summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/vDSO/vdso_test_correctness.c
blob: e691a3cf14911237190c048f658830078dc90c3b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
// SPDX-License-Identifier: GPL-2.0
/*
 * ldt_gdt.c - Test cases for LDT and GDT access
 * Copyright (c) 2011-2015 Andrew Lutomirski
 */

#define _GNU_SOURCE

#include <stdio.h>
#include <sys/time.h>
#include <time.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <dlfcn.h>
#include <string.h>
#include <errno.h>
#include <sched.h>
#include <stdbool.h>
#include <limits.h>

#include "vdso_config.h"
#include "../kselftest.h"

static const char **name;

#ifndef SYS_getcpu
# ifdef __x86_64__
#  define SYS_getcpu 309
# else
#  define SYS_getcpu 318
# endif
#endif

#ifndef __NR_clock_gettime64
#define __NR_clock_gettime64	403
#endif

#ifndef __kernel_timespec
struct __kernel_timespec {
	long long	tv_sec;
	long long	tv_nsec;
};
#endif

/* max length of lines in /proc/self/maps - anything longer is skipped here */
#define MAPS_LINE_LEN 128

int nerrs = 0;

typedef int (*vgettime_t)(clockid_t, struct timespec *);

vgettime_t vdso_clock_gettime;

typedef int (*vgettime64_t)(clockid_t, struct __kernel_timespec *);

vgettime64_t vdso_clock_gettime64;

typedef long (*vgtod_t)(struct timeval *tv, struct timezone *tz);

vgtod_t vdso_gettimeofday;

typedef long (*getcpu_t)(unsigned *, unsigned *, void *);

getcpu_t vgetcpu;
getcpu_t vdso_getcpu;

static void *vsyscall_getcpu(void)
{
#ifdef __x86_64__
	FILE *maps;
	char line[MAPS_LINE_LEN];
	bool found = false;

	maps = fopen("/proc/self/maps", "r");
	if (!maps) /* might still be present, but ignore it here, as we test vDSO not vsyscall */
		return NULL;

	while (fgets(line, MAPS_LINE_LEN, maps)) {
		char r, x;
		void *start, *end;
		char name[MAPS_LINE_LEN];

		/* sscanf() is safe here as strlen(name) >= strlen(line) */
		if (sscanf(line, "%p-%p %c-%cp %*x %*x:%*x %*u %s",
			   &start, &end, &r, &x, name) != 5)
			continue;

		if (strcmp(name, "[vsyscall]"))
			continue;

		/* assume entries are OK, as we test vDSO here not vsyscall */
		found = true;
		break;
	}

	fclose(maps);

	if (!found) {
		printf("Warning: failed to find vsyscall getcpu\n");
		return NULL;
	}
	return (void *) (0xffffffffff600800);
#else
	return NULL;
#endif
}


static void fill_function_pointers()
{
	void *vdso = dlopen("linux-vdso.so.1",
			    RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
	if (!vdso)
		vdso = dlopen("linux-gate.so.1",
			      RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
	if (!vdso) {
		printf("[WARN]\tfailed to find vDSO\n");
		return;
	}

	vdso_getcpu = (getcpu_t)dlsym(vdso, name[4]);
	if (!vdso_getcpu)
		printf("Warning: failed to find getcpu in vDSO\n");

	vgetcpu = (getcpu_t) vsyscall_getcpu();

	vdso_clock_gettime = (vgettime_t)dlsym(vdso, name[1]);
	if (!vdso_clock_gettime)
		printf("Warning: failed to find clock_gettime in vDSO\n");

#if defined(VDSO_32BIT)
	vdso_clock_gettime64 = (vgettime64_t)dlsym(vdso, name[5]);
	if (!vdso_clock_gettime64)
		printf("Warning: failed to find clock_gettime64 in vDSO\n");
#endif

	vdso_gettimeofday = (vgtod_t)dlsym(vdso, name[0]);
	if (!vdso_gettimeofday)
		printf("Warning: failed to find gettimeofday in vDSO\n");

}

static long sys_getcpu(unsigned * cpu, unsigned * node,
		       void* cache)
{
	return syscall(__NR_getcpu, cpu, node, cache);
}

static inline int sys_clock_gettime(clockid_t id, struct timespec *ts)
{
	return syscall(__NR_clock_gettime, id, ts);
}

static inline int sys_clock_gettime64(clockid_t id, struct __kernel_timespec *ts)
{
	return syscall(__NR_clock_gettime64, id, ts);
}

static inline int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
{
	return syscall(__NR_gettimeofday, tv, tz);
}

static void test_getcpu(void)
{
	printf("[RUN]\tTesting getcpu...\n");

	for (int cpu = 0; ; cpu++) {
		cpu_set_t cpuset;
		CPU_ZERO(&cpuset);
		CPU_SET(cpu, &cpuset);
		if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0)
			return;

		unsigned cpu_sys, cpu_vdso, cpu_vsys,
			node_sys, node_vdso, node_vsys;
		long ret_sys, ret_vdso = 1, ret_vsys = 1;
		unsigned node;

		ret_sys = sys_getcpu(&cpu_sys, &node_sys, 0);
		if (vdso_getcpu)
			ret_vdso = vdso_getcpu(&cpu_vdso, &node_vdso, 0);
		if (vgetcpu)
			ret_vsys = vgetcpu(&cpu_vsys, &node_vsys, 0);

		if (!ret_sys)
			node = node_sys;
		else if (!ret_vdso)
			node = node_vdso;
		else if (!ret_vsys)
			node = node_vsys;

		bool ok = true;
		if (!ret_sys && (cpu_sys != cpu || node_sys != node))
			ok = false;
		if (!ret_vdso && (cpu_vdso != cpu || node_vdso != node))
			ok = false;
		if (!ret_vsys && (cpu_vsys != cpu || node_vsys != node))
			ok = false;

		printf("[%s]\tCPU %u:", ok ? "OK" : "FAIL", cpu);
		if (!ret_sys)
			printf(" syscall: cpu %u, node %u", cpu_sys, node_sys);
		if (!ret_vdso)
			printf(" vdso: cpu %u, node %u", cpu_vdso, node_vdso);
		if (!ret_vsys)
			printf(" vsyscall: cpu %u, node %u", cpu_vsys,
			       node_vsys);
		printf("\n");

		if (!ok)
			nerrs++;
	}
}

static bool ts_leq(const struct timespec *a, const struct timespec *b)
{
	if (a->tv_sec != b->tv_sec)
		return a->tv_sec < b->tv_sec;
	else
		return a->tv_nsec <= b->tv_nsec;
}

static bool ts64_leq(const struct __kernel_timespec *a,
		     const struct __kernel_timespec *b)
{
	if (a->tv_sec != b->tv_sec)
		return a->tv_sec < b->tv_sec;
	else
		return a->tv_nsec <= b->tv_nsec;
}

static bool tv_leq(const struct timeval *a, const struct timeval *b)
{
	if (a->tv_sec != b->tv_sec)
		return a->tv_sec < b->tv_sec;
	else
		return a->tv_usec <= b->tv_usec;
}

static char const * const clocknames[] = {
	[0] = "CLOCK_REALTIME",
	[1] = "CLOCK_MONOTONIC",
	[2] = "CLOCK_PROCESS_CPUTIME_ID",
	[3] = "CLOCK_THREAD_CPUTIME_ID",
	[4] = "CLOCK_MONOTONIC_RAW",
	[5] = "CLOCK_REALTIME_COARSE",
	[6] = "CLOCK_MONOTONIC_COARSE",
	[7] = "CLOCK_BOOTTIME",
	[8] = "CLOCK_REALTIME_ALARM",
	[9] = "CLOCK_BOOTTIME_ALARM",
	[10] = "CLOCK_SGI_CYCLE",
	[11] = "CLOCK_TAI",
};

static void test_one_clock_gettime(int clock, const char *name)
{
	struct timespec start, vdso, end;
	int vdso_ret, end_ret;

	printf("[RUN]\tTesting clock_gettime for clock %s (%d)...\n", name, clock);

	if (sys_clock_gettime(clock, &start) < 0) {
		if (errno == EINVAL) {
			vdso_ret = vdso_clock_gettime(clock, &vdso);
			if (vdso_ret == -EINVAL) {
				printf("[OK]\tNo such clock.\n");
			} else {
				printf("[FAIL]\tNo such clock, but __vdso_clock_gettime returned %d\n", vdso_ret);
				nerrs++;
			}
		} else {
			printf("[WARN]\t clock_gettime(%d) syscall returned error %d\n", clock, errno);
		}
		return;
	}

	vdso_ret = vdso_clock_gettime(clock, &vdso);
	end_ret = sys_clock_gettime(clock, &end);

	if (vdso_ret != 0 || end_ret != 0) {
		printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n",
		       vdso_ret, errno);
		nerrs++;
		return;
	}

	printf("\t%llu.%09ld %llu.%09ld %llu.%09ld\n",
	       (unsigned long long)start.tv_sec, start.tv_nsec,
	       (unsigned long long)vdso.tv_sec, vdso.tv_nsec,
	       (unsigned long long)end.tv_sec, end.tv_nsec);

	if (!ts_leq(&start, &vdso) || !ts_leq(&vdso, &end)) {
		printf("[FAIL]\tTimes are out of sequence\n");
		nerrs++;
		return;
	}

	printf("[OK]\tTest Passed.\n");
}

static void test_clock_gettime(void)
{
	if (!vdso_clock_gettime) {
		printf("[SKIP]\tNo vDSO, so skipping clock_gettime() tests\n");
		return;
	}

	for (int clock = 0; clock < ARRAY_SIZE(clocknames); clock++)
		test_one_clock_gettime(clock, clocknames[clock]);

	/* Also test some invalid clock ids */
	test_one_clock_gettime(-1, "invalid");
	test_one_clock_gettime(INT_MIN, "invalid");
	test_one_clock_gettime(INT_MAX, "invalid");
}

static void test_one_clock_gettime64(int clock, const char *name)
{
	struct __kernel_timespec start, vdso, end;
	int vdso_ret, end_ret;

	printf("[RUN]\tTesting clock_gettime64 for clock %s (%d)...\n", name, clock);

	if (sys_clock_gettime64(clock, &start) < 0) {
		if (errno == EINVAL) {
			vdso_ret = vdso_clock_gettime64(clock, &vdso);
			if (vdso_ret == -EINVAL) {
				printf("[OK]\tNo such clock.\n");
			} else {
				printf("[FAIL]\tNo such clock, but __vdso_clock_gettime64 returned %d\n", vdso_ret);
				nerrs++;
			}
		} else {
			printf("[WARN]\t clock_gettime64(%d) syscall returned error %d\n", clock, errno);
		}
		return;
	}

	vdso_ret = vdso_clock_gettime64(clock, &vdso);
	end_ret = sys_clock_gettime64(clock, &end);

	if (vdso_ret != 0 || end_ret != 0) {
		printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n",
		       vdso_ret, errno);
		nerrs++;
		return;
	}

	printf("\t%llu.%09lld %llu.%09lld %llu.%09lld\n",
	       (unsigned long long)start.tv_sec, start.tv_nsec,
	       (unsigned long long)vdso.tv_sec, vdso.tv_nsec,
	       (unsigned long long)end.tv_sec, end.tv_nsec);

	if (!ts64_leq(&start, &vdso) || !ts64_leq(&vdso, &end)) {
		printf("[FAIL]\tTimes are out of sequence\n");
		nerrs++;
		return;
	}

	printf("[OK]\tTest Passed.\n");
}

static void test_clock_gettime64(void)
{
	if (!vdso_clock_gettime64) {
		printf("[SKIP]\tNo vDSO, so skipping clock_gettime64() tests\n");
		return;
	}

	for (int clock = 0; clock < ARRAY_SIZE(clocknames); clock++)
		test_one_clock_gettime64(clock, clocknames[clock]);

	/* Also test some invalid clock ids */
	test_one_clock_gettime64(-1, "invalid");
	test_one_clock_gettime64(INT_MIN, "invalid");
	test_one_clock_gettime64(INT_MAX, "invalid");
}

static void test_gettimeofday(void)
{
	struct timeval start, vdso, end;
	struct timezone sys_tz, vdso_tz;
	int vdso_ret, end_ret;

	if (!vdso_gettimeofday)
		return;

	printf("[RUN]\tTesting gettimeofday...\n");

	if (sys_gettimeofday(&start, &sys_tz) < 0) {
		printf("[FAIL]\tsys_gettimeofday failed (%d)\n", errno);
		nerrs++;
		return;
	}

	vdso_ret = vdso_gettimeofday(&vdso, &vdso_tz);
	end_ret = sys_gettimeofday(&end, NULL);

	if (vdso_ret != 0 || end_ret != 0) {
		printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n",
		       vdso_ret, errno);
		nerrs++;
		return;
	}

	printf("\t%llu.%06ld %llu.%06ld %llu.%06ld\n",
	       (unsigned long long)start.tv_sec, start.tv_usec,
	       (unsigned long long)vdso.tv_sec, vdso.tv_usec,
	       (unsigned long long)end.tv_sec, end.tv_usec);

	if (!tv_leq(&start, &vdso) || !tv_leq(&vdso, &end)) {
		printf("[FAIL]\tTimes are out of sequence\n");
		nerrs++;
	}

	if (sys_tz.tz_minuteswest == vdso_tz.tz_minuteswest &&
	    sys_tz.tz_dsttime == vdso_tz.tz_dsttime) {
		printf("[OK]\ttimezones match: minuteswest=%d, dsttime=%d\n",
		       sys_tz.tz_minuteswest, sys_tz.tz_dsttime);
	} else {
		printf("[FAIL]\ttimezones do not match\n");
		nerrs++;
	}

	/* And make sure that passing NULL for tz doesn't crash. */
	vdso_gettimeofday(&vdso, NULL);
}

int main(int argc, char **argv)
{
	name = (const char **)&names[VDSO_NAMES];

	fill_function_pointers();

	test_clock_gettime();
	test_clock_gettime64();
	test_gettimeofday();

	/*
	 * Test getcpu() last so that, if something goes wrong setting affinity,
	 * we still run the other tests.
	 */
	test_getcpu();

	return nerrs ? 1 : 0;
}