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 * The concept of process and threads in userland and the kernel is a confusing 47 * one - within the kernel every thread is a 'task' with its own individual PID, 48 * however from userland's point of view threads are grouped by a single PID, 49 * which is that of the 'thread group leader', typically the first thread 50 * spawned. 51 * 52 * To cut the Gideon knot, for internal kernel usage, we refer to 53 * PIDFD_SELF_THREAD to refer to the current thread (or task from a kernel 54 * perspective), and PIDFD_SELF_THREAD_GROUP to refer to the current thread 55 * group leader... 56 */ 57 #define PIDFD_SELF_THREAD -10000 /* Current thread. */ 58 #define PIDFD_SELF_THREAD_GROUP -20000 /* Current thread group leader. */ 59 60 /* 61 * ...and for userland we make life simpler - PIDFD_SELF refers to the current 62 * thread, PIDFD_SELF_PROCESS refers to the process thread group leader. 63 * 64 * For nearly all practical uses, a user will want to use PIDFD_SELF. 65 */ 66 #define PIDFD_SELF PIDFD_SELF_THREAD 67 #define PIDFD_SELF_PROCESS PIDFD_SELF_THREAD_GROUP 68 69 struct pidfd_info { 70 /* 71 * This mask is similar to the request_mask in statx(2). 72 * 73 * Userspace indicates what extensions or expensive-to-calculate fields 74 * they want by setting the corresponding bits in mask. The kernel 75 * will ignore bits that it does not know about. 76 * 77 * When filling the structure, the kernel will only set bits 78 * corresponding to the fields that were actually filled by the kernel. 79 * This also includes any future extensions that might be automatically 80 * filled. If the structure size is too small to contain a field 81 * (requested or not), to avoid confusion the mask will not 82 * contain a bit for that field. 83 * 84 * As such, userspace MUST verify that mask contains the 85 * corresponding flags after the ioctl(2) returns to ensure that it is 86 * using valid data. 87 */ 88 __u64 mask; 89 /* 90 * The information contained in the following fields might be stale at the 91 * time it is received, as the target process might have exited as soon as 92 * the IOCTL was processed, and there is no way to avoid that. However, it 93 * is guaranteed that if the call was successful, then the information was 94 * correct and referred to the intended process at the time the work was 95 * performed. */ 96 __u64 cgroupid; 97 __u32 pid; 98 __u32 tgid; 99 __u32 ppid; 100 __u32 ruid; 101 __u32 rgid; 102 __u32 euid; 103 __u32 egid; 104 __u32 suid; 105 __u32 sgid; 106 __u32 fsuid; 107 __u32 fsgid; 108 __s32 exit_code; 109 __u32 coredump_mask; 110 __u32 __spare1; 111 }; 112 113 #define PIDFS_IOCTL_MAGIC 0xFF 114 115 #define PIDFD_GET_CGROUP_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 1) 116 #define PIDFD_GET_IPC_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 2) 117 #define PIDFD_GET_MNT_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 3) 118 #define PIDFD_GET_NET_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 4) 119 #define PIDFD_GET_PID_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 5) 120 #define PIDFD_GET_PID_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 6) 121 #define PIDFD_GET_TIME_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 7) 122 #define PIDFD_GET_TIME_FOR_CHILDREN_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 8) 123 #define PIDFD_GET_USER_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 9) 124 #define PIDFD_GET_UTS_NAMESPACE _IO(PIDFS_IOCTL_MAGIC, 10) 125 #define PIDFD_GET_INFO _IOWR(PIDFS_IOCTL_MAGIC, 11, struct pidfd_info) 126 127 #endif /* _UAPI_LINUX_PIDFD_H */ 128