1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ldt_gdt.c - Test cases for LDT and GDT access 4 * Copyright (c) 2011-2015 Andrew Lutomirski 5 */ 6 7 #define _GNU_SOURCE 8 9 #include <stdio.h> 10 #include <sys/time.h> 11 #include <time.h> 12 #include <stdlib.h> 13 #include <unistd.h> 14 #include <sys/syscall.h> 15 #include <dlfcn.h> 16 #include <string.h> 17 #include <errno.h> 18 #include <sched.h> 19 #include <stdbool.h> 20 #include <limits.h> 21 22 #include "vdso_config.h" 23 #include "vdso_call.h" 24 #include "../kselftest.h" 25 26 static const char **name; 27 28 #ifndef SYS_getcpu 29 # ifdef __x86_64__ 30 # define SYS_getcpu 309 31 # else 32 # define SYS_getcpu 318 33 # endif 34 #endif 35 36 #ifndef __NR_clock_gettime64 37 #define __NR_clock_gettime64 403 38 #endif 39 40 #ifndef __kernel_timespec 41 struct __kernel_timespec { 42 long long tv_sec; 43 long long tv_nsec; 44 }; 45 #endif 46 47 /* max length of lines in /proc/self/maps - anything longer is skipped here */ 48 #define MAPS_LINE_LEN 128 49 50 int nerrs = 0; 51 52 typedef int (*vgettime_t)(clockid_t, struct timespec *); 53 54 vgettime_t vdso_clock_gettime; 55 56 typedef int (*vgettime64_t)(clockid_t, struct __kernel_timespec *); 57 58 vgettime64_t vdso_clock_gettime64; 59 60 typedef long (*vgtod_t)(struct timeval *tv, struct timezone *tz); 61 62 vgtod_t vdso_gettimeofday; 63 64 typedef long (*getcpu_t)(unsigned *, unsigned *, void *); 65 66 getcpu_t vgetcpu; 67 getcpu_t vdso_getcpu; 68 69 static void *vsyscall_getcpu(void) 70 { 71 #ifdef __x86_64__ 72 FILE *maps; 73 char line[MAPS_LINE_LEN]; 74 bool found = false; 75 76 maps = fopen("/proc/self/maps", "r"); 77 if (!maps) /* might still be present, but ignore it here, as we test vDSO not vsyscall */ 78 return NULL; 79 80 while (fgets(line, MAPS_LINE_LEN, maps)) { 81 char r, x; 82 void *start, *end; 83 char name[MAPS_LINE_LEN]; 84 85 /* sscanf() is safe here as strlen(name) >= strlen(line) */ 86 if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s", 87 &start, &end, &r, &x, name) != 5) 88 continue; 89 90 if (strcmp(name, "[vsyscall]")) 91 continue; 92 93 /* assume entries are OK, as we test vDSO here not vsyscall */ 94 found = true; 95 break; 96 } 97 98 fclose(maps); 99 100 if (!found) { 101 printf("Warning: failed to find vsyscall getcpu\n"); 102 return NULL; 103 } 104 return (void *) (0xffffffffff600800); 105 #else 106 return NULL; 107 #endif 108 } 109 110 111 static void fill_function_pointers() 112 { 113 void *vdso = dlopen("linux-vdso.so.1", 114 RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); 115 if (!vdso) 116 vdso = dlopen("linux-gate.so.1", 117 RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); 118 if (!vdso) 119 vdso = dlopen("linux-vdso32.so.1", 120 RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); 121 if (!vdso) 122 vdso = dlopen("linux-vdso64.so.1", 123 RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); 124 if (!vdso) { 125 printf("[WARN]\tfailed to find vDSO\n"); 126 return; 127 } 128 129 vdso_getcpu = (getcpu_t)dlsym(vdso, name[4]); 130 if (!vdso_getcpu) 131 printf("Warning: failed to find getcpu in vDSO\n"); 132 133 vgetcpu = (getcpu_t) vsyscall_getcpu(); 134 135 vdso_clock_gettime = (vgettime_t)dlsym(vdso, name[1]); 136 if (!vdso_clock_gettime) 137 printf("Warning: failed to find clock_gettime in vDSO\n"); 138 139 #if defined(VDSO_32BIT) 140 vdso_clock_gettime64 = (vgettime64_t)dlsym(vdso, name[5]); 141 if (!vdso_clock_gettime64) 142 printf("Warning: failed to find clock_gettime64 in vDSO\n"); 143 #endif 144 145 vdso_gettimeofday = (vgtod_t)dlsym(vdso, name[0]); 146 if (!vdso_gettimeofday) 147 printf("Warning: failed to find gettimeofday in vDSO\n"); 148 149 } 150 151 static long sys_getcpu(unsigned * cpu, unsigned * node, 152 void* cache) 153 { 154 return syscall(__NR_getcpu, cpu, node, cache); 155 } 156 157 static inline int sys_clock_gettime(clockid_t id, struct timespec *ts) 158 { 159 return syscall(__NR_clock_gettime, id, ts); 160 } 161 162 static inline int sys_clock_gettime64(clockid_t id, struct __kernel_timespec *ts) 163 { 164 return syscall(__NR_clock_gettime64, id, ts); 165 } 166 167 static inline int sys_gettimeofday(struct timeval *tv, struct timezone *tz) 168 { 169 return syscall(__NR_gettimeofday, tv, tz); 170 } 171 172 static void test_getcpu(void) 173 { 174 printf("[RUN]\tTesting getcpu...\n"); 175 176 for (int cpu = 0; ; cpu++) { 177 cpu_set_t cpuset; 178 CPU_ZERO(&cpuset); 179 CPU_SET(cpu, &cpuset); 180 if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) 181 return; 182 183 unsigned cpu_sys, cpu_vdso, cpu_vsys, 184 node_sys, node_vdso, node_vsys; 185 long ret_sys, ret_vdso = 1, ret_vsys = 1; 186 unsigned node; 187 188 ret_sys = sys_getcpu(&cpu_sys, &node_sys, 0); 189 if (vdso_getcpu) 190 ret_vdso = VDSO_CALL(vdso_getcpu, 3, &cpu_vdso, &node_vdso, 0); 191 if (vgetcpu) 192 ret_vsys = vgetcpu(&cpu_vsys, &node_vsys, 0); 193 194 if (!ret_sys) 195 node = node_sys; 196 else if (!ret_vdso) 197 node = node_vdso; 198 else if (!ret_vsys) 199 node = node_vsys; 200 201 bool ok = true; 202 if (!ret_sys && (cpu_sys != cpu || node_sys != node)) 203 ok = false; 204 if (!ret_vdso && (cpu_vdso != cpu || node_vdso != node)) 205 ok = false; 206 if (!ret_vsys && (cpu_vsys != cpu || node_vsys != node)) 207 ok = false; 208 209 printf("[%s]\tCPU %u:", ok ? "OK" : "FAIL", cpu); 210 if (!ret_sys) 211 printf(" syscall: cpu %u, node %u", cpu_sys, node_sys); 212 if (!ret_vdso) 213 printf(" vdso: cpu %u, node %u", cpu_vdso, node_vdso); 214 if (!ret_vsys) 215 printf(" vsyscall: cpu %u, node %u", cpu_vsys, 216 node_vsys); 217 printf("\n"); 218 219 if (!ok) 220 nerrs++; 221 } 222 } 223 224 static bool ts_leq(const struct timespec *a, const struct timespec *b) 225 { 226 if (a->tv_sec != b->tv_sec) 227 return a->tv_sec < b->tv_sec; 228 else 229 return a->tv_nsec <= b->tv_nsec; 230 } 231 232 static bool ts64_leq(const struct __kernel_timespec *a, 233 const struct __kernel_timespec *b) 234 { 235 if (a->tv_sec != b->tv_sec) 236 return a->tv_sec < b->tv_sec; 237 else 238 return a->tv_nsec <= b->tv_nsec; 239 } 240 241 static bool tv_leq(const struct timeval *a, const struct timeval *b) 242 { 243 if (a->tv_sec != b->tv_sec) 244 return a->tv_sec < b->tv_sec; 245 else 246 return a->tv_usec <= b->tv_usec; 247 } 248 249 static char const * const clocknames[] = { 250 [0] = "CLOCK_REALTIME", 251 [1] = "CLOCK_MONOTONIC", 252 [2] = "CLOCK_PROCESS_CPUTIME_ID", 253 [3] = "CLOCK_THREAD_CPUTIME_ID", 254 [4] = "CLOCK_MONOTONIC_RAW", 255 [5] = "CLOCK_REALTIME_COARSE", 256 [6] = "CLOCK_MONOTONIC_COARSE", 257 [7] = "CLOCK_BOOTTIME", 258 [8] = "CLOCK_REALTIME_ALARM", 259 [9] = "CLOCK_BOOTTIME_ALARM", 260 [10] = "CLOCK_SGI_CYCLE", 261 [11] = "CLOCK_TAI", 262 }; 263 264 static void test_one_clock_gettime(int clock, const char *name) 265 { 266 struct timespec start, vdso, end; 267 int vdso_ret, end_ret; 268 269 printf("[RUN]\tTesting clock_gettime for clock %s (%d)...\n", name, clock); 270 271 if (sys_clock_gettime(clock, &start) < 0) { 272 if (errno == EINVAL) { 273 vdso_ret = VDSO_CALL(vdso_clock_gettime, 2, clock, &vdso); 274 if (vdso_ret == -EINVAL) { 275 printf("[OK]\tNo such clock.\n"); 276 } else { 277 printf("[FAIL]\tNo such clock, but __vdso_clock_gettime returned %d\n", vdso_ret); 278 nerrs++; 279 } 280 } else { 281 printf("[WARN]\t clock_gettime(%d) syscall returned error %d\n", clock, errno); 282 } 283 return; 284 } 285 286 vdso_ret = VDSO_CALL(vdso_clock_gettime, 2, clock, &vdso); 287 end_ret = sys_clock_gettime(clock, &end); 288 289 if (vdso_ret != 0 || end_ret != 0) { 290 printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n", 291 vdso_ret, errno); 292 nerrs++; 293 return; 294 } 295 296 printf("\t%llu.%09ld %llu.%09ld %llu.%09ld\n", 297 (unsigned long long)start.tv_sec, start.tv_nsec, 298 (unsigned long long)vdso.tv_sec, vdso.tv_nsec, 299 (unsigned long long)end.tv_sec, end.tv_nsec); 300 301 if (!ts_leq(&start, &vdso) || !ts_leq(&vdso, &end)) { 302 printf("[FAIL]\tTimes are out of sequence\n"); 303 nerrs++; 304 return; 305 } 306 307 printf("[OK]\tTest Passed.\n"); 308 } 309 310 static void test_clock_gettime(void) 311 { 312 if (!vdso_clock_gettime) { 313 printf("[SKIP]\tNo vDSO, so skipping clock_gettime() tests\n"); 314 return; 315 } 316 317 for (int clock = 0; clock < ARRAY_SIZE(clocknames); clock++) 318 test_one_clock_gettime(clock, clocknames[clock]); 319 320 /* Also test some invalid clock ids */ 321 test_one_clock_gettime(-1, "invalid"); 322 test_one_clock_gettime(INT_MIN, "invalid"); 323 test_one_clock_gettime(INT_MAX, "invalid"); 324 } 325 326 static void test_one_clock_gettime64(int clock, const char *name) 327 { 328 struct __kernel_timespec start, vdso, end; 329 int vdso_ret, end_ret; 330 331 printf("[RUN]\tTesting clock_gettime64 for clock %s (%d)...\n", name, clock); 332 333 if (sys_clock_gettime64(clock, &start) < 0) { 334 if (errno == EINVAL) { 335 vdso_ret = VDSO_CALL(vdso_clock_gettime64, 2, clock, &vdso); 336 if (vdso_ret == -EINVAL) { 337 printf("[OK]\tNo such clock.\n"); 338 } else { 339 printf("[FAIL]\tNo such clock, but __vdso_clock_gettime64 returned %d\n", vdso_ret); 340 nerrs++; 341 } 342 } else { 343 printf("[WARN]\t clock_gettime64(%d) syscall returned error %d\n", clock, errno); 344 } 345 return; 346 } 347 348 vdso_ret = VDSO_CALL(vdso_clock_gettime64, 2, clock, &vdso); 349 end_ret = sys_clock_gettime64(clock, &end); 350 351 if (vdso_ret != 0 || end_ret != 0) { 352 printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n", 353 vdso_ret, errno); 354 nerrs++; 355 return; 356 } 357 358 printf("\t%llu.%09lld %llu.%09lld %llu.%09lld\n", 359 (unsigned long long)start.tv_sec, start.tv_nsec, 360 (unsigned long long)vdso.tv_sec, vdso.tv_nsec, 361 (unsigned long long)end.tv_sec, end.tv_nsec); 362 363 if (!ts64_leq(&start, &vdso) || !ts64_leq(&vdso, &end)) { 364 printf("[FAIL]\tTimes are out of sequence\n"); 365 nerrs++; 366 return; 367 } 368 369 printf("[OK]\tTest Passed.\n"); 370 } 371 372 static void test_clock_gettime64(void) 373 { 374 if (!vdso_clock_gettime64) { 375 printf("[SKIP]\tNo vDSO, so skipping clock_gettime64() tests\n"); 376 return; 377 } 378 379 for (int clock = 0; clock < ARRAY_SIZE(clocknames); clock++) 380 test_one_clock_gettime64(clock, clocknames[clock]); 381 382 /* Also test some invalid clock ids */ 383 test_one_clock_gettime64(-1, "invalid"); 384 test_one_clock_gettime64(INT_MIN, "invalid"); 385 test_one_clock_gettime64(INT_MAX, "invalid"); 386 } 387 388 static void test_gettimeofday(void) 389 { 390 struct timeval start, vdso, end; 391 struct timezone sys_tz, vdso_tz; 392 int vdso_ret, end_ret; 393 394 if (!vdso_gettimeofday) 395 return; 396 397 printf("[RUN]\tTesting gettimeofday...\n"); 398 399 if (sys_gettimeofday(&start, &sys_tz) < 0) { 400 printf("[FAIL]\tsys_gettimeofday failed (%d)\n", errno); 401 nerrs++; 402 return; 403 } 404 405 vdso_ret = VDSO_CALL(vdso_gettimeofday, 2, &vdso, &vdso_tz); 406 end_ret = sys_gettimeofday(&end, NULL); 407 408 if (vdso_ret != 0 || end_ret != 0) { 409 printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n", 410 vdso_ret, errno); 411 nerrs++; 412 return; 413 } 414 415 printf("\t%llu.%06ld %llu.%06ld %llu.%06ld\n", 416 (unsigned long long)start.tv_sec, start.tv_usec, 417 (unsigned long long)vdso.tv_sec, vdso.tv_usec, 418 (unsigned long long)end.tv_sec, end.tv_usec); 419 420 if (!tv_leq(&start, &vdso) || !tv_leq(&vdso, &end)) { 421 printf("[FAIL]\tTimes are out of sequence\n"); 422 nerrs++; 423 } 424 425 if (sys_tz.tz_minuteswest == vdso_tz.tz_minuteswest && 426 sys_tz.tz_dsttime == vdso_tz.tz_dsttime) { 427 printf("[OK]\ttimezones match: minuteswest=%d, dsttime=%d\n", 428 sys_tz.tz_minuteswest, sys_tz.tz_dsttime); 429 } else { 430 printf("[FAIL]\ttimezones do not match\n"); 431 nerrs++; 432 } 433 434 /* And make sure that passing NULL for tz doesn't crash. */ 435 VDSO_CALL(vdso_gettimeofday, 2, &vdso, NULL); 436 } 437 438 int main(int argc, char **argv) 439 { 440 name = (const char **)&names[VDSO_NAMES]; 441 442 fill_function_pointers(); 443 444 test_clock_gettime(); 445 test_clock_gettime64(); 446 test_gettimeofday(); 447 448 /* 449 * Test getcpu() last so that, if something goes wrong setting affinity, 450 * we still run the other tests. 451 */ 452 test_getcpu(); 453 454 return nerrs ? 1 : 0; 455 } 456