1 /* Test framework for wait3 and wait4.
2 Copyright (C) 2020-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <errno.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <unistd.h>
23 #include <sys/wait.h>
24 #include <sys/resource.h>
25 #include <signal.h>
26 #include <time.h>
27 #include <stdatomic.h>
28 #include <stdbool.h>
29
30 #include <support/xsignal.h>
31 #include <support/xunistd.h>
32 #include <support/check.h>
33 #include <support/process_state.h>
34
35 static void
36 test_child (void)
37 {
38 /* First thing, we stop ourselves. */
39 raise (SIGSTOP);
40
41 /* Hey, we got continued! */
42 while (1)
43 pause ();
44 }
45
46 #ifndef WEXITED
47 # define WEXITED 0
48 # define WCONTINUED 0
49 # define WSTOPPED WUNTRACED
50 #endif
51
52 /* Set with only SIGCHLD on do_test_waitid. */
53 static sigset_t chldset;
54
55 #ifdef SA_SIGINFO
56 static void
57 sigchld (int signo, siginfo_t *info, void *ctx)
58 {
59 }
60 #endif
61
62 static void
63 check_sigchld (int code, int status, pid_t pid)
64 {
65 #ifdef SA_SIGINFO
66 siginfo_t siginfo;
67 TEST_COMPARE (sigwaitinfo (&chldset, &siginfo), SIGCHLD);
68
69 TEST_COMPARE (siginfo.si_signo, SIGCHLD);
70 TEST_COMPARE (siginfo.si_code, code);
71 TEST_COMPARE (siginfo.si_status, status);
72 TEST_COMPARE (siginfo.si_pid, pid);
73 #endif
74 }
75
76 static int
77 do_test_wait (pid_t pid)
78 {
79 /* Adding process_state_tracing_stop ('t') allows the test to work under
80 trace programs such as ptrace. */
81 enum support_process_state stop_state = support_process_state_stopped
82 | support_process_state_tracing_stop;
83
84 support_process_state_wait (pid, stop_state);
85
86 check_sigchld (CLD_STOPPED, SIGSTOP, pid);
87
88 pid_t ret;
89 int wstatus;
90 struct rusage rusage;
91
92 ret = WAIT_CALL (pid, &wstatus, WUNTRACED|WCONTINUED|WNOHANG, NULL);
93 if (ret == -1 && errno == ENOTSUP)
94 FAIL_RET ("waitid WNOHANG on stopped: %m");
95 TEST_COMPARE (ret, pid);
96 TEST_VERIFY (WIFSTOPPED (wstatus));
97
98 /* Issue again but with struct rusage input. */
99 ret = WAIT_CALL (pid, &wstatus, WUNTRACED|WCONTINUED|WNOHANG, &rusage);
100 /* With WNOHANG and WUNTRACED, if the children has not changes its state
101 since previous call the expected result it 0. */
102 TEST_COMPARE (ret, 0);
103
104 /* Some sanity tests to check if 'wtatus' and 'rusage' possible
105 input values. */
106 ret = WAIT_CALL (pid, NULL, WUNTRACED|WCONTINUED|WNOHANG, &rusage);
107 TEST_COMPARE (ret, 0);
108 ret = WAIT_CALL (pid, NULL, WUNTRACED|WCONTINUED|WNOHANG, NULL);
109 TEST_COMPARE (ret, 0);
110
111 if (kill (pid, SIGCONT) != 0)
112 FAIL_RET ("kill (%d, SIGCONT): %m\n", pid);
113
114 /* Wait for the child to have continued. */
115 support_process_state_wait (pid, support_process_state_sleeping);
116
117 #if WCONTINUED != 0
118 check_sigchld (CLD_CONTINUED, SIGCONT, pid);
119
120 ret = WAIT_CALL (pid, &wstatus, WCONTINUED|WNOHANG, NULL);
121 TEST_COMPARE (ret, pid);
122 TEST_VERIFY (WIFCONTINUED (wstatus));
123
124 /* Issue again but with struct rusage input. */
125 ret = WAIT_CALL (pid, &wstatus, WUNTRACED|WCONTINUED|WNOHANG, &rusage);
126 /* With WNOHANG and WUNTRACED, if the children has not changes its state
127 since previous call the expected result it 0. */
128 TEST_COMPARE (ret, 0);
129
130 /* Now stop him again and test waitpid with WCONTINUED. */
131 if (kill (pid, SIGSTOP) != 0)
132 FAIL_RET ("kill (%d, SIGSTOP): %m\n", pid);
133
134 /* Wait the child stop. The waitid call below will block until it has
135 stopped, but if we are real quick and enter the waitid system call
136 before the SIGCHLD has been generated, then it will be discarded and
137 never delivered. */
138 support_process_state_wait (pid, stop_state);
139
140 ret = WAIT_CALL (pid, &wstatus, WUNTRACED|WNOHANG, &rusage);
141 TEST_COMPARE (ret, pid);
142
143 check_sigchld (CLD_STOPPED, SIGSTOP, pid);
144
145 if (kill (pid, SIGCONT) != 0)
146 FAIL_RET ("kill (%d, SIGCONT): %m\n", pid);
147
148 /* Wait for the child to have continued. */
149 support_process_state_wait (pid, support_process_state_sleeping);
150
151 check_sigchld (CLD_CONTINUED, SIGCONT, pid);
152
153 ret = WAIT_CALL (pid, &wstatus, WCONTINUED|WNOHANG, NULL);
154 TEST_COMPARE (ret, pid);
155 TEST_VERIFY (WIFCONTINUED (wstatus));
156 #endif
157
158 /* Die, child, die! */
159 if (kill (pid, SIGKILL) != 0)
160 FAIL_RET ("kill (%d, SIGKILL): %m\n", pid);
161
162 support_process_state_wait (pid, support_process_state_zombie);
163
164 ret = WAIT_CALL (pid, &wstatus, 0, &rusage);
165 TEST_COMPARE (ret, pid);
166 TEST_VERIFY (WIFSIGNALED (wstatus));
167 TEST_VERIFY (WTERMSIG (wstatus) == SIGKILL);
168
169 check_sigchld (CLD_KILLED, SIGKILL, pid);
170
171 return 0;
172 }
173
174 static int
175 do_test (void)
176 {
177 #ifdef SA_SIGINFO
178 {
179 struct sigaction sa;
180 sa.sa_flags = SA_SIGINFO | SA_RESTART;
181 sa.sa_sigaction = sigchld;
182 sigemptyset (&sa.sa_mask);
183 xsigaction (SIGCHLD, &sa, NULL);
184 }
185 #endif
186
187 sigemptyset (&chldset);
188 sigaddset (&chldset, SIGCHLD);
189
190 /* The SIGCHLD shall has blocked at the time of the call to sigwait;
191 otherwise, the behavior is undefined. */
192 sigprocmask (SIG_BLOCK, &chldset, NULL);
193
194 pid_t pid = xfork ();
195 if (pid == 0)
196 {
197 test_child ();
198 _exit (127);
199 }
200
201 do_test_wait (pid);
202
203 xsignal (SIGCHLD, SIG_IGN);
204 kill (pid, SIGKILL); /* Make sure it's dead if we bailed early. */
205
206 return 0;
207 }
208
209 #include <support/test-driver.c>