xref: /linux/include/uapi/linux/pidfd.h (revision 672dcda246071e1940eab8bb5a03d04ea026f46e)
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_STALE 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 #define PIDFD_INFO_COREDUMP		(1UL << 4) /* Only returned if requested. */
29 
30 #define PIDFD_INFO_SIZE_VER0		64 /* sizeof first published struct */
31 
32 /*
33  * Values for @coredump_mask in pidfd_info.
34  * Only valid if PIDFD_INFO_COREDUMP is set in @mask.
35  *
36  * Note, the @PIDFD_COREDUMP_ROOT flag indicates that the generated
37  * coredump should be treated as sensitive and access should only be
38  * granted to privileged users.
39  */
40 #define PIDFD_COREDUMPED	(1U << 0) /* Did crash and... */
41 #define PIDFD_COREDUMP_SKIP	(1U << 1) /* coredumping generation was skipped. */
42 #define PIDFD_COREDUMP_USER	(1U << 2) /* coredump was done as the user. */
43 #define PIDFD_COREDUMP_ROOT	(1U << 3) /* coredump was done as root. */
44 
45 /*
46  * ...and for userland we make life simpler - PIDFD_SELF refers to the current
47  * thread, PIDFD_SELF_PROCESS refers to the process thread group leader.
48  *
49  * For nearly all practical uses, a user will want to use PIDFD_SELF.
50  */
51 #define PIDFD_SELF		PIDFD_SELF_THREAD
52 #define PIDFD_SELF_PROCESS	PIDFD_SELF_THREAD_GROUP
53 
54 struct pidfd_info {
55 	/*
56 	 * This mask is similar to the request_mask in statx(2).
57 	 *
58 	 * Userspace indicates what extensions or expensive-to-calculate fields
59 	 * they want by setting the corresponding bits in mask. The kernel
60 	 * will ignore bits that it does not know about.
61 	 *
62 	 * When filling the structure, the kernel will only set bits
63 	 * corresponding to the fields that were actually filled by the kernel.
64 	 * This also includes any future extensions that might be automatically
65 	 * filled. If the structure size is too small to contain a field
66 	 * (requested or not), to avoid confusion the mask will not
67 	 * contain a bit for that field.
68 	 *
69 	 * As such, userspace MUST verify that mask contains the
70 	 * corresponding flags after the ioctl(2) returns to ensure that it is
71 	 * using valid data.
72 	 */
73 	__u64 mask;
74 	/*
75 	 * The information contained in the following fields might be stale at the
76 	 * time it is received, as the target process might have exited as soon as
77 	 * the IOCTL was processed, and there is no way to avoid that. However, it
78 	 * is guaranteed that if the call was successful, then the information was
79 	 * correct and referred to the intended process at the time the work was
80 	 * performed. */
81 	__u64 cgroupid;
82 	__u32 pid;
83 	__u32 tgid;
84 	__u32 ppid;
85 	__u32 ruid;
86 	__u32 rgid;
87 	__u32 euid;
88 	__u32 egid;
89 	__u32 suid;
90 	__u32 sgid;
91 	__u32 fsuid;
92 	__u32 fsgid;
93 	__s32 exit_code;
94 	__u32 coredump_mask;
95 	__u32 __spare1;
96 };
97 
98 #define PIDFS_IOCTL_MAGIC 0xFF
99 
100 #define PIDFD_GET_CGROUP_NAMESPACE            _IO(PIDFS_IOCTL_MAGIC, 1)
101 #define PIDFD_GET_IPC_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 2)
102 #define PIDFD_GET_MNT_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 3)
103 #define PIDFD_GET_NET_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 4)
104 #define PIDFD_GET_PID_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 5)
105 #define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE  _IO(PIDFS_IOCTL_MAGIC, 6)
106 #define PIDFD_GET_TIME_NAMESPACE              _IO(PIDFS_IOCTL_MAGIC, 7)
107 #define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8)
108 #define PIDFD_GET_USER_NAMESPACE              _IO(PIDFS_IOCTL_MAGIC, 9)
109 #define PIDFD_GET_UTS_NAMESPACE               _IO(PIDFS_IOCTL_MAGIC, 10)
110 #define PIDFD_GET_INFO                        _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info)
111 
112 #endif /* _UAPI_LINUX_PIDFD_H */
113