osfmk/kern/exception.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 /*
  57  */
  58
  59 #include <mach_kdb.h>
  60
  61 #include <mach/mach_types.h>
  62 #include <mach/boolean.h>
  63 #include <mach/kern_return.h>
  64 #include <mach/message.h>
  65 #include <mach/port.h>
  66 #include <mach/mig_errors.h>
  67 #include <mach/task.h>
  68 #include <mach/thread_status.h>
  69 #include <mach/exception_types.h>
  70 #include <mach/exc.h>
  71 #include <mach/mach_exc.h>
  72 #include <ipc/port.h>
  73 #include <ipc/ipc_entry.h>
  74 #include <ipc/ipc_object.h>
  75 #include <ipc/ipc_notify.h>
  76 #include <ipc/ipc_space.h>
  77 #include <ipc/ipc_pset.h>
  78 #include <ipc/ipc_machdep.h>
  79 #include <kern/counters.h>
  80 #include <kern/ipc_tt.h>
  81 #include <kern/task.h>
  82 #include <kern/thread.h>
  83 #include <kern/processor.h>
  84 #include <kern/sched.h>
  85 #include <kern/sched_prim.h>
  86 #include <kern/host.h>
  87 #include <kern/misc_protos.h>
  88 #include <string.h>
  89
  90 #if     MACH_KDB
  91 #include <ddb/db_trap.h>
  92 #endif  /* MACH_KDB */
  93
  94 #if     MACH_KDB
  95
  96 #include <ddb/db_output.h>
  97
  98 #if iPSC386 || iPSC860
  99 boolean_t debug_user_with_kdb = TRUE;
 100 #else
 101 boolean_t debug_user_with_kdb = FALSE;
 102 #endif
 103
 104 #endif  /* MACH_KDB */
 105
 106 unsigned long c_thr_exc_raise = 0;
 107 unsigned long c_thr_exc_raise_state = 0;
 108 unsigned long c_thr_exc_raise_state_id = 0;
 109 unsigned long c_tsk_exc_raise = 0;
 110 unsigned long c_tsk_exc_raise_state = 0;
 111 unsigned long c_tsk_exc_raise_state_id = 0;
 112
 113 /* forward declarations */
 114 kern_return_t exception_deliver(
 115         thread_t                thread,
 116         exception_type_t        exception,
 117         mach_exception_data_t   code,
 118         mach_msg_type_number_t  codeCnt,
 119         struct exception_action *excp,
 120         lck_mtx_t                       *mutex);
 121
 122 #ifdef MACH_BSD
 123 kern_return_t bsd_exception(
 124         exception_type_t        exception,
 125         mach_exception_data_t   code,
 126         mach_msg_type_number_t  codeCnt);
 127 #endif /* MACH_BSD */
 128
 129 /*
 130  *      Routine:        exception_deliver
 131  *      Purpose:
 132  *              Make an upcall to the exception server provided.
 133  *      Conditions:
 134  *              Nothing locked and no resources held.
 135  *              Called from an exception context, so
 136  *              thread_exception_return and thread_kdb_return
 137  *              are possible.
 138  *      Returns:
 139  *              KERN_SUCCESS if the exception was handled
 140  */
 141 kern_return_t
 142 exception_deliver(
 143         thread_t                thread,
 144         exception_type_t        exception,
 145         mach_exception_data_t   code,
 146         mach_msg_type_number_t  codeCnt,
 147         struct exception_action *excp,
 148         lck_mtx_t                       *mutex)
 149 {
 150         ipc_port_t              exc_port;
 151         exception_data_type_t   small_code[EXCEPTION_CODE_MAX];
 152         int                     code64;
 153         int                     behavior;
 154         int                     flavor;
 155         kern_return_t           kr;
 156
 157         /*
 158          *  Save work if we are terminating.
 159          *  Just go back to our AST handler.
 160          */
 161         if (!thread->active)
 162                 return KERN_SUCCESS;
 163
 164         /*
 165          * Snapshot the exception action data under lock for consistency.
 166          * Hold a reference to the port over the exception_raise_* calls
 167          * so it can't be destroyed.  This seems like overkill, but keeps
 168          * the port from disappearing between now and when
 169          * ipc_object_copyin_from_kernel is finally called.
 170          */
 171         lck_mtx_lock(mutex);
 172         exc_port = excp->port;
 173         if (!IP_VALID(exc_port)) {
 174                 lck_mtx_unlock(mutex);
 175                 return KERN_FAILURE;
 176         }
 177         ip_lock(exc_port);
 178         if (!ip_active(exc_port)) {
 179                 ip_unlock(exc_port);
 180                 lck_mtx_unlock(mutex);
 181                 return KERN_FAILURE;
 182         }
 183         ip_reference(exc_port);
 184         exc_port->ip_srights++;
 185         ip_unlock(exc_port);
 186
 187         flavor = excp->flavor;
 188         behavior = excp->behavior;
 189         lck_mtx_unlock(mutex);
 190
 191         code64 = (behavior & MACH_EXCEPTION_CODES);
 192         behavior &= ~MACH_EXCEPTION_CODES;
 193
 194         if (!code64) {
 195                 small_code[0] = CAST_DOWN_EXPLICIT(exception_data_type_t, code[0]);
 196                 small_code[1] = CAST_DOWN_EXPLICIT(exception_data_type_t, code[1]);
 197         }
 198
 199
 200         switch (behavior) {
 201         case EXCEPTION_STATE: {
 202                 mach_msg_type_number_t state_cnt;
 203                 thread_state_data_t state;
 204
 205                 c_thr_exc_raise_state++;
 206                 state_cnt = _MachineStateCount[flavor];
 207                 kr = thread_getstatus(thread, flavor,
 208                                       (thread_state_t)state,
 209                                       &state_cnt);
 210                 if (kr == KERN_SUCCESS) {
 211                         if (code64) {
 212                                 kr = mach_exception_raise_state(exc_port,
 213                                                 exception,
 214                                                 code,
 215                                                 codeCnt,
 216                                                 &flavor,
 217                                                 state, state_cnt,
 218                                                 state, &state_cnt);
 219                         } else {
 220                                 kr = exception_raise_state(exc_port, exception,
 221                                                 small_code,
 222                                                 codeCnt,
 223                                                 &flavor,
 224                                                 state, state_cnt,
 225                                                 state, &state_cnt);
 226                         }
 227                         if (kr == MACH_MSG_SUCCESS)
 228                                 kr = thread_setstatus(thread, flavor,
 229                                                 (thread_state_t)state,
 230                                                 state_cnt);
 231                 }
 232
 233                 return kr;
 234         }
 235
 236         case EXCEPTION_DEFAULT:
 237                 c_thr_exc_raise++;
 238                 if (code64) {
 239                         kr = mach_exception_raise(exc_port,
 240                                         retrieve_thread_self_fast(thread),
 241                                         retrieve_task_self_fast(thread->task),
 242                                         exception,
 243                                         code,
 244                                         codeCnt);
 245                 } else {
 246                         kr = exception_raise(exc_port,
 247                                         retrieve_thread_self_fast(thread),
 248                                         retrieve_task_self_fast(thread->task),
 249                                         exception,
 250                                         small_code,
 251                                         codeCnt);
 252                 }
 253
 254                 return kr;
 255
 256         case EXCEPTION_STATE_IDENTITY: {
 257                 mach_msg_type_number_t state_cnt;
 258                 thread_state_data_t state;
 259
 260                 c_thr_exc_raise_state_id++;
 261                 state_cnt = _MachineStateCount[flavor];
 262                 kr = thread_getstatus(thread, flavor,
 263                                       (thread_state_t)state,
 264                                       &state_cnt);
 265                 if (kr == KERN_SUCCESS) {
 266                         if (code64) {
 267                                 kr = mach_exception_raise_state_identity(
 268                                                 exc_port,
 269                                                 retrieve_thread_self_fast(thread),
 270                                                 retrieve_task_self_fast(thread->task),
 271                                                 exception,
 272                                                 code,
 273                                                 codeCnt,
 274                                                 &flavor,
 275                                                 state, state_cnt,
 276                                                 state, &state_cnt);
 277                         } else {
 278                                 kr = exception_raise_state_identity(exc_port,
 279                                                 retrieve_thread_self_fast(thread),
 280                                                 retrieve_task_self_fast(thread->task),
 281                                                 exception,
 282                                                 small_code,
 283                                                 codeCnt,
 284                                                 &flavor,
 285                                                 state, state_cnt,
 286                                                 state, &state_cnt);
 287                         }
 288                         if (kr == MACH_MSG_SUCCESS)
 289                                 kr = thread_setstatus(thread, flavor,
 290                                                 (thread_state_t)state,
 291                                                 state_cnt);
 292                 }
 293
 294                 return kr;
 295         }
 296
 297         default:
 298                panic ("bad exception behavior!");
 299                return KERN_FAILURE;
 300         }/* switch */
 301 }
 302
 303 /*
 304  *      Routine:        exception
 305  *      Purpose:
 306  *              The current thread caught an exception.
 307  *              We make an up-call to the thread's exception server.
 308  *      Conditions:
 309  *              Nothing locked and no resources held.
 310  *              Called from an exception context, so
 311  *              thread_exception_return and thread_kdb_return
 312  *              are possible.
 313  *      Returns:
 314  *              Doesn't return.
 315  */
 316 void
 317 exception_triage(
 318         exception_type_t        exception,
 319         mach_exception_data_t   code,
 320         mach_msg_type_number_t  codeCnt)
 321 {
 322         thread_t                thread;
 323         task_t                  task;
 324         host_priv_t             host_priv;
 325         struct exception_action *excp;
 326         lck_mtx_t                       *mutex;
 327         kern_return_t           kr;
 328
 329         assert(exception != EXC_RPC_ALERT);
 330
 331         if (exception == KERN_SUCCESS)
 332                 panic("exception");
 333
 334         /*
 335          * Try to raise the exception at the activation level.
 336          */
 337         thread = current_thread();
 338         mutex = &thread->mutex;
 339         excp = &thread->exc_actions[exception];
 340         kr = exception_deliver(thread, exception, code, codeCnt, excp, mutex);
 341         if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 342                 goto out;
 343
 344         /*
 345          * Maybe the task level will handle it.
 346          */
 347         task = current_task();
 348         mutex = &task->lock;
 349         excp = &task->exc_actions[exception];
 350         kr = exception_deliver(thread, exception, code, codeCnt, excp, mutex);
 351         if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 352                 goto out;
 353
 354         /*
 355          * How about at the host level?
 356          */
 357         host_priv = host_priv_self();
 358         mutex = &host_priv->lock;
 359         excp = &host_priv->exc_actions[exception];
 360         kr = exception_deliver(thread, exception, code, codeCnt, excp, mutex);
 361         if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 362                 goto out;
 363
 364         /*
 365          * Nobody handled it, terminate the task.
 366          */
 367
 368 #if     MACH_KDB
 369         if (debug_user_with_kdb) {
 370                 /*
 371                  *      Debug the exception with kdb.
 372                  *      If kdb handles the exception,
 373                  *      then thread_kdb_return won't return.
 374                  */
 375                 db_printf("No exception server, calling kdb...\n");
 376                 thread_kdb_return();
 377         }
 378 #endif  /* MACH_KDB */
 379
 380         (void) task_terminate(task);
 381
 382 out:
 383         if (exception != EXC_CRASH)
 384                 thread_exception_return();
 385         return;
 386 }
 387
 388 kern_return_t
 389 bsd_exception(
 390         exception_type_t        exception,
 391         mach_exception_data_t   code,
 392         mach_msg_type_number_t  codeCnt)
 393 {
 394         task_t                  task;
 395         struct exception_action *excp;
 396         lck_mtx_t               *mutex;
 397         thread_t                self = current_thread();
 398         kern_return_t           kr;
 399
 400         /*
 401          * Maybe the task level will handle it.
 402          */
 403         task = current_task();
 404         mutex = &task->lock;
 405         excp = &task->exc_actions[exception];
 406
 407         kr = exception_deliver(self, exception, code, codeCnt, excp, mutex);
 408
 409         if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 410                 return(KERN_SUCCESS);
 411         return(KERN_FAILURE);
 412 }
 413
 414
 415 /*
 416  * Raise an EXC_CRASH exception on the dying task.
 417  * This should tell launchd to launch Crash Reporter for this task.
 418  */
 419 kern_return_t abnormal_exit_notify(mach_exception_data_type_t exccode,
 420                 mach_exception_data_type_t excsubcode)
 421 {
 422         mach_exception_data_type_t      code[EXCEPTION_CODE_MAX];
 423         wait_interrupt_t                wsave;
 424
 425         code[0] = exccode;
 426         code[1] = excsubcode;
 427
 428         wsave = thread_interrupt_level(THREAD_UNINT);
 429         exception_triage(EXC_CRASH, code, EXCEPTION_CODE_MAX);
 430         (void) thread_interrupt_level(wsave);
 431         return (KERN_SUCCESS);
 432 }
 433
 434
 435 /*
 436  *      Handle interface for special performance monitoring
 437  *      This is a special case of the host exception handler
 438  */
 439 kern_return_t sys_perf_notify(thread_t thread, int pid)
 440 {
 441         host_priv_t             hostp;
 442         struct exception_action *excp;
 443         ipc_port_t              xport;
 444         wait_interrupt_t        wsave;
 445         kern_return_t           ret;
 446
 447         hostp = host_priv_self();       /* Get the host privileged ports */
 448         mach_exception_data_type_t      code[EXCEPTION_CODE_MAX];
 449         code[0] = 0xFF000001;           /* Set terminate code */
 450         code[1] = pid;          /* Pass out the pid */
 451
 452         struct task *task = thread->task;
 453         excp = &hostp->exc_actions[EXC_RPC_ALERT];
 454         xport = excp->port;
 455
 456         /* Make sure we're not catching our own exception */
 457         if (!IP_VALID(xport) ||
 458                         !ip_active(xport) ||
 459                         task->itk_space == xport->data.receiver) {
 460
 461                 return(KERN_FAILURE);
 462         }
 463
 464         wsave = thread_interrupt_level(THREAD_UNINT);
 465         ret = exception_deliver(
 466                         thread,
 467                         EXC_RPC_ALERT,
 468                         code,
 469                         2,
 470                         excp,
 471                         &hostp->lock);
 472         (void)thread_interrupt_level(wsave);
 473
 474         return(ret);
 475 }
 476