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#define PIDFD_INFO_SUPPORTED_MASK (1UL << 5) /* Want/got supported mask flags */
26#define PIDFD_INFO_COREDUMP_SIGNAL (1UL << 6) /* Always returned if PIDFD_INFO_COREDUMP is requested. */
27#define PIDFD_INFO_COREDUMP_CODE (1UL << 7) /* Always returned if PIDFD_INFO_COREDUMP is requested. */
28
29#define PIDFD_INFO_SIZE_VER0 64 /* sizeof first published struct */
30#define PIDFD_INFO_SIZE_VER1 72 /* sizeof second published struct */
31#define PIDFD_INFO_SIZE_VER2 80 /* sizeof third published struct */
32#define PIDFD_INFO_SIZE_VER3 88 /* sizeof fourth published struct */
33
34/*
35 * Values for @coredump_mask in pidfd_info.
36 * Only valid if PIDFD_INFO_COREDUMP is set in @mask.
37 *
38 * Note, the @PIDFD_COREDUMP_ROOT flag indicates that the generated
39 * coredump should be treated as sensitive and access should only be
40 * granted to privileged users.
41 */
42#define PIDFD_COREDUMPED (1U << 0) /* Did crash and... */
43#define PIDFD_COREDUMP_SKIP (1U << 1) /* coredumping generation was skipped. */
44#define PIDFD_COREDUMP_USER (1U << 2) /* coredump was done as the user. */
45#define PIDFD_COREDUMP_ROOT (1U << 3) /* coredump was done as root. */
46
47/*
48 * ...and for userland we make life simpler - PIDFD_SELF refers to the current
49 * thread, PIDFD_SELF_PROCESS refers to the process thread group leader.
50 *
51 * For nearly all practical uses, a user will want to use PIDFD_SELF.
52 */
53#define PIDFD_SELF PIDFD_SELF_THREAD
54#define PIDFD_SELF_PROCESS PIDFD_SELF_THREAD_GROUP
55
56struct pidfd_info {
57 /*
58 * This mask is similar to the request_mask in statx(2).
59 *
60 * Userspace indicates what extensions or expensive-to-calculate fields
61 * they want by setting the corresponding bits in mask. The kernel
62 * will ignore bits that it does not know about.
63 *
64 * When filling the structure, the kernel will only set bits
65 * corresponding to the fields that were actually filled by the kernel.
66 * This also includes any future extensions that might be automatically
67 * filled. If the structure size is too small to contain a field
68 * (requested or not), to avoid confusion the mask will not
69 * contain a bit for that field.
70 *
71 * As such, userspace MUST verify that mask contains the
72 * corresponding flags after the ioctl(2) returns to ensure that it is
73 * using valid data.
74 */
75 __u64 mask;
76 /*
77 * The information contained in the following fields might be stale at the
78 * time it is received, as the target process might have exited as soon as
79 * the IOCTL was processed, and there is no way to avoid that. However, it
80 * is guaranteed that if the call was successful, then the information was
81 * correct and referred to the intended process at the time the work was
82 * performed. */
83 __u64 cgroupid;
84 __u32 pid;
85 __u32 tgid;
86 __u32 ppid;
87 __u32 ruid;
88 __u32 rgid;
89 __u32 euid;
90 __u32 egid;
91 __u32 suid;
92 __u32 sgid;
93 __u32 fsuid;
94 __u32 fsgid;
95 __s32 exit_code;
96 struct /* coredump info */ {
97 __u32 coredump_mask;
98 __u32 coredump_signal;
99 __u32 coredump_code;
100 __u32 coredump_pad; /* align supported_mask to 8 bytes */
101 };
102 __u64 supported_mask; /* Mask flags that this kernel supports */
103};
104
105#define PIDFS_IOCTL_MAGIC 0xFF
106
107#define PIDFD_GET_CGROUP_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 1)
108#define PIDFD_GET_IPC_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 2)
109#define PIDFD_GET_MNT_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 3)
110#define PIDFD_GET_NET_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 4)
111#define PIDFD_GET_PID_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 5)
112#define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 6)
113#define PIDFD_GET_TIME_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 7)
114#define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8)
115#define PIDFD_GET_USER_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 9)
116#define PIDFD_GET_UTS_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 10)
117#define PIDFD_GET_INFO _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info)
118
119#endif /* _LINUX_PIDFD_H */