pidfd.h

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