tools/testing/selftests/breakpoints/step_after_suspend_test.c

   1 /*
   2  * Copyright (C) 2016 Google, Inc.
   3  *
   4  * This software is licensed under the terms of the GNU General Public
   5  * License version 2, as published by the Free Software Foundation, and
   6  * may be copied, distributed, and modified under those terms.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  */
  14
  15 #define _GNU_SOURCE
  16
  17 #include <errno.h>
  18 #include <fcntl.h>
  19 #include <sched.h>
  20 #include <signal.h>
  21 #include <stdbool.h>
  22 #include <stdio.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <sys/ptrace.h>
  26 #include <sys/stat.h>
  27 #include <sys/timerfd.h>
  28 #include <sys/types.h>
  29 #include <sys/wait.h>
  30
  31 #include "../kselftest.h"
  32
  33 void child(int cpu)
  34 {
  35         cpu_set_t set;
  36
  37         CPU_ZERO(&set);
  38         CPU_SET(cpu, &set);
  39         if (sched_setaffinity(0, sizeof(set), &set) != 0) {
  40                 ksft_print_msg("sched_setaffinity() failed: %s\n",
  41                         strerror(errno));
  42                 _exit(1);
  43         }
  44
  45         if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {
  46                 ksft_print_msg("ptrace(PTRACE_TRACEME) failed: %s\n",
  47                         strerror(errno));
  48                 _exit(1);
  49         }
  50
  51         if (raise(SIGSTOP) != 0) {
  52                 ksft_print_msg("raise(SIGSTOP) failed: %s\n", strerror(errno));
  53                 _exit(1);
  54         }
  55
  56         _exit(0);
  57 }
  58
  59 bool run_test(int cpu)
  60 {
  61         int status;
  62         pid_t pid = fork();
  63         pid_t wpid;
  64
  65         if (pid < 0) {
  66                 ksft_print_msg("fork() failed: %s\n", strerror(errno));
  67                 return false;
  68         }
  69         if (pid == 0)
  70                 child(cpu);
  71
  72         wpid = waitpid(pid, &status, __WALL);
  73         if (wpid != pid) {
  74                 ksft_print_msg("waitpid() failed: %s\n", strerror(errno));
  75                 return false;
  76         }
  77         if (!WIFSTOPPED(status)) {
  78                 ksft_print_msg("child did not stop: %s\n", strerror(errno));
  79                 return false;
  80         }
  81         if (WSTOPSIG(status) != SIGSTOP) {
  82                 ksft_print_msg("child did not stop with SIGSTOP: %s\n",
  83                         strerror(errno));
  84                 return false;
  85         }
  86
  87         if (ptrace(PTRACE_SINGLESTEP, pid, NULL, NULL) < 0) {
  88                 if (errno == EIO) {
  89                         ksft_exit_skip(
  90                                 "ptrace(PTRACE_SINGLESTEP) not supported on this architecture: %s\n",
  91                                 strerror(errno));
  92                 }
  93                 ksft_print_msg("ptrace(PTRACE_SINGLESTEP) failed: %s\n",
  94                         strerror(errno));
  95                 return false;
  96         }
  97
  98         wpid = waitpid(pid, &status, __WALL);
  99         if (wpid != pid) {
 100                 ksft_print_msg("waitpid() failed: $s\n", strerror(errno));
 101                 return false;
 102         }
 103         if (WIFEXITED(status)) {
 104                 ksft_print_msg("child did not single-step: %s\n",
 105                         strerror(errno));
 106                 return false;
 107         }
 108         if (!WIFSTOPPED(status)) {
 109                 ksft_print_msg("child did not stop: %s\n", strerror(errno));
 110                 return false;
 111         }
 112         if (WSTOPSIG(status) != SIGTRAP) {
 113                 ksft_print_msg("child did not stop with SIGTRAP: %s\n",
 114                         strerror(errno));
 115                 return false;
 116         }
 117
 118         if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
 119                 ksft_print_msg("ptrace(PTRACE_CONT) failed: %s\n",
 120                         strerror(errno));
 121                 return false;
 122         }
 123
 124         wpid = waitpid(pid, &status, __WALL);
 125         if (wpid != pid) {
 126                 ksft_print_msg("waitpid() failed: %s\n", strerror(errno));
 127                 return false;
 128         }
 129         if (!WIFEXITED(status)) {
 130                 ksft_print_msg("child did not exit after PTRACE_CONT: %s\n",
 131                         strerror(errno));
 132                 return false;
 133         }
 134
 135         return true;
 136 }
 137
 138 void suspend(void)
 139 {
 140         int power_state_fd;
 141         struct sigevent event = {};
 142         int timerfd;
 143         int err;
 144         struct itimerspec spec = {};
 145
 146         power_state_fd = open("/sys/power/state", O_RDWR);
 147         if (power_state_fd < 0)
 148                 ksft_exit_fail_msg(
 149                         "open(\"/sys/power/state\") failed (is this test running as root?)\n");
 150
 151         timerfd = timerfd_create(CLOCK_BOOTTIME_ALARM, 0);
 152         if (timerfd < 0)
 153                 ksft_exit_fail_msg("timerfd_create() failed\n");
 154
 155         spec.it_value.tv_sec = 5;
 156         err = timerfd_settime(timerfd, 0, &spec, NULL);
 157         if (err < 0)
 158                 ksft_exit_fail_msg("timerfd_settime() failed\n");
 159
 160         if (write(power_state_fd, "mem", strlen("mem")) != strlen("mem"))
 161                 ksft_exit_fail_msg("Failed to enter Suspend state\n");
 162
 163         close(timerfd);
 164         close(power_state_fd);
 165 }
 166
 167 int main(int argc, char **argv)
 168 {
 169         int opt;
 170         bool do_suspend = true;
 171         bool succeeded = true;
 172         cpu_set_t available_cpus;
 173         int err;
 174         int cpu;
 175
 176         ksft_print_header();
 177
 178         while ((opt = getopt(argc, argv, "n")) != -1) {
 179                 switch (opt) {
 180                 case 'n':
 181                         do_suspend = false;
 182                         break;
 183                 default:
 184                         printf("Usage: %s [-n]\n", argv[0]);
 185                         printf("        -n: do not trigger a suspend/resume cycle before the test\n");
 186                         return -1;
 187                 }
 188         }
 189
 190         if (do_suspend)
 191                 suspend();
 192
 193         err = sched_getaffinity(0, sizeof(available_cpus), &available_cpus);
 194         if (err < 0)
 195                 ksft_exit_fail_msg("sched_getaffinity() failed\n");
 196
 197         for (cpu = 0; cpu < CPU_SETSIZE; cpu++) {
 198                 bool test_success;
 199
 200                 if (!CPU_ISSET(cpu, &available_cpus))
 201                         continue;
 202
 203                 test_success = run_test(cpu);
 204                 if (test_success) {
 205                         ksft_test_result_pass("CPU %d\n", cpu);
 206                 } else {
 207                         ksft_test_result_fail("CPU %d\n", cpu);
 208                         succeeded = false;
 209                 }
 210         }
 211
 212         if (succeeded)
 213                 ksft_exit_pass();
 214         else
 215                 ksft_exit_fail();
 216 }