1 /* Check if posix_spawn does not act as a cancellation entrypoint.
2 Copyright (C) 2016-2022 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 <paths.h>
21 #include <pthread.h>
22 #include <signal.h>
23 #include <spawn.h>
24 #include <stdbool.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <unistd.h>
28 #include <sys/wait.h>
29
30 static int do_test (void);
31 #define TEST_FUNCTION do_test ()
32 #include <test-skeleton.c>
33
34 static pthread_barrier_t b;
35
36 static pid_t pid;
37 static int pipefd[2];
38
39 static void *
tf(void * arg)40 tf (void *arg)
41 {
42 xpthread_barrier_wait (&b);
43
44 posix_spawn_file_actions_t a;
45 if (posix_spawn_file_actions_init (&a) != 0)
46 {
47 puts ("error: spawn_file_actions_init failed");
48 exit (1);
49 }
50
51 if (posix_spawn_file_actions_adddup2 (&a, pipefd[1], STDOUT_FILENO) != 0)
52 {
53 puts ("error: spawn_file_actions_adddup2 failed");
54 exit (1);
55 }
56
57 if (posix_spawn_file_actions_addclose (&a, pipefd[0]) != 0)
58 {
59 puts ("error: spawn_file_actions_addclose");
60 exit (1);
61 }
62
63 char *argv[] = { (char *) _PATH_BSHELL, (char *) "-c", (char *) "echo $$",
64 NULL };
65 if (posix_spawn (&pid, _PATH_BSHELL, &a, NULL, argv, NULL) != 0)
66 {
67 puts ("error: spawn failed");
68 exit (1);
69 }
70
71 return NULL;
72 }
73
74
75 static int
do_test(void)76 do_test (void)
77 {
78 /* The test basically pipe a 'echo $$' created by a thread with a
79 cancellation pending. It then checks if the thread is not cancelled,
80 the process is created and if the output is the expected one. */
81
82 if (pipe (pipefd) != 0)
83 {
84 puts ("error: pipe failed");
85 exit (1);
86 }
87
88 /* Not interested in knowing when the pipe is closed. */
89 xsignal (SIGPIPE, SIG_IGN);
90
91 /* To synchronize with the thread. */
92 if (pthread_barrier_init (&b, NULL, 2) != 0)
93 {
94 puts ("error: pthread_barrier_init failed");
95 exit (1);
96 }
97
98 pthread_t th = xpthread_create (NULL, &tf, NULL);
99
100 if (pthread_cancel (th) != 0)
101 {
102 puts ("error: pthread_cancel failed");
103 return 1;
104 }
105
106 xpthread_barrier_wait (&b);
107
108 if (xpthread_join (th) == PTHREAD_CANCELED)
109 {
110 puts ("error: thread cancelled");
111 exit (1);
112 }
113
114 close (pipefd[1]);
115
116 /* The global 'pid' should be set by thread posix_spawn calling. Check
117 below if it was executed correctly and with expected output. */
118
119 char buf[64];
120 ssize_t n;
121 bool seen_pid = false;
122 while (TEMP_FAILURE_RETRY ((n = read (pipefd[0], buf, sizeof (buf)))) > 0)
123 {
124 /* We only expect to read the PID. */
125 char *endp;
126 long int rpid = strtol (buf, &endp, 10);
127
128 if (*endp != '\n')
129 {
130 printf ("error: didn't parse whole line: \"%s\"\n", buf);
131 exit (1);
132 }
133 if (endp == buf)
134 {
135 puts ("error: read empty line");
136 exit (1);
137 }
138
139 if (rpid != pid)
140 {
141 printf ("error: found \"%s\", expected PID %ld\n", buf,
142 (long int) pid);
143 exit (1);
144 }
145
146 if (seen_pid)
147 {
148 puts ("error: found more than one PID line");
149 exit (1);
150 }
151
152 seen_pid = true;
153 }
154
155 close (pipefd[0]);
156
157 int status;
158 int err = waitpid (pid, &status, 0);
159 if (err != pid)
160 {
161 puts ("errnor: waitpid failed");
162 exit (1);
163 }
164
165 if (!seen_pid)
166 {
167 puts ("error: didn't get PID");
168 exit (1);
169 }
170
171 return 0;
172 }
173