root/lib/test_overflow.c

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DEFINITIONS

This source file includes following definitions.
  1. test_overflow_calculation
  2. test_overflow_shift
  3. test_overflow_allocation
  4. test_module_init
  5. test_module_exit

   1 // SPDX-License-Identifier: GPL-2.0 OR MIT
   2 /*
   3  * Test cases for arithmetic overflow checks.
   4  */
   5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   6 
   7 #include <linux/device.h>
   8 #include <linux/init.h>
   9 #include <linux/kernel.h>
  10 #include <linux/mm.h>
  11 #include <linux/module.h>
  12 #include <linux/overflow.h>
  13 #include <linux/slab.h>
  14 #include <linux/types.h>
  15 #include <linux/vmalloc.h>
  16 
  17 #define DEFINE_TEST_ARRAY(t)                    \
  18         static const struct test_ ## t {        \
  19                 t a, b;                         \
  20                 t sum, diff, prod;              \
  21                 bool s_of, d_of, p_of;          \
  22         } t ## _tests[] __initconst
  23 
  24 DEFINE_TEST_ARRAY(u8) = {
  25         {0, 0, 0, 0, 0, false, false, false},
  26         {1, 1, 2, 0, 1, false, false, false},
  27         {0, 1, 1, U8_MAX, 0, false, true, false},
  28         {1, 0, 1, 1, 0, false, false, false},
  29         {0, U8_MAX, U8_MAX, 1, 0, false, true, false},
  30         {U8_MAX, 0, U8_MAX, U8_MAX, 0, false, false, false},
  31         {1, U8_MAX, 0, 2, U8_MAX, true, true, false},
  32         {U8_MAX, 1, 0, U8_MAX-1, U8_MAX, true, false, false},
  33         {U8_MAX, U8_MAX, U8_MAX-1, 0, 1, true, false, true},
  34 
  35         {U8_MAX, U8_MAX-1, U8_MAX-2, 1, 2, true, false, true},
  36         {U8_MAX-1, U8_MAX, U8_MAX-2, U8_MAX, 2, true, true, true},
  37 
  38         {1U << 3, 1U << 3, 1U << 4, 0, 1U << 6, false, false, false},
  39         {1U << 4, 1U << 4, 1U << 5, 0, 0, false, false, true},
  40         {1U << 4, 1U << 3, 3*(1U << 3), 1U << 3, 1U << 7, false, false, false},
  41         {1U << 7, 1U << 7, 0, 0, 0, true, false, true},
  42 
  43         {48, 32, 80, 16, 0, false, false, true},
  44         {128, 128, 0, 0, 0, true, false, true},
  45         {123, 234, 101, 145, 110, true, true, true},
  46 };
  47 DEFINE_TEST_ARRAY(u16) = {
  48         {0, 0, 0, 0, 0, false, false, false},
  49         {1, 1, 2, 0, 1, false, false, false},
  50         {0, 1, 1, U16_MAX, 0, false, true, false},
  51         {1, 0, 1, 1, 0, false, false, false},
  52         {0, U16_MAX, U16_MAX, 1, 0, false, true, false},
  53         {U16_MAX, 0, U16_MAX, U16_MAX, 0, false, false, false},
  54         {1, U16_MAX, 0, 2, U16_MAX, true, true, false},
  55         {U16_MAX, 1, 0, U16_MAX-1, U16_MAX, true, false, false},
  56         {U16_MAX, U16_MAX, U16_MAX-1, 0, 1, true, false, true},
  57 
  58         {U16_MAX, U16_MAX-1, U16_MAX-2, 1, 2, true, false, true},
  59         {U16_MAX-1, U16_MAX, U16_MAX-2, U16_MAX, 2, true, true, true},
  60 
  61         {1U << 7, 1U << 7, 1U << 8, 0, 1U << 14, false, false, false},
  62         {1U << 8, 1U << 8, 1U << 9, 0, 0, false, false, true},
  63         {1U << 8, 1U << 7, 3*(1U << 7), 1U << 7, 1U << 15, false, false, false},
  64         {1U << 15, 1U << 15, 0, 0, 0, true, false, true},
  65 
  66         {123, 234, 357, 65425, 28782, false, true, false},
  67         {1234, 2345, 3579, 64425, 10146, false, true, true},
  68 };
  69 DEFINE_TEST_ARRAY(u32) = {
  70         {0, 0, 0, 0, 0, false, false, false},
  71         {1, 1, 2, 0, 1, false, false, false},
  72         {0, 1, 1, U32_MAX, 0, false, true, false},
  73         {1, 0, 1, 1, 0, false, false, false},
  74         {0, U32_MAX, U32_MAX, 1, 0, false, true, false},
  75         {U32_MAX, 0, U32_MAX, U32_MAX, 0, false, false, false},
  76         {1, U32_MAX, 0, 2, U32_MAX, true, true, false},
  77         {U32_MAX, 1, 0, U32_MAX-1, U32_MAX, true, false, false},
  78         {U32_MAX, U32_MAX, U32_MAX-1, 0, 1, true, false, true},
  79 
  80         {U32_MAX, U32_MAX-1, U32_MAX-2, 1, 2, true, false, true},
  81         {U32_MAX-1, U32_MAX, U32_MAX-2, U32_MAX, 2, true, true, true},
  82 
  83         {1U << 15, 1U << 15, 1U << 16, 0, 1U << 30, false, false, false},
  84         {1U << 16, 1U << 16, 1U << 17, 0, 0, false, false, true},
  85         {1U << 16, 1U << 15, 3*(1U << 15), 1U << 15, 1U << 31, false, false, false},
  86         {1U << 31, 1U << 31, 0, 0, 0, true, false, true},
  87 
  88         {-2U, 1U, -1U, -3U, -2U, false, false, false},
  89         {-4U, 5U, 1U, -9U, -20U, true, false, true},
  90 };
  91 
  92 DEFINE_TEST_ARRAY(u64) = {
  93         {0, 0, 0, 0, 0, false, false, false},
  94         {1, 1, 2, 0, 1, false, false, false},
  95         {0, 1, 1, U64_MAX, 0, false, true, false},
  96         {1, 0, 1, 1, 0, false, false, false},
  97         {0, U64_MAX, U64_MAX, 1, 0, false, true, false},
  98         {U64_MAX, 0, U64_MAX, U64_MAX, 0, false, false, false},
  99         {1, U64_MAX, 0, 2, U64_MAX, true, true, false},
 100         {U64_MAX, 1, 0, U64_MAX-1, U64_MAX, true, false, false},
 101         {U64_MAX, U64_MAX, U64_MAX-1, 0, 1, true, false, true},
 102 
 103         {U64_MAX, U64_MAX-1, U64_MAX-2, 1, 2, true, false, true},
 104         {U64_MAX-1, U64_MAX, U64_MAX-2, U64_MAX, 2, true, true, true},
 105 
 106         {1ULL << 31, 1ULL << 31, 1ULL << 32, 0, 1ULL << 62, false, false, false},
 107         {1ULL << 32, 1ULL << 32, 1ULL << 33, 0, 0, false, false, true},
 108         {1ULL << 32, 1ULL << 31, 3*(1ULL << 31), 1ULL << 31, 1ULL << 63, false, false, false},
 109         {1ULL << 63, 1ULL << 63, 0, 0, 0, true, false, true},
 110         {1000000000ULL /* 10^9 */, 10000000000ULL /* 10^10 */,
 111          11000000000ULL, 18446744064709551616ULL, 10000000000000000000ULL,
 112          false, true, false},
 113         {-15ULL, 10ULL, -5ULL, -25ULL, -150ULL, false, false, true},
 114 };
 115 
 116 DEFINE_TEST_ARRAY(s8) = {
 117         {0, 0, 0, 0, 0, false, false, false},
 118 
 119         {0, S8_MAX, S8_MAX, -S8_MAX, 0, false, false, false},
 120         {S8_MAX, 0, S8_MAX, S8_MAX, 0, false, false, false},
 121         {0, S8_MIN, S8_MIN, S8_MIN, 0, false, true, false},
 122         {S8_MIN, 0, S8_MIN, S8_MIN, 0, false, false, false},
 123 
 124         {-1, S8_MIN, S8_MAX, S8_MAX, S8_MIN, true, false, true},
 125         {S8_MIN, -1, S8_MAX, -S8_MAX, S8_MIN, true, false, true},
 126         {-1, S8_MAX, S8_MAX-1, S8_MIN, -S8_MAX, false, false, false},
 127         {S8_MAX, -1, S8_MAX-1, S8_MIN, -S8_MAX, false, true, false},
 128         {-1, -S8_MAX, S8_MIN, S8_MAX-1, S8_MAX, false, false, false},
 129         {-S8_MAX, -1, S8_MIN, S8_MIN+2, S8_MAX, false, false, false},
 130 
 131         {1, S8_MIN, -S8_MAX, -S8_MAX, S8_MIN, false, true, false},
 132         {S8_MIN, 1, -S8_MAX, S8_MAX, S8_MIN, false, true, false},
 133         {1, S8_MAX, S8_MIN, S8_MIN+2, S8_MAX, true, false, false},
 134         {S8_MAX, 1, S8_MIN, S8_MAX-1, S8_MAX, true, false, false},
 135 
 136         {S8_MIN, S8_MIN, 0, 0, 0, true, false, true},
 137         {S8_MAX, S8_MAX, -2, 0, 1, true, false, true},
 138 
 139         {-4, -32, -36, 28, -128, false, false, true},
 140         {-4, 32, 28, -36, -128, false, false, false},
 141 };
 142 
 143 DEFINE_TEST_ARRAY(s16) = {
 144         {0, 0, 0, 0, 0, false, false, false},
 145 
 146         {0, S16_MAX, S16_MAX, -S16_MAX, 0, false, false, false},
 147         {S16_MAX, 0, S16_MAX, S16_MAX, 0, false, false, false},
 148         {0, S16_MIN, S16_MIN, S16_MIN, 0, false, true, false},
 149         {S16_MIN, 0, S16_MIN, S16_MIN, 0, false, false, false},
 150 
 151         {-1, S16_MIN, S16_MAX, S16_MAX, S16_MIN, true, false, true},
 152         {S16_MIN, -1, S16_MAX, -S16_MAX, S16_MIN, true, false, true},
 153         {-1, S16_MAX, S16_MAX-1, S16_MIN, -S16_MAX, false, false, false},
 154         {S16_MAX, -1, S16_MAX-1, S16_MIN, -S16_MAX, false, true, false},
 155         {-1, -S16_MAX, S16_MIN, S16_MAX-1, S16_MAX, false, false, false},
 156         {-S16_MAX, -1, S16_MIN, S16_MIN+2, S16_MAX, false, false, false},
 157 
 158         {1, S16_MIN, -S16_MAX, -S16_MAX, S16_MIN, false, true, false},
 159         {S16_MIN, 1, -S16_MAX, S16_MAX, S16_MIN, false, true, false},
 160         {1, S16_MAX, S16_MIN, S16_MIN+2, S16_MAX, true, false, false},
 161         {S16_MAX, 1, S16_MIN, S16_MAX-1, S16_MAX, true, false, false},
 162 
 163         {S16_MIN, S16_MIN, 0, 0, 0, true, false, true},
 164         {S16_MAX, S16_MAX, -2, 0, 1, true, false, true},
 165 };
 166 DEFINE_TEST_ARRAY(s32) = {
 167         {0, 0, 0, 0, 0, false, false, false},
 168 
 169         {0, S32_MAX, S32_MAX, -S32_MAX, 0, false, false, false},
 170         {S32_MAX, 0, S32_MAX, S32_MAX, 0, false, false, false},
 171         {0, S32_MIN, S32_MIN, S32_MIN, 0, false, true, false},
 172         {S32_MIN, 0, S32_MIN, S32_MIN, 0, false, false, false},
 173 
 174         {-1, S32_MIN, S32_MAX, S32_MAX, S32_MIN, true, false, true},
 175         {S32_MIN, -1, S32_MAX, -S32_MAX, S32_MIN, true, false, true},
 176         {-1, S32_MAX, S32_MAX-1, S32_MIN, -S32_MAX, false, false, false},
 177         {S32_MAX, -1, S32_MAX-1, S32_MIN, -S32_MAX, false, true, false},
 178         {-1, -S32_MAX, S32_MIN, S32_MAX-1, S32_MAX, false, false, false},
 179         {-S32_MAX, -1, S32_MIN, S32_MIN+2, S32_MAX, false, false, false},
 180 
 181         {1, S32_MIN, -S32_MAX, -S32_MAX, S32_MIN, false, true, false},
 182         {S32_MIN, 1, -S32_MAX, S32_MAX, S32_MIN, false, true, false},
 183         {1, S32_MAX, S32_MIN, S32_MIN+2, S32_MAX, true, false, false},
 184         {S32_MAX, 1, S32_MIN, S32_MAX-1, S32_MAX, true, false, false},
 185 
 186         {S32_MIN, S32_MIN, 0, 0, 0, true, false, true},
 187         {S32_MAX, S32_MAX, -2, 0, 1, true, false, true},
 188 };
 189 DEFINE_TEST_ARRAY(s64) = {
 190         {0, 0, 0, 0, 0, false, false, false},
 191 
 192         {0, S64_MAX, S64_MAX, -S64_MAX, 0, false, false, false},
 193         {S64_MAX, 0, S64_MAX, S64_MAX, 0, false, false, false},
 194         {0, S64_MIN, S64_MIN, S64_MIN, 0, false, true, false},
 195         {S64_MIN, 0, S64_MIN, S64_MIN, 0, false, false, false},
 196 
 197         {-1, S64_MIN, S64_MAX, S64_MAX, S64_MIN, true, false, true},
 198         {S64_MIN, -1, S64_MAX, -S64_MAX, S64_MIN, true, false, true},
 199         {-1, S64_MAX, S64_MAX-1, S64_MIN, -S64_MAX, false, false, false},
 200         {S64_MAX, -1, S64_MAX-1, S64_MIN, -S64_MAX, false, true, false},
 201         {-1, -S64_MAX, S64_MIN, S64_MAX-1, S64_MAX, false, false, false},
 202         {-S64_MAX, -1, S64_MIN, S64_MIN+2, S64_MAX, false, false, false},
 203 
 204         {1, S64_MIN, -S64_MAX, -S64_MAX, S64_MIN, false, true, false},
 205         {S64_MIN, 1, -S64_MAX, S64_MAX, S64_MIN, false, true, false},
 206         {1, S64_MAX, S64_MIN, S64_MIN+2, S64_MAX, true, false, false},
 207         {S64_MAX, 1, S64_MIN, S64_MAX-1, S64_MAX, true, false, false},
 208 
 209         {S64_MIN, S64_MIN, 0, 0, 0, true, false, true},
 210         {S64_MAX, S64_MAX, -2, 0, 1, true, false, true},
 211 
 212         {-1, -1, -2, 0, 1, false, false, false},
 213         {-1, -128, -129, 127, 128, false, false, false},
 214         {-128, -1, -129, -127, 128, false, false, false},
 215         {0, -S64_MAX, -S64_MAX, S64_MAX, 0, false, false, false},
 216 };
 217 
 218 #define check_one_op(t, fmt, op, sym, a, b, r, of) do {         \
 219         t _r;                                                   \
 220         bool _of;                                               \
 221                                                                 \
 222         _of = check_ ## op ## _overflow(a, b, &_r);             \
 223         if (_of != of) {                                        \
 224                 pr_warn("expected "fmt" "sym" "fmt              \
 225                         " to%s overflow (type %s)\n",           \
 226                         a, b, of ? "" : " not", #t);            \
 227                 err = 1;                                        \
 228         }                                                       \
 229         if (_r != r) {                                          \
 230                 pr_warn("expected "fmt" "sym" "fmt" == "        \
 231                         fmt", got "fmt" (type %s)\n",           \
 232                         a, b, r, _r, #t);                       \
 233                 err = 1;                                        \
 234         }                                                       \
 235 } while (0)
 236 
 237 #define DEFINE_TEST_FUNC(t, fmt)                                        \
 238 static int __init do_test_ ## t(const struct test_ ## t *p)             \
 239 {                                                                       \
 240         int err = 0;                                                    \
 241                                                                         \
 242         check_one_op(t, fmt, add, "+", p->a, p->b, p->sum, p->s_of);    \
 243         check_one_op(t, fmt, add, "+", p->b, p->a, p->sum, p->s_of);    \
 244         check_one_op(t, fmt, sub, "-", p->a, p->b, p->diff, p->d_of);   \
 245         check_one_op(t, fmt, mul, "*", p->a, p->b, p->prod, p->p_of);   \
 246         check_one_op(t, fmt, mul, "*", p->b, p->a, p->prod, p->p_of);   \
 247                                                                         \
 248         return err;                                                     \
 249 }                                                                       \
 250                                                                         \
 251 static int __init test_ ## t ## _overflow(void) {                       \
 252         int err = 0;                                                    \
 253         unsigned i;                                                     \
 254                                                                         \
 255         pr_info("%-3s: %zu arithmetic tests\n", #t,                     \
 256                 ARRAY_SIZE(t ## _tests));                               \
 257         for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i)                   \
 258                 err |= do_test_ ## t(&t ## _tests[i]);                  \
 259         return err;                                                     \
 260 }
 261 
 262 DEFINE_TEST_FUNC(u8, "%d");
 263 DEFINE_TEST_FUNC(s8, "%d");
 264 DEFINE_TEST_FUNC(u16, "%d");
 265 DEFINE_TEST_FUNC(s16, "%d");
 266 DEFINE_TEST_FUNC(u32, "%u");
 267 DEFINE_TEST_FUNC(s32, "%d");
 268 #if BITS_PER_LONG == 64
 269 DEFINE_TEST_FUNC(u64, "%llu");
 270 DEFINE_TEST_FUNC(s64, "%lld");
 271 #endif
 272 
 273 static int __init test_overflow_calculation(void)
 274 {
 275         int err = 0;
 276 
 277         err |= test_u8_overflow();
 278         err |= test_s8_overflow();
 279         err |= test_u16_overflow();
 280         err |= test_s16_overflow();
 281         err |= test_u32_overflow();
 282         err |= test_s32_overflow();
 283 #if BITS_PER_LONG == 64
 284         err |= test_u64_overflow();
 285         err |= test_s64_overflow();
 286 #endif
 287 
 288         return err;
 289 }
 290 
 291 static int __init test_overflow_shift(void)
 292 {
 293         int err = 0;
 294 
 295 /* Args are: value, shift, type, expected result, overflow expected */
 296 #define TEST_ONE_SHIFT(a, s, t, expect, of) ({                          \
 297         int __failed = 0;                                               \
 298         typeof(a) __a = (a);                                            \
 299         typeof(s) __s = (s);                                            \
 300         t __e = (expect);                                               \
 301         t __d;                                                          \
 302         bool __of = check_shl_overflow(__a, __s, &__d);                 \
 303         if (__of != of) {                                               \
 304                 pr_warn("expected (%s)(%s << %s) to%s overflow\n",      \
 305                         #t, #a, #s, of ? "" : " not");                  \
 306                 __failed = 1;                                           \
 307         } else if (!__of && __d != __e) {                               \
 308                 pr_warn("expected (%s)(%s << %s) == %s\n",              \
 309                         #t, #a, #s, #expect);                           \
 310                 if ((t)-1 < 0)                                          \
 311                         pr_warn("got %lld\n", (s64)__d);                \
 312                 else                                                    \
 313                         pr_warn("got %llu\n", (u64)__d);                \
 314                 __failed = 1;                                           \
 315         }                                                               \
 316         if (!__failed)                                                  \
 317                 pr_info("ok: (%s)(%s << %s) == %s\n", #t, #a, #s,       \
 318                         of ? "overflow" : #expect);                     \
 319         __failed;                                                       \
 320 })
 321 
 322         /* Sane shifts. */
 323         err |= TEST_ONE_SHIFT(1, 0, u8, 1 << 0, false);
 324         err |= TEST_ONE_SHIFT(1, 4, u8, 1 << 4, false);
 325         err |= TEST_ONE_SHIFT(1, 7, u8, 1 << 7, false);
 326         err |= TEST_ONE_SHIFT(0xF, 4, u8, 0xF << 4, false);
 327         err |= TEST_ONE_SHIFT(1, 0, u16, 1 << 0, false);
 328         err |= TEST_ONE_SHIFT(1, 10, u16, 1 << 10, false);
 329         err |= TEST_ONE_SHIFT(1, 15, u16, 1 << 15, false);
 330         err |= TEST_ONE_SHIFT(0xFF, 8, u16, 0xFF << 8, false);
 331         err |= TEST_ONE_SHIFT(1, 0, int, 1 << 0, false);
 332         err |= TEST_ONE_SHIFT(1, 16, int, 1 << 16, false);
 333         err |= TEST_ONE_SHIFT(1, 30, int, 1 << 30, false);
 334         err |= TEST_ONE_SHIFT(1, 0, s32, 1 << 0, false);
 335         err |= TEST_ONE_SHIFT(1, 16, s32, 1 << 16, false);
 336         err |= TEST_ONE_SHIFT(1, 30, s32, 1 << 30, false);
 337         err |= TEST_ONE_SHIFT(1, 0, unsigned int, 1U << 0, false);
 338         err |= TEST_ONE_SHIFT(1, 20, unsigned int, 1U << 20, false);
 339         err |= TEST_ONE_SHIFT(1, 31, unsigned int, 1U << 31, false);
 340         err |= TEST_ONE_SHIFT(0xFFFFU, 16, unsigned int, 0xFFFFU << 16, false);
 341         err |= TEST_ONE_SHIFT(1, 0, u32, 1U << 0, false);
 342         err |= TEST_ONE_SHIFT(1, 20, u32, 1U << 20, false);
 343         err |= TEST_ONE_SHIFT(1, 31, u32, 1U << 31, false);
 344         err |= TEST_ONE_SHIFT(0xFFFFU, 16, u32, 0xFFFFU << 16, false);
 345         err |= TEST_ONE_SHIFT(1, 0, u64, 1ULL << 0, false);
 346         err |= TEST_ONE_SHIFT(1, 40, u64, 1ULL << 40, false);
 347         err |= TEST_ONE_SHIFT(1, 63, u64, 1ULL << 63, false);
 348         err |= TEST_ONE_SHIFT(0xFFFFFFFFULL, 32, u64,
 349                               0xFFFFFFFFULL << 32, false);
 350 
 351         /* Sane shift: start and end with 0, without a too-wide shift. */
 352         err |= TEST_ONE_SHIFT(0, 7, u8, 0, false);
 353         err |= TEST_ONE_SHIFT(0, 15, u16, 0, false);
 354         err |= TEST_ONE_SHIFT(0, 31, unsigned int, 0, false);
 355         err |= TEST_ONE_SHIFT(0, 31, u32, 0, false);
 356         err |= TEST_ONE_SHIFT(0, 63, u64, 0, false);
 357 
 358         /* Sane shift: start and end with 0, without reaching signed bit. */
 359         err |= TEST_ONE_SHIFT(0, 6, s8, 0, false);
 360         err |= TEST_ONE_SHIFT(0, 14, s16, 0, false);
 361         err |= TEST_ONE_SHIFT(0, 30, int, 0, false);
 362         err |= TEST_ONE_SHIFT(0, 30, s32, 0, false);
 363         err |= TEST_ONE_SHIFT(0, 62, s64, 0, false);
 364 
 365         /* Overflow: shifted the bit off the end. */
 366         err |= TEST_ONE_SHIFT(1, 8, u8, 0, true);
 367         err |= TEST_ONE_SHIFT(1, 16, u16, 0, true);
 368         err |= TEST_ONE_SHIFT(1, 32, unsigned int, 0, true);
 369         err |= TEST_ONE_SHIFT(1, 32, u32, 0, true);
 370         err |= TEST_ONE_SHIFT(1, 64, u64, 0, true);
 371 
 372         /* Overflow: shifted into the signed bit. */
 373         err |= TEST_ONE_SHIFT(1, 7, s8, 0, true);
 374         err |= TEST_ONE_SHIFT(1, 15, s16, 0, true);
 375         err |= TEST_ONE_SHIFT(1, 31, int, 0, true);
 376         err |= TEST_ONE_SHIFT(1, 31, s32, 0, true);
 377         err |= TEST_ONE_SHIFT(1, 63, s64, 0, true);
 378 
 379         /* Overflow: high bit falls off unsigned types. */
 380         /* 10010110 */
 381         err |= TEST_ONE_SHIFT(150, 1, u8, 0, true);
 382         /* 1000100010010110 */
 383         err |= TEST_ONE_SHIFT(34966, 1, u16, 0, true);
 384         /* 10000100000010001000100010010110 */
 385         err |= TEST_ONE_SHIFT(2215151766U, 1, u32, 0, true);
 386         err |= TEST_ONE_SHIFT(2215151766U, 1, unsigned int, 0, true);
 387         /* 1000001000010000010000000100000010000100000010001000100010010110 */
 388         err |= TEST_ONE_SHIFT(9372061470395238550ULL, 1, u64, 0, true);
 389 
 390         /* Overflow: bit shifted into signed bit on signed types. */
 391         /* 01001011 */
 392         err |= TEST_ONE_SHIFT(75, 1, s8, 0, true);
 393         /* 0100010001001011 */
 394         err |= TEST_ONE_SHIFT(17483, 1, s16, 0, true);
 395         /* 01000010000001000100010001001011 */
 396         err |= TEST_ONE_SHIFT(1107575883, 1, s32, 0, true);
 397         err |= TEST_ONE_SHIFT(1107575883, 1, int, 0, true);
 398         /* 0100000100001000001000000010000001000010000001000100010001001011 */
 399         err |= TEST_ONE_SHIFT(4686030735197619275LL, 1, s64, 0, true);
 400 
 401         /* Overflow: bit shifted past signed bit on signed types. */
 402         /* 01001011 */
 403         err |= TEST_ONE_SHIFT(75, 2, s8, 0, true);
 404         /* 0100010001001011 */
 405         err |= TEST_ONE_SHIFT(17483, 2, s16, 0, true);
 406         /* 01000010000001000100010001001011 */
 407         err |= TEST_ONE_SHIFT(1107575883, 2, s32, 0, true);
 408         err |= TEST_ONE_SHIFT(1107575883, 2, int, 0, true);
 409         /* 0100000100001000001000000010000001000010000001000100010001001011 */
 410         err |= TEST_ONE_SHIFT(4686030735197619275LL, 2, s64, 0, true);
 411 
 412         /* Overflow: values larger than destination type. */
 413         err |= TEST_ONE_SHIFT(0x100, 0, u8, 0, true);
 414         err |= TEST_ONE_SHIFT(0xFF, 0, s8, 0, true);
 415         err |= TEST_ONE_SHIFT(0x10000U, 0, u16, 0, true);
 416         err |= TEST_ONE_SHIFT(0xFFFFU, 0, s16, 0, true);
 417         err |= TEST_ONE_SHIFT(0x100000000ULL, 0, u32, 0, true);
 418         err |= TEST_ONE_SHIFT(0x100000000ULL, 0, unsigned int, 0, true);
 419         err |= TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, s32, 0, true);
 420         err |= TEST_ONE_SHIFT(0xFFFFFFFFUL, 0, int, 0, true);
 421         err |= TEST_ONE_SHIFT(0xFFFFFFFFFFFFFFFFULL, 0, s64, 0, true);
 422 
 423         /* Nonsense: negative initial value. */
 424         err |= TEST_ONE_SHIFT(-1, 0, s8, 0, true);
 425         err |= TEST_ONE_SHIFT(-1, 0, u8, 0, true);
 426         err |= TEST_ONE_SHIFT(-5, 0, s16, 0, true);
 427         err |= TEST_ONE_SHIFT(-5, 0, u16, 0, true);
 428         err |= TEST_ONE_SHIFT(-10, 0, int, 0, true);
 429         err |= TEST_ONE_SHIFT(-10, 0, unsigned int, 0, true);
 430         err |= TEST_ONE_SHIFT(-100, 0, s32, 0, true);
 431         err |= TEST_ONE_SHIFT(-100, 0, u32, 0, true);
 432         err |= TEST_ONE_SHIFT(-10000, 0, s64, 0, true);
 433         err |= TEST_ONE_SHIFT(-10000, 0, u64, 0, true);
 434 
 435         /* Nonsense: negative shift values. */
 436         err |= TEST_ONE_SHIFT(0, -5, s8, 0, true);
 437         err |= TEST_ONE_SHIFT(0, -5, u8, 0, true);
 438         err |= TEST_ONE_SHIFT(0, -10, s16, 0, true);
 439         err |= TEST_ONE_SHIFT(0, -10, u16, 0, true);
 440         err |= TEST_ONE_SHIFT(0, -15, int, 0, true);
 441         err |= TEST_ONE_SHIFT(0, -15, unsigned int, 0, true);
 442         err |= TEST_ONE_SHIFT(0, -20, s32, 0, true);
 443         err |= TEST_ONE_SHIFT(0, -20, u32, 0, true);
 444         err |= TEST_ONE_SHIFT(0, -30, s64, 0, true);
 445         err |= TEST_ONE_SHIFT(0, -30, u64, 0, true);
 446 
 447         /* Overflow: shifted at or beyond entire type's bit width. */
 448         err |= TEST_ONE_SHIFT(0, 8, u8, 0, true);
 449         err |= TEST_ONE_SHIFT(0, 9, u8, 0, true);
 450         err |= TEST_ONE_SHIFT(0, 8, s8, 0, true);
 451         err |= TEST_ONE_SHIFT(0, 9, s8, 0, true);
 452         err |= TEST_ONE_SHIFT(0, 16, u16, 0, true);
 453         err |= TEST_ONE_SHIFT(0, 17, u16, 0, true);
 454         err |= TEST_ONE_SHIFT(0, 16, s16, 0, true);
 455         err |= TEST_ONE_SHIFT(0, 17, s16, 0, true);
 456         err |= TEST_ONE_SHIFT(0, 32, u32, 0, true);
 457         err |= TEST_ONE_SHIFT(0, 33, u32, 0, true);
 458         err |= TEST_ONE_SHIFT(0, 32, int, 0, true);
 459         err |= TEST_ONE_SHIFT(0, 33, int, 0, true);
 460         err |= TEST_ONE_SHIFT(0, 32, s32, 0, true);
 461         err |= TEST_ONE_SHIFT(0, 33, s32, 0, true);
 462         err |= TEST_ONE_SHIFT(0, 64, u64, 0, true);
 463         err |= TEST_ONE_SHIFT(0, 65, u64, 0, true);
 464         err |= TEST_ONE_SHIFT(0, 64, s64, 0, true);
 465         err |= TEST_ONE_SHIFT(0, 65, s64, 0, true);
 466 
 467         /*
 468          * Corner case: for unsigned types, we fail when we've shifted
 469          * through the entire width of bits. For signed types, we might
 470          * want to match this behavior, but that would mean noticing if
 471          * we shift through all but the signed bit, and this is not
 472          * currently detected (but we'll notice an overflow into the
 473          * signed bit). So, for now, we will test this condition but
 474          * mark it as not expected to overflow.
 475          */
 476         err |= TEST_ONE_SHIFT(0, 7, s8, 0, false);
 477         err |= TEST_ONE_SHIFT(0, 15, s16, 0, false);
 478         err |= TEST_ONE_SHIFT(0, 31, int, 0, false);
 479         err |= TEST_ONE_SHIFT(0, 31, s32, 0, false);
 480         err |= TEST_ONE_SHIFT(0, 63, s64, 0, false);
 481 
 482         return err;
 483 }
 484 
 485 /*
 486  * Deal with the various forms of allocator arguments. See comments above
 487  * the DEFINE_TEST_ALLOC() instances for mapping of the "bits".
 488  */
 489 #define alloc_GFP                (GFP_KERNEL | __GFP_NOWARN)
 490 #define alloc010(alloc, arg, sz) alloc(sz, alloc_GFP)
 491 #define alloc011(alloc, arg, sz) alloc(sz, alloc_GFP, NUMA_NO_NODE)
 492 #define alloc000(alloc, arg, sz) alloc(sz)
 493 #define alloc001(alloc, arg, sz) alloc(sz, NUMA_NO_NODE)
 494 #define alloc110(alloc, arg, sz) alloc(arg, sz, alloc_GFP)
 495 #define free0(free, arg, ptr)    free(ptr)
 496 #define free1(free, arg, ptr)    free(arg, ptr)
 497 
 498 /* Wrap around to 16K */
 499 #define TEST_SIZE               (5 * 4096)
 500 
 501 #define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\
 502 static int __init test_ ## func (void *arg)                             \
 503 {                                                                       \
 504         volatile size_t a = TEST_SIZE;                                  \
 505         volatile size_t b = (SIZE_MAX / TEST_SIZE) + 1;                 \
 506         void *ptr;                                                      \
 507                                                                         \
 508         /* Tiny allocation test. */                                     \
 509         ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, 1);\
 510         if (!ptr) {                                                     \
 511                 pr_warn(#func " failed regular allocation?!\n");        \
 512                 return 1;                                               \
 513         }                                                               \
 514         free ## want_arg (free_func, arg, ptr);                         \
 515                                                                         \
 516         /* Wrapped allocation test. */                                  \
 517         ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,    \
 518                                                           a * b);       \
 519         if (!ptr) {                                                     \
 520                 pr_warn(#func " unexpectedly failed bad wrapping?!\n"); \
 521                 return 1;                                               \
 522         }                                                               \
 523         free ## want_arg (free_func, arg, ptr);                         \
 524                                                                         \
 525         /* Saturated allocation test. */                                \
 526         ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,    \
 527                                                    array_size(a, b));   \
 528         if (ptr) {                                                      \
 529                 pr_warn(#func " missed saturation!\n");                 \
 530                 free ## want_arg (free_func, arg, ptr);                 \
 531                 return 1;                                               \
 532         }                                                               \
 533         pr_info(#func " detected saturation\n");                        \
 534         return 0;                                                       \
 535 }
 536 
 537 /*
 538  * Allocator uses a trailing node argument --------+  (e.g. kmalloc_node())
 539  * Allocator uses the gfp_t argument -----------+  |  (e.g. kmalloc())
 540  * Allocator uses a special leading argument +  |  |  (e.g. devm_kmalloc())
 541  *                                           |  |  |
 542  */
 543 DEFINE_TEST_ALLOC(kmalloc,       kfree,      0, 1, 0);
 544 DEFINE_TEST_ALLOC(kmalloc_node,  kfree,      0, 1, 1);
 545 DEFINE_TEST_ALLOC(kzalloc,       kfree,      0, 1, 0);
 546 DEFINE_TEST_ALLOC(kzalloc_node,  kfree,      0, 1, 1);
 547 DEFINE_TEST_ALLOC(vmalloc,       vfree,      0, 0, 0);
 548 DEFINE_TEST_ALLOC(vmalloc_node,  vfree,      0, 0, 1);
 549 DEFINE_TEST_ALLOC(vzalloc,       vfree,      0, 0, 0);
 550 DEFINE_TEST_ALLOC(vzalloc_node,  vfree,      0, 0, 1);
 551 DEFINE_TEST_ALLOC(kvmalloc,      kvfree,     0, 1, 0);
 552 DEFINE_TEST_ALLOC(kvmalloc_node, kvfree,     0, 1, 1);
 553 DEFINE_TEST_ALLOC(kvzalloc,      kvfree,     0, 1, 0);
 554 DEFINE_TEST_ALLOC(kvzalloc_node, kvfree,     0, 1, 1);
 555 DEFINE_TEST_ALLOC(devm_kmalloc,  devm_kfree, 1, 1, 0);
 556 DEFINE_TEST_ALLOC(devm_kzalloc,  devm_kfree, 1, 1, 0);
 557 
 558 static int __init test_overflow_allocation(void)
 559 {
 560         const char device_name[] = "overflow-test";
 561         struct device *dev;
 562         int err = 0;
 563 
 564         /* Create dummy device for devm_kmalloc()-family tests. */
 565         dev = root_device_register(device_name);
 566         if (IS_ERR(dev)) {
 567                 pr_warn("Cannot register test device\n");
 568                 return 1;
 569         }
 570 
 571         err |= test_kmalloc(NULL);
 572         err |= test_kmalloc_node(NULL);
 573         err |= test_kzalloc(NULL);
 574         err |= test_kzalloc_node(NULL);
 575         err |= test_kvmalloc(NULL);
 576         err |= test_kvmalloc_node(NULL);
 577         err |= test_kvzalloc(NULL);
 578         err |= test_kvzalloc_node(NULL);
 579         err |= test_vmalloc(NULL);
 580         err |= test_vmalloc_node(NULL);
 581         err |= test_vzalloc(NULL);
 582         err |= test_vzalloc_node(NULL);
 583         err |= test_devm_kmalloc(dev);
 584         err |= test_devm_kzalloc(dev);
 585 
 586         device_unregister(dev);
 587 
 588         return err;
 589 }
 590 
 591 static int __init test_module_init(void)
 592 {
 593         int err = 0;
 594 
 595         err |= test_overflow_calculation();
 596         err |= test_overflow_shift();
 597         err |= test_overflow_allocation();
 598 
 599         if (err) {
 600                 pr_warn("FAIL!\n");
 601                 err = -EINVAL;
 602         } else {
 603                 pr_info("all tests passed\n");
 604         }
 605 
 606         return err;
 607 }
 608 
 609 static void __exit test_module_exit(void)
 610 { }
 611 
 612 module_init(test_module_init);
 613 module_exit(test_module_exit);
 614 MODULE_LICENSE("Dual MIT/GPL");

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