xref: /linux/tools/testing/selftests/pidfd/pidfd.h (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef __PIDFD_H
4 #define __PIDFD_H
5 
6 #define _GNU_SOURCE
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <sched.h>
10 #include <signal.h>
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <syscall.h>
15 #include <sys/ioctl.h>
16 #include <sys/types.h>
17 #include <sys/wait.h>
18 
19 /*
20  * Remove the userspace definitions of the following preprocessor symbols
21  * to avoid duplicate-definition warnings from the subsequent in-kernel
22  * definitions.
23  */
24 #undef SCHED_NORMAL
25 #undef SCHED_FLAG_KEEP_ALL
26 #undef SCHED_FLAG_UTIL_CLAMP
27 
28 #include "../kselftest.h"
29 #include "../clone3/clone3_selftests.h"
30 
31 #ifndef FD_PIDFS_ROOT
32 #define FD_PIDFS_ROOT -10002
33 #endif
34 
35 #ifndef P_PIDFD
36 #define P_PIDFD 3
37 #endif
38 
39 #ifndef CLONE_NEWTIME
40 #define CLONE_NEWTIME 0x00000080
41 #endif
42 
43 #ifndef CLONE_PIDFD
44 #define CLONE_PIDFD 0x00001000
45 #endif
46 
47 #ifndef __NR_pidfd_open
48 #define __NR_pidfd_open 434
49 #endif
50 
51 #ifndef __NR_pidfd_send_signal
52 #define __NR_pidfd_send_signal 424
53 #endif
54 
55 #ifndef __NR_clone3
56 #define __NR_clone3 435
57 #endif
58 
59 #ifndef __NR_pidfd_getfd
60 #define __NR_pidfd_getfd 438
61 #endif
62 
63 #ifndef PIDFD_NONBLOCK
64 #define PIDFD_NONBLOCK O_NONBLOCK
65 #endif
66 
67 #ifndef PIDFD_SELF_THREAD
68 #define PIDFD_SELF_THREAD		-10000 /* Current thread. */
69 #endif
70 
71 #ifndef PIDFD_SELF_THREAD_GROUP
72 #define PIDFD_SELF_THREAD_GROUP		-10001 /* Current thread group leader. */
73 #endif
74 
75 #ifndef PIDFD_SELF
76 #define PIDFD_SELF		PIDFD_SELF_THREAD
77 #endif
78 
79 #ifndef PIDFD_SELF_PROCESS
80 #define PIDFD_SELF_PROCESS	PIDFD_SELF_THREAD_GROUP
81 #endif
82 
83 #ifndef PIDFS_IOCTL_MAGIC
84 #define PIDFS_IOCTL_MAGIC 0xFF
85 #endif
86 
87 #ifndef PIDFD_GET_CGROUP_NAMESPACE
88 #define PIDFD_GET_CGROUP_NAMESPACE            _IO(PIDFS_IOCTL_MAGIC, 1)
89 #endif
90 
91 #ifndef PIDFD_GET_IPC_NAMESPACE
92 #define PIDFD_GET_IPC_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 2)
93 #endif
94 
95 #ifndef PIDFD_GET_MNT_NAMESPACE
96 #define PIDFD_GET_MNT_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 3)
97 #endif
98 
99 #ifndef PIDFD_GET_NET_NAMESPACE
100 #define PIDFD_GET_NET_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 4)
101 #endif
102 
103 #ifndef PIDFD_GET_PID_NAMESPACE
104 #define PIDFD_GET_PID_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 5)
105 #endif
106 
107 #ifndef PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE
108 #define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE  _IO(PIDFS_IOCTL_MAGIC, 6)
109 #endif
110 
111 #ifndef PIDFD_GET_TIME_NAMESPACE
112 #define PIDFD_GET_TIME_NAMESPACE              _IO(PIDFS_IOCTL_MAGIC, 7)
113 #endif
114 
115 #ifndef PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE
116 #define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8)
117 #endif
118 
119 #ifndef PIDFD_GET_USER_NAMESPACE
120 #define PIDFD_GET_USER_NAMESPACE              _IO(PIDFS_IOCTL_MAGIC, 9)
121 #endif
122 
123 #ifndef PIDFD_GET_UTS_NAMESPACE
124 #define PIDFD_GET_UTS_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 10)
125 #endif
126 
127 #ifndef PIDFD_GET_INFO
128 #define PIDFD_GET_INFO			      _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info)
129 #endif
130 
131 #ifndef PIDFD_INFO_PID
132 #define PIDFD_INFO_PID			(1UL << 0) /* Always returned, even if not requested */
133 #endif
134 
135 #ifndef PIDFD_INFO_CREDS
136 #define PIDFD_INFO_CREDS		(1UL << 1) /* Always returned, even if not requested */
137 #endif
138 
139 #ifndef PIDFD_INFO_CGROUPID
140 #define PIDFD_INFO_CGROUPID		(1UL << 2) /* Always returned if available, even if not requested */
141 #endif
142 
143 #ifndef PIDFD_INFO_EXIT
144 #define PIDFD_INFO_EXIT			(1UL << 3) /* Always returned if available, even if not requested */
145 #endif
146 
147 #ifndef PIDFD_INFO_COREDUMP
148 #define PIDFD_INFO_COREDUMP	(1UL << 4)
149 #endif
150 
151 #ifndef PIDFD_INFO_SUPPORTED_MASK
152 #define PIDFD_INFO_SUPPORTED_MASK	(1UL << 5)
153 #endif
154 
155 #ifndef PIDFD_INFO_COREDUMP_SIGNAL
156 #define PIDFD_INFO_COREDUMP_SIGNAL	(1UL << 6)
157 #endif
158 
159 #ifndef PIDFD_COREDUMPED
160 #define PIDFD_COREDUMPED	(1U << 0) /* Did crash and... */
161 #endif
162 
163 #ifndef PIDFD_COREDUMP_SKIP
164 #define PIDFD_COREDUMP_SKIP	(1U << 1) /* coredumping generation was skipped. */
165 #endif
166 
167 #ifndef PIDFD_COREDUMP_USER
168 #define PIDFD_COREDUMP_USER	(1U << 2) /* coredump was done as the user. */
169 #endif
170 
171 #ifndef PIDFD_COREDUMP_ROOT
172 #define PIDFD_COREDUMP_ROOT	(1U << 3) /* coredump was done as root. */
173 #endif
174 
175 #ifndef PIDFD_THREAD
176 #define PIDFD_THREAD O_EXCL
177 #endif
178 
179 struct pidfd_info {
180 	__u64 mask;
181 	__u64 cgroupid;
182 	__u32 pid;
183 	__u32 tgid;
184 	__u32 ppid;
185 	__u32 ruid;
186 	__u32 rgid;
187 	__u32 euid;
188 	__u32 egid;
189 	__u32 suid;
190 	__u32 sgid;
191 	__u32 fsuid;
192 	__u32 fsgid;
193 	__s32 exit_code;
194 	struct {
195 		__u32 coredump_mask;
196 		__u32 coredump_signal;
197 	};
198 	__u64 supported_mask;
199 };
200 
201 /*
202  * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c
203  * That means, when it wraps around any pid < 300 will be skipped.
204  * So we need to use a pid > 300 in order to test recycling.
205  */
206 #define PID_RECYCLE 1000
207 
208 /*
209  * Define a few custom error codes for the child process to clearly indicate
210  * what is happening. This way we can tell the difference between a system
211  * error, a test error, etc.
212  */
213 #define PIDFD_PASS 0
214 #define PIDFD_FAIL 1
215 #define PIDFD_ERROR 2
216 #define PIDFD_SKIP 3
217 #define PIDFD_XFAIL 4
218 
219 static inline int sys_waitid(int which, pid_t pid, siginfo_t *info, int options)
220 {
221 	return syscall(__NR_waitid, which, pid, info, options, NULL);
222 }
223 
224 static inline int wait_for_pid(pid_t pid)
225 {
226 	int status, ret;
227 
228 again:
229 	ret = waitpid(pid, &status, 0);
230 	if (ret == -1) {
231 		if (errno == EINTR)
232 			goto again;
233 
234 		ksft_print_msg("waitpid returned -1, errno=%d\n", errno);
235 		return -1;
236 	}
237 
238 	if (!WIFEXITED(status)) {
239 		ksft_print_msg(
240 		       "waitpid !WIFEXITED, WIFSIGNALED=%d, WTERMSIG=%d\n",
241 		       WIFSIGNALED(status), WTERMSIG(status));
242 		return -1;
243 	}
244 
245 	ret = WEXITSTATUS(status);
246 	return ret;
247 }
248 
249 static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
250 {
251 	return syscall(__NR_pidfd_open, pid, flags);
252 }
253 
254 static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
255 					unsigned int flags)
256 {
257 	return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
258 }
259 
260 static inline int sys_pidfd_getfd(int pidfd, int fd, int flags)
261 {
262 	return syscall(__NR_pidfd_getfd, pidfd, fd, flags);
263 }
264 
265 static inline int sys_memfd_create(const char *name, unsigned int flags)
266 {
267 	return syscall(__NR_memfd_create, name, flags);
268 }
269 
270 static inline pid_t create_child(int *pidfd, unsigned flags)
271 {
272 	struct __clone_args args = {
273 		.flags		= CLONE_PIDFD | flags,
274 		.exit_signal	= SIGCHLD,
275 		.pidfd		= ptr_to_u64(pidfd),
276 	};
277 
278 	return sys_clone3(&args, sizeof(struct __clone_args));
279 }
280 
281 static inline ssize_t read_nointr(int fd, void *buf, size_t count)
282 {
283 	ssize_t ret;
284 
285 	do {
286 		ret = read(fd, buf, count);
287 	} while (ret < 0 && errno == EINTR);
288 
289 	return ret;
290 }
291 
292 static inline ssize_t write_nointr(int fd, const void *buf, size_t count)
293 {
294 	ssize_t ret;
295 
296 	do {
297 		ret = write(fd, buf, count);
298 	} while (ret < 0 && errno == EINTR);
299 
300 	return ret;
301 }
302 
303 static inline int sys_execveat(int dirfd, const char *pathname,
304 			       char *const argv[], char *const envp[],
305 			       int flags)
306 {
307         return syscall(__NR_execveat, dirfd, pathname, argv, envp, flags);
308 }
309 
310 #endif /* __PIDFD_H */
311