2 * Copyright (c) 2009 Robert N. M. Watson
5 * This software was developed at the University of Cambridge Computer
6 * Laboratory with support from a grant from Google, Inc.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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.
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
32 #ifndef _SYS_PROCDESC_H_
33 #define _SYS_PROCDESC_H_
36 #include <sys/selinfo.h> /* struct selinfo */
37 #include <sys/_lock.h>
38 #include <sys/_mutex.h>
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.
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
58 * Basic process descriptor state: the process, a cache of its pid to
59 * satisfy queries after the process exits, and process descriptor
62 struct proc *pd_proc; /* (t) Process. */
63 pid_t pd_pid; /* (c) Cached pid. */
64 u_int pd_refcount; /* (r) Reference count. */
67 * In-flight data and notification of events.
69 int pd_flags; /* (p) PD_ flags. */
70 struct selinfo pd_selinfo; /* (p) Event notification. */
71 struct mtx pd_lock; /* Protect data + events. */
75 * Locking macros for the procdesc itself.
77 #define PROCDESC_LOCK_DESTROY(pd) mtx_destroy(&(pd)->pd_lock)
78 #define PROCDESC_LOCK_INIT(pd) mtx_init(&(pd)->pd_lock, "procdesc", NULL, \
80 #define PROCDESC_LOCK(pd) mtx_lock(&(pd)->pd_lock)
81 #define PROCDESC_UNLOCK(pd) mtx_unlock(&(pd)->pd_lock)
84 * Flags for the pd_flags field.
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. */
92 * In-kernel interfaces to process descriptors.
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 *);
105 * Process descriptor system calls.
108 int pdfork(int *, int);
109 int pdkill(int, int);
110 int pdgetpid(int, pid_t *);
115 * Flags which can be passed to pdfork(2).
117 #define PD_DAEMON 0x00000001 /* Don't exit when procdesc closes. */
119 #endif /* !_SYS_PROCDESC_H_ */