1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2016 Google, Inc.
4  */
5 
6 #define _GNU_SOURCE
7 
8 #include <errno.h>
9 #include <fcntl.h>
10 #include <sched.h>
11 #include <signal.h>
12 #include <stdbool.h>
13 #include <stdio.h>
14 #include <string.h>
15 #include <unistd.h>
16 #include <sys/ptrace.h>
17 #include <sys/stat.h>
18 #include <sys/timerfd.h>
19 #include <sys/types.h>
20 #include <sys/wait.h>
21 
22 #include "../kselftest.h"
23 
24 void child(int cpu)
25 {
26 	cpu_set_t set;
27 
28 	CPU_ZERO(&set);
29 	CPU_SET(cpu, &set);
30 	if (sched_setaffinity(0, sizeof(set), &set) != 0) {
31 		ksft_print_msg("sched_setaffinity() failed: %s\n",
32 			strerror(errno));
33 		_exit(1);
34 	}
35 
36 	if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {
37 		ksft_print_msg("ptrace(PTRACE_TRACEME) failed: %s\n",
38 			strerror(errno));
39 		_exit(1);
40 	}
41 
42 	if (raise(SIGSTOP) != 0) {
43 		ksft_print_msg("raise(SIGSTOP) failed: %s\n", strerror(errno));
44 		_exit(1);
45 	}
46 
47 	_exit(0);
48 }
49 
50 int run_test(int cpu)
51 {
52 	int status;
53 	pid_t pid = fork();
54 	pid_t wpid;
55 
56 	if (pid < 0) {
57 		ksft_print_msg("fork() failed: %s\n", strerror(errno));
58 		return KSFT_FAIL;
59 	}
60 	if (pid == 0)
61 		child(cpu);
62 
63 	wpid = waitpid(pid, &status, __WALL);
64 	if (wpid != pid) {
65 		ksft_print_msg("waitpid() failed: %s\n", strerror(errno));
66 		return KSFT_FAIL;
67 	}
68 	if (!WIFSTOPPED(status)) {
69 		ksft_print_msg("child did not stop: %s\n", strerror(errno));
70 		return KSFT_FAIL;
71 	}
72 	if (WSTOPSIG(status) != SIGSTOP) {
73 		ksft_print_msg("child did not stop with SIGSTOP: %s\n",
74 			strerror(errno));
75 		return KSFT_FAIL;
76 	}
77 
78 	if (ptrace(PTRACE_SINGLESTEP, pid, NULL, NULL) < 0) {
79 		if (errno == EIO) {
80 			ksft_print_msg(
81 				"ptrace(PTRACE_SINGLESTEP) not supported on this architecture: %s\n",
82 				strerror(errno));
83 			return KSFT_SKIP;
84 		}
85 		ksft_print_msg("ptrace(PTRACE_SINGLESTEP) failed: %s\n",
86 			strerror(errno));
87 		return KSFT_FAIL;
88 	}
89 
90 	wpid = waitpid(pid, &status, __WALL);
91 	if (wpid != pid) {
92 		ksft_print_msg("waitpid() failed: $s\n", strerror(errno));
93 		return KSFT_FAIL;
94 	}
95 	if (WIFEXITED(status)) {
96 		ksft_print_msg("child did not single-step: %s\n",
97 			strerror(errno));
98 		return KSFT_FAIL;
99 	}
100 	if (!WIFSTOPPED(status)) {
101 		ksft_print_msg("child did not stop: %s\n", strerror(errno));
102 		return KSFT_FAIL;
103 	}
104 	if (WSTOPSIG(status) != SIGTRAP) {
105 		ksft_print_msg("child did not stop with SIGTRAP: %s\n",
106 			strerror(errno));
107 		return KSFT_FAIL;
108 	}
109 
110 	if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
111 		ksft_print_msg("ptrace(PTRACE_CONT) failed: %s\n",
112 			strerror(errno));
113 		return KSFT_FAIL;
114 	}
115 
116 	wpid = waitpid(pid, &status, __WALL);
117 	if (wpid != pid) {
118 		ksft_print_msg("waitpid() failed: %s\n", strerror(errno));
119 		return KSFT_FAIL;
120 	}
121 	if (!WIFEXITED(status)) {
122 		ksft_print_msg("child did not exit after PTRACE_CONT: %s\n",
123 			strerror(errno));
124 		return KSFT_FAIL;
125 	}
126 
127 	return KSFT_PASS;
128 }
129 
130 void suspend(void)
131 {
132 	int power_state_fd;
133 	struct sigevent event = {};
134 	int timerfd;
135 	int err;
136 	struct itimerspec spec = {};
137 
138 	if (getuid() != 0)
139 		ksft_exit_skip("Please run the test as root - Exiting.\n");
140 
141 	power_state_fd = open("/sys/power/state", O_RDWR);
142 	if (power_state_fd < 0)
143 		ksft_exit_fail_msg(
144 			"open(\"/sys/power/state\") failed %s)\n",
145 			strerror(errno));
146 
147 	timerfd = timerfd_create(CLOCK_BOOTTIME_ALARM, 0);
148 	if (timerfd < 0)
149 		ksft_exit_fail_msg("timerfd_create() failed\n");
150 
151 	spec.it_value.tv_sec = 5;
152 	err = timerfd_settime(timerfd, 0, &spec, NULL);
153 	if (err < 0)
154 		ksft_exit_fail_msg("timerfd_settime() failed\n");
155 
156 	system("(echo mem > /sys/power/state) 2> /dev/null");
157 
158 	timerfd_gettime(timerfd, &spec);
159 	if (spec.it_value.tv_sec != 0 || spec.it_value.tv_nsec != 0)
160 		ksft_exit_fail_msg("Failed to enter Suspend state\n");
161 
162 	close(timerfd);
163 	close(power_state_fd);
164 }
165 
166 int main(int argc, char **argv)
167 {
168 	int opt;
169 	bool do_suspend = true;
170 	bool succeeded = true;
171 	unsigned int tests = 0;
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 	err = sched_getaffinity(0, sizeof(available_cpus), &available_cpus);
191 	if (err < 0)
192 		ksft_exit_fail_msg("sched_getaffinity() failed\n");
193 
194 	for (cpu = 0; cpu < CPU_SETSIZE; cpu++) {
195 		if (!CPU_ISSET(cpu, &available_cpus))
196 			continue;
197 		tests++;
198 	}
199 
200 	if (do_suspend)
201 		suspend();
202 
203 	ksft_set_plan(tests);
204 	for (cpu = 0; cpu < CPU_SETSIZE; cpu++) {
205 		int test_success;
206 
207 		if (!CPU_ISSET(cpu, &available_cpus))
208 			continue;
209 
210 		test_success = run_test(cpu);
211 		switch (test_success) {
212 		case KSFT_PASS:
213 			ksft_test_result_pass("CPU %d\n", cpu);
214 			break;
215 		case KSFT_SKIP:
216 			ksft_test_result_skip("CPU %d\n", cpu);
217 			break;
218 		case KSFT_FAIL:
219 			ksft_test_result_fail("CPU %d\n", cpu);
220 			succeeded = false;
221 			break;
222 		}
223 	}
224 
225 	if (succeeded)
226 		ksft_exit_pass();
227 	else
228 		ksft_exit_fail();
229 }
230