xref: /netbsd-src/sys/kern/kern_stub.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: kern_stub.c,v 1.29 2010/06/13 13:43:02 simonb 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 1.29 2010/06/13 13:43:02 simonb 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/fstypes.h>
75 #include <sys/signalvar.h>
76 #include <sys/syscall.h>
77 #include <sys/ktrace.h>
78 #include <sys/intr.h>
79 #include <sys/cpu.h>
80 #include <sys/module.h>
81 #include <sys/bus.h>
82 
83 bool default_bus_space_is_equal(bus_space_tag_t, bus_space_tag_t);
84 
85 /*
86  * Nonexistent system call-- signal process (may want to handle it).  Flag
87  * error in case process won't see signal immediately (blocked or ignored).
88  */
89 #ifndef PTRACE
90 __weak_alias(sys_ptrace,sys_nosys);
91 #endif	/* PTRACE */
92 
93 /*
94  * ktrace stubs.  ktruser() goes to enosys as we want to fail the syscall,
95  * but not kill the process: utrace() is a debugging feature.
96  */
97 #ifndef KTRACE
98 __weak_alias(ktr_csw,nullop);		/* Probes */
99 __weak_alias(ktr_emul,nullop);
100 __weak_alias(ktr_geniov,nullop);
101 __weak_alias(ktr_genio,nullop);
102 __weak_alias(ktr_mibio,nullop);
103 __weak_alias(ktr_namei,nullop);
104 __weak_alias(ktr_namei2,nullop);
105 __weak_alias(ktr_psig,nullop);
106 __weak_alias(ktr_saupcall,nullop);
107 __weak_alias(ktr_syscall,nullop);
108 __weak_alias(ktr_sysret,nullop);
109 __weak_alias(ktr_kuser,nullop);
110 __weak_alias(ktr_mmsg,nullop);
111 __weak_alias(ktr_mib,nullop);
112 __weak_alias(ktr_mool,nullop);
113 __weak_alias(ktr_execarg,nullop);
114 __weak_alias(ktr_execenv,nullop);
115 
116 __weak_alias(sys_fktrace,sys_nosys);	/* Syscalls */
117 __weak_alias(sys_ktrace,sys_nosys);
118 __weak_alias(sys_utrace,sys_nosys);
119 
120 int	ktrace_on;			/* Misc */
121 __weak_alias(ktruser,enosys);
122 __weak_alias(ktr_point,nullop);
123 #endif	/* KTRACE */
124 
125 __weak_alias(spldebug_start, voidop);
126 __weak_alias(spldebug_stop, voidop);
127 __weak_alias(machdep_init,nullop);
128 __weak_alias(pci_chipset_tag_create, eopnotsupp);
129 __weak_alias(pci_chipset_tag_destroy, voidop);
130 __weak_alias(bus_space_tag_create, eopnotsupp);
131 __weak_alias(bus_space_tag_destroy, voidop);
132 __weak_alias(bus_space_is_equal, default_bus_space_is_equal);
133 
134 __weak_alias(kobj_renamespace, nullop);
135 
136 #if !defined(KERN_SA)
137 /*
138  * Scheduler activations system calls.  These need to remain, even when
139  * KERN_SA isn't defined, until libc's major version is bumped.
140  */
141 __strong_alias(sys_sa_register,sys_nosys);
142 __strong_alias(sys_sa_stacks,sys_nosys);
143 __strong_alias(sys_sa_enable,sys_nosys);
144 __strong_alias(sys_sa_setconcurrency,sys_nosys);
145 __strong_alias(sys_sa_yield,sys_nosys);
146 __strong_alias(sys_sa_preempt,sys_nosys);
147 __strong_alias(sys_sa_unblockyield,sys_nosys);
148 
149 /*
150  * Stubs for compat_netbsd32.
151  */
152 __strong_alias(dosa_register,sys_nosys);
153 __strong_alias(sa_stacks1,sys_nosys);
154 #endif
155 
156 /*
157  * Stubs for architectures that do not support kernel preemption.
158  */
159 #ifndef __HAVE_PREEMPTION
160 bool
161 cpu_kpreempt_enter(uintptr_t where, int s)
162 {
163 
164 	return false;
165 }
166 
167 void
168 cpu_kpreempt_exit(uintptr_t where)
169 {
170 
171 }
172 
173 bool
174 cpu_kpreempt_disabled(void)
175 {
176 
177 	return true;
178 }
179 #else
180 # ifndef MULTIPROCESSOR
181 #   error __HAVE_PREEMPTION requires MULTIPROCESSOR
182 # endif
183 #endif	/* !__HAVE_PREEMPTION */
184 
185 int
186 sys_nosys(struct lwp *l, const void *v, register_t *retval)
187 {
188 
189 	mutex_enter(proc_lock);
190 	psignal(l->l_proc, SIGSYS);
191 	mutex_exit(proc_lock);
192 	return ENOSYS;
193 }
194 
195 /*
196  * Unsupported device function (e.g. writing to read-only device).
197  */
198 int
199 enodev(void)
200 {
201 
202 	return (ENODEV);
203 }
204 
205 /*
206  * Unconfigured device function; driver not configured.
207  */
208 int
209 enxio(void)
210 {
211 
212 	return (ENXIO);
213 }
214 
215 /*
216  * Unsupported ioctl function.
217  */
218 int
219 enoioctl(void)
220 {
221 
222 	return (ENOTTY);
223 }
224 
225 /*
226  * Unsupported system function.
227  * This is used for an otherwise-reasonable operation
228  * that is not supported by the current system binary.
229  */
230 int
231 enosys(void)
232 {
233 
234 	return (ENOSYS);
235 }
236 
237 /*
238  * Return error for operation not supported
239  * on a specific object or file type.
240  */
241 int
242 eopnotsupp(void)
243 {
244 
245 	return (EOPNOTSUPP);
246 }
247 
248 /*
249  * Generic null operation, void return value.
250  */
251 void
252 voidop(void)
253 {
254 }
255 
256 /*
257  * Generic null operation, always returns success.
258  */
259 /*ARGSUSED*/
260 int
261 nullop(void *v)
262 {
263 
264 	return (0);
265 }
266 
267 bool
268 default_bus_space_is_equal(bus_space_tag_t t1, bus_space_tag_t t2)
269 {
270 
271 	return memcmp(&t1, &t2, sizeof(t1)) == 0;
272 }
273