osfmk/kern/exception.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52
  53 #include <mach_kdb.h>
  54
  55 #include <mach/boolean.h>
  56 #include <mach/kern_return.h>
  57 #include <mach/message.h>
  58 #include <mach/port.h>
  59 #include <mach/mig_errors.h>
  60 #include <mach/thread_status.h>
  61 #include <mach/exception_types.h>
  62 #include <ipc/port.h>
  63 #include <ipc/ipc_entry.h>
  64 #include <ipc/ipc_object.h>
  65 #include <ipc/ipc_notify.h>
  66 #include <ipc/ipc_space.h>
  67 #include <ipc/ipc_pset.h>
  68 #include <ipc/ipc_machdep.h>
  69 #include <kern/etap_macros.h>
  70 #include <kern/counters.h>
  71 #include <kern/ipc_tt.h>
  72 #include <kern/task.h>
  73 #include <kern/thread.h>
  74 #include <kern/thread_swap.h>
  75 #include <kern/processor.h>
  76 #include <kern/sched.h>
  77 #include <kern/sched_prim.h>
  78 #include <kern/host.h>
  79 #include <kern/misc_protos.h>
  80 #include <string.h>
  81 #include <mach/exc.h>
  82
  83 #if     MACH_KDB
  84 #include <ddb/db_trap.h>
  85 #endif  /* MACH_KDB */
  86
  87 #if     MACH_KDB
  88
  89 #include <ddb/db_output.h>
  90
  91 #if iPSC386 || iPSC860
  92 boolean_t debug_user_with_kdb = TRUE;
  93 #else
  94 boolean_t debug_user_with_kdb = FALSE;
  95 #endif
  96
  97 #endif  /* MACH_KDB */
  98
  99 unsigned long c_thr_exc_raise = 0;
 100 unsigned long c_thr_exc_raise_state = 0;
 101 unsigned long c_thr_exc_raise_state_id = 0;
 102 unsigned long c_tsk_exc_raise = 0;
 103 unsigned long c_tsk_exc_raise_state = 0;
 104 unsigned long c_tsk_exc_raise_state_id = 0;
 105
 106
 107 /*
 108  *      Routine:        exception_deliver
 109  *      Purpose:
 110  *              Make an upcall to the exception server provided.
 111  *      Conditions:
 112  *              Nothing locked and no resources held.
 113  *              Called from an exception context, so
 114  *              thread_exception_return and thread_kdb_return
 115  *              are possible.
 116  *      Returns:
 117  *              If the exception was not handled by this handler
 118  */
 119 void
 120 exception_deliver(
 121         exception_type_t        exception,
 122         exception_data_t        code,
 123         mach_msg_type_number_t  codeCnt,
 124         struct exception_action *excp,
 125         mutex_t                 *mutex)
 126 {
 127         thread_act_t            a_self = current_act();
 128         ipc_port_t              exc_port;
 129         int                     behavior;
 130         int                     flavor;
 131         kern_return_t           kr;
 132
 133         /*
 134          *  Save work if we are terminating.
 135          *  Just go back to our AST handler.
 136          */
 137         if (!a_self->active)
 138                 thread_exception_return();
 139
 140         /*
 141          * Snapshot the exception action data under lock for consistency.
 142          * Hold a reference to the port over the exception_raise_* calls
 143          * so it can't be destroyed.  This seems like overkill, but keeps
 144          * the port from disappearing between now and when
 145          * ipc_object_copyin_from_kernel is finally called.
 146          */
 147         mutex_lock(mutex);
 148         exc_port = excp->port;
 149         if (!IP_VALID(exc_port)) {
 150                 mutex_unlock(mutex);
 151                 return;
 152         }
 153         ip_lock(exc_port);
 154         if (!ip_active(exc_port)) {
 155                 ip_unlock(exc_port);
 156                 mutex_unlock(mutex);
 157                 return;
 158         }
 159         ip_reference(exc_port);
 160         exc_port->ip_srights++;
 161         ip_unlock(exc_port);
 162
 163         flavor = excp->flavor;
 164         behavior = excp->behavior;
 165         mutex_unlock(mutex);
 166
 167         switch (behavior) {
 168         case EXCEPTION_STATE: {
 169                 mach_msg_type_number_t state_cnt;
 170                 natural_t state[ THREAD_MACHINE_STATE_MAX ];
 171
 172                 c_thr_exc_raise_state++;
 173                 state_cnt = state_count[flavor];
 174                 kr = thread_getstatus(a_self, flavor,
 175                                       (thread_state_t)state,
 176                                       &state_cnt);
 177                 if (kr == KERN_SUCCESS) {
 178                         kr = exception_raise_state(exc_port, exception,
 179                                                    code, codeCnt,
 180                                                    &flavor,
 181                                                    state, state_cnt,
 182                                                    state, &state_cnt);
 183                         if (kr == MACH_MSG_SUCCESS)
 184                                 kr = thread_setstatus(a_self, flavor,
 185                                                       (thread_state_t)state,
 186                                                       state_cnt);
 187                 }
 188
 189                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 190                         thread_exception_return();
 191                         /*NOTREACHED*/
 192                 return;
 193         }
 194
 195         case EXCEPTION_DEFAULT:
 196                 c_thr_exc_raise++;
 197                 kr = exception_raise(exc_port,
 198                                 retrieve_act_self_fast(a_self),
 199                                 retrieve_task_self_fast(a_self->task),
 200                                 exception,
 201                                 code, codeCnt);
 202
 203                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 204                         thread_exception_return();
 205                         /*NOTREACHED*/
 206                 return;
 207
 208         case EXCEPTION_STATE_IDENTITY: {
 209                 mach_msg_type_number_t state_cnt;
 210                 natural_t state[ THREAD_MACHINE_STATE_MAX ];
 211
 212                 c_thr_exc_raise_state_id++;
 213                 state_cnt = state_count[flavor];
 214                 kr = thread_getstatus(a_self, flavor,
 215                                       (thread_state_t)state,
 216                                       &state_cnt);
 217                 if (kr == KERN_SUCCESS) {
 218                     kr = exception_raise_state_identity(exc_port,
 219                                 retrieve_act_self_fast(a_self),
 220                                 retrieve_task_self_fast(a_self->task),
 221                                 exception,
 222                                 code, codeCnt,
 223                                 &flavor,
 224                                 state, state_cnt,
 225                                 state, &state_cnt);
 226                     if (kr == MACH_MSG_SUCCESS)
 227                         kr = thread_setstatus(a_self, flavor,
 228                                               (thread_state_t)state,
 229                                               state_cnt);
 230                 }
 231
 232                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 233                         thread_exception_return();
 234                         /*NOTREACHED*/
 235                 return;
 236         }
 237
 238         default:
 239                 panic ("bad exception behavior!");
 240         }/* switch */
 241 }
 242
 243 /*
 244  *      Routine:        exception
 245  *      Purpose:
 246  *              The current thread caught an exception.
 247  *              We make an up-call to the thread's exception server.
 248  *      Conditions:
 249  *              Nothing locked and no resources held.
 250  *              Called from an exception context, so
 251  *              thread_exception_return and thread_kdb_return
 252  *              are possible.
 253  *      Returns:
 254  *              Doesn't return.
 255  */
 256 void
 257 exception(
 258         exception_type_t        exception,
 259         exception_data_t        code,
 260         mach_msg_type_number_t  codeCnt)
 261 {
 262         thread_act_t            thr_act;
 263         task_t                  task;
 264         host_priv_t             host_priv;
 265         struct exception_action *excp;
 266         mutex_t                 *mutex;
 267
 268         assert(exception != EXC_RPC_ALERT);
 269
 270         if (exception == KERN_SUCCESS)
 271                 panic("exception");
 272
 273         /*
 274          * Try to raise the exception at the activation level.
 275          */
 276         thr_act = current_act();
 277         mutex = mutex_addr(thr_act->lock);
 278         excp = &thr_act->exc_actions[exception];
 279         exception_deliver(exception, code, codeCnt, excp, mutex);
 280
 281         /*
 282          * Maybe the task level will handle it.
 283          */
 284         task = current_task();
 285         mutex = mutex_addr(task->lock);
 286         excp = &task->exc_actions[exception];
 287         exception_deliver(exception, code, codeCnt, excp, mutex);
 288
 289         /*
 290          * How about at the host level?
 291          */
 292         host_priv = host_priv_self();
 293         mutex = mutex_addr(host_priv->lock);
 294         excp = &host_priv->exc_actions[exception];
 295         exception_deliver(exception, code, codeCnt, excp, mutex);
 296
 297         /*
 298          * Nobody handled it, terminate the task.
 299          */
 300
 301 #if     MACH_KDB
 302         if (debug_user_with_kdb) {
 303                 /*
 304                  *      Debug the exception with kdb.
 305                  *      If kdb handles the exception,
 306                  *      then thread_kdb_return won't return.
 307                  */
 308                 db_printf("No exception server, calling kdb...\n");
 309                 thread_kdb_return();
 310         }
 311 #endif  /* MACH_KDB */
 312
 313         (void) task_terminate(task);
 314         thread_exception_return();
 315         /*NOTREACHED*/
 316 }
 317
 318 kern_return_t
 319 bsd_exception(
 320         exception_type_t        exception,
 321         exception_data_t        code,
 322         mach_msg_type_number_t  codeCnt)
 323 {
 324         task_t                  task;
 325         host_priv_t             host_priv;
 326         struct exception_action *excp;
 327         mutex_t                 *mutex;
 328         thread_act_t            a_self = current_act();
 329         ipc_port_t              exc_port;
 330         int                     behavior;
 331         int                     flavor;
 332         kern_return_t           kr;
 333
 334         /*
 335          * Maybe the task level will handle it.
 336          */
 337         task = current_task();
 338         mutex = mutex_addr(task->lock);
 339         excp = &task->exc_actions[exception];
 340
 341         /*
 342          *  Save work if we are terminating.
 343          *  Just go back to our AST handler.
 344          */
 345         if (!a_self->active) {
 346                 return(KERN_FAILURE);
 347         }
 348
 349         /*
 350          * Snapshot the exception action data under lock for consistency.
 351          * Hold a reference to the port over the exception_raise_* calls
 352          * so it can't be destroyed.  This seems like overkill, but keeps
 353          * the port from disappearing between now and when
 354          * ipc_object_copyin_from_kernel is finally called.
 355          */
 356         mutex_lock(mutex);
 357         exc_port = excp->port;
 358         if (!IP_VALID(exc_port)) {
 359                 mutex_unlock(mutex);
 360                 return(KERN_FAILURE);
 361         }
 362         ip_lock(exc_port);
 363         if (!ip_active(exc_port)) {
 364                 ip_unlock(exc_port);
 365                 mutex_unlock(mutex);
 366                 return(KERN_FAILURE);
 367         }
 368         ip_reference(exc_port);
 369         exc_port->ip_srights++;
 370         ip_unlock(exc_port);
 371
 372         flavor = excp->flavor;
 373         behavior = excp->behavior;
 374         mutex_unlock(mutex);
 375
 376         switch (behavior) {
 377         case EXCEPTION_STATE: {
 378                 mach_msg_type_number_t state_cnt;
 379                 natural_t state[ THREAD_MACHINE_STATE_MAX ];
 380
 381                 c_thr_exc_raise_state++;
 382                 state_cnt = state_count[flavor];
 383                 kr = thread_getstatus(a_self, flavor,
 384                                       (thread_state_t)state,
 385                                       &state_cnt);
 386                 if (kr == KERN_SUCCESS) {
 387                         kr = exception_raise_state(exc_port, exception,
 388                                                    code, codeCnt,
 389                                                    &flavor,
 390                                                    state, state_cnt,
 391                                                    state, &state_cnt);
 392                         if (kr == MACH_MSG_SUCCESS)
 393                                 kr = thread_setstatus(a_self, flavor,
 394                                                       (thread_state_t)state,
 395                                                       state_cnt);
 396                 }
 397
 398                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 399                         return(KERN_SUCCESS);
 400
 401                 return(KERN_FAILURE);
 402         }
 403
 404         case EXCEPTION_DEFAULT:
 405                 c_thr_exc_raise++;
 406                 kr = exception_raise(exc_port,
 407                                 retrieve_act_self_fast(a_self),
 408                                 retrieve_task_self_fast(a_self->task),
 409                                 exception,
 410                                 code, codeCnt);
 411
 412                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 413                         return(KERN_SUCCESS);
 414                 return(KERN_FAILURE);
 415
 416         case EXCEPTION_STATE_IDENTITY: {
 417                 mach_msg_type_number_t state_cnt;
 418                 natural_t state[ THREAD_MACHINE_STATE_MAX ];
 419
 420                 c_thr_exc_raise_state_id++;
 421                 state_cnt = state_count[flavor];
 422                 kr = thread_getstatus(a_self, flavor,
 423                                       (thread_state_t)state,
 424                                       &state_cnt);
 425                 if (kr == KERN_SUCCESS) {
 426                     kr = exception_raise_state_identity(exc_port,
 427                                 retrieve_act_self_fast(a_self),
 428                                 retrieve_task_self_fast(a_self->task),
 429                                 exception,
 430                                 code, codeCnt,
 431                                 &flavor,
 432                                 state, state_cnt,
 433                                 state, &state_cnt);
 434                     if (kr == MACH_MSG_SUCCESS)
 435                         kr = thread_setstatus(a_self, flavor,
 436                                               (thread_state_t)state,
 437                                               state_cnt);
 438                 }
 439
 440                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 441                         return(KERN_SUCCESS);
 442                 return(KERN_FAILURE);
 443         }
 444
 445         default:
 446
 447                 return(KERN_FAILURE);
 448         }/* switch */
 449         return(KERN_FAILURE);
 450 }
 451