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