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 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 24 #define PIDFD_INFO_SIZE_VER0 64 /* sizeof first published struct */ 25 26 /* 27 * The concept of process and threads in userland and the kernel is a confusing 28 * one - within the kernel every thread is a 'task' with its own individual PID, 29 * however from userland's point of view threads are grouped by a single PID, 30 * which is that of the 'thread group leader', typically the first thread 31 * spawned. 32 * 33 * To cut the Gideon knot, for internal kernel usage, we refer to 34 * PIDFD_SELF_THREAD to refer to the current thread (or task from a kernel 35 * perspective), and PIDFD_SELF_THREAD_GROUP to refer to the current thread 36 * group leader... 37 */ 38 #define PIDFD_SELF_THREAD -10000 /* Current thread. */ 39 #define PIDFD_SELF_THREAD_GROUP -20000 /* Current thread group leader. */ 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 50 struct 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 __u32 spare0[1]; 90 }; 91 92 #define PIDFS_IOCTL_MAGIC 0xFF 93 94 #define PIDFD_GET_CGROUP_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 1) 95 #define PIDFD_GET_IPC_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 2) 96 #define PIDFD_GET_MNT_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 3) 97 #define PIDFD_GET_NET_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 4) 98 #define PIDFD_GET_PID_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 5) 99 #define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 6) 100 #define PIDFD_GET_TIME_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 7) 101 #define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8) 102 #define PIDFD_GET_USER_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 9) 103 #define PIDFD_GET_UTS_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 10) 104 #define PIDFD_GET_INFO _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info) 105 106 #endif /* _UAPI_LINUX_PIDFD_H */ 107