xref: /netbsd-src/sys/kern/kern_stub.c (revision 1b9578b8c2c1f848eeb16dabbfd7d1f0d9fdefbd)
1 /*	$NetBSD: kern_stub.c,v 1.33 2011/06/01 21:25:01 alnsn 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 1.33 2011/06/01 21:25:01 alnsn 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 #include <sys/userconf.h>
83 
84 bool default_bus_space_is_equal(bus_space_tag_t, bus_space_tag_t);
85 
86 /*
87  * Nonexistent system call-- signal process (may want to handle it).  Flag
88  * error in case process won't see signal immediately (blocked or ignored).
89  */
90 #ifndef PTRACE
91 __weak_alias(sys_ptrace,sys_nosys);
92 #endif	/* PTRACE */
93 
94 /*
95  * ktrace stubs.  ktruser() goes to enosys as we want to fail the syscall,
96  * but not kill the process: utrace() is a debugging feature.
97  */
98 #ifndef KTRACE
99 __weak_alias(ktr_csw,nullop);		/* Probes */
100 __weak_alias(ktr_emul,nullop);
101 __weak_alias(ktr_geniov,nullop);
102 __weak_alias(ktr_genio,nullop);
103 __weak_alias(ktr_mibio,nullop);
104 __weak_alias(ktr_namei,nullop);
105 __weak_alias(ktr_namei2,nullop);
106 __weak_alias(ktr_psig,nullop);
107 __weak_alias(ktr_saupcall,nullop);
108 __weak_alias(ktr_syscall,nullop);
109 __weak_alias(ktr_sysret,nullop);
110 __weak_alias(ktr_kuser,nullop);
111 __weak_alias(ktr_mib,nullop);
112 __weak_alias(ktr_execarg,nullop);
113 __weak_alias(ktr_execenv,nullop);
114 __weak_alias(ktr_execfd,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(device_register, voidop);
126 __weak_alias(device_register_post_config, voidop);
127 __weak_alias(spldebug_start, voidop);
128 __weak_alias(spldebug_stop, voidop);
129 __weak_alias(machdep_init,nullop);
130 __weak_alias(pci_chipset_tag_create, eopnotsupp);
131 __weak_alias(pci_chipset_tag_destroy, voidop);
132 __weak_alias(bus_space_tag_create, eopnotsupp);
133 __weak_alias(bus_space_tag_destroy, voidop);
134 __weak_alias(bus_space_is_equal, default_bus_space_is_equal);
135 __weak_alias(userconf_bootinfo, voidop);
136 __weak_alias(userconf_init, voidop);
137 __weak_alias(userconf_prompt, voidop);
138 
139 __weak_alias(kobj_renamespace, nullop);
140 
141 #if !defined(KERN_SA)
142 /*
143  * Scheduler activations system calls.  These need to remain, even when
144  * KERN_SA isn't defined, until libc's major version is bumped.
145  */
146 __strong_alias(sys_sa_register,sys_nosys);
147 __strong_alias(sys_sa_stacks,sys_nosys);
148 __strong_alias(sys_sa_enable,sys_nosys);
149 __strong_alias(sys_sa_setconcurrency,sys_nosys);
150 __strong_alias(sys_sa_yield,sys_nosys);
151 __strong_alias(sys_sa_preempt,sys_nosys);
152 __strong_alias(sys_sa_unblockyield,sys_nosys);
153 
154 /*
155  * Stubs for compat_netbsd32.
156  */
157 __strong_alias(dosa_register,sys_nosys);
158 __strong_alias(sa_stacks1,sys_nosys);
159 #endif
160 
161 /*
162  * Stubs for architectures that do not support kernel preemption.
163  */
164 #ifndef __HAVE_PREEMPTION
165 bool
166 cpu_kpreempt_enter(uintptr_t where, int s)
167 {
168 
169 	return false;
170 }
171 
172 void
173 cpu_kpreempt_exit(uintptr_t where)
174 {
175 
176 }
177 
178 bool
179 cpu_kpreempt_disabled(void)
180 {
181 
182 	return true;
183 }
184 #else
185 # ifndef MULTIPROCESSOR
186 #   error __HAVE_PREEMPTION requires MULTIPROCESSOR
187 # endif
188 #endif	/* !__HAVE_PREEMPTION */
189 
190 int
191 sys_nosys(struct lwp *l, const void *v, register_t *retval)
192 {
193 
194 	mutex_enter(proc_lock);
195 	psignal(l->l_proc, SIGSYS);
196 	mutex_exit(proc_lock);
197 	return ENOSYS;
198 }
199 
200 /*
201  * Unsupported device function (e.g. writing to read-only device).
202  */
203 int
204 enodev(void)
205 {
206 
207 	return (ENODEV);
208 }
209 
210 /*
211  * Unconfigured device function; driver not configured.
212  */
213 int
214 enxio(void)
215 {
216 
217 	return (ENXIO);
218 }
219 
220 /*
221  * Unsupported ioctl function.
222  */
223 int
224 enoioctl(void)
225 {
226 
227 	return (ENOTTY);
228 }
229 
230 /*
231  * Unsupported system function.
232  * This is used for an otherwise-reasonable operation
233  * that is not supported by the current system binary.
234  */
235 int
236 enosys(void)
237 {
238 
239 	return (ENOSYS);
240 }
241 
242 /*
243  * Return error for operation not supported
244  * on a specific object or file type.
245  */
246 int
247 eopnotsupp(void)
248 {
249 
250 	return (EOPNOTSUPP);
251 }
252 
253 /*
254  * Generic null operation, void return value.
255  */
256 void
257 voidop(void)
258 {
259 }
260 
261 /*
262  * Generic null operation, always returns success.
263  */
264 /*ARGSUSED*/
265 int
266 nullop(void *v)
267 {
268 
269 	return (0);
270 }
271 
272 bool
273 default_bus_space_is_equal(bus_space_tag_t t1, bus_space_tag_t t2)
274 {
275 
276 	return memcmp(&t1, &t2, sizeof(t1)) == 0;
277 }
278