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1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2
3#ifndef _LINUX_PIDFD_H
4#define _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#define PIDFD_INFO_EXIT (1UL << 3) /* Only returned if requested. */
24#define PIDFD_INFO_COREDUMP (1UL << 4) /* Only returned if requested. */
25
26#define PIDFD_INFO_SIZE_VER0 64 /* sizeof first published struct */
27
28/*
29 * Values for @coredump_mask in pidfd_info.
30 * Only valid if PIDFD_INFO_COREDUMP is set in @mask.
31 *
32 * Note, the @PIDFD_COREDUMP_ROOT flag indicates that the generated
33 * coredump should be treated as sensitive and access should only be
34 * granted to privileged users.
35 */
36#define PIDFD_COREDUMPED (1U << 0) /* Did crash and... */
37#define PIDFD_COREDUMP_SKIP (1U << 1) /* coredumping generation was skipped. */
38#define PIDFD_COREDUMP_USER (1U << 2) /* coredump was done as the user. */
39#define PIDFD_COREDUMP_ROOT (1U << 3) /* coredump was done as root. */
40
41/*
42 * ...and for userland we make life simpler - PIDFD_SELF refers to the current
43 * thread, PIDFD_SELF_PROCESS refers to the process thread group leader.
44 *
45 * For nearly all practical uses, a user will want to use PIDFD_SELF.
46 */
47#define PIDFD_SELF PIDFD_SELF_THREAD
48#define PIDFD_SELF_PROCESS PIDFD_SELF_THREAD_GROUP
49
50struct pidfd_info {
51 /*
52 * This mask is similar to the request_mask in statx(2).
53 *
54 * Userspace indicates what extensions or expensive-to-calculate fields
55 * they want by setting the corresponding bits in mask. The kernel
56 * will ignore bits that it does not know about.
57 *
58 * When filling the structure, the kernel will only set bits
59 * corresponding to the fields that were actually filled by the kernel.
60 * This also includes any future extensions that might be automatically
61 * filled. If the structure size is too small to contain a field
62 * (requested or not), to avoid confusion the mask will not
63 * contain a bit for that field.
64 *
65 * As such, userspace MUST verify that mask contains the
66 * corresponding flags after the ioctl(2) returns to ensure that it is
67 * using valid data.
68 */
69 __u64 mask;
70 /*
71 * The information contained in the following fields might be stale at the
72 * time it is received, as the target process might have exited as soon as
73 * the IOCTL was processed, and there is no way to avoid that. However, it
74 * is guaranteed that if the call was successful, then the information was
75 * correct and referred to the intended process at the time the work was
76 * performed. */
77 __u64 cgroupid;
78 __u32 pid;
79 __u32 tgid;
80 __u32 ppid;
81 __u32 ruid;
82 __u32 rgid;
83 __u32 euid;
84 __u32 egid;
85 __u32 suid;
86 __u32 sgid;
87 __u32 fsuid;
88 __u32 fsgid;
89 __s32 exit_code;
90 __u32 coredump_mask;
91 __u32 __spare1;
92};
93
94#define PIDFS_IOCTL_MAGIC 0xFF
95
96#define PIDFD_GET_CGROUP_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 1)
97#define PIDFD_GET_IPC_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 2)
98#define PIDFD_GET_MNT_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 3)
99#define PIDFD_GET_NET_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 4)
100#define PIDFD_GET_PID_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 5)
101#define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 6)
102#define PIDFD_GET_TIME_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 7)
103#define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8)
104#define PIDFD_GET_USER_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 9)
105#define PIDFD_GET_UTS_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 10)
106#define PIDFD_GET_INFO _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info)
107
108#endif /* _LINUX_PIDFD_H */