, 2, s8, 0, true); + /* 0100010001001011 */ + err |= TEST_ONE_SHIFT(17483, 2, s16, 0, true); + /* 01000010000001000100010001001011 */ + err |= TEST_ONE_SHIFT(1107575883, 2, s32, 0, true); + err |= TEST_ONE_SHIFT(1107575883, 2, int, 0, true); + /* 0100000100001000001000000010000001000010000001000100010001001011 */ + err |= TEST_ONE_SHIFT(4686030735197619275LL, 2, s64, 0, true); + + /* Overflow: values larger than destination type. */ + err |= TEST_ONE_SHIFT(0x100, 0, u8, 0, true); + err |= TEST_ONE_SHIFT(0xFF, 0, s8, 0, true); + err |= TEST_ONE_SHIFT(0x10000U, 0, u16, 0, true); + err |= TEST_ONE_SHIFT(0xFFFFU, 0, s16, 0, true); + err |= TEST_ONE_SHIFT(0x100000000ULL, 0, u32, 0, true); + err |= TEST_ONE_SHIFT(0x100000000ULL, 0, unsigned int, 0, true); + err |= TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, s32, 0, true); + err |= TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, int, 0, true); + err |= TEST_ONE_SHIFT(0xFFFFFFFFFFFFFFFFULL, 0, s64, 0, true); + + /* Nonsense: negative initial value. */ + err |= TEST_ONE_SHIFT(-1, 0, s8, 0, true); + err |= TEST_ONE_SHIFT(-1, 0, u8, 0, true); + err |= TEST_ONE_SHIFT(-5, 0, s16, 0, true); + err |= TEST_ONE_SHIFT(-5, 0, u16, 0, true); + err |= TEST_ONE_SHIFT(-10, 0, int, 0, true); + err |= TEST_ONE_SHIFT(-10, 0, unsigned int, 0, true); + err |= TEST_ONE_SHIFT(-100, 0, s32, 0, true); + err |= TEST_ONE_SHIFT(-100, 0, u32, 0, true); + err |= TEST_ONE_SHIFT(-10000, 0, s64, 0, true); + err |= TEST_ONE_SHIFT(-10000, 0, u64, 0, true); + + /* Nonsense: negative shift values. */ + err |= TEST_ONE_SHIFT(0, -5, s8, 0, true); + err |= TEST_ONE_SHIFT(0, -5, u8, 0, true); + err |= TEST_ONE_SHIFT(0, -10, s16, 0, true); + err |= TEST_ONE_SHIFT(0, -10, u16, 0, true); + err |= TEST_ONE_SHIFT(0, -15, int, 0, true); + err |= TEST_ONE_SHIFT(0, -15, unsigned int, 0, true); + err |= TEST_ONE_SHIFT(0, -20, s32, 0, true); + err |= TEST_ONE_SHIFT(0, -20, u32, 0, true); + err |= TEST_ONE_SHIFT(0, -30, s64, 0, true); + err |= TEST_ONE_SHIFT(0, -30, u64, 0, true); + + /* Overflow: shifted at or beyond entire type's bit width. */ + err |= TEST_ONE_SHIFT(0, 8, u8, 0, true); + err |= TEST_ONE_SHIFT(0, 9, u8, 0, true); + err |= TEST_ONE_SHIFT(0, 8, s8, 0, true); + err |= TEST_ONE_SHIFT(0, 9, s8, 0, true); + err |= TEST_ONE_SHIFT(0, 16, u16, 0, true); + err |= TEST_ONE_SHIFT(0, 17, u16, 0, true); + err |= TEST_ONE_SHIFT(0, 16, s16, 0, true); + err |= TEST_ONE_SHIFT(0, 17, s16, 0, true); + err |= TEST_ONE_SHIFT(0, 32, u32, 0, true); + err |= TEST_ONE_SHIFT(0, 33, u32, 0, true); + err |= TEST_ONE_SHIFT(0, 32, int, 0, true); + err |= TEST_ONE_SHIFT(0, 33, int, 0, true); + err |= TEST_ONE_SHIFT(0, 32, s32, 0, true); + err |= TEST_ONE_SHIFT(0, 33, s32, 0, true); + err |= TEST_ONE_SHIFT(0, 64, u64, 0, true); + err |= TEST_ONE_SHIFT(0, 65, u64, 0, true); + err |= TEST_ONE_SHIFT(0, 64, s64, 0, true); + err |= TEST_ONE_SHIFT(0, 65, s64, 0, true); + + /* + * Corner case: for unsigned types, we fail when we've shifted + * through the entire width of bits. For signed types, we might + * want to match this behavior, but that would mean noticing if + * we shift through all but the signed bit, and this is not + * currently detected (but we'll notice an overflow into the + * signed bit). So, for now, we will test this condition but + * mark it as not expected to overflow. + */ + err |= TEST_ONE_SHIFT(0, 7, s8, 0, false); + err |= TEST_ONE_SHIFT(0, 15, s16, 0, false); + err |= TEST_ONE_SHIFT(0, 31, int, 0, false); + err |= TEST_ONE_SHIFT(0, 31, s32, 0, false); + err |= TEST_ONE_SHIFT(0, 63, s64, 0, false); + + return err; +} + /* * Deal with the various forms of allocator arguments. See comments above * the DEFINE_TEST_ALLOC() instances for mapping of the "bits". @@ -397,6 +592,7 @@ static int __init test_module_init(void) int err = 0; err |= test_overflow_calculation(); + err |= test_overflow_shift(); err |= test_overflow_allocation(); if (err) { |