xref: /netbsd-src/sys/kern/kern_stub.c (revision 96230fab84e26a6435963032070e916a951a8b2e)
1 /*	$NetBSD: kern_stub.c,v 1.11 2008/10/15 16:03:29 wrstuden 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 1.11 2008/10/15 16:03:29 wrstuden Exp $");
66 
67 #include "opt_ptrace.h"
68 #include "opt_ktrace.h"
69 #include "opt_sa.h"
70 
71 #include <sys/param.h>
72 #include <sys/kernel.h>
73 #include <sys/proc.h>
74 #include <sys/signalvar.h>
75 #include <sys/syscallargs.h>
76 #include <sys/ktrace.h>
77 #include <sys/intr.h>
78 #include <sys/cpu.h>
79 
80 /*
81  * Nonexistent system call-- signal process (may want to handle it).  Flag
82  * error in case process won't see signal immediately (blocked or ignored).
83  */
84 #ifndef PTRACE
85 __weak_alias(sys_ptrace,sys_nosys);
86 #endif	/* PTRACE */
87 
88 /*
89  * ktrace stubs.  ktruser() goes to enosys as we want to fail the syscall,
90  * but not kill the process: utrace() is a debugging feature.
91  */
92 #ifndef KTRACE
93 __weak_alias(ktr_csw,nullop);		/* Probes */
94 __weak_alias(ktr_emul,nullop);
95 __weak_alias(ktr_geniov,nullop);
96 __weak_alias(ktr_genio,nullop);
97 __weak_alias(ktr_mibio,nullop);
98 __weak_alias(ktr_namei,nullop);
99 __weak_alias(ktr_namei2,nullop);
100 __weak_alias(ktr_psig,nullop);
101 __weak_alias(ktr_saupcall,nullop);
102 __weak_alias(ktr_syscall,nullop);
103 __weak_alias(ktr_sysret,nullop);
104 __weak_alias(ktr_kuser,nullop);
105 __weak_alias(ktr_mmsg,nullop);
106 __weak_alias(ktr_mib,nullop);
107 __weak_alias(ktr_mool,nullop);
108 __weak_alias(ktr_execarg,nullop);
109 __weak_alias(ktr_execenv,nullop);
110 
111 __weak_alias(sys_fktrace,sys_nosys);	/* Syscalls */
112 __weak_alias(sys_ktrace,sys_nosys);
113 __weak_alias(sys_utrace,sys_nosys);
114 
115 int	ktrace_on;			/* Misc */
116 __weak_alias(ktruser,enosys);
117 __weak_alias(ktr_point,nullop);
118 #endif	/* KTRACE */
119 
120 /*
121  * Scheduler activations system calls.  These need to remain, even when
122  * KERN_SA isn't defined, until libc's major version is bumped.
123  */
124 #if !defined(KERN_SA)
125 __strong_alias(sys_sa_register,sys_nosys);
126 __strong_alias(sys_sa_stacks,sys_nosys);
127 __strong_alias(sys_sa_enable,sys_nosys);
128 __strong_alias(sys_sa_setconcurrency,sys_nosys);
129 __strong_alias(sys_sa_yield,sys_nosys);
130 __strong_alias(sys_sa_preempt,sys_nosys);
131 __strong_alias(sys_sa_unblockyield,sys_nosys);
132 #endif
133 
134 /*
135  * Stubs for architectures that do not support kernel preemption.
136  */
137 #ifndef __HAVE_PREEMPTION
138 bool
139 cpu_kpreempt_enter(uintptr_t where, int s)
140 {
141 
142 	return false;
143 }
144 
145 void
146 cpu_kpreempt_exit(uintptr_t where)
147 {
148 
149 }
150 
151 bool
152 cpu_kpreempt_disabled(void)
153 {
154 
155 	return true;
156 }
157 #else
158 # ifndef MULTIPROCESSOR
159 #   error __HAVE_PREEMPTION requires MULTIPROCESSOR
160 # endif
161 #endif	/* !__HAVE_PREEMPTION */
162 
163 /* ARGSUSED */
164 int
165 sys_nosys(struct lwp *l, const void *v, register_t *retval)
166 {
167 
168 	mutex_enter(proc_lock);
169 	psignal(l->l_proc, SIGSYS);
170 	mutex_exit(proc_lock);
171 	return ENOSYS;
172 }
173 
174 /*
175  * Unsupported device function (e.g. writing to read-only device).
176  */
177 int
178 enodev(void)
179 {
180 
181 	return (ENODEV);
182 }
183 
184 /*
185  * Unconfigured device function; driver not configured.
186  */
187 int
188 enxio(void)
189 {
190 
191 	return (ENXIO);
192 }
193 
194 /*
195  * Unsupported ioctl function.
196  */
197 int
198 enoioctl(void)
199 {
200 
201 	return (ENOTTY);
202 }
203 
204 /*
205  * Unsupported system function.
206  * This is used for an otherwise-reasonable operation
207  * that is not supported by the current system binary.
208  */
209 int
210 enosys(void)
211 {
212 
213 	return (ENOSYS);
214 }
215 
216 /*
217  * Return error for operation not supported
218  * on a specific object or file type.
219  */
220 int
221 eopnotsupp(void)
222 {
223 
224 	return (EOPNOTSUPP);
225 }
226 
227 /*
228  * Generic null operation, always returns success.
229  */
230 /*ARGSUSED*/
231 int
232 nullop(void *v)
233 {
234 
235 	return (0);
236 }
237