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/mount.h>
16 #include <sys/types.h>
17 #include <sys/wait.h>
18 
19 #include "../kselftest.h"
20 
21 #ifndef P_PIDFD
22 #define P_PIDFD 3
23 #endif
24 
25 #ifndef CLONE_NEWTIME
26 #define CLONE_NEWTIME 0x00000080
27 #endif
28 
29 #ifndef CLONE_PIDFD
30 #define CLONE_PIDFD 0x00001000
31 #endif
32 
33 #ifndef __NR_pidfd_open
34 #define __NR_pidfd_open -1
35 #endif
36 
37 #ifndef __NR_pidfd_send_signal
38 #define __NR_pidfd_send_signal -1
39 #endif
40 
41 #ifndef __NR_clone3
42 #define __NR_clone3 -1
43 #endif
44 
45 #ifndef __NR_pidfd_getfd
46 #define __NR_pidfd_getfd -1
47 #endif
48 
49 #ifndef PIDFD_NONBLOCK
50 #define PIDFD_NONBLOCK O_NONBLOCK
51 #endif
52 
53 /*
54  * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c
55  * That means, when it wraps around any pid < 300 will be skipped.
56  * So we need to use a pid > 300 in order to test recycling.
57  */
58 #define PID_RECYCLE 1000
59 
60 /*
61  * Define a few custom error codes for the child process to clearly indicate
62  * what is happening. This way we can tell the difference between a system
63  * error, a test error, etc.
64  */
65 #define PIDFD_PASS 0
66 #define PIDFD_FAIL 1
67 #define PIDFD_ERROR 2
68 #define PIDFD_SKIP 3
69 #define PIDFD_XFAIL 4
70 
71 int wait_for_pid(pid_t pid)
72 {
73 	int status, ret;
74 
75 again:
76 	ret = waitpid(pid, &status, 0);
77 	if (ret == -1) {
78 		if (errno == EINTR)
79 			goto again;
80 
81 		return -1;
82 	}
83 
84 	if (!WIFEXITED(status))
85 		return -1;
86 
87 	return WEXITSTATUS(status);
88 }
89 
90 static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
91 {
92 	return syscall(__NR_pidfd_open, pid, flags);
93 }
94 
95 static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
96 					unsigned int flags)
97 {
98 	return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
99 }
100 
101 static inline int sys_pidfd_getfd(int pidfd, int fd, int flags)
102 {
103 	return syscall(__NR_pidfd_getfd, pidfd, fd, flags);
104 }
105 
106 static inline int sys_memfd_create(const char *name, unsigned int flags)
107 {
108 	return syscall(__NR_memfd_create, name, flags);
109 }
110 
111 #endif /* __PIDFD_H */
112