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
17typedef int (*vgettime_t)(clockid_t, struct timespec *);
18
19vgettime_t vdso_clock_gettime;
20
21static 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
47static 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(msg: "%s:\tclock: %10s\tcycles:\t%10ld\n",
62 in_ns ? "ns" : "host", clockstr, i);
63}
64
65int main(int argc, char *argv[])
66{
67 time_t offset = 10;
68 int nsfd;
69
70 ksft_set_plan(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

source code of linux/tools/testing/selftests/timens/gettime_perf.c