kern_stub.c revision 1.13
1 /* $NetBSD: kern_stub.c,v 1.13 2008/11/14 23:33:45 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 1.13 2008/11/14 23:33:45 ad 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/syscall.h> 76 #include <sys/syscallargs.h> 77 #include <sys/syscallvar.h> 78 #include <sys/ktrace.h> 79 #include <sys/intr.h> 80 #include <sys/cpu.h> 81 #include <sys/module.h> 82 83 /* 84 * Nonexistent system call-- signal process (may want to handle it). Flag 85 * error in case process won't see signal immediately (blocked or ignored). 86 */ 87 #ifndef PTRACE 88 __weak_alias(sys_ptrace,sys_nosys); 89 #endif /* PTRACE */ 90 91 /* 92 * ktrace stubs. ktruser() goes to enosys as we want to fail the syscall, 93 * but not kill the process: utrace() is a debugging feature. 94 */ 95 #ifndef KTRACE 96 __weak_alias(ktr_csw,nullop); /* Probes */ 97 __weak_alias(ktr_emul,nullop); 98 __weak_alias(ktr_geniov,nullop); 99 __weak_alias(ktr_genio,nullop); 100 __weak_alias(ktr_mibio,nullop); 101 __weak_alias(ktr_namei,nullop); 102 __weak_alias(ktr_namei2,nullop); 103 __weak_alias(ktr_psig,nullop); 104 __weak_alias(ktr_saupcall,nullop); 105 __weak_alias(ktr_syscall,nullop); 106 __weak_alias(ktr_sysret,nullop); 107 __weak_alias(ktr_kuser,nullop); 108 __weak_alias(ktr_mmsg,nullop); 109 __weak_alias(ktr_mib,nullop); 110 __weak_alias(ktr_mool,nullop); 111 __weak_alias(ktr_execarg,nullop); 112 __weak_alias(ktr_execenv,nullop); 113 114 __weak_alias(sys_fktrace,sys_nosys); /* Syscalls */ 115 __weak_alias(sys_ktrace,sys_nosys); 116 __weak_alias(sys_utrace,sys_nosys); 117 118 int ktrace_on; /* Misc */ 119 __weak_alias(ktruser,enosys); 120 __weak_alias(ktr_point,nullop); 121 #endif /* KTRACE */ 122 123 /* 124 * Scheduler activations system calls. These need to remain, even when 125 * KERN_SA isn't defined, until libc's major version is bumped. 126 */ 127 #if !defined(KERN_SA) 128 __strong_alias(sys_sa_register,sys_nosys); 129 __strong_alias(sys_sa_stacks,sys_nosys); 130 __strong_alias(sys_sa_enable,sys_nosys); 131 __strong_alias(sys_sa_setconcurrency,sys_nosys); 132 __strong_alias(sys_sa_yield,sys_nosys); 133 __strong_alias(sys_sa_preempt,sys_nosys); 134 __strong_alias(sys_sa_unblockyield,sys_nosys); 135 #endif 136 137 /* 138 * Stubs for architectures that do not support kernel preemption. 139 */ 140 #ifndef __HAVE_PREEMPTION 141 bool 142 cpu_kpreempt_enter(uintptr_t where, int s) 143 { 144 145 return false; 146 } 147 148 void 149 cpu_kpreempt_exit(uintptr_t where) 150 { 151 152 } 153 154 bool 155 cpu_kpreempt_disabled(void) 156 { 157 158 return true; 159 } 160 #else 161 # ifndef MULTIPROCESSOR 162 # error __HAVE_PREEMPTION requires MULTIPROCESSOR 163 # endif 164 #endif /* !__HAVE_PREEMPTION */ 165 166 int 167 sys_nosys(struct lwp *l, const void *v, register_t *retval) 168 { 169 170 mutex_enter(proc_lock); 171 psignal(l->l_proc, SIGSYS); 172 mutex_exit(proc_lock); 173 return ENOSYS; 174 } 175 176 int 177 sys_nomodule(struct lwp *l, const void *v, register_t *retval) 178 { 179 #ifdef MODULAR 180 static struct { 181 u_int al_code; 182 const char *al_module; 183 } const autoload[] = { 184 { SYS_aio_cancel, "aio" }, 185 { SYS_aio_error, "aio" }, 186 { SYS_aio_fsync, "aio" }, 187 { SYS_aio_read, "aio" }, 188 { SYS_aio_return, "aio" }, 189 { SYS_aio_suspend, "aio" }, 190 { SYS_aio_write, "aio" }, 191 { SYS_lio_listio, "aio" }, 192 { SYS__ksem_init, "ksem" }, 193 { SYS__ksem_open, "ksem" }, 194 { SYS__ksem_unlink, "ksem" }, 195 { SYS__ksem_close, "ksem" }, 196 { SYS__ksem_post, "ksem" }, 197 { SYS__ksem_wait, "ksem" }, 198 { SYS__ksem_trywait, "ksem" }, 199 { SYS__ksem_getvalue, "ksem" }, 200 { SYS__ksem_destroy, "ksem" }, 201 }; 202 const struct sysent *sy; 203 const struct emul *em; 204 int code, i; 205 206 /* 207 * Restart the syscall if we interrupted a module unload that 208 * failed. Acquiring module_lock delays us until any unload 209 * has been completed or rolled back. 210 */ 211 mutex_enter(&module_lock); 212 sy = l->l_sysent; 213 if (sy->sy_call != sys_nomodule) { 214 mutex_exit(&module_lock); 215 return ERESTART; 216 } 217 /* 218 * Try to autoload a module to satisfy the request. If it 219 * works, retry the request. 220 */ 221 em = l->l_proc->p_emul; 222 if (em == &emul_netbsd) { 223 code = sy - em->e_sysent; 224 for (i = 0; i < __arraycount(autoload); i++) { 225 if (autoload[i].al_code != code) { 226 continue; 227 } 228 if (module_autoload(autoload[i].al_module, 229 MODULE_CLASS_ANY) != 0 || 230 sy->sy_call == sys_nomodule) { 231 break; 232 } 233 mutex_exit(&module_lock); 234 return ERESTART; 235 } 236 } 237 mutex_exit(&module_lock); 238 #endif /* MODULAR */ 239 240 return sys_nosys(l, v, retval); 241 } 242 243 /* 244 * Unsupported device function (e.g. writing to read-only device). 245 */ 246 int 247 enodev(void) 248 { 249 250 return (ENODEV); 251 } 252 253 /* 254 * Unconfigured device function; driver not configured. 255 */ 256 int 257 enxio(void) 258 { 259 260 return (ENXIO); 261 } 262 263 /* 264 * Unsupported ioctl function. 265 */ 266 int 267 enoioctl(void) 268 { 269 270 return (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 (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 (EOPNOTSUPP); 294 } 295 296 /* 297 * Generic null operation, always returns success. 298 */ 299 /*ARGSUSED*/ 300 int 301 nullop(void *v) 302 { 303 304 return (0); 305 } 306
Indexes created Tue Sep 23 22:09:46 GMT 2025