1 /* Test for the close_range system call.
2 Copyright (C) 2021-2023 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 <dirent.h>
20 #include <errno.h>
21 #include <fcntl.h>
22 #include <limits.h>
23 #include <getopt.h>
24 #include <signal.h>
25 #include <stdbool.h>
26 #include <stdlib.h>
27 #include <stdint.h>
28
29 #include <array_length.h>
30 #include <support/capture_subprocess.h>
31 #include <support/check.h>
32 #include <support/descriptors.h>
33 #include <support/support.h>
34 #include <support/xsched.h>
35 #include <support/xunistd.h>
36
37 #define NFDS 100
38
39 static void
40 close_range_test_max_upper_limit (void)
41 {
42 struct support_descriptors *descrs = support_descriptors_list ();
43
44 int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
45
46 {
47 int r = close_range (lowfd, ~0U, 0);
48 if (r == -1 && errno == ENOSYS)
49 FAIL_UNSUPPORTED ("close_range not supported");
50 TEST_COMPARE (r, 0);
51 }
52
53 support_descriptors_check (descrs);
54 support_descriptors_free (descrs);
55 }
56
57 static void
58 close_range_test_common (int lowfd, unsigned int flags)
59 {
60 const int maximum_fd = lowfd + NFDS - 1;
61 const int half_fd = lowfd + NFDS / 2;
62 const int gap_1 = maximum_fd - 8;
63
64 /* Close half of the descriptors and check result. */
65 TEST_COMPARE (close_range (lowfd, half_fd, flags), 0);
66 for (int i = lowfd; i <= half_fd; i++)
67 {
68 TEST_COMPARE (fcntl (i, F_GETFL), -1);
69 TEST_COMPARE (errno, EBADF);
70 }
71 for (int i = half_fd + 1; i < maximum_fd; i++)
72 TEST_VERIFY (fcntl (i, F_GETFL) > -1);
73
74 /* Create some gaps, close up to a threshold, and check result. */
75 xclose (lowfd + 57);
76 xclose (lowfd + 78);
77 xclose (lowfd + 81);
78 xclose (lowfd + 82);
79 xclose (lowfd + 84);
80 xclose (lowfd + 90);
81
82 TEST_COMPARE (close_range (half_fd + 1, gap_1, flags), 0);
83 for (int i = half_fd + 1; i < gap_1; i++)
84 {
85 TEST_COMPARE (fcntl (i, F_GETFL), -1);
86 TEST_COMPARE (errno, EBADF);
87 }
88 for (int i = gap_1 + 1; i < maximum_fd; i++)
89 TEST_VERIFY (fcntl (i, F_GETFL) > -1);
90
91 /* Close the remaining but the last one. */
92 TEST_COMPARE (close_range (gap_1 + 1, maximum_fd - 1, flags), 0);
93 for (int i = gap_1 + 1; i < maximum_fd - 1; i++)
94 {
95 TEST_COMPARE (fcntl (i, F_GETFL), -1);
96 TEST_COMPARE (errno, EBADF);
97 }
98 TEST_VERIFY (fcntl (maximum_fd, F_GETFL) > -1);
99
100 /* Close the last one. */
101 TEST_COMPARE (close_range (maximum_fd, maximum_fd, flags), 0);
102 TEST_COMPARE (fcntl (maximum_fd, F_GETFL), -1);
103 TEST_COMPARE (errno, EBADF);
104 }
105
106 /* Basic tests: check if the syscall close ranges with and without gaps. */
107 static void
108 close_range_test (void)
109 {
110 struct support_descriptors *descrs = support_descriptors_list ();
111
112 /* Check if the temporary file descriptor has no no gaps. */
113 int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
114
115 close_range_test_common (lowfd, 0);
116
117 /* Double check by check the /proc. */
118 support_descriptors_check (descrs);
119 support_descriptors_free (descrs);
120 }
121
122 #ifdef __linux__
123 _Noreturn static int
124 close_range_test_fn (void *arg)
125 {
126 int lowfd = (int) ((uintptr_t) arg);
127 close_range_test_common (lowfd, 0);
128 exit (EXIT_SUCCESS);
129 }
130
131 /* Check if a clone_range on a subprocess created with CLONE_FILES close
132 the shared file descriptor table entries in the parent. */
133 static void
134 close_range_test_subprocess (void)
135 {
136 struct support_descriptors *descrs = support_descriptors_list ();
137
138 /* Check if the temporary file descriptor has no no gaps. */
139 int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
140
141 struct support_stack stack = support_stack_alloc (4096);
142
143 pid_t pid = xclone (close_range_test_fn, (void*) (uintptr_t) lowfd,
144 stack.stack, stack.size, CLONE_FILES | SIGCHLD);
145 TEST_VERIFY_EXIT (pid > 0);
146 int status;
147 xwaitpid (pid, &status, 0);
148 TEST_VERIFY (WIFEXITED (status));
149 TEST_COMPARE (WEXITSTATUS (status), 0);
150
151 support_stack_free (&stack);
152
153 for (int i = lowfd; i < NFDS; i++)
154 TEST_VERIFY (fcntl (i, F_GETFL) < 0);
155
156 support_descriptors_check (descrs);
157 support_descriptors_free (descrs);
158 }
159 #endif
160
161
162 #ifdef CLOSE_RANGE_UNSHARE
163 _Noreturn static int
164 close_range_unshare_test_fn (void *arg)
165 {
166 int lowfd = (int) ((uintptr_t) arg);
167 close_range_test_common (lowfd, CLOSE_RANGE_UNSHARE);
168 exit (EXIT_SUCCESS);
169 }
170
171 /* Check if a close_range with CLOSE_RANGE_UNSHARE issued from a subprocess
172 created with CLONE_FILES does not close the parent file descriptor list. */
173 static void
174 close_range_unshare_test (void)
175 {
176 struct support_descriptors *descrs1 = support_descriptors_list ();
177
178 /* Check if the temporary file descriptor has no no gaps. */
179 int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
180
181 struct support_descriptors *descrs2 = support_descriptors_list ();
182
183 struct support_stack stack = support_stack_alloc (4096);
184
185 pid_t pid = xclone (close_range_unshare_test_fn, (void*) (uintptr_t) lowfd,
186 stack.stack, stack.size, CLONE_FILES | SIGCHLD);
187 TEST_VERIFY_EXIT (pid > 0);
188 int status;
189 xwaitpid (pid, &status, 0);
190 TEST_VERIFY (WIFEXITED (status));
191 TEST_COMPARE (WEXITSTATUS (status), 0);
192
193 support_stack_free (&stack);
194
195 for (int i = lowfd; i < lowfd + NFDS; i++)
196 TEST_VERIFY (fcntl (i, F_GETFL) > -1);
197
198 support_descriptors_check (descrs2);
199 support_descriptors_free (descrs2);
200
201 TEST_COMPARE (close_range (lowfd, lowfd + NFDS, 0), 0);
202
203 support_descriptors_check (descrs1);
204 support_descriptors_free (descrs1);
205 }
206 #endif
207
208 static bool
209 is_in_array (int *arr, size_t len, int fd)
210 {
211 bool r = false;
212 for (int i = 0; i < len; i++)
213 if (arr[i] == fd)
214 return true;
215 return r;
216 }
217
218 static void
219 close_range_cloexec_test (void)
220 {
221 /* Check if the temporary file descriptor has no no gaps. */
222 int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
223
224 const int maximum_fd = lowfd + NFDS - 1;
225 const int half_fd = lowfd + NFDS / 2;
226 const int gap_1 = maximum_fd - 8;
227
228 /* Close half of the descriptors and check result. */
229 int r = close_range (lowfd, half_fd, CLOSE_RANGE_CLOEXEC);
230 if (r == -1 && errno == EINVAL)
231 {
232 printf ("%s: CLOSE_RANGE_CLOEXEC not supported\n", __func__);
233 return;
234 }
235 for (int i = lowfd; i <= half_fd; i++)
236 {
237 int flags = fcntl (i, F_GETFD);
238 TEST_VERIFY (flags > -1);
239 TEST_COMPARE (flags & FD_CLOEXEC, FD_CLOEXEC);
240 }
241 for (int i = half_fd + 1; i < maximum_fd; i++)
242 TEST_VERIFY (fcntl (i, F_GETFL) > -1);
243
244 /* Create some gaps, close up to a threshold, and check result. */
245 static int gap_close[] = { 57, 78, 81, 82, 84, 90 };
246 for (int i = 0; i < array_length (gap_close); i++)
247 xclose (lowfd + gap_close[i]);
248
249 TEST_COMPARE (close_range (half_fd + 1, gap_1, CLOSE_RANGE_CLOEXEC), 0);
250 for (int i = half_fd + 1; i < gap_1; i++)
251 {
252 int flags = fcntl (i, F_GETFD);
253 if (is_in_array (gap_close, array_length (gap_close), i - lowfd))
254 TEST_COMPARE (flags, -1);
255 else
256 {
257 TEST_VERIFY (flags > -1);
258 TEST_COMPARE (flags & FD_CLOEXEC, FD_CLOEXEC);
259 }
260 }
261 for (int i = gap_1 + 1; i < maximum_fd; i++)
262 TEST_VERIFY (fcntl (i, F_GETFL) > -1);
263
264 /* Close the remaining but the last one. */
265 TEST_COMPARE (close_range (gap_1 + 1, maximum_fd - 1, CLOSE_RANGE_CLOEXEC),
266 0);
267 for (int i = gap_1 + 1; i < maximum_fd - 1; i++)
268 {
269 int flags = fcntl (i, F_GETFD);
270 TEST_VERIFY (flags > -1);
271 TEST_COMPARE (flags & FD_CLOEXEC, FD_CLOEXEC);
272 }
273 TEST_VERIFY (fcntl (maximum_fd, F_GETFL) > -1);
274
275 /* Close the last one. */
276 TEST_COMPARE (close_range (maximum_fd, maximum_fd, CLOSE_RANGE_CLOEXEC), 0);
277 {
278 int flags = fcntl (maximum_fd, F_GETFD);
279 TEST_VERIFY (flags > -1);
280 TEST_COMPARE (flags & FD_CLOEXEC, FD_CLOEXEC);
281 }
282 }
283
284 static int
285 do_test (void)
286 {
287 close_range_test_max_upper_limit ();
288 close_range_test ();
289 #ifdef __linux__
290 close_range_test_subprocess ();
291 #endif
292 #ifdef CLOSE_RANGE_UNSHARE
293 close_range_unshare_test ();
294 #endif
295 close_range_cloexec_test ();
296
297 return 0;
298 }
299
300 #include <support/test-driver.c>