2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2009 Robert N. M. Watson
7 * This software was developed at the University of Cambridge Computer
8 * Laboratory with support from a grant from Google, Inc.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
34 #ifndef _SYS_PROCDESC_H_
35 #define _SYS_PROCDESC_H_
39 #include <sys/selinfo.h> /* struct selinfo */
40 #include <sys/_lock.h>
41 #include <sys/_mutex.h>
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.
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
61 * Basic process descriptor state: the process, a cache of its pid to
62 * satisfy queries after the process exits, and process descriptor
65 struct proc *pd_proc; /* (t) Process. */
66 pid_t pd_pid; /* (c) Cached pid. */
67 u_int pd_refcount; /* (r) Reference count. */
70 * In-flight data and notification of events.
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. */
79 * Locking macros for the procdesc itself.
81 #define PROCDESC_LOCK_DESTROY(pd) mtx_destroy(&(pd)->pd_lock)
82 #define PROCDESC_LOCK_INIT(pd) mtx_init(&(pd)->pd_lock, "procdesc", NULL, \
84 #define PROCDESC_LOCK(pd) mtx_lock(&(pd)->pd_lock)
85 #define PROCDESC_UNLOCK(pd) mtx_unlock(&(pd)->pd_lock)
88 * Flags for the pd_flags field.
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. */
96 * In-kernel interfaces to process descriptors.
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 *);
106 int procdesc_falloc(struct thread *, struct file **, int *, int,
111 #include <sys/_types.h>
113 #ifndef _PID_T_DECLARED
114 typedef __pid_t pid_t;
115 #define _PID_T_DECLARED
121 * Process descriptor system calls.
124 pid_t pdfork(int *, int);
125 int pdkill(int, int);
126 int pdgetpid(int, pid_t *);
132 * Flags which can be passed to pdfork(2).
134 #define PD_DAEMON 0x00000001 /* Don't exit when procdesc closes. */
135 #define PD_CLOEXEC 0x00000002 /* Close file descriptor on exec. */
137 #define PD_ALLOWED_AT_FORK (PD_DAEMON | PD_CLOEXEC)
139 #endif /* !_SYS_PROCDESC_H_ */