Linux kernel mirror (for testing)
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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#ifdef __KERNEL__
14#include <linux/sched.h>
15#define PIDFD_CLONE CLONE_PIDFD
16#endif
17
18/* Flags for pidfd_send_signal(). */
19#define PIDFD_SIGNAL_THREAD (1UL << 0)
20#define PIDFD_SIGNAL_THREAD_GROUP (1UL << 1)
21#define PIDFD_SIGNAL_PROCESS_GROUP (1UL << 2)
22
23/* Flags for pidfd_info. */
24#define PIDFD_INFO_PID (1UL << 0) /* Always returned, even if not requested */
25#define PIDFD_INFO_CREDS (1UL << 1) /* Always returned, even if not requested */
26#define PIDFD_INFO_CGROUPID (1UL << 2) /* Always returned if available, even if not requested */
27#define PIDFD_INFO_EXIT (1UL << 3) /* Only returned if requested. */
28
29#define PIDFD_INFO_SIZE_VER0 64 /* sizeof first published struct */
30
31/*
32 * The concept of process and threads in userland and the kernel is a confusing
33 * one - within the kernel every thread is a 'task' with its own individual PID,
34 * however from userland's point of view threads are grouped by a single PID,
35 * which is that of the 'thread group leader', typically the first thread
36 * spawned.
37 *
38 * To cut the Gideon knot, for internal kernel usage, we refer to
39 * PIDFD_SELF_THREAD to refer to the current thread (or task from a kernel
40 * perspective), and PIDFD_SELF_THREAD_GROUP to refer to the current thread
41 * group leader...
42 */
43#define PIDFD_SELF_THREAD -10000 /* Current thread. */
44#define PIDFD_SELF_THREAD_GROUP -20000 /* Current thread group leader. */
45
46/*
47 * ...and for userland we make life simpler - PIDFD_SELF refers to the current
48 * thread, PIDFD_SELF_PROCESS refers to the process thread group leader.
49 *
50 * For nearly all practical uses, a user will want to use PIDFD_SELF.
51 */
52#define PIDFD_SELF PIDFD_SELF_THREAD
53#define PIDFD_SELF_PROCESS PIDFD_SELF_THREAD_GROUP
54
55struct pidfd_info {
56 /*
57 * This mask is similar to the request_mask in statx(2).
58 *
59 * Userspace indicates what extensions or expensive-to-calculate fields
60 * they want by setting the corresponding bits in mask. The kernel
61 * will ignore bits that it does not know about.
62 *
63 * When filling the structure, the kernel will only set bits
64 * corresponding to the fields that were actually filled by the kernel.
65 * This also includes any future extensions that might be automatically
66 * filled. If the structure size is too small to contain a field
67 * (requested or not), to avoid confusion the mask will not
68 * contain a bit for that field.
69 *
70 * As such, userspace MUST verify that mask contains the
71 * corresponding flags after the ioctl(2) returns to ensure that it is
72 * using valid data.
73 */
74 __u64 mask;
75 /*
76 * The information contained in the following fields might be stale at the
77 * time it is received, as the target process might have exited as soon as
78 * the IOCTL was processed, and there is no way to avoid that. However, it
79 * is guaranteed that if the call was successful, then the information was
80 * correct and referred to the intended process at the time the work was
81 * performed. */
82 __u64 cgroupid;
83 __u32 pid;
84 __u32 tgid;
85 __u32 ppid;
86 __u32 ruid;
87 __u32 rgid;
88 __u32 euid;
89 __u32 egid;
90 __u32 suid;
91 __u32 sgid;
92 __u32 fsuid;
93 __u32 fsgid;
94 __s32 exit_code;
95};
96
97#define PIDFS_IOCTL_MAGIC 0xFF
98
99#define PIDFD_GET_CGROUP_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 1)
100#define PIDFD_GET_IPC_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 2)
101#define PIDFD_GET_MNT_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 3)
102#define PIDFD_GET_NET_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 4)
103#define PIDFD_GET_PID_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 5)
104#define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 6)
105#define PIDFD_GET_TIME_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 7)
106#define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8)
107#define PIDFD_GET_USER_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 9)
108#define PIDFD_GET_UTS_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 10)
109#define PIDFD_GET_INFO _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info)
110
111#endif /* _UAPI_LINUX_PIDFD_H */