Home | History | Annotate | Line # | Download | only in kern
      1 /*	$NetBSD: kern_stub.c,v 1.54 2026/04/07 14:47:23 thorpej 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 1.54 2026/04/07 14:47:23 thorpej Exp $");
     66 
     67 #ifdef _KERNEL_OPT
     68 #include "opt_ktrace.h"
     69 #include "opt_sysv.h"
     70 #include "opt_modular.h"
     71 #endif
     72 
     73 #include <sys/param.h>
     74 
     75 #include <sys/bus.h>
     76 #include <sys/cpu.h>
     77 #include <sys/fstypes.h>
     78 #include <sys/intr.h>
     79 #include <sys/kernel.h>
     80 #include <sys/ktrace.h>
     81 #include <sys/module.h>
     82 #include <sys/proc.h>
     83 #include <sys/sdt.h>
     84 #include <sys/signalvar.h>
     85 #include <sys/syscall.h>
     86 #include <sys/userconf.h>
     87 
     88 bool default_bus_space_is_equal(bus_space_tag_t, bus_space_tag_t);
     89 bool default_bus_space_handle_is_equal(bus_space_tag_t, bus_space_handle_t,
     90     bus_space_handle_t);
     91 
     92 /*
     93  * SYSV Semaphores, Shared Memory, Message Queues
     94  */
     95 #ifndef MODULAR
     96 #ifndef SYSVMSG
     97 __strong_alias(msgctl1,enosys);
     98 #endif
     99 #ifndef SYSVSHM
    100 __strong_alias(shmctl1,enosys);
    101 #endif
    102 #ifndef SYSVSEM
    103  __strong_alias(semctl1,enosys);
    104 #endif
    105 #endif
    106 
    107 /*
    108  * ktrace stubs.  ktruser() goes to enosys as we want to fail the syscall,
    109  * but not kill the process: utrace() is a debugging feature.
    110  */
    111 #ifndef KTRACE
    112 __strong_alias(ktr_csw,nullop);		/* Probes */
    113 __strong_alias(ktr_emul,nullop);
    114 __strong_alias(ktr_geniov,nullop);
    115 __strong_alias(ktr_genio,nullop);
    116 __strong_alias(ktr_mibio,nullop);
    117 __strong_alias(ktr_namei,nullop);
    118 __strong_alias(ktr_namei2,nullop);
    119 __strong_alias(ktr_psig,nullop);
    120 __strong_alias(ktr_syscall,nullop);
    121 __strong_alias(ktr_sysret,nullop);
    122 __strong_alias(ktr_kuser,nullop);
    123 __strong_alias(ktr_mib,nullop);
    124 __strong_alias(ktr_execarg,nullop);
    125 __strong_alias(ktr_execenv,nullop);
    126 __strong_alias(ktr_execfd,nullop);
    127 __strong_alias(ktr_sigmask,nullop);
    128 
    129 __strong_alias(sys_fktrace,sys_nosys);	/* Syscalls */
    130 __strong_alias(sys_ktrace,sys_nosys);
    131 __strong_alias(sys_utrace,sys_nosys);
    132 
    133 int	ktrace_on;			/* Misc */
    134 __strong_alias(ktruser,enosys);
    135 __strong_alias(ktr_point,nullop);
    136 #endif	/* KTRACE */
    137 
    138 __weak_alias(device_register, voidop);
    139 __weak_alias(device_register_post_config, voidop);
    140 __weak_alias(spldebug_start, voidop);
    141 __weak_alias(spldebug_stop, voidop);
    142 __weak_alias(machdep_init,nullop);
    143 __weak_alias(pci_chipset_tag_create, eopnotsupp);
    144 __weak_alias(pci_chipset_tag_destroy, voidop);
    145 __weak_alias(bus_space_reserve, eopnotsupp);
    146 __weak_alias(bus_space_reserve_subregion, eopnotsupp);
    147 __weak_alias(bus_space_release, voidop);
    148 __weak_alias(bus_space_reservation_map, eopnotsupp);
    149 __weak_alias(bus_space_reservation_unmap, voidop);
    150 __weak_alias(bus_dma_tag_create, eopnotsupp);
    151 __weak_alias(bus_dma_tag_destroy, voidop);
    152 __weak_alias(bus_space_tag_create, eopnotsupp);
    153 __weak_alias(bus_space_tag_destroy, voidop);
    154 __strict_weak_alias(bus_space_is_equal, default_bus_space_is_equal);
    155 __strict_weak_alias(bus_space_handle_is_equal,
    156     default_bus_space_handle_is_equal);
    157 __weak_alias(userconf_bootinfo, voidop);
    158 __weak_alias(userconf_init, voidop);
    159 __weak_alias(userconf_prompt, voidop);
    160 
    161 #ifdef MODULAR
    162 __weak_alias(module_init_md, voidop);
    163 #endif
    164 
    165 __weak_alias(kobj_renamespace, nullop);
    166 
    167 __weak_alias(interrupt_get_count, nullop);
    168 __weak_alias(interrupt_get_assigned, voidop);
    169 __weak_alias(interrupt_get_available, voidop);
    170 __weak_alias(interrupt_get_devname, voidop);
    171 __weak_alias(interrupt_construct_intrids, nullret);
    172 __weak_alias(interrupt_destruct_intrids, voidop);
    173 __weak_alias(interrupt_distribute, eopnotsupp);
    174 __weak_alias(interrupt_distribute_handler, eopnotsupp);
    175 
    176 /*
    177  * Scheduler activations system calls.  These need to remain until libc's
    178  * major version is bumped.
    179  */
    180 __strong_alias(sys_sa_register,sys_nosys);
    181 __strong_alias(sys_sa_stacks,sys_nosys);
    182 __strong_alias(sys_sa_enable,sys_nosys);
    183 __strong_alias(sys_sa_setconcurrency,sys_nosys);
    184 __strong_alias(sys_sa_yield,sys_nosys);
    185 __strong_alias(sys_sa_preempt,sys_nosys);
    186 __strong_alias(sys_sa_unblockyield,sys_nosys);
    187 
    188 /*
    189  * Stubs for compat_netbsd32.
    190  */
    191 __strong_alias(dosa_register,sys_nosys);
    192 __strong_alias(sa_stacks1,sys_nosys);
    193 
    194 /*
    195  * Stubs for drivers.  See sys/conf.h.
    196  */
    197 __strong_alias(devenodev,enodev);
    198 __strong_alias(deveopnotsupp,eopnotsupp);
    199 __strong_alias(devnullop,nullop);
    200 __strong_alias(ttyenodev,enodev);
    201 __strong_alias(ttyvenodev,voidop);
    202 __strong_alias(ttyvnullop,nullop);
    203 
    204 /*
    205  * Stubs for architectures that do not support kernel preemption.
    206  */
    207 #ifndef __HAVE_PREEMPTION
    208 bool
    209 cpu_kpreempt_enter(uintptr_t where, int s)
    210 {
    211 
    212 	return false;
    213 }
    214 
    215 void
    216 cpu_kpreempt_exit(uintptr_t where)
    217 {
    218 
    219 }
    220 
    221 bool
    222 cpu_kpreempt_disabled(void)
    223 {
    224 
    225 	return true;
    226 }
    227 #else
    228 # ifndef MULTIPROCESSOR
    229 #   error __HAVE_PREEMPTION requires MULTIPROCESSOR
    230 # endif
    231 #endif	/* !__HAVE_PREEMPTION */
    232 
    233 int
    234 sys_nosys(struct lwp *l, const void *v, register_t *retval)
    235 {
    236 
    237 	mutex_enter(&proc_lock);
    238 	psignal(l->l_proc, SIGSYS);
    239 	mutex_exit(&proc_lock);
    240 	return SET_ERROR(ENOSYS);
    241 }
    242 
    243 /*
    244  * Unsupported device function (e.g. writing to read-only device).
    245  */
    246 int
    247 enodev(void)
    248 {
    249 
    250 	return SET_ERROR(ENODEV);
    251 }
    252 
    253 /*
    254  * Unconfigured device function; driver not configured.
    255  */
    256 int
    257 enxio(void)
    258 {
    259 
    260 	return SET_ERROR(ENXIO);
    261 }
    262 
    263 /*
    264  * Unsupported ioctl function.
    265  */
    266 int
    267 enoioctl(void)
    268 {
    269 
    270 	return SET_ERROR(ENOTTY);
    271 }
    272 
    273 /*
    274  * Unsupported system function.
    275  * This is used for an otherwise-reasonable operation
    276  * that is not supported by the current system binary.
    277  */
    278 int
    279 enosys(void)
    280 {
    281 
    282 	return SET_ERROR(ENOSYS);
    283 }
    284 
    285 /*
    286  * Return error for operation not supported
    287  * on a specific object or file type.
    288  */
    289 int
    290 eopnotsupp(void)
    291 {
    292 
    293 	return SET_ERROR(EOPNOTSUPP);
    294 }
    295 
    296 /*
    297  * Generic null operation, void return value.
    298  */
    299 void
    300 voidop(void)
    301 {
    302 }
    303 
    304 /*
    305  * Generic null operation, always returns success.
    306  */
    307 int
    308 nullop(void *v)
    309 {
    310 
    311 	return (0);
    312 }
    313 
    314 /*
    315  * Generic null operation, always returns null.
    316  */
    317 void *
    318 nullret(void)
    319 {
    320 
    321 	return (NULL);
    322 }
    323 
    324 bool
    325 default_bus_space_handle_is_equal(bus_space_tag_t t,
    326     bus_space_handle_t h1, bus_space_handle_t h2)
    327 {
    328 
    329 	return memcmp(&h1, &h2, sizeof(h1)) == 0;
    330 }
    331 
    332 bool
    333 default_bus_space_is_equal(bus_space_tag_t t1, bus_space_tag_t t2)
    334 {
    335 
    336 	return memcmp(&t1, &t2, sizeof(t1)) == 0;
    337 }
    338 
    339 /* Stubs for architectures with no kernel FPU access.  */
    340 __weak_alias(kthread_fpu_enter_md, voidop);
    341 __weak_alias(kthread_fpu_exit_md, voidop);
    342