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