pidfd.h

  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
179struct 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
219static 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
224static inline int wait_for_pid(pid_t pid)
225{
226	int status, ret;
227
228again:
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
249static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
250{
251	return syscall(__NR_pidfd_open, pid, flags);
252}
253
254static 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
260static inline int sys_pidfd_getfd(int pidfd, int fd, int flags)
261{
262	return syscall(__NR_pidfd_getfd, pidfd, fd, flags);
263}
264
265static inline int sys_memfd_create(const char *name, unsigned int flags)
266{
267	return syscall(__NR_memfd_create, name, flags);
268}
269
270static 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
281static 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
292static 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
303static 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 */