104 lines · c
1// SPDX-License-Identifier: GPL-2.02#define _GNU_SOURCE3#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("%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(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