1 // SPDX-License-Identifier: GPL-2.0
2 #define _GNU_SOURCE
3 #include <sys/types.h>
4 #include <sys/stat.h>
5 #include <errno.h>
6 #include <fcntl.h>
7 #include <sched.h>
8 #include <time.h>
9 #include <stdio.h>
10 #include <unistd.h>
11 #include <sys/syscall.h>
12 #include <dlfcn.h>
13 
14 #include "log.h"
15 #include "timens.h"
16 
17 typedef int (*vgettime_t)(clockid_t, struct timespec *);
18 
19 vgettime_t vdso_clock_gettime;
20 
fill_function_pointers(void)21 static void fill_function_pointers(void)
22 {
23 	void *vdso = dlopen("linux-vdso.so.1",
24 			    RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
25 	if (!vdso)
26 		vdso = dlopen("linux-gate.so.1",
27 			      RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
28 	if (!vdso)
29 		vdso = dlopen("linux-vdso32.so.1",
30 			      RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
31 	if (!vdso)
32 		vdso = dlopen("linux-vdso64.so.1",
33 			      RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
34 	if (!vdso) {
35 		pr_err("[WARN]\tfailed to find vDSO\n");
36 		return;
37 	}
38 
39 	vdso_clock_gettime = (vgettime_t)dlsym(vdso, "__vdso_clock_gettime");
40 	if (!vdso_clock_gettime)
41 		vdso_clock_gettime = (vgettime_t)dlsym(vdso, "__kernel_clock_gettime");
42 	if (!vdso_clock_gettime)
43 		pr_err("Warning: failed to find clock_gettime in vDSO\n");
44 
45 }
46 
test(clock_t clockid,char * clockstr,bool in_ns)47 static void test(clock_t clockid, char *clockstr, bool in_ns)
48 {
49 	struct timespec tp, start;
50 	long i = 0;
51 	const int timeout = 3;
52 
53 	vdso_clock_gettime(clockid, &start);
54 	tp = start;
55 	for (tp = start; start.tv_sec + timeout > tp.tv_sec ||
56 			 (start.tv_sec + timeout == tp.tv_sec &&
57 			  start.tv_nsec > tp.tv_nsec); i++) {
58 		vdso_clock_gettime(clockid, &tp);
59 	}
60 
61 	ksft_test_result_pass("%s:\tclock: %10s\tcycles:\t%10ld\n",
62 			      in_ns ? "ns" : "host", clockstr, i);
63 }
64 
main(int argc,char * argv[])65 int main(int argc, char *argv[])
66 {
67 	time_t offset = 10;
68 	int nsfd;
69 
70 	ksft_set_plan(8);
71 
72 	fill_function_pointers();
73 
74 	test(CLOCK_MONOTONIC, "monotonic", false);
75 	test(CLOCK_MONOTONIC_COARSE, "monotonic-coarse", false);
76 	test(CLOCK_MONOTONIC_RAW, "monotonic-raw", false);
77 	test(CLOCK_BOOTTIME, "boottime", false);
78 
79 	nscheck();
80 
81 	if (unshare_timens())
82 		return 1;
83 
84 	nsfd = open("/proc/self/ns/time_for_children", O_RDONLY);
85 	if (nsfd < 0)
86 		return pr_perror("Can't open a time namespace");
87 
88 	if (_settime(CLOCK_MONOTONIC, offset))
89 		return 1;
90 	if (_settime(CLOCK_BOOTTIME, offset))
91 		return 1;
92 
93 	if (setns(nsfd, CLONE_NEWTIME))
94 		return pr_perror("setns");
95 
96 	test(CLOCK_MONOTONIC, "monotonic", true);
97 	test(CLOCK_MONOTONIC_COARSE, "monotonic-coarse", true);
98 	test(CLOCK_MONOTONIC_RAW, "monotonic-raw", true);
99 	test(CLOCK_BOOTTIME, "boottime", true);
100 
101 	ksft_exit_pass();
102 	return 0;
103 }
104