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
 33void 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		perror("sched_setaffinity() failed");
 41		_exit(1);
 42	}
 43
 44	if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {
 45		perror("ptrace(PTRACE_TRACEME) failed");
 46		_exit(1);
 47	}
 48
 49	if (raise(SIGSTOP) != 0) {
 50		perror("raise(SIGSTOP) failed");
 51		_exit(1);
 52	}
 53
 54	_exit(0);
 55}
 56
 57bool run_test(int cpu)
 58{
 59	int status;
 60	pid_t pid = fork();
 61	pid_t wpid;
 62
 63	if (pid < 0) {
 64		perror("fork() failed");
 65		return false;
 66	}
 67	if (pid == 0)
 68		child(cpu);
 69
 70	wpid = waitpid(pid, &status, __WALL);
 71	if (wpid != pid) {
 72		perror("waitpid() failed");
 73		return false;
 74	}
 75	if (!WIFSTOPPED(status)) {
 76		printf("child did not stop\n");
 77		return false;
 78	}
 79	if (WSTOPSIG(status) != SIGSTOP) {
 80		printf("child did not stop with SIGSTOP\n");
 81		return false;
 82	}
 83
 84	if (ptrace(PTRACE_SINGLESTEP, pid, NULL, NULL) < 0) {
 85		if (errno == EIO) {
 86			printf("ptrace(PTRACE_SINGLESTEP) not supported on this architecture\n");
 87			ksft_exit_skip();
 88		}
 89		perror("ptrace(PTRACE_SINGLESTEP) failed");
 90		return false;
 91	}
 92
 93	wpid = waitpid(pid, &status, __WALL);
 94	if (wpid != pid) {
 95		perror("waitpid() failed");
 96		return false;
 97	}
 98	if (WIFEXITED(status)) {
 99		printf("child did not single-step\n");
100		return false;
101	}
102	if (!WIFSTOPPED(status)) {
103		printf("child did not stop\n");
104		return false;
105	}
106	if (WSTOPSIG(status) != SIGTRAP) {
107		printf("child did not stop with SIGTRAP\n");
108		return false;
109	}
110
111	if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
112		perror("ptrace(PTRACE_CONT) failed");
113		return false;
114	}
115
116	wpid = waitpid(pid, &status, __WALL);
117	if (wpid != pid) {
118		perror("waitpid() failed");
119		return false;
120	}
121	if (!WIFEXITED(status)) {
122		printf("child did not exit after PTRACE_CONT\n");
123		return false;
124	}
125
126	return true;
127}
128
129void suspend(void)
130{
131	int power_state_fd;
132	struct sigevent event = {};
133	int timerfd;
134	int err;
135	struct itimerspec spec = {};
136
137	power_state_fd = open("/sys/power/state", O_RDWR);
138	if (power_state_fd < 0) {
139		perror("open(\"/sys/power/state\") failed (is this test running as root?)");
140		ksft_exit_fail();
141	}
142
143	timerfd = timerfd_create(CLOCK_BOOTTIME_ALARM, 0);
144	if (timerfd < 0) {
145		perror("timerfd_create() failed");
146		ksft_exit_fail();
147	}
148
149	spec.it_value.tv_sec = 5;
150	err = timerfd_settime(timerfd, 0, &spec, NULL);
151	if (err < 0) {
152		perror("timerfd_settime() failed");
153		ksft_exit_fail();
154	}
155
156	if (write(power_state_fd, "mem", strlen("mem")) != strlen("mem")) {
157		perror("entering suspend failed");
158		ksft_exit_fail();
159	}
160
161	close(timerfd);
162	close(power_state_fd);
163}
164
165int main(int argc, char **argv)
166{
167	int opt;
168	bool do_suspend = true;
169	bool succeeded = true;
170	cpu_set_t available_cpus;
171	int err;
172	int cpu;
173
174	while ((opt = getopt(argc, argv, "n")) != -1) {
175		switch (opt) {
176		case 'n':
177			do_suspend = false;
178			break;
179		default:
180			printf("Usage: %s [-n]\n", argv[0]);
181			printf("        -n: do not trigger a suspend/resume cycle before the test\n");
182			return -1;
183		}
184	}
185
186	if (do_suspend)
187		suspend();
188
189	err = sched_getaffinity(0, sizeof(available_cpus), &available_cpus);
190	if (err < 0) {
191		perror("sched_getaffinity() failed");
192		ksft_exit_fail();
193	}
194
195	for (cpu = 0; cpu < CPU_SETSIZE; cpu++) {
196		bool test_success;
197
198		if (!CPU_ISSET(cpu, &available_cpus))
199			continue;
200
201		test_success = run_test(cpu);
202		printf("CPU %d: ", cpu);
203		if (test_success) {
204			printf("[OK]\n");
205			ksft_inc_pass_cnt();
206		} else {
207			printf("[FAILED]\n");
208			ksft_inc_fail_cnt();
209			succeeded = false;
210		}
211	}
212
213	ksft_print_cnts();
214	if (succeeded)
215		ksft_exit_pass();
216	else
217		ksft_exit_fail();
218}