1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2009 Robert N. M. Watson 5 * All rights reserved. 6 * 7 * This software was developed at the University of Cambridge Computer 8 * Laboratory with support from a grant from Google, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $FreeBSD$ 32 */ 33 34 #ifndef _SYS_PROCDESC_H_ 35 #define _SYS_PROCDESC_H_ 36 37 #ifdef _KERNEL 38 39 #include <sys/selinfo.h> /* struct selinfo */ 40 #include <sys/_lock.h> 41 #include <sys/_mutex.h> 42 43 /*- 44 * struct procdesc describes a process descriptor, and essentially consists 45 * of two pointers -- one to the file descriptor, and one to the process. 46 * When both become NULL, the process descriptor will be freed. An important 47 * invariant is that there is only ever one process descriptor for a process, 48 * so a single file pointer will suffice. 49 * 50 * Locking key: 51 * (c) - Constant after initial setup. 52 * (p) - Protected by the process descriptor mutex. 53 * (r) - Atomic reference count. 54 * (s) - Protected by selinfo. 55 * (t) - Protected by the proctree_lock 56 */ 57 struct proc; 58 struct sigio; 59 struct procdesc { 60 /* 61 * Basic process descriptor state: the process, a cache of its pid to 62 * satisfy queries after the process exits, and process descriptor 63 * refcount. 64 */ 65 struct proc *pd_proc; /* (t) Process. */ 66 pid_t pd_pid; /* (c) Cached pid. */ 67 u_int pd_refcount; /* (r) Reference count. */ 68 69 /* 70 * In-flight data and notification of events. 71 */ 72 int pd_flags; /* (p) PD_ flags. */ 73 u_short pd_xstat; /* (p) Exit status. */ 74 struct selinfo pd_selinfo; /* (p) Event notification. */ 75 struct mtx pd_lock; /* Protect data + events. */ 76 }; 77 78 /* 79 * Locking macros for the procdesc itself. 80 */ 81 #define PROCDESC_LOCK_DESTROY(pd) mtx_destroy(&(pd)->pd_lock) 82 #define PROCDESC_LOCK_INIT(pd) mtx_init(&(pd)->pd_lock, "procdesc", NULL, \ 83 MTX_DEF) 84 #define PROCDESC_LOCK(pd) mtx_lock(&(pd)->pd_lock) 85 #define PROCDESC_UNLOCK(pd) mtx_unlock(&(pd)->pd_lock) 86 87 /* 88 * Flags for the pd_flags field. 89 */ 90 #define PDF_CLOSED 0x00000001 /* Descriptor has closed. */ 91 #define PDF_SELECTED 0x00000002 /* Issue selwakeup(). */ 92 #define PDF_EXITED 0x00000004 /* Process exited. */ 93 #define PDF_DAEMON 0x00000008 /* Don't exit when procdesc closes. */ 94 95 /* 96 * In-kernel interfaces to process descriptors. 97 */ 98 int procdesc_exit(struct proc *); 99 int procdesc_find(struct thread *, int fd, cap_rights_t *, struct proc **); 100 int kern_pdgetpid(struct thread *, int fd, cap_rights_t *, pid_t *pidp); 101 void procdesc_new(struct proc *, int); 102 void procdesc_finit(struct procdesc *, struct file *); 103 pid_t procdesc_pid(struct file *); 104 void procdesc_reap(struct proc *); 105 106 int procdesc_falloc(struct thread *, struct file **, int *, int, 107 struct filecaps *); 108 109 #else /* !_KERNEL */ 110 111 #include <sys/_types.h> 112 113 #ifndef _PID_T_DECLARED 114 typedef __pid_t pid_t; 115 #define _PID_T_DECLARED 116 #endif 117 118 struct rusage; 119 120 /* 121 * Process descriptor system calls. 122 */ 123 __BEGIN_DECLS 124 pid_t pdfork(int *, int); 125 int pdkill(int, int); 126 int pdgetpid(int, pid_t *); 127 __END_DECLS 128 129 #endif /* _KERNEL */ 130 131 /* 132 * Flags which can be passed to pdfork(2). 133 */ 134 #define PD_DAEMON 0x00000001 /* Don't exit when procdesc closes. */ 135 #define PD_CLOEXEC 0x00000002 /* Close file descriptor on exec. */ 136 137 #define PD_ALLOWED_AT_FORK (PD_DAEMON | PD_CLOEXEC) 138 139 #endif /* !_SYS_PROCDESC_H_ */ 140