tools/testing/selftests/vDSO/vdso_test_correctness.c

   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 }