lib/test_overflow.c

   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 tests\n", #t, ARRAY_SIZE(t ## _tests));      \
 256         for (i = 0; i < ARRAY_SIZE(t ## _tests); ++i)                   \
 257                 err |= do_test_ ## t(&t ## _tests[i]);                  \
 258         return err;                                                     \
 259 }
 260
 261 DEFINE_TEST_FUNC(u8, "%d");
 262 DEFINE_TEST_FUNC(s8, "%d");
 263 DEFINE_TEST_FUNC(u16, "%d");
 264 DEFINE_TEST_FUNC(s16, "%d");
 265 DEFINE_TEST_FUNC(u32, "%u");
 266 DEFINE_TEST_FUNC(s32, "%d");
 267 #if BITS_PER_LONG == 64
 268 DEFINE_TEST_FUNC(u64, "%llu");
 269 DEFINE_TEST_FUNC(s64, "%lld");
 270 #endif
 271
 272 static int __init test_overflow_calculation(void)
 273 {
 274         int err = 0;
 275
 276         err |= test_u8_overflow();
 277         err |= test_s8_overflow();
 278         err |= test_u16_overflow();
 279         err |= test_s16_overflow();
 280         err |= test_u32_overflow();
 281         err |= test_s32_overflow();
 282 #if BITS_PER_LONG == 64
 283         err |= test_u64_overflow();
 284         err |= test_s64_overflow();
 285 #endif
 286
 287         return err;
 288 }
 289
 290 /*
 291  * Deal with the various forms of allocator arguments. See comments above
 292  * the DEFINE_TEST_ALLOC() instances for mapping of the "bits".
 293  */
 294 #define alloc010(alloc, arg, sz) alloc(sz, GFP_KERNEL)
 295 #define alloc011(alloc, arg, sz) alloc(sz, GFP_KERNEL, NUMA_NO_NODE)
 296 #define alloc000(alloc, arg, sz) alloc(sz)
 297 #define alloc001(alloc, arg, sz) alloc(sz, NUMA_NO_NODE)
 298 #define alloc110(alloc, arg, sz) alloc(arg, sz, GFP_KERNEL)
 299 #define free0(free, arg, ptr)    free(ptr)
 300 #define free1(free, arg, ptr)    free(arg, ptr)
 301
 302 /* Wrap around to 8K */
 303 #define TEST_SIZE               (9 << PAGE_SHIFT)
 304
 305 #define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\
 306 static int __init test_ ## func (void *arg)                             \
 307 {                                                                       \
 308         volatile size_t a = TEST_SIZE;                                  \
 309         volatile size_t b = (SIZE_MAX / TEST_SIZE) + 1;                 \
 310         void *ptr;                                                      \
 311                                                                         \
 312         /* Tiny allocation test. */                                     \
 313         ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, 1);\
 314         if (!ptr) {                                                     \
 315                 pr_warn(#func " failed regular allocation?!\n");        \
 316                 return 1;                                               \
 317         }                                                               \
 318         free ## want_arg (free_func, arg, ptr);                         \
 319                                                                         \
 320         /* Wrapped allocation test. */                                  \
 321         ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,    \
 322                                                           a * b);       \
 323         if (!ptr) {                                                     \
 324                 pr_warn(#func " unexpectedly failed bad wrapping?!\n"); \
 325                 return 1;                                               \
 326         }                                                               \
 327         free ## want_arg (free_func, arg, ptr);                         \
 328                                                                         \
 329         /* Saturated allocation test. */                                \
 330         ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,    \
 331                                                    array_size(a, b));   \
 332         if (ptr) {                                                      \
 333                 pr_warn(#func " missed saturation!\n");                 \
 334                 free ## want_arg (free_func, arg, ptr);                 \
 335                 return 1;                                               \
 336         }                                                               \
 337         pr_info(#func " detected saturation\n");                        \
 338         return 0;                                                       \
 339 }
 340
 341 /*
 342  * Allocator uses a trailing node argument --------+  (e.g. kmalloc_node())
 343  * Allocator uses the gfp_t argument -----------+  |  (e.g. kmalloc())
 344  * Allocator uses a special leading argument +  |  |  (e.g. devm_kmalloc())
 345  *                                           |  |  |
 346  */
 347 DEFINE_TEST_ALLOC(kmalloc,       kfree,      0, 1, 0);
 348 DEFINE_TEST_ALLOC(kmalloc_node,  kfree,      0, 1, 1);
 349 DEFINE_TEST_ALLOC(kzalloc,       kfree,      0, 1, 0);
 350 DEFINE_TEST_ALLOC(kzalloc_node,  kfree,      0, 1, 1);
 351 DEFINE_TEST_ALLOC(vmalloc,       vfree,      0, 0, 0);
 352 DEFINE_TEST_ALLOC(vmalloc_node,  vfree,      0, 0, 1);
 353 DEFINE_TEST_ALLOC(vzalloc,       vfree,      0, 0, 0);
 354 DEFINE_TEST_ALLOC(vzalloc_node,  vfree,      0, 0, 1);
 355 DEFINE_TEST_ALLOC(kvmalloc,      kvfree,     0, 1, 0);
 356 DEFINE_TEST_ALLOC(kvmalloc_node, kvfree,     0, 1, 1);
 357 DEFINE_TEST_ALLOC(kvzalloc,      kvfree,     0, 1, 0);
 358 DEFINE_TEST_ALLOC(kvzalloc_node, kvfree,     0, 1, 1);
 359 DEFINE_TEST_ALLOC(devm_kmalloc,  devm_kfree, 1, 1, 0);
 360 DEFINE_TEST_ALLOC(devm_kzalloc,  devm_kfree, 1, 1, 0);
 361
 362 static int __init test_overflow_allocation(void)
 363 {
 364         const char device_name[] = "overflow-test";
 365         struct device *dev;
 366         int err = 0;
 367
 368         /* Create dummy device for devm_kmalloc()-family tests. */
 369         dev = root_device_register(device_name);
 370         if (IS_ERR(dev)) {
 371                 pr_warn("Cannot register test device\n");
 372                 return 1;
 373         }
 374
 375         err |= test_kmalloc(NULL);
 376         err |= test_kmalloc_node(NULL);
 377         err |= test_kzalloc(NULL);
 378         err |= test_kzalloc_node(NULL);
 379         err |= test_kvmalloc(NULL);
 380         err |= test_kvmalloc_node(NULL);
 381         err |= test_kvzalloc(NULL);
 382         err |= test_kvzalloc_node(NULL);
 383         err |= test_vmalloc(NULL);
 384         err |= test_vmalloc_node(NULL);
 385         err |= test_vzalloc(NULL);
 386         err |= test_vzalloc_node(NULL);
 387         err |= test_devm_kmalloc(dev);
 388         err |= test_devm_kzalloc(dev);
 389
 390         device_unregister(dev);
 391
 392         return err;
 393 }
 394
 395 static int __init test_module_init(void)
 396 {
 397         int err = 0;
 398
 399         err |= test_overflow_calculation();
 400         err |= test_overflow_allocation();
 401
 402         if (err) {
 403                 pr_warn("FAIL!\n");
 404                 err = -EINVAL;
 405         } else {
 406                 pr_info("all tests passed\n");
 407         }
 408
 409         return err;
 410 }
 411
 412 static void __exit test_module_exit(void)
 413 { }
 414
 415 module_init(test_module_init);
 416 module_exit(test_module_exit);
 417 MODULE_LICENSE("Dual MIT/GPL");