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/mach_types.h>
  56 #include <mach/boolean.h>
  57 #include <mach/kern_return.h>
  58 #include <mach/message.h>
  59 #include <mach/port.h>
  60 #include <mach/mig_errors.h>
  61 #include <mach/thread_status.h>
  62 #include <mach/exception_types.h>
  63 #include <ipc/port.h>
  64 #include <ipc/ipc_entry.h>
  65 #include <ipc/ipc_object.h>
  66 #include <ipc/ipc_notify.h>
  67 #include <ipc/ipc_space.h>
  68 #include <ipc/ipc_pset.h>
  69 #include <ipc/ipc_machdep.h>
  70 #include <kern/etap_macros.h>
  71 #include <kern/counters.h>
  72 #include <kern/ipc_tt.h>
  73 #include <kern/task.h>
  74 #include <kern/thread.h>
  75 #include <kern/thread_swap.h>
  76 #include <kern/processor.h>
  77 #include <kern/sched.h>
  78 #include <kern/sched_prim.h>
  79 #include <kern/host.h>
  80 #include <kern/misc_protos.h>
  81 #include <string.h>
  82 #include <mach/exc.h>
  83
  84 #if     MACH_KDB
  85 #include <ddb/db_trap.h>
  86 #endif  /* MACH_KDB */
  87
  88 #if     MACH_KDB
  89
  90 #include <ddb/db_output.h>
  91
  92 #if iPSC386 || iPSC860
  93 boolean_t debug_user_with_kdb = TRUE;
  94 #else
  95 boolean_t debug_user_with_kdb = FALSE;
  96 #endif
  97
  98 #endif  /* MACH_KDB */
  99
 100 unsigned long c_thr_exc_raise = 0;
 101 unsigned long c_thr_exc_raise_state = 0;
 102 unsigned long c_thr_exc_raise_state_id = 0;
 103 unsigned long c_tsk_exc_raise = 0;
 104 unsigned long c_tsk_exc_raise_state = 0;
 105 unsigned long c_tsk_exc_raise_state_id = 0;
 106
 107
 108 /*
 109  *      Routine:        exception_deliver
 110  *      Purpose:
 111  *              Make an upcall to the exception server provided.
 112  *      Conditions:
 113  *              Nothing locked and no resources held.
 114  *              Called from an exception context, so
 115  *              thread_exception_return and thread_kdb_return
 116  *              are possible.
 117  *      Returns:
 118  *              If the exception was not handled by this handler
 119  */
 120 void
 121 exception_deliver(
 122         exception_type_t        exception,
 123         exception_data_t        code,
 124         mach_msg_type_number_t  codeCnt,
 125         struct exception_action *excp,
 126         mutex_t                 *mutex)
 127 {
 128         thread_act_t            a_self = current_act();
 129         ipc_port_t              exc_port;
 130         int                     behavior;
 131         int                     flavor;
 132         kern_return_t           kr;
 133
 134         /*
 135          *  Save work if we are terminating.
 136          *  Just go back to our AST handler.
 137          */
 138         if (!a_self->active)
 139                 thread_exception_return();
 140
 141         /*
 142          * Snapshot the exception action data under lock for consistency.
 143          * Hold a reference to the port over the exception_raise_* calls
 144          * so it can't be destroyed.  This seems like overkill, but keeps
 145          * the port from disappearing between now and when
 146          * ipc_object_copyin_from_kernel is finally called.
 147          */
 148         mutex_lock(mutex);
 149         exc_port = excp->port;
 150         if (!IP_VALID(exc_port)) {
 151                 mutex_unlock(mutex);
 152                 return;
 153         }
 154         ip_lock(exc_port);
 155         if (!ip_active(exc_port)) {
 156                 ip_unlock(exc_port);
 157                 mutex_unlock(mutex);
 158                 return;
 159         }
 160         ip_reference(exc_port);
 161         exc_port->ip_srights++;
 162         ip_unlock(exc_port);
 163
 164         flavor = excp->flavor;
 165         behavior = excp->behavior;
 166         mutex_unlock(mutex);
 167
 168         switch (behavior) {
 169         case EXCEPTION_STATE: {
 170                 mach_msg_type_number_t state_cnt;
 171                 thread_state_data_t state;
 172
 173                 c_thr_exc_raise_state++;
 174                 state_cnt = state_count[flavor];
 175                 kr = thread_getstatus(a_self, flavor,
 176                                       (thread_state_t)state,
 177                                       &state_cnt);
 178                 if (kr == KERN_SUCCESS) {
 179                         kr = exception_raise_state(exc_port, exception,
 180                                                    code, codeCnt,
 181                                                    &flavor,
 182                                                    state, state_cnt,
 183                                                    state, &state_cnt);
 184                         if (kr == MACH_MSG_SUCCESS)
 185                                 kr = thread_setstatus(a_self, flavor,
 186                                                       (thread_state_t)state,
 187                                                       state_cnt);
 188                 }
 189
 190                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 191                         thread_exception_return();
 192                         /*NOTREACHED*/
 193                 return;
 194         }
 195
 196         case EXCEPTION_DEFAULT:
 197                 c_thr_exc_raise++;
 198                 kr = exception_raise(exc_port,
 199                                 retrieve_act_self_fast(a_self),
 200                                 retrieve_task_self_fast(a_self->task),
 201                                 exception,
 202                                 code, codeCnt);
 203
 204                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 205                         thread_exception_return();
 206                         /*NOTREACHED*/
 207                 return;
 208
 209         case EXCEPTION_STATE_IDENTITY: {
 210                 mach_msg_type_number_t state_cnt;
 211                 thread_state_data_t state;
 212
 213                 c_thr_exc_raise_state_id++;
 214                 state_cnt = state_count[flavor];
 215                 kr = thread_getstatus(a_self, flavor,
 216                                       (thread_state_t)state,
 217                                       &state_cnt);
 218                 if (kr == KERN_SUCCESS) {
 219                     kr = exception_raise_state_identity(exc_port,
 220                                 retrieve_act_self_fast(a_self),
 221                                 retrieve_task_self_fast(a_self->task),
 222                                 exception,
 223                                 code, codeCnt,
 224                                 &flavor,
 225                                 state, state_cnt,
 226                                 state, &state_cnt);
 227                     if (kr == MACH_MSG_SUCCESS)
 228                         kr = thread_setstatus(a_self, flavor,
 229                                               (thread_state_t)state,
 230                                               state_cnt);
 231                 }
 232
 233                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 234                         thread_exception_return();
 235                         /*NOTREACHED*/
 236                 return;
 237         }
 238
 239         default:
 240                 panic ("bad exception behavior!");
 241         }/* switch */
 242 }
 243
 244 /*
 245  *      Routine:        exception
 246  *      Purpose:
 247  *              The current thread caught an exception.
 248  *              We make an up-call to the thread's exception server.
 249  *      Conditions:
 250  *              Nothing locked and no resources held.
 251  *              Called from an exception context, so
 252  *              thread_exception_return and thread_kdb_return
 253  *              are possible.
 254  *      Returns:
 255  *              Doesn't return.
 256  */
 257 void
 258 exception(
 259         exception_type_t        exception,
 260         exception_data_t        code,
 261         mach_msg_type_number_t  codeCnt)
 262 {
 263         thread_act_t            thr_act;
 264         task_t                  task;
 265         host_priv_t             host_priv;
 266         struct exception_action *excp;
 267         mutex_t                 *mutex;
 268
 269         assert(exception != EXC_RPC_ALERT);
 270
 271         if (exception == KERN_SUCCESS)
 272                 panic("exception");
 273
 274         /*
 275          * Try to raise the exception at the activation level.
 276          */
 277         thr_act = current_act();
 278         mutex = mutex_addr(thr_act->lock);
 279         excp = &thr_act->exc_actions[exception];
 280         exception_deliver(exception, code, codeCnt, excp, mutex);
 281
 282         /*
 283          * Maybe the task level will handle it.
 284          */
 285         task = current_task();
 286         mutex = mutex_addr(task->lock);
 287         excp = &task->exc_actions[exception];
 288         exception_deliver(exception, code, codeCnt, excp, mutex);
 289
 290         /*
 291          * How about at the host level?
 292          */
 293         host_priv = host_priv_self();
 294         mutex = mutex_addr(host_priv->lock);
 295         excp = &host_priv->exc_actions[exception];
 296         exception_deliver(exception, code, codeCnt, excp, mutex);
 297
 298         /*
 299          * Nobody handled it, terminate the task.
 300          */
 301
 302 #if     MACH_KDB
 303         if (debug_user_with_kdb) {
 304                 /*
 305                  *      Debug the exception with kdb.
 306                  *      If kdb handles the exception,
 307                  *      then thread_kdb_return won't return.
 308                  */
 309                 db_printf("No exception server, calling kdb...\n");
 310                 thread_kdb_return();
 311         }
 312 #endif  /* MACH_KDB */
 313
 314         (void) task_terminate(task);
 315         thread_exception_return();
 316         /*NOTREACHED*/
 317 }
 318
 319 kern_return_t
 320 bsd_exception(
 321         exception_type_t        exception,
 322         exception_data_t        code,
 323         mach_msg_type_number_t  codeCnt)
 324 {
 325         task_t                  task;
 326         host_priv_t             host_priv;
 327         struct exception_action *excp;
 328         mutex_t                 *mutex;
 329         thread_act_t            a_self = current_act();
 330         ipc_port_t              exc_port;
 331         int                     behavior;
 332         int                     flavor;
 333         kern_return_t           kr;
 334
 335         /*
 336          * Maybe the task level will handle it.
 337          */
 338         task = current_task();
 339         mutex = mutex_addr(task->lock);
 340         excp = &task->exc_actions[exception];
 341
 342         /*
 343          *  Save work if we are terminating.
 344          *  Just go back to our AST handler.
 345          */
 346         if (!a_self->active) {
 347                 return(KERN_FAILURE);
 348         }
 349
 350         /*
 351          * Snapshot the exception action data under lock for consistency.
 352          * Hold a reference to the port over the exception_raise_* calls
 353          * so it can't be destroyed.  This seems like overkill, but keeps
 354          * the port from disappearing between now and when
 355          * ipc_object_copyin_from_kernel is finally called.
 356          */
 357         mutex_lock(mutex);
 358         exc_port = excp->port;
 359         if (!IP_VALID(exc_port)) {
 360                 mutex_unlock(mutex);
 361                 return(KERN_FAILURE);
 362         }
 363         ip_lock(exc_port);
 364         if (!ip_active(exc_port)) {
 365                 ip_unlock(exc_port);
 366                 mutex_unlock(mutex);
 367                 return(KERN_FAILURE);
 368         }
 369         ip_reference(exc_port);
 370         exc_port->ip_srights++;
 371         ip_unlock(exc_port);
 372
 373         flavor = excp->flavor;
 374         behavior = excp->behavior;
 375         mutex_unlock(mutex);
 376
 377         switch (behavior) {
 378         case EXCEPTION_STATE: {
 379                 mach_msg_type_number_t state_cnt;
 380                 thread_state_data_t state;
 381
 382                 c_thr_exc_raise_state++;
 383                 state_cnt = state_count[flavor];
 384                 kr = thread_getstatus(a_self, flavor,
 385                                       (thread_state_t)state,
 386                                       &state_cnt);
 387                 if (kr == KERN_SUCCESS) {
 388                         kr = exception_raise_state(exc_port, exception,
 389                                                    code, codeCnt,
 390                                                    &flavor,
 391                                                    state, state_cnt,
 392                                                    state, &state_cnt);
 393                         if (kr == MACH_MSG_SUCCESS)
 394                                 kr = thread_setstatus(a_self, flavor,
 395                                                       (thread_state_t)state,
 396                                                       state_cnt);
 397                 }
 398
 399                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 400                         return(KERN_SUCCESS);
 401
 402                 return(KERN_FAILURE);
 403         }
 404
 405         case EXCEPTION_DEFAULT:
 406                 c_thr_exc_raise++;
 407                 kr = exception_raise(exc_port,
 408                                 retrieve_act_self_fast(a_self),
 409                                 retrieve_task_self_fast(a_self->task),
 410                                 exception,
 411                                 code, codeCnt);
 412
 413                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 414                         return(KERN_SUCCESS);
 415                 return(KERN_FAILURE);
 416
 417         case EXCEPTION_STATE_IDENTITY: {
 418                 mach_msg_type_number_t state_cnt;
 419                 thread_state_data_t state;
 420
 421                 c_thr_exc_raise_state_id++;
 422                 state_cnt = state_count[flavor];
 423                 kr = thread_getstatus(a_self, flavor,
 424                                       (thread_state_t)state,
 425                                       &state_cnt);
 426                 if (kr == KERN_SUCCESS) {
 427                     kr = exception_raise_state_identity(exc_port,
 428                                 retrieve_act_self_fast(a_self),
 429                                 retrieve_task_self_fast(a_self->task),
 430                                 exception,
 431                                 code, codeCnt,
 432                                 &flavor,
 433                                 state, state_cnt,
 434                                 state, &state_cnt);
 435                     if (kr == MACH_MSG_SUCCESS)
 436                         kr = thread_setstatus(a_self, flavor,
 437                                               (thread_state_t)state,
 438                                               state_cnt);
 439                 }
 440
 441                 if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 442                         return(KERN_SUCCESS);
 443                 return(KERN_FAILURE);
 444         }
 445
 446         default:
 447
 448                 return(KERN_FAILURE);
 449         }/* switch */
 450         return(KERN_FAILURE);
 451 }
 452
 453
 454
 455
 456 /*
 457  *      Handle interface for special perfomance monitoring
 458  *      This is a special case of the host exception handler
 459  */
 460
 461 kern_return_t sys_perf_notify(struct task *task,
 462         exception_data_t code,
 463         mach_msg_type_number_t codeCnt)
 464 {
 465         host_priv_t             hostp;
 466         struct exception_action *excp;
 467         thread_act_t    act = current_act();
 468         thread_t                thr = current_thread();
 469         ipc_port_t              xport;
 470         kern_return_t   ret;
 471         int                             abrt;
 472         spl_t                   ints;
 473         wait_interrupt_t        wsave;
 474
 475         hostp = host_priv_self();                               /* Get the host privileged ports */
 476         excp = &hostp->exc_actions[EXC_RPC_ALERT];      /* Point to the RPC_ALERT action */
 477
 478         mutex_lock(&hostp->lock);                               /* Lock the priv port */
 479         xport = excp->port;                                             /* Get the port for this exception */
 480         if (!IP_VALID(xport)) {                                 /* Is it valid? */
 481                 mutex_unlock(&hostp->lock);                     /* Unlock */
 482                 return(KERN_FAILURE);                           /* Go away... */
 483         }
 484
 485         ip_lock(xport);                                                 /* Lock the exception port */
 486         if (!ip_active(xport)) {                                /* and is it active? */
 487                 ip_unlock(xport);                                       /* Nope, fail */
 488                 mutex_unlock(&hostp->lock);                     /* Unlock */
 489                 return(KERN_FAILURE);                           /* Go away... */
 490         }
 491
 492         if (task->itk_space == xport->data.receiver) {  /* Are we trying to send to ourselves? */
 493                 ip_unlock(xport);                                       /* Yes, fail */
 494                 mutex_unlock(&hostp->lock);                     /* Unlock */
 495                 return(KERN_FAILURE);                           /* Go away... */
 496         }
 497
 498         ip_reference(xport);                                    /* Bump reference so it doesn't go away */
 499         xport->ip_srights++;                                    /* Bump send rights */
 500         ip_unlock(xport);                                               /* We can unlock it now */
 501
 502         mutex_unlock(&hostp->lock);                             /* All done with the lock */
 503
 504         wsave = thread_interrupt_level(THREAD_UNINT);   /* Make sure we aren't aborted here */
 505
 506         ret = exception_raise(xport,                    /* Send the exception to the perf handler */
 507                 retrieve_act_self_fast(act),            /* Not always the dying guy */
 508                 retrieve_task_self_fast(act->task),     /* Not always the dying guy */
 509                 EXC_RPC_ALERT,                                          /* Unused exception type until now */
 510                 code, codeCnt);
 511
 512         (void)thread_interrupt_level(wsave);    /* Restore interrupt level */
 513
 514         return(ret);                                                    /* Tell caller how it went */
 515 }
 516