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 55 struct 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 */ 112