FreeBSD/Linux Kernel Cross Reference
sys/sys/procdesc.h
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: releng/11.2/sys/sys/procdesc.h 331722 2018-03-29 02:50:57Z eadler $
30 */
31
32 #ifndef _SYS_PROCDESC_H_
33 #define _SYS_PROCDESC_H_
34
35 #ifdef _KERNEL
36
37 #include <sys/selinfo.h> /* struct selinfo */
38 #include <sys/_lock.h>
39 #include <sys/_mutex.h>
40
41 /*-
42 * struct procdesc describes a process descriptor, and essentially consists
43 * of two pointers -- one to the file descriptor, and one to the process.
44 * When both become NULL, the process descriptor will be freed. An important
45 * invariant is that there is only ever one process descriptor for a process,
46 * so a single file pointer will suffice.
47 *
48 * Locking key:
49 * (c) - Constant after initial setup.
50 * (p) - Protected by the process descriptor mutex.
51 * (r) - Atomic reference count.
52 * (s) - Protected by selinfo.
53 * (t) - Protected by the proctree_lock
54 */
55 struct proc;
56 struct sigio;
57 struct procdesc {
58 /*
59 * Basic process descriptor state: the process, a cache of its pid to
60 * satisfy queries after the process exits, and process descriptor
61 * refcount.
62 */
63 struct proc *pd_proc; /* (t) Process. */
64 pid_t pd_pid; /* (c) Cached pid. */
65 u_int pd_refcount; /* (r) Reference count. */
66
67 /*
68 * In-flight data and notification of events.
69 */
70 int pd_flags; /* (p) PD_ flags. */
71 u_short pd_xstat; /* (p) Exit status. */
72 struct selinfo pd_selinfo; /* (p) Event notification. */
73 struct mtx pd_lock; /* Protect data + events. */
74 };
75
76 /*
77 * Locking macros for the procdesc itself.
78 */
79 #define PROCDESC_LOCK_DESTROY(pd) mtx_destroy(&(pd)->pd_lock)
80 #define PROCDESC_LOCK_INIT(pd) mtx_init(&(pd)->pd_lock, "procdesc", NULL, \
81 MTX_DEF)
82 #define PROCDESC_LOCK(pd) mtx_lock(&(pd)->pd_lock)
83 #define PROCDESC_UNLOCK(pd) mtx_unlock(&(pd)->pd_lock)
84
85 /*
86 * Flags for the pd_flags field.
87 */
88 #define PDF_CLOSED 0x00000001 /* Descriptor has closed. */
89 #define PDF_SELECTED 0x00000002 /* Issue selwakeup(). */
90 #define PDF_EXITED 0x00000004 /* Process exited. */
91 #define PDF_DAEMON 0x00000008 /* Don't exit when procdesc closes. */
92
93 /*
94 * In-kernel interfaces to process descriptors.
95 */
96 int procdesc_exit(struct proc *);
97 int procdesc_find(struct thread *, int fd, cap_rights_t *, struct proc **);
98 int kern_pdgetpid(struct thread *, int fd, cap_rights_t *, pid_t *pidp);
99 void procdesc_new(struct proc *, int);
100 void procdesc_finit(struct procdesc *, struct file *);
101 pid_t procdesc_pid(struct file *);
102 void procdesc_reap(struct proc *);
103
104 int procdesc_falloc(struct thread *, struct file **, int *, int,
105 struct filecaps *);
106
107 #else /* !_KERNEL */
108
109 #include <sys/_types.h>
110
111 #ifndef _PID_T_DECLARED
112 typedef __pid_t pid_t;
113 #define _PID_T_DECLARED
114 #endif
115
116 struct rusage;
117
118 /*
119 * Process descriptor system calls.
120 */
121 __BEGIN_DECLS
122 pid_t pdfork(int *, int);
123 int pdkill(int, int);
124 int pdgetpid(int, pid_t *);
125 __END_DECLS
126
127 #endif /* _KERNEL */
128
129 /*
130 * Flags which can be passed to pdfork(2).
131 */
132 #define PD_DAEMON 0x00000001 /* Don't exit when procdesc closes. */
133 #define PD_CLOEXEC 0x00000002 /* Close file descriptor on exec. */
134
135 #define PD_ALLOWED_AT_FORK (PD_DAEMON | PD_CLOEXEC)
136
137 #endif /* !_SYS_PROCDESC_H_ */
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