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 #define PIDFD_INFO_EXIT (1UL << 3) /* Only returned if requested. */ 24 25 #define PIDFD_INFO_SIZE_VER0 64 /* sizeof first published struct */ 26 27 /* 28 * The concept of process and threads in userland and the kernel is a confusing 29 * one - within the kernel every thread is a 'task' with its own individual PID, 30 * however from userland's point of view threads are grouped by a single PID, 31 * which is that of the 'thread group leader', typically the first thread 32 * spawned. 33 * 34 * To cut the Gideon knot, for internal kernel usage, we refer to 35 * PIDFD_SELF_THREAD to refer to the current thread (or task from a kernel 36 * perspective), and PIDFD_SELF_THREAD_GROUP to refer to the current thread 37 * group leader... 38 */ 39 #define PIDFD_SELF_THREAD -10000 /* Current thread. */ 40 #define PIDFD_SELF_THREAD_GROUP -20000 /* Current thread group leader. */ 41 42 /* 43 * ...and for userland we make life simpler - PIDFD_SELF refers to the current 44 * thread, PIDFD_SELF_PROCESS refers to the process thread group leader. 45 * 46 * For nearly all practical uses, a user will want to use PIDFD_SELF. 47 */ 48 #define PIDFD_SELF PIDFD_SELF_THREAD 49 #define PIDFD_SELF_PROCESS PIDFD_SELF_THREAD_GROUP 50 51 struct pidfd_info { 52 /* 53 * This mask is similar to the request_mask in statx(2). 54 * 55 * Userspace indicates what extensions or expensive-to-calculate fields 56 * they want by setting the corresponding bits in mask. The kernel 57 * will ignore bits that it does not know about. 58 * 59 * When filling the structure, the kernel will only set bits 60 * corresponding to the fields that were actually filled by the kernel. 61 * This also includes any future extensions that might be automatically 62 * filled. If the structure size is too small to contain a field 63 * (requested or not), to avoid confusion the mask will not 64 * contain a bit for that field. 65 * 66 * As such, userspace MUST verify that mask contains the 67 * corresponding flags after the ioctl(2) returns to ensure that it is 68 * using valid data. 69 */ 70 __u64 mask; 71 /* 72 * The information contained in the following fields might be stale at the 73 * time it is received, as the target process might have exited as soon as 74 * the IOCTL was processed, and there is no way to avoid that. However, it 75 * is guaranteed that if the call was successful, then the information was 76 * correct and referred to the intended process at the time the work was 77 * performed. */ 78 __u64 cgroupid; 79 __u32 pid; 80 __u32 tgid; 81 __u32 ppid; 82 __u32 ruid; 83 __u32 rgid; 84 __u32 euid; 85 __u32 egid; 86 __u32 suid; 87 __u32 sgid; 88 __u32 fsuid; 89 __u32 fsgid; 90 __s32 exit_code; 91 }; 92 93 #define PIDFS_IOCTL_MAGIC 0xFF 94 95 #define PIDFD_GET_CGROUP_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 1) 96 #define PIDFD_GET_IPC_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 2) 97 #define PIDFD_GET_MNT_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 3) 98 #define PIDFD_GET_NET_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 4) 99 #define PIDFD_GET_PID_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 5) 100 #define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 6) 101 #define PIDFD_GET_TIME_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 7) 102 #define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8) 103 #define PIDFD_GET_USER_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 9) 104 #define PIDFD_GET_UTS_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 10) 105 #define PIDFD_GET_INFO _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info) 106 107 #endif /* _UAPI_LINUX_PIDFD_H */ 108