1 // SPDX-License-Identifier: GPL-2.0
3 * ldt_gdt.c - Test cases for LDT and GDT access
4 * Copyright (c) 2011-2015 Andrew Lutomirski
14 #include <sys/syscall.h>
24 # define SYS_getcpu 309
26 # define SYS_getcpu 318
30 /* max length of lines in /proc/self/maps - anything longer is skipped here */
31 #define MAPS_LINE_LEN 128
35 typedef int (*vgettime_t)(clockid_t, struct timespec *);
37 vgettime_t vdso_clock_gettime;
39 typedef long (*vgtod_t)(struct timeval *tv, struct timezone *tz);
41 vgtod_t vdso_gettimeofday;
43 typedef long (*getcpu_t)(unsigned *, unsigned *, void *);
48 static void *vsyscall_getcpu(void)
52 char line[MAPS_LINE_LEN];
55 maps = fopen("/proc/self/maps", "r");
56 if (!maps) /* might still be present, but ignore it here, as we test vDSO not vsyscall */
59 while (fgets(line, MAPS_LINE_LEN, maps)) {
62 char name[MAPS_LINE_LEN];
64 /* sscanf() is safe here as strlen(name) >= strlen(line) */
65 if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s",
66 &start, &end, &r, &x, name) != 5)
69 if (strcmp(name, "[vsyscall]"))
72 /* assume entries are OK, as we test vDSO here not vsyscall */
80 printf("Warning: failed to find vsyscall getcpu\n");
83 return (void *) (0xffffffffff600800);
90 static void fill_function_pointers()
92 void *vdso = dlopen("linux-vdso.so.1",
93 RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
95 vdso = dlopen("linux-gate.so.1",
96 RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
98 printf("[WARN]\tfailed to find vDSO\n");
102 vdso_getcpu = (getcpu_t)dlsym(vdso, "__vdso_getcpu");
104 printf("Warning: failed to find getcpu in vDSO\n");
106 vgetcpu = (getcpu_t) vsyscall_getcpu();
108 vdso_clock_gettime = (vgettime_t)dlsym(vdso, "__vdso_clock_gettime");
109 if (!vdso_clock_gettime)
110 printf("Warning: failed to find clock_gettime in vDSO\n");
112 vdso_gettimeofday = (vgtod_t)dlsym(vdso, "__vdso_gettimeofday");
113 if (!vdso_gettimeofday)
114 printf("Warning: failed to find gettimeofday in vDSO\n");
118 static long sys_getcpu(unsigned * cpu, unsigned * node,
121 return syscall(__NR_getcpu, cpu, node, cache);
124 static inline int sys_clock_gettime(clockid_t id, struct timespec *ts)
126 return syscall(__NR_clock_gettime, id, ts);
129 static inline int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
131 return syscall(__NR_gettimeofday, tv, tz);
134 static void test_getcpu(void)
136 printf("[RUN]\tTesting getcpu...\n");
138 for (int cpu = 0; ; cpu++) {
141 CPU_SET(cpu, &cpuset);
142 if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0)
145 unsigned cpu_sys, cpu_vdso, cpu_vsys,
146 node_sys, node_vdso, node_vsys;
147 long ret_sys, ret_vdso = 1, ret_vsys = 1;
150 ret_sys = sys_getcpu(&cpu_sys, &node_sys, 0);
152 ret_vdso = vdso_getcpu(&cpu_vdso, &node_vdso, 0);
154 ret_vsys = vgetcpu(&cpu_vsys, &node_vsys, 0);
164 if (!ret_sys && (cpu_sys != cpu || node_sys != node))
166 if (!ret_vdso && (cpu_vdso != cpu || node_vdso != node))
168 if (!ret_vsys && (cpu_vsys != cpu || node_vsys != node))
171 printf("[%s]\tCPU %u:", ok ? "OK" : "FAIL", cpu);
173 printf(" syscall: cpu %u, node %u", cpu_sys, node_sys);
175 printf(" vdso: cpu %u, node %u", cpu_vdso, node_vdso);
177 printf(" vsyscall: cpu %u, node %u", cpu_vsys,
186 static bool ts_leq(const struct timespec *a, const struct timespec *b)
188 if (a->tv_sec != b->tv_sec)
189 return a->tv_sec < b->tv_sec;
191 return a->tv_nsec <= b->tv_nsec;
194 static bool tv_leq(const struct timeval *a, const struct timeval *b)
196 if (a->tv_sec != b->tv_sec)
197 return a->tv_sec < b->tv_sec;
199 return a->tv_usec <= b->tv_usec;
202 static char const * const clocknames[] = {
203 [0] = "CLOCK_REALTIME",
204 [1] = "CLOCK_MONOTONIC",
205 [2] = "CLOCK_PROCESS_CPUTIME_ID",
206 [3] = "CLOCK_THREAD_CPUTIME_ID",
207 [4] = "CLOCK_MONOTONIC_RAW",
208 [5] = "CLOCK_REALTIME_COARSE",
209 [6] = "CLOCK_MONOTONIC_COARSE",
210 [7] = "CLOCK_BOOTTIME",
211 [8] = "CLOCK_REALTIME_ALARM",
212 [9] = "CLOCK_BOOTTIME_ALARM",
213 [10] = "CLOCK_SGI_CYCLE",
217 static void test_one_clock_gettime(int clock, const char *name)
219 struct timespec start, vdso, end;
220 int vdso_ret, end_ret;
222 printf("[RUN]\tTesting clock_gettime for clock %s (%d)...\n", name, clock);
224 if (sys_clock_gettime(clock, &start) < 0) {
225 if (errno == EINVAL) {
226 vdso_ret = vdso_clock_gettime(clock, &vdso);
227 if (vdso_ret == -EINVAL) {
228 printf("[OK]\tNo such clock.\n");
230 printf("[FAIL]\tNo such clock, but __vdso_clock_gettime returned %d\n", vdso_ret);
234 printf("[WARN]\t clock_gettime(%d) syscall returned error %d\n", clock, errno);
239 vdso_ret = vdso_clock_gettime(clock, &vdso);
240 end_ret = sys_clock_gettime(clock, &end);
242 if (vdso_ret != 0 || end_ret != 0) {
243 printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n",
249 printf("\t%llu.%09ld %llu.%09ld %llu.%09ld\n",
250 (unsigned long long)start.tv_sec, start.tv_nsec,
251 (unsigned long long)vdso.tv_sec, vdso.tv_nsec,
252 (unsigned long long)end.tv_sec, end.tv_nsec);
254 if (!ts_leq(&start, &vdso) || !ts_leq(&vdso, &end)) {
255 printf("[FAIL]\tTimes are out of sequence\n");
260 static void test_clock_gettime(void)
262 for (int clock = 0; clock < sizeof(clocknames) / sizeof(clocknames[0]);
264 test_one_clock_gettime(clock, clocknames[clock]);
267 /* Also test some invalid clock ids */
268 test_one_clock_gettime(-1, "invalid");
269 test_one_clock_gettime(INT_MIN, "invalid");
270 test_one_clock_gettime(INT_MAX, "invalid");
273 static void test_gettimeofday(void)
275 struct timeval start, vdso, end;
276 struct timezone sys_tz, vdso_tz;
277 int vdso_ret, end_ret;
279 if (!vdso_gettimeofday)
282 printf("[RUN]\tTesting gettimeofday...\n");
284 if (sys_gettimeofday(&start, &sys_tz) < 0) {
285 printf("[FAIL]\tsys_gettimeofday failed (%d)\n", errno);
290 vdso_ret = vdso_gettimeofday(&vdso, &vdso_tz);
291 end_ret = sys_gettimeofday(&end, NULL);
293 if (vdso_ret != 0 || end_ret != 0) {
294 printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n",
300 printf("\t%llu.%06ld %llu.%06ld %llu.%06ld\n",
301 (unsigned long long)start.tv_sec, start.tv_usec,
302 (unsigned long long)vdso.tv_sec, vdso.tv_usec,
303 (unsigned long long)end.tv_sec, end.tv_usec);
305 if (!tv_leq(&start, &vdso) || !tv_leq(&vdso, &end)) {
306 printf("[FAIL]\tTimes are out of sequence\n");
310 if (sys_tz.tz_minuteswest == vdso_tz.tz_minuteswest &&
311 sys_tz.tz_dsttime == vdso_tz.tz_dsttime) {
312 printf("[OK]\ttimezones match: minuteswest=%d, dsttime=%d\n",
313 sys_tz.tz_minuteswest, sys_tz.tz_dsttime);
315 printf("[FAIL]\ttimezones do not match\n");
319 /* And make sure that passing NULL for tz doesn't crash. */
320 vdso_gettimeofday(&vdso, NULL);
323 int main(int argc, char **argv)
325 fill_function_pointers();
327 test_clock_gettime();
331 * Test getcpu() last so that, if something goes wrong setting affinity,
332 * we still run the other tests.
336 return nerrs ? 1 : 0;