1 | /* Check posix_spawn add file actions. |
2 | Copyright (C) 2016-2024 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 <stdio.h> |
20 | #include <spawn.h> |
21 | #include <error.h> |
22 | #include <errno.h> |
23 | #include <stdlib.h> |
24 | #include <string.h> |
25 | #include <unistd.h> |
26 | #include <sys/wait.h> |
27 | #include <sys/resource.h> |
28 | #include <fcntl.h> |
29 | #include <paths.h> |
30 | #include <intprops.h> |
31 | |
32 | #include <support/check.h> |
33 | #include <support/temp_file.h> |
34 | #include <support/xunistd.h> |
35 | #include <tst-spawn.h> |
36 | |
37 | static int |
38 | do_test (void) |
39 | { |
40 | /* The test checks if posix_spawn open file action close the file descriptor |
41 | before opening a new one in case the input file descriptor is already |
42 | opened. It does by exhausting all file descriptors on the process before |
43 | issue posix_spawn. It then issues a posix_spawn for '/bin/sh echo $$' |
44 | and add two rules: |
45 | |
46 | 1. Redirect stdout to a temporary filepath |
47 | 2. Redirect stderr to stdout |
48 | |
49 | If the implementation does not close the file 1. will fail with |
50 | EMFILE. */ |
51 | |
52 | struct rlimit rl; |
53 | int max_fd = 24; |
54 | |
55 | /* Set maximum number of file descriptor to a low value to avoid open |
56 | too many files in environments where RLIMIT_NOFILE is large and to |
57 | limit the array size to track the opened file descriptors. */ |
58 | |
59 | if (getrlimit (RLIMIT_NOFILE, rlimits: &rl) == -1) |
60 | FAIL_EXIT1 ("getrlimit (RLIMIT_NOFILE): %m" ); |
61 | |
62 | max_fd = (rl.rlim_cur < max_fd ? rl.rlim_cur : max_fd); |
63 | rl.rlim_cur = max_fd; |
64 | |
65 | if (setrlimit (RLIMIT_NOFILE, rlimits: &rl) == 1) |
66 | FAIL_EXIT1 ("setrlimit (RLIMIT_NOFILE): %m" ); |
67 | |
68 | /* Exhauste the file descriptor limit with temporary files. */ |
69 | int files[max_fd]; |
70 | int nfiles = 0; |
71 | for (; nfiles < max_fd; nfiles++) |
72 | { |
73 | int fd = create_temp_file (base: "tst-spawn3." , NULL); |
74 | if (fd == -1) |
75 | { |
76 | if (errno != EMFILE) |
77 | FAIL_EXIT1 ("create_temp_file: %m" ); |
78 | break; |
79 | } |
80 | files[nfiles] = fd; |
81 | } |
82 | TEST_VERIFY_EXIT (nfiles != 0); |
83 | |
84 | posix_spawn_file_actions_t a; |
85 | TEST_COMPARE (posix_spawn_file_actions_init (&a), 0); |
86 | |
87 | /* Executes a /bin/sh echo $$ 2>&1 > ${objpfx}tst-spawn3.pid . */ |
88 | const char pidfile[] = OBJPFX "tst-spawn3.pid" ; |
89 | TEST_COMPARE (posix_spawn_file_actions_addopen (&a, STDOUT_FILENO, pidfile, |
90 | O_WRONLY| O_CREAT | O_TRUNC, |
91 | 0644), |
92 | 0); |
93 | |
94 | TEST_COMPARE (posix_spawn_file_actions_adddup2 (&a, STDOUT_FILENO, |
95 | STDERR_FILENO), |
96 | 0); |
97 | |
98 | /* Since execve (called by posix_spawn) might require to open files to |
99 | actually execute the shell script, setup to close the temporary file |
100 | descriptors. */ |
101 | int maxnfiles = |
102 | #ifdef TST_SPAWN_PIDFD |
103 | /* The sparing file descriptor will be returned as the pid descriptor, |
104 | otherwise clone fail with EMFILE. */ |
105 | nfiles - 1; |
106 | #else |
107 | nfiles; |
108 | #endif |
109 | |
110 | for (int i=0; i<maxnfiles; i++) |
111 | TEST_COMPARE (posix_spawn_file_actions_addclose (&a, files[i]), 0); |
112 | |
113 | char *spawn_argv[] = { (char *) _PATH_BSHELL, (char *) "-c" , |
114 | (char *) "echo $$" , NULL }; |
115 | PID_T_TYPE pid; |
116 | |
117 | { |
118 | int r = POSIX_SPAWN (&pid, _PATH_BSHELL, &a, NULL, spawn_argv, NULL); |
119 | if (r == ENOSYS) |
120 | FAIL_UNSUPPORTED ("kernel does not support CLONE_PIDFD clone flag" ); |
121 | #ifdef TST_SPAWN_PIDFD |
122 | TEST_COMPARE (r, EMFILE); |
123 | |
124 | /* Free up one file descriptor, so posix_spawn_pidfd_ex can return it. */ |
125 | xclose (files[nfiles-1]); |
126 | nfiles--; |
127 | r = POSIX_SPAWN (&pid, _PATH_BSHELL, &a, NULL, spawn_argv, NULL); |
128 | #endif |
129 | TEST_COMPARE (r, 0); |
130 | } |
131 | |
132 | siginfo_t sinfo; |
133 | TEST_COMPARE (WAITID (P_PID, pid, &sinfo, WEXITED), 0); |
134 | TEST_COMPARE (sinfo.si_code, CLD_EXITED); |
135 | TEST_COMPARE (sinfo.si_status, 0); |
136 | |
137 | /* Close the temporary files descriptor so it can check posix_spawn |
138 | output. */ |
139 | for (int i=0; i<nfiles; i++) |
140 | xclose (files[i]); |
141 | |
142 | int pidfd = xopen (path: pidfile, O_RDONLY, 0); |
143 | |
144 | char buf[INT_BUFSIZE_BOUND (pid_t)]; |
145 | ssize_t n = read (pidfd, buf, sizeof (buf)); |
146 | TEST_VERIFY (n < sizeof buf && n >= 0); |
147 | |
148 | xunlink (path: pidfile); |
149 | |
150 | /* We only expect to read the PID. */ |
151 | char *endp; |
152 | long int rpid = strtol (buf, &endp, 10); |
153 | TEST_VERIFY (*endp == '\n' && endp != buf); |
154 | |
155 | TEST_COMPARE (rpid, sinfo.si_pid); |
156 | |
157 | return 0; |
158 | } |
159 | |
160 | #include <support/test-driver.c> |
161 | |