xref: /linux/include/uapi/linux/pidfd.h (revision b50ecc5aca4d18f1f0c4942f5c797bc85edef144)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 
3 #ifndef _UAPI_LINUX_PIDFD_H
4 #define _UAPI_LINUX_PIDFD_H
5 
6 #include <linux/types.h>
7 #include <linux/fcntl.h>
8 #include <linux/ioctl.h>
9 
10 /* Flags for pidfd_open().  */
11 #define PIDFD_NONBLOCK	O_NONBLOCK
12 #define PIDFD_THREAD	O_EXCL
13 
14 /* Flags for pidfd_send_signal(). */
15 #define PIDFD_SIGNAL_THREAD		(1UL << 0)
16 #define PIDFD_SIGNAL_THREAD_GROUP	(1UL << 1)
17 #define PIDFD_SIGNAL_PROCESS_GROUP	(1UL << 2)
18 
19 /* Flags for pidfd_info. */
20 #define PIDFD_INFO_PID			(1UL << 0) /* Always returned, even if not requested */
21 #define PIDFD_INFO_CREDS		(1UL << 1) /* Always returned, even if not requested */
22 #define PIDFD_INFO_CGROUPID		(1UL << 2) /* Always returned if available, even if not requested */
23 
24 #define PIDFD_INFO_SIZE_VER0		64 /* sizeof first published struct */
25 
26 struct pidfd_info {
27 	/*
28 	 * This mask is similar to the request_mask in statx(2).
29 	 *
30 	 * Userspace indicates what extensions or expensive-to-calculate fields
31 	 * they want by setting the corresponding bits in mask. The kernel
32 	 * will ignore bits that it does not know about.
33 	 *
34 	 * When filling the structure, the kernel will only set bits
35 	 * corresponding to the fields that were actually filled by the kernel.
36 	 * This also includes any future extensions that might be automatically
37 	 * filled. If the structure size is too small to contain a field
38 	 * (requested or not), to avoid confusion the mask will not
39 	 * contain a bit for that field.
40 	 *
41 	 * As such, userspace MUST verify that mask contains the
42 	 * corresponding flags after the ioctl(2) returns to ensure that it is
43 	 * using valid data.
44 	 */
45 	__u64 mask;
46 	/*
47 	 * The information contained in the following fields might be stale at the
48 	 * time it is received, as the target process might have exited as soon as
49 	 * the IOCTL was processed, and there is no way to avoid that. However, it
50 	 * is guaranteed that if the call was successful, then the information was
51 	 * correct and referred to the intended process at the time the work was
52 	 * performed. */
53 	__u64 cgroupid;
54 	__u32 pid;
55 	__u32 tgid;
56 	__u32 ppid;
57 	__u32 ruid;
58 	__u32 rgid;
59 	__u32 euid;
60 	__u32 egid;
61 	__u32 suid;
62 	__u32 sgid;
63 	__u32 fsuid;
64 	__u32 fsgid;
65 	__u32 spare0[1];
66 };
67 
68 #define PIDFS_IOCTL_MAGIC 0xFF
69 
70 #define PIDFD_GET_CGROUP_NAMESPACE            _IO(PIDFS_IOCTL_MAGIC, 1)
71 #define PIDFD_GET_IPC_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 2)
72 #define PIDFD_GET_MNT_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 3)
73 #define PIDFD_GET_NET_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 4)
74 #define PIDFD_GET_PID_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 5)
75 #define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE  _IO(PIDFS_IOCTL_MAGIC, 6)
76 #define PIDFD_GET_TIME_NAMESPACE              _IO(PIDFS_IOCTL_MAGIC, 7)
77 #define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8)
78 #define PIDFD_GET_USER_NAMESPACE              _IO(PIDFS_IOCTL_MAGIC, 9)
79 #define PIDFD_GET_UTS_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 10)
80 #define PIDFD_GET_INFO                        _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info)
81 
82 #endif /* _UAPI_LINUX_PIDFD_H */
83