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
25static 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
40struct __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
49int nerrs = 0;
50
51typedef int (*vgettime_t)(clockid_t, struct timespec *);
52
53vgettime_t vdso_clock_gettime;
54
55typedef int (*vgettime64_t)(clockid_t, struct __kernel_timespec *);
56
57vgettime64_t vdso_clock_gettime64;
58
59typedef long (*vgtod_t)(struct timeval *tv, struct timezone *tz);
60
61vgtod_t vdso_gettimeofday;
62
63typedef long (*getcpu_t)(unsigned *, unsigned *, void *);
64
65getcpu_t vgetcpu;
66getcpu_t vdso_getcpu;
67
68static 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
110static 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
144static long sys_getcpu(unsigned * cpu, unsigned * node,
145		       void* cache)
146{
147	return syscall(__NR_getcpu, cpu, node, cache);
148}
149
150static inline int sys_clock_gettime(clockid_t id, struct timespec *ts)
151{
152	return syscall(__NR_clock_gettime, id, ts);
153}
154
155static inline int sys_clock_gettime64(clockid_t id, struct __kernel_timespec *ts)
156{
157	return syscall(__NR_clock_gettime64, id, ts);
158}
159
160static inline int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
161{
162	return syscall(__NR_gettimeofday, tv, tz);
163}
164
165static 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
217static 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
225static 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
234static 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
242static 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
257static 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
303static 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
319static 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
365static 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
381static 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
431int 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}
449