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/mach_types.h>
  60 #include <mach/boolean.h>
  61 #include <mach/kern_return.h>
  62 #include <mach/message.h>
  63 #include <mach/port.h>
  64 #include <mach/mig_errors.h>
  65 #include <mach/task.h>
  66 #include <mach/thread_status.h>
  67 #include <mach/exception_types.h>
  68 #include <mach/exc.h>
  69 #include <mach/mach_exc.h>
  70 #include <ipc/port.h>
  71 #include <ipc/ipc_entry.h>
  72 #include <ipc/ipc_object.h>
  73 #include <ipc/ipc_notify.h>
  74 #include <ipc/ipc_space.h>
  75 #include <ipc/ipc_pset.h>
  76 #include <ipc/ipc_machdep.h>
  77 #include <kern/counters.h>
  78 #include <kern/ipc_tt.h>
  79 #include <kern/task.h>
  80 #include <kern/thread.h>
  81 #include <kern/processor.h>
  82 #include <kern/sched.h>
  83 #include <kern/sched_prim.h>
  84 #include <kern/host.h>
  85 #include <kern/misc_protos.h>
  86 #include <string.h>
  87 #include <pexpert/pexpert.h>
  88
  89 unsigned long c_thr_exc_raise = 0;
  90 unsigned long c_thr_exc_raise_state = 0;
  91 unsigned long c_thr_exc_raise_state_id = 0;
  92 unsigned long c_tsk_exc_raise = 0;
  93 unsigned long c_tsk_exc_raise_state = 0;
  94 unsigned long c_tsk_exc_raise_state_id = 0;
  95
  96 /* forward declarations */
  97 kern_return_t exception_deliver(
  98         thread_t                thread,
  99         exception_type_t        exception,
 100         mach_exception_data_t   code,
 101         mach_msg_type_number_t  codeCnt,
 102         struct exception_action *excp,
 103         lck_mtx_t                       *mutex);
 104
 105 #ifdef MACH_BSD
 106 kern_return_t bsd_exception(
 107         exception_type_t        exception,
 108         mach_exception_data_t   code,
 109         mach_msg_type_number_t  codeCnt);
 110 #endif /* MACH_BSD */
 111
 112 /*
 113  *      Routine:        exception_deliver
 114  *      Purpose:
 115  *              Make an upcall to the exception server provided.
 116  *      Conditions:
 117  *              Nothing locked and no resources held.
 118  *              Called from an exception context, so
 119  *              thread_exception_return and thread_kdb_return
 120  *              are possible.
 121  *      Returns:
 122  *              KERN_SUCCESS if the exception was handled
 123  */
 124 kern_return_t
 125 exception_deliver(
 126         thread_t                thread,
 127         exception_type_t        exception,
 128         mach_exception_data_t   code,
 129         mach_msg_type_number_t  codeCnt,
 130         struct exception_action *excp,
 131         lck_mtx_t                       *mutex)
 132 {
 133         ipc_port_t              exc_port;
 134         exception_data_type_t   small_code[EXCEPTION_CODE_MAX];
 135         int                     code64;
 136         int                     behavior;
 137         int                     flavor;
 138         kern_return_t           kr;
 139
 140         /*
 141          *  Save work if we are terminating.
 142          *  Just go back to our AST handler.
 143          */
 144         if (!thread->active)
 145                 return KERN_SUCCESS;
 146
 147         /*
 148          * Snapshot the exception action data under lock for consistency.
 149          * Hold a reference to the port over the exception_raise_* calls
 150          * so it can't be destroyed.  This seems like overkill, but keeps
 151          * the port from disappearing between now and when
 152          * ipc_object_copyin_from_kernel is finally called.
 153          */
 154         lck_mtx_lock(mutex);
 155         exc_port = excp->port;
 156         if (!IP_VALID(exc_port)) {
 157                 lck_mtx_unlock(mutex);
 158                 return KERN_FAILURE;
 159         }
 160         ip_lock(exc_port);
 161         if (!ip_active(exc_port)) {
 162                 ip_unlock(exc_port);
 163                 lck_mtx_unlock(mutex);
 164                 return KERN_FAILURE;
 165         }
 166         ip_reference(exc_port);
 167         exc_port->ip_srights++;
 168         ip_unlock(exc_port);
 169
 170         flavor = excp->flavor;
 171         behavior = excp->behavior;
 172         lck_mtx_unlock(mutex);
 173
 174         code64 = (behavior & MACH_EXCEPTION_CODES);
 175         behavior &= ~MACH_EXCEPTION_CODES;
 176
 177         if (!code64) {
 178                 small_code[0] = CAST_DOWN_EXPLICIT(exception_data_type_t, code[0]);
 179                 small_code[1] = CAST_DOWN_EXPLICIT(exception_data_type_t, code[1]);
 180         }
 181
 182
 183         switch (behavior) {
 184         case EXCEPTION_STATE: {
 185                 mach_msg_type_number_t state_cnt;
 186                 thread_state_data_t state;
 187
 188                 c_thr_exc_raise_state++;
 189                 state_cnt = _MachineStateCount[flavor];
 190                 kr = thread_getstatus(thread, flavor,
 191                                       (thread_state_t)state,
 192                                       &state_cnt);
 193                 if (kr == KERN_SUCCESS) {
 194                         if (code64) {
 195                                 kr = mach_exception_raise_state(exc_port,
 196                                                 exception,
 197                                                 code,
 198                                                 codeCnt,
 199                                                 &flavor,
 200                                                 state, state_cnt,
 201                                                 state, &state_cnt);
 202                         } else {
 203                                 kr = exception_raise_state(exc_port, exception,
 204                                                 small_code,
 205                                                 codeCnt,
 206                                                 &flavor,
 207                                                 state, state_cnt,
 208                                                 state, &state_cnt);
 209                         }
 210                         if (kr == MACH_MSG_SUCCESS)
 211                                 kr = thread_setstatus(thread, flavor,
 212                                                 (thread_state_t)state,
 213                                                 state_cnt);
 214                 }
 215
 216                 return kr;
 217         }
 218
 219         case EXCEPTION_DEFAULT:
 220                 c_thr_exc_raise++;
 221                 if (code64) {
 222                         kr = mach_exception_raise(exc_port,
 223                                         retrieve_thread_self_fast(thread),
 224                                         retrieve_task_self_fast(thread->task),
 225                                         exception,
 226                                         code,
 227                                         codeCnt);
 228                 } else {
 229                         kr = exception_raise(exc_port,
 230                                         retrieve_thread_self_fast(thread),
 231                                         retrieve_task_self_fast(thread->task),
 232                                         exception,
 233                                         small_code,
 234                                         codeCnt);
 235                 }
 236
 237                 return kr;
 238
 239         case EXCEPTION_STATE_IDENTITY: {
 240                 mach_msg_type_number_t state_cnt;
 241                 thread_state_data_t state;
 242
 243                 c_thr_exc_raise_state_id++;
 244                 state_cnt = _MachineStateCount[flavor];
 245                 kr = thread_getstatus(thread, flavor,
 246                                       (thread_state_t)state,
 247                                       &state_cnt);
 248                 if (kr == KERN_SUCCESS) {
 249                         if (code64) {
 250                                 kr = mach_exception_raise_state_identity(
 251                                                 exc_port,
 252                                                 retrieve_thread_self_fast(thread),
 253                                                 retrieve_task_self_fast(thread->task),
 254                                                 exception,
 255                                                 code,
 256                                                 codeCnt,
 257                                                 &flavor,
 258                                                 state, state_cnt,
 259                                                 state, &state_cnt);
 260                         } else {
 261                                 kr = exception_raise_state_identity(exc_port,
 262                                                 retrieve_thread_self_fast(thread),
 263                                                 retrieve_task_self_fast(thread->task),
 264                                                 exception,
 265                                                 small_code,
 266                                                 codeCnt,
 267                                                 &flavor,
 268                                                 state, state_cnt,
 269                                                 state, &state_cnt);
 270                         }
 271                         if (kr == MACH_MSG_SUCCESS)
 272                                 kr = thread_setstatus(thread, flavor,
 273                                                 (thread_state_t)state,
 274                                                 state_cnt);
 275                 }
 276
 277                 return kr;
 278         }
 279
 280         default:
 281                panic ("bad exception behavior!");
 282                return KERN_FAILURE;
 283         }/* switch */
 284 }
 285
 286 /*
 287  *      Routine:        exception
 288  *      Purpose:
 289  *              The current thread caught an exception.
 290  *              We make an up-call to the thread's exception server.
 291  *      Conditions:
 292  *              Nothing locked and no resources held.
 293  *              Called from an exception context, so
 294  *              thread_exception_return and thread_kdb_return
 295  *              are possible.
 296  *      Returns:
 297  *              Doesn't return.
 298  */
 299 void
 300 exception_triage(
 301         exception_type_t        exception,
 302         mach_exception_data_t   code,
 303         mach_msg_type_number_t  codeCnt)
 304 {
 305         thread_t                thread;
 306         task_t                  task;
 307         host_priv_t             host_priv;
 308         struct exception_action *excp;
 309         lck_mtx_t                       *mutex;
 310         kern_return_t           kr;
 311
 312         assert(exception != EXC_RPC_ALERT);
 313
 314         thread = current_thread();
 315
 316         /*
 317          * Try to raise the exception at the activation level.
 318          */
 319         mutex = &thread->mutex;
 320         excp = &thread->exc_actions[exception];
 321         kr = exception_deliver(thread, exception, code, codeCnt, excp, mutex);
 322         if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 323                 goto out;
 324
 325         /*
 326          * Maybe the task level will handle it.
 327          */
 328         task = current_task();
 329         mutex = &task->lock;
 330         excp = &task->exc_actions[exception];
 331         kr = exception_deliver(thread, exception, code, codeCnt, excp, mutex);
 332         if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 333                 goto out;
 334
 335         /*
 336          * How about at the host level?
 337          */
 338         host_priv = host_priv_self();
 339         mutex = &host_priv->lock;
 340         excp = &host_priv->exc_actions[exception];
 341         kr = exception_deliver(thread, exception, code, codeCnt, excp, mutex);
 342         if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 343                 goto out;
 344
 345         /*
 346          * Nobody handled it, terminate the task.
 347          */
 348
 349         (void) task_terminate(task);
 350
 351 out:
 352         if ((exception != EXC_CRASH) && (exception != EXC_RESOURCE))
 353                 thread_exception_return();
 354         return;
 355 }
 356
 357 kern_return_t
 358 bsd_exception(
 359         exception_type_t        exception,
 360         mach_exception_data_t   code,
 361         mach_msg_type_number_t  codeCnt)
 362 {
 363         task_t                  task;
 364         struct exception_action *excp;
 365         lck_mtx_t               *mutex;
 366         thread_t                self = current_thread();
 367         kern_return_t           kr;
 368
 369         /*
 370          * Maybe the task level will handle it.
 371          */
 372         task = current_task();
 373         mutex = &task->lock;
 374         excp = &task->exc_actions[exception];
 375
 376         kr = exception_deliver(self, exception, code, codeCnt, excp, mutex);
 377
 378         if (kr == KERN_SUCCESS || kr == MACH_RCV_PORT_DIED)
 379                 return(KERN_SUCCESS);
 380         return(KERN_FAILURE);
 381 }
 382
 383
 384 /*
 385  * Raise an exception on a task.
 386  * This should tell launchd to launch Crash Reporter for this task.
 387  */
 388 kern_return_t task_exception_notify(exception_type_t exception,
 389         mach_exception_data_type_t exccode, mach_exception_data_type_t excsubcode)
 390 {
 391         mach_exception_data_type_t      code[EXCEPTION_CODE_MAX];
 392         wait_interrupt_t                wsave;
 393
 394         code[0] = exccode;
 395         code[1] = excsubcode;
 396
 397         wsave = thread_interrupt_level(THREAD_UNINT);
 398         exception_triage(exception, code, EXCEPTION_CODE_MAX);
 399         (void) thread_interrupt_level(wsave);
 400         return (KERN_SUCCESS);
 401 }
 402
 403
 404 /*
 405  *      Handle interface for special performance monitoring
 406  *      This is a special case of the host exception handler
 407  */
 408 kern_return_t sys_perf_notify(thread_t thread, int pid)
 409 {
 410         host_priv_t             hostp;
 411         struct exception_action *excp;
 412         ipc_port_t              xport;
 413         wait_interrupt_t        wsave;
 414         kern_return_t           ret;
 415
 416         hostp = host_priv_self();       /* Get the host privileged ports */
 417         mach_exception_data_type_t      code[EXCEPTION_CODE_MAX];
 418         code[0] = 0xFF000001;           /* Set terminate code */
 419         code[1] = pid;          /* Pass out the pid */
 420
 421         struct task *task = thread->task;
 422         excp = &hostp->exc_actions[EXC_RPC_ALERT];
 423         xport = excp->port;
 424
 425         /* Make sure we're not catching our own exception */
 426         if (!IP_VALID(xport) ||
 427                         !ip_active(xport) ||
 428                         task->itk_space == xport->data.receiver) {
 429
 430                 return(KERN_FAILURE);
 431         }
 432
 433         wsave = thread_interrupt_level(THREAD_UNINT);
 434         ret = exception_deliver(
 435                         thread,
 436                         EXC_RPC_ALERT,
 437                         code,
 438                         2,
 439                         excp,
 440                         &hostp->lock);
 441         (void)thread_interrupt_level(wsave);
 442
 443         return(ret);
 444 }
 445