xref: /netbsd-src/sys/kern/kern_stub.c (revision cac8e449158efc7261bebc8657cbb0125a2cfdde)
1 /*	$NetBSD: kern_stub.c,v 1.9 2008/05/01 00:20:12 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 2007, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * Copyright (c) 1982, 1986, 1991, 1993
31  *	The Regents of the University of California.  All rights reserved.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice, this list of conditions and the following disclaimer.
38  * 2. Redistributions in binary form must reproduce the above copyright
39  *    notice, this list of conditions and the following disclaimer in the
40  *    documentation and/or other materials provided with the distribution.
41  * 3. Neither the name of the University nor the names of its contributors
42  *    may be used to endorse or promote products derived from this software
43  *    without specific prior written permission.
44  *
45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55  * SUCH DAMAGE.
56  *
57  *	@(#)subr_xxx.c	8.3 (Berkeley) 3/29/95
58  */
59 
60 /*
61  * Stubs for system calls and facilities not included in the system.
62  */
63 
64 #include <sys/cdefs.h>
65 __KERNEL_RCSID(0, "$NetBSD: kern_stub.c,v 1.9 2008/05/01 00:20:12 ad Exp $");
66 
67 #include "opt_ptrace.h"
68 #include "opt_ktrace.h"
69 
70 #include <sys/param.h>
71 #include <sys/kernel.h>
72 #include <sys/proc.h>
73 #include <sys/signalvar.h>
74 #include <sys/syscallargs.h>
75 #include <sys/ktrace.h>
76 #include <sys/intr.h>
77 #include <sys/cpu.h>
78 
79 /*
80  * Nonexistent system call-- signal process (may want to handle it).  Flag
81  * error in case process won't see signal immediately (blocked or ignored).
82  */
83 #ifndef PTRACE
84 __weak_alias(sys_ptrace,sys_nosys);
85 #endif	/* PTRACE */
86 
87 /*
88  * ktrace stubs.  ktruser() goes to enosys as we want to fail the syscall,
89  * but not kill the process: utrace() is a debugging feature.
90  */
91 #ifndef KTRACE
92 __weak_alias(ktr_csw,nullop);		/* Probes */
93 __weak_alias(ktr_emul,nullop);
94 __weak_alias(ktr_geniov,nullop);
95 __weak_alias(ktr_genio,nullop);
96 __weak_alias(ktr_mibio,nullop);
97 __weak_alias(ktr_namei,nullop);
98 __weak_alias(ktr_namei2,nullop);
99 __weak_alias(ktr_psig,nullop);
100 __weak_alias(ktr_syscall,nullop);
101 __weak_alias(ktr_sysret,nullop);
102 __weak_alias(ktr_kuser,nullop);
103 __weak_alias(ktr_mmsg,nullop);
104 __weak_alias(ktr_mib,nullop);
105 __weak_alias(ktr_mool,nullop);
106 __weak_alias(ktr_execarg,nullop);
107 __weak_alias(ktr_execenv,nullop);
108 
109 __weak_alias(sys_fktrace,sys_nosys);	/* Syscalls */
110 __weak_alias(sys_ktrace,sys_nosys);
111 __weak_alias(sys_utrace,sys_nosys);
112 
113 int	ktrace_on;			/* Misc */
114 __weak_alias(ktruser,enosys);
115 __weak_alias(ktr_point,nullop);
116 #endif	/* KTRACE */
117 
118 /*
119  * Scheduler activations system calls.  These need to remain until libc's
120  * major version is bumped.
121  */
122 __strong_alias(sys_sa_register,sys_nosys);
123 __strong_alias(sys_sa_stacks,sys_nosys);
124 __strong_alias(sys_sa_enable,sys_nosys);
125 __strong_alias(sys_sa_setconcurrency,sys_nosys);
126 __strong_alias(sys_sa_yield,sys_nosys);
127 __strong_alias(sys_sa_preempt,sys_nosys);
128 __strong_alias(sys_sa_unblockyield,sys_nosys);
129 
130 /*
131  * Stubs for architectures that do not support kernel preemption.
132  */
133 #ifndef __HAVE_PREEMPTION
134 bool
135 cpu_kpreempt_enter(uintptr_t where, int s)
136 {
137 
138 	return false;
139 }
140 
141 void
142 cpu_kpreempt_exit(uintptr_t where)
143 {
144 
145 }
146 
147 bool
148 cpu_kpreempt_disabled(void)
149 {
150 
151 	return true;
152 }
153 #else
154 # ifndef MULTIPROCESSOR
155 #   error __HAVE_PREEMPTION requires MULTIPROCESSOR
156 # endif
157 #endif	/* !__HAVE_PREEMPTION */
158 
159 /* ARGSUSED */
160 int
161 sys_nosys(struct lwp *l, const void *v, register_t *retval)
162 {
163 
164 	mutex_enter(proc_lock);
165 	psignal(l->l_proc, SIGSYS);
166 	mutex_exit(proc_lock);
167 	return ENOSYS;
168 }
169 
170 /*
171  * Unsupported device function (e.g. writing to read-only device).
172  */
173 int
174 enodev(void)
175 {
176 
177 	return (ENODEV);
178 }
179 
180 /*
181  * Unconfigured device function; driver not configured.
182  */
183 int
184 enxio(void)
185 {
186 
187 	return (ENXIO);
188 }
189 
190 /*
191  * Unsupported ioctl function.
192  */
193 int
194 enoioctl(void)
195 {
196 
197 	return (ENOTTY);
198 }
199 
200 /*
201  * Unsupported system function.
202  * This is used for an otherwise-reasonable operation
203  * that is not supported by the current system binary.
204  */
205 int
206 enosys(void)
207 {
208 
209 	return (ENOSYS);
210 }
211 
212 /*
213  * Return error for operation not supported
214  * on a specific object or file type.
215  */
216 int
217 eopnotsupp(void)
218 {
219 
220 	return (EOPNOTSUPP);
221 }
222 
223 /*
224  * Generic null operation, always returns success.
225  */
226 /*ARGSUSED*/
227 int
228 nullop(void *v)
229 {
230 
231 	return (0);
232 }
233