| 1 | /* |
| 2 | * Copyright (c) 2012-2013, 2015 Apple 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 | |
| 30 | /* |
| 31 | * Corpses Overview |
| 32 | * ================ |
| 33 | * |
| 34 | * A corpse is a state of process that is past the point of its death. This means that process has |
| 35 | * completed all its termination operations like releasing file descriptors, mach ports, sockets and |
| 36 | * other constructs used to identify a process. For all the processes this mimics the behavior as if |
| 37 | * the process has died and no longer available by any means. |
| 38 | * |
| 39 | * Why do we need Corpses? |
| 40 | * ----------------------- |
| 41 | * For crash inspection we need to inspect the state and data that is associated with process so that |
| 42 | * crash reporting infrastructure can build backtraces, find leaks etc. For example a crash |
| 43 | * |
| 44 | * Corpses functionality in kernel |
| 45 | * =============================== |
| 46 | * The corpse functionality is an extension of existing exception reporting mechanisms we have. The |
| 47 | * exception_triage calls will try to deliver the first round of exceptions allowing |
| 48 | * task/debugger/ReportCrash/launchd level exception handlers to respond to exception. If even after |
| 49 | * notification the exception is not handled, then the process begins the death operations and during |
| 50 | * proc_prepareexit, we decide to create a corpse for inspection. Following is a sample run through |
| 51 | * of events and data shuffling that happens when corpses is enabled. |
| 52 | * |
| 53 | * * a process causes an exception during normal execution of threads. |
| 54 | * * The exception generated by either mach(e.g GUARDED_MARCHPORT) or bsd(eg SIGABORT, GUARDED_FD |
| 55 | * etc) side is passed through the exception_triage() function to follow the thread -> task -> host |
| 56 | * level exception handling system. This set of steps are same as before and allow for existing |
| 57 | * crash reporting systems (both internal and 3rd party) to catch and create reports as required. |
| 58 | * * If above exception handling returns failed (when nobody handles the notification), then the |
| 59 | * proc_prepareexit path has logic to decide to create corpse. |
| 60 | * * The task_mark_corpse function allocates userspace vm memory and attaches the information |
| 61 | * kcdata_descriptor_t to task->corpse_info field of task. |
| 62 | * - All the task's threads are marked with the "inspection" flag which signals the termination |
| 63 | * daemon to not reap them but hold until they are being inspected. |
| 64 | * - task flags t_flags reflect the corpse bit and also a PENDING_CORPSE bit. PENDING_CORPSE |
| 65 | * prevents task_terminate from stripping important data from task. |
| 66 | * - It marks all the threads to terminate and return to AST for termination. |
| 67 | * - The allocation logic takes into account the rate limiting policy of allowing only |
| 68 | * TOTAL_CORPSES_ALLOWED in flight. |
| 69 | * * The proc exit threads continues and collects required information in the allocated vm region. |
| 70 | * Once complete it marks itself for termination. |
| 71 | * * In the thread_terminate_self(), the last thread to enter will do a call to proc_exit(). |
| 72 | * Following this is a check to see if task is marked for corpse notification and will |
| 73 | * invoke the the task_deliver_crash_notification(). |
| 74 | * * Once EXC_CORPSE_NOTIFY is delivered, it removes the PENDING_CORPSE flag from task (and |
| 75 | * inspection flag from all its threads) and allows task_terminate to go ahead and continue |
| 76 | * the mach task termination process. |
| 77 | * * ASIDE: The rest of the threads that are reaching the thread_terminate_daemon() with the |
| 78 | * inspection flag set are just bounced to another holding queue (crashed_threads_queue). |
| 79 | * Only after the corpse notification these are pulled out from holding queue and enqueued |
| 80 | * back to termination queue |
| 81 | * |
| 82 | * |
| 83 | * Corpse info format |
| 84 | * ================== |
| 85 | * The kernel (task_mark_corpse()) makes a vm allocation in the dead task's vm space (with tag |
| 86 | * VM_MEMORY_CORPSEINFO (80)). Within this memory all corpse information is saved by various |
| 87 | * subsystems like |
| 88 | * * bsd proc exit path may write down pid, parent pid, number of file descriptors etc |
| 89 | * * mach side may append data regarding ledger usage, memory stats etc |
| 90 | * See detailed info about the memory structure and format in kern_cdata.h documentation. |
| 91 | * |
| 92 | * Configuring Corpses functionality |
| 93 | * ================================= |
| 94 | * boot-arg: -no_corpses disables the corpse generation. This can be added/removed without affecting |
| 95 | * any other subsystem. |
| 96 | * TOTAL_CORPSES_ALLOWED : (recompilation required) - Changing this number allows for controlling |
| 97 | * the number of corpse instances to be held for inspection before allowing memory to be reclaimed |
| 98 | * by system. |
| 99 | * CORPSEINFO_ALLOCATION_SIZE: is the default size of vm allocation. If in future there is much more |
| 100 | * data to be put in, then please re-tune this parameter. |
| 101 | * |
| 102 | * Debugging/Visibility |
| 103 | * ==================== |
| 104 | * * lldbmacros for thread and task summary are updated to show "C" flag for corpse task/threads. |
| 105 | * * there are macros to see list of threads in termination queue (dumpthread_terminate_queue) |
| 106 | * and holding queue (dumpcrashed_thread_queue). |
| 107 | * * In case of corpse creation is disabled of ignored then the system log is updated with |
| 108 | * printf data with reason. |
| 109 | * |
| 110 | * Limitations of Corpses |
| 111 | * ====================== |
| 112 | * With holding off memory for inspection, it creates vm pressure which might not be desirable |
| 113 | * on low memory devices. There are limits to max corpses being inspected at a time which is |
| 114 | * marked by TOTAL_CORPSES_ALLOWED. |
| 115 | * |
| 116 | */ |
| 117 | |
| 118 | |
| 119 | #include <stdatomic.h> |
| 120 | #include <kern/assert.h> |
| 121 | #include <mach/mach_types.h> |
| 122 | #include <mach/boolean.h> |
| 123 | #include <mach/vm_param.h> |
| 124 | #include <kern/kern_types.h> |
| 125 | #include <kern/mach_param.h> |
| 126 | #include <kern/thread.h> |
| 127 | #include <kern/task.h> |
| 128 | #include <corpses/task_corpse.h> |
| 129 | #include <kern/kalloc.h> |
| 130 | #include <kern/kern_cdata.h> |
| 131 | #include <mach/mach_vm.h> |
| 132 | #include <kern/exc_guard.h> |
| 133 | |
| 134 | #if CONFIG_MACF |
| 135 | #include <security/mac_mach_internal.h> |
| 136 | #endif |
| 137 | |
| 138 | /* |
| 139 | * Exported interfaces |
| 140 | */ |
| 141 | #include <mach/task_server.h> |
| 142 | |
| 143 | union corpse_creation_gate { |
| 144 | struct { |
| 145 | uint16_t user_faults; |
| 146 | uint16_t corpses; |
| 147 | }; |
| 148 | uint32_t value; |
| 149 | }; |
| 150 | |
| 151 | static _Atomic uint32_t inflight_corpses; |
| 152 | unsigned long total_corpses_created = 0; |
| 153 | boolean_t corpse_enabled_config = TRUE; |
| 154 | |
| 155 | /* bootarg to turn on corpse forking for EXC_RESOURCE */ |
| 156 | int exc_via_corpse_forking = 1; |
| 157 | |
| 158 | /* bootarg to generate corpse for fatal high memory watermark violation */ |
| 159 | int corpse_for_fatal_memkill = 1; |
| 160 | |
| 161 | #ifdef __arm__ |
| 162 | static inline int IS_64BIT_PROCESS(__unused void *p) { return 0; } |
| 163 | #else |
| 164 | extern int IS_64BIT_PROCESS(void *); |
| 165 | #endif /* __arm__ */ |
| 166 | extern void gather_populate_corpse_crashinfo(void *p, task_t task, |
| 167 | mach_exception_data_type_t code, mach_exception_data_type_t subcode, |
| 168 | uint64_t *udata_buffer, int num_udata, void *reason); |
| 169 | extern void *proc_find(int pid); |
| 170 | extern int proc_rele(void *p); |
| 171 | |
| 172 | |
| 173 | void corpses_init(){ |
| 174 | char temp_buf[20]; |
| 175 | int exc_corpse_forking; |
| 176 | int fatal_memkill; |
| 177 | if (PE_parse_boot_argn("-no_corpses" , temp_buf, sizeof(temp_buf))) { |
| 178 | corpse_enabled_config = FALSE; |
| 179 | } |
| 180 | if (PE_parse_boot_argn("exc_via_corpse_forking" , &exc_corpse_forking, sizeof(exc_corpse_forking))) { |
| 181 | exc_via_corpse_forking = exc_corpse_forking; |
| 182 | } |
| 183 | if (PE_parse_boot_argn("corpse_for_fatal_memkill" , &fatal_memkill, sizeof(fatal_memkill))) { |
| 184 | corpse_for_fatal_memkill = fatal_memkill; |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | /* |
| 189 | * Routine: corpses_enabled |
| 190 | * returns FALSE if not enabled |
| 191 | */ |
| 192 | boolean_t corpses_enabled() |
| 193 | { |
| 194 | return corpse_enabled_config; |
| 195 | } |
| 196 | |
| 197 | unsigned long |
| 198 | total_corpses_count(void) |
| 199 | { |
| 200 | union corpse_creation_gate gate; |
| 201 | |
| 202 | gate.value = atomic_load_explicit(&inflight_corpses, memory_order_relaxed); |
| 203 | return gate.corpses; |
| 204 | } |
| 205 | |
| 206 | /* |
| 207 | * Routine: task_crashinfo_get_ref() |
| 208 | * Grab a slot at creating a corpse. |
| 209 | * Returns: KERN_SUCCESS if the policy allows for creating a corpse. |
| 210 | */ |
| 211 | static kern_return_t |
| 212 | task_crashinfo_get_ref(uint16_t kcd_u_flags) |
| 213 | { |
| 214 | union corpse_creation_gate oldgate, newgate; |
| 215 | |
| 216 | assert(kcd_u_flags & CORPSE_CRASHINFO_HAS_REF); |
| 217 | |
| 218 | oldgate.value = atomic_load_explicit(&inflight_corpses, memory_order_relaxed); |
| 219 | for (;;) { |
| 220 | newgate = oldgate; |
| 221 | if (kcd_u_flags & CORPSE_CRASHINFO_USER_FAULT) { |
| 222 | if (newgate.user_faults++ >= TOTAL_USER_FAULTS_ALLOWED) { |
| 223 | return KERN_RESOURCE_SHORTAGE; |
| 224 | } |
| 225 | } |
| 226 | if (newgate.corpses++ >= TOTAL_CORPSES_ALLOWED) { |
| 227 | return KERN_RESOURCE_SHORTAGE; |
| 228 | } |
| 229 | |
| 230 | // this reloads the value in oldgate |
| 231 | if (atomic_compare_exchange_strong_explicit(&inflight_corpses, |
| 232 | &oldgate.value, newgate.value, memory_order_relaxed, |
| 233 | memory_order_relaxed)) { |
| 234 | return KERN_SUCCESS; |
| 235 | } |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | /* |
| 240 | * Routine: task_crashinfo_release_ref |
| 241 | * release the slot for corpse being used. |
| 242 | */ |
| 243 | static kern_return_t |
| 244 | task_crashinfo_release_ref(uint16_t kcd_u_flags) |
| 245 | { |
| 246 | union corpse_creation_gate oldgate, newgate; |
| 247 | |
| 248 | assert(kcd_u_flags & CORPSE_CRASHINFO_HAS_REF); |
| 249 | |
| 250 | oldgate.value = atomic_load_explicit(&inflight_corpses, memory_order_relaxed); |
| 251 | for (;;) { |
| 252 | newgate = oldgate; |
| 253 | if (kcd_u_flags & CORPSE_CRASHINFO_USER_FAULT) { |
| 254 | if (newgate.user_faults-- == 0) { |
| 255 | panic("corpse in flight count over-release" ); |
| 256 | } |
| 257 | } |
| 258 | if (newgate.corpses-- == 0) { |
| 259 | panic("corpse in flight count over-release" ); |
| 260 | } |
| 261 | // this reloads the value in oldgate |
| 262 | if (atomic_compare_exchange_strong_explicit(&inflight_corpses, |
| 263 | &oldgate.value, newgate.value, memory_order_relaxed, |
| 264 | memory_order_relaxed)) { |
| 265 | return KERN_SUCCESS; |
| 266 | } |
| 267 | } |
| 268 | } |
| 269 | |
| 270 | |
| 271 | kcdata_descriptor_t |
| 272 | task_crashinfo_alloc_init(mach_vm_address_t crash_data_p, unsigned size, |
| 273 | uint32_t kc_u_flags, unsigned kc_flags) |
| 274 | { |
| 275 | kcdata_descriptor_t kcdata; |
| 276 | |
| 277 | if (kc_u_flags & CORPSE_CRASHINFO_HAS_REF) { |
| 278 | if (KERN_SUCCESS != task_crashinfo_get_ref(kc_u_flags)) { |
| 279 | return NULL; |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | kcdata = kcdata_memory_alloc_init(crash_data_p, TASK_CRASHINFO_BEGIN, size, |
| 284 | kc_flags); |
| 285 | if (kcdata) { |
| 286 | kcdata->kcd_user_flags = kc_u_flags; |
| 287 | } else if (kc_u_flags & CORPSE_CRASHINFO_HAS_REF) { |
| 288 | task_crashinfo_release_ref(kc_u_flags); |
| 289 | } |
| 290 | return kcdata; |
| 291 | } |
| 292 | |
| 293 | |
| 294 | /* |
| 295 | * Free up the memory associated with task_crashinfo_data |
| 296 | */ |
| 297 | kern_return_t |
| 298 | task_crashinfo_destroy(kcdata_descriptor_t data) |
| 299 | { |
| 300 | if (!data) { |
| 301 | return KERN_INVALID_ARGUMENT; |
| 302 | } |
| 303 | if (data->kcd_user_flags & CORPSE_CRASHINFO_HAS_REF) { |
| 304 | task_crashinfo_release_ref(data->kcd_user_flags); |
| 305 | } |
| 306 | return kcdata_memory_destroy(data); |
| 307 | } |
| 308 | |
| 309 | /* |
| 310 | * Routine: task_get_corpseinfo |
| 311 | * params: task - task which has corpse info setup. |
| 312 | * returns: crash info data attached to task. |
| 313 | * NULL if task is null or has no corpse info |
| 314 | */ |
| 315 | kcdata_descriptor_t task_get_corpseinfo(task_t task) |
| 316 | { |
| 317 | kcdata_descriptor_t retval = NULL; |
| 318 | if (task != NULL){ |
| 319 | retval = task->corpse_info; |
| 320 | } |
| 321 | return retval; |
| 322 | } |
| 323 | |
| 324 | /* |
| 325 | * Routine: task_add_to_corpse_task_list |
| 326 | * params: task - task to be added to corpse task list |
| 327 | * returns: None. |
| 328 | */ |
| 329 | void |
| 330 | task_add_to_corpse_task_list(task_t corpse_task) |
| 331 | { |
| 332 | lck_mtx_lock(&tasks_corpse_lock); |
| 333 | queue_enter(&corpse_tasks, corpse_task, task_t, corpse_tasks); |
| 334 | lck_mtx_unlock(&tasks_corpse_lock); |
| 335 | } |
| 336 | |
| 337 | /* |
| 338 | * Routine: task_remove_from_corpse_task_list |
| 339 | * params: task - task to be removed from corpse task list |
| 340 | * returns: None. |
| 341 | */ |
| 342 | void |
| 343 | task_remove_from_corpse_task_list(task_t corpse_task) |
| 344 | { |
| 345 | lck_mtx_lock(&tasks_corpse_lock); |
| 346 | queue_remove(&corpse_tasks, corpse_task, task_t, corpse_tasks); |
| 347 | lck_mtx_unlock(&tasks_corpse_lock); |
| 348 | } |
| 349 | |
| 350 | /* |
| 351 | * Routine: task_purge_all_corpses |
| 352 | * params: None. |
| 353 | * returns: None. |
| 354 | */ |
| 355 | void |
| 356 | task_purge_all_corpses(void) |
| 357 | { |
| 358 | task_t task; |
| 359 | |
| 360 | printf("Purging corpses......\n\n" ); |
| 361 | |
| 362 | lck_mtx_lock(&tasks_corpse_lock); |
| 363 | /* Iterate through all the corpse tasks and clear all map entries */ |
| 364 | queue_iterate(&corpse_tasks, task, task_t, corpse_tasks) { |
| 365 | vm_map_remove(task->map, |
| 366 | task->map->min_offset, |
| 367 | task->map->max_offset, |
| 368 | /* |
| 369 | * Final cleanup: |
| 370 | * + no unnesting |
| 371 | * + remove immutable mappings |
| 372 | * + allow gaps in the range |
| 373 | */ |
| 374 | (VM_MAP_REMOVE_NO_UNNESTING | |
| 375 | VM_MAP_REMOVE_IMMUTABLE | |
| 376 | VM_MAP_REMOVE_GAPS_OK)); |
| 377 | } |
| 378 | |
| 379 | lck_mtx_unlock(&tasks_corpse_lock); |
| 380 | } |
| 381 | |
| 382 | /* |
| 383 | * Routine: task_generate_corpse |
| 384 | * params: task - task to fork a corpse |
| 385 | * corpse_task - task port of the generated corpse |
| 386 | * returns: KERN_SUCCESS on Success. |
| 387 | * KERN_FAILURE on Failure. |
| 388 | * KERN_NOT_SUPPORTED on corpse disabled. |
| 389 | * KERN_RESOURCE_SHORTAGE on memory alloc failure or reaching max corpse. |
| 390 | */ |
| 391 | kern_return_t |
| 392 | task_generate_corpse( |
| 393 | task_t task, |
| 394 | ipc_port_t *corpse_task_port) |
| 395 | { |
| 396 | task_t new_task; |
| 397 | kern_return_t kr; |
| 398 | thread_t thread, th_iter; |
| 399 | ipc_port_t corpse_port; |
| 400 | ipc_port_t old_notify; |
| 401 | |
| 402 | if (task == kernel_task || task == TASK_NULL || task == current_task()) { |
| 403 | return KERN_INVALID_ARGUMENT; |
| 404 | } |
| 405 | |
| 406 | task_lock(task); |
| 407 | if (task_is_a_corpse_fork(task)) { |
| 408 | task_unlock(task); |
| 409 | return KERN_INVALID_ARGUMENT; |
| 410 | } |
| 411 | task_unlock(task); |
| 412 | |
| 413 | /* Generate a corpse for the given task, will return with a ref on corpse task */ |
| 414 | kr = task_generate_corpse_internal(task, &new_task, &thread, 0, 0, 0, NULL); |
| 415 | if (kr != KERN_SUCCESS) { |
| 416 | return kr; |
| 417 | } |
| 418 | if (thread != THREAD_NULL) { |
| 419 | thread_deallocate(thread); |
| 420 | } |
| 421 | |
| 422 | /* wait for all the threads in the task to terminate */ |
| 423 | task_lock(new_task); |
| 424 | task_wait_till_threads_terminate_locked(new_task); |
| 425 | |
| 426 | /* Reset thread ports of all the threads in task */ |
| 427 | queue_iterate(&new_task->threads, th_iter, thread_t, task_threads) |
| 428 | { |
| 429 | /* Do not reset the thread port for inactive threads */ |
| 430 | if (th_iter->corpse_dup == FALSE) { |
| 431 | ipc_thread_reset(th_iter); |
| 432 | } |
| 433 | } |
| 434 | task_unlock(new_task); |
| 435 | |
| 436 | /* transfer the task ref to port and arm the no-senders notification */ |
| 437 | corpse_port = convert_task_to_port(new_task); |
| 438 | assert(IP_NULL != corpse_port); |
| 439 | |
| 440 | ip_lock(corpse_port); |
| 441 | assert(ip_active(corpse_port)); |
| 442 | ipc_port_nsrequest(corpse_port, corpse_port->ip_mscount, ipc_port_make_sonce_locked(corpse_port), &old_notify); |
| 443 | /* port unlocked */ |
| 444 | |
| 445 | assert(IP_NULL == old_notify); |
| 446 | *corpse_task_port = corpse_port; |
| 447 | return KERN_SUCCESS; |
| 448 | } |
| 449 | |
| 450 | /* |
| 451 | * Routine: task_enqueue_exception_with_corpse |
| 452 | * params: task - task to generate a corpse and enqueue it |
| 453 | * etype - EXC_RESOURCE or EXC_GUARD |
| 454 | * code - exception code to be enqueued |
| 455 | * codeCnt - code array count - code and subcode |
| 456 | * |
| 457 | * returns: KERN_SUCCESS on Success. |
| 458 | * KERN_FAILURE on Failure. |
| 459 | * KERN_INVALID_ARGUMENT on invalid arguments passed. |
| 460 | * KERN_NOT_SUPPORTED on corpse disabled. |
| 461 | * KERN_RESOURCE_SHORTAGE on memory alloc failure or reaching max corpse. |
| 462 | */ |
| 463 | kern_return_t |
| 464 | task_enqueue_exception_with_corpse( |
| 465 | task_t task, |
| 466 | exception_type_t etype, |
| 467 | mach_exception_data_t code, |
| 468 | mach_msg_type_number_t codeCnt, |
| 469 | void *reason) |
| 470 | { |
| 471 | task_t new_task = TASK_NULL; |
| 472 | thread_t thread = THREAD_NULL; |
| 473 | kern_return_t kr; |
| 474 | |
| 475 | if (codeCnt < 2) { |
| 476 | return KERN_INVALID_ARGUMENT; |
| 477 | } |
| 478 | |
| 479 | /* Generate a corpse for the given task, will return with a ref on corpse task */ |
| 480 | kr = task_generate_corpse_internal(task, &new_task, &thread, |
| 481 | etype, code[0], code[1], reason); |
| 482 | if (kr == KERN_SUCCESS) { |
| 483 | if (thread == THREAD_NULL) { |
| 484 | return KERN_FAILURE; |
| 485 | } |
| 486 | assert(new_task != TASK_NULL); |
| 487 | assert(etype == EXC_RESOURCE || etype == EXC_GUARD); |
| 488 | thread_exception_enqueue(new_task, thread, etype); |
| 489 | } |
| 490 | return kr; |
| 491 | } |
| 492 | |
| 493 | /* |
| 494 | * Routine: task_generate_corpse_internal |
| 495 | * params: task - task to fork a corpse |
| 496 | * corpse_task - task of the generated corpse |
| 497 | * exc_thread - equivalent thread in corpse enqueuing exception |
| 498 | * etype - EXC_RESOURCE or EXC_GUARD or 0 |
| 499 | * code - mach exception code to be passed in corpse blob |
| 500 | * subcode - mach exception subcode to be passed in corpse blob |
| 501 | * returns: KERN_SUCCESS on Success. |
| 502 | * KERN_FAILURE on Failure. |
| 503 | * KERN_NOT_SUPPORTED on corpse disabled. |
| 504 | * KERN_RESOURCE_SHORTAGE on memory alloc failure or reaching max corpse. |
| 505 | */ |
| 506 | kern_return_t |
| 507 | task_generate_corpse_internal( |
| 508 | task_t task, |
| 509 | task_t *corpse_task, |
| 510 | thread_t *exc_thread, |
| 511 | exception_type_t etype, |
| 512 | mach_exception_data_type_t code, |
| 513 | mach_exception_data_type_t subcode, |
| 514 | void *reason) |
| 515 | { |
| 516 | task_t new_task = TASK_NULL; |
| 517 | thread_t thread = THREAD_NULL; |
| 518 | thread_t thread_next = THREAD_NULL; |
| 519 | kern_return_t kr; |
| 520 | struct proc *p = NULL; |
| 521 | int is_64bit_addr; |
| 522 | int is_64bit_data; |
| 523 | int t_flags; |
| 524 | uint64_t *udata_buffer = NULL; |
| 525 | int size = 0; |
| 526 | int num_udata = 0; |
| 527 | uint16_t kc_u_flags = CORPSE_CRASHINFO_HAS_REF; |
| 528 | |
| 529 | #if CONFIG_MACF |
| 530 | struct label *label = NULL; |
| 531 | #endif |
| 532 | |
| 533 | if (!corpses_enabled()) { |
| 534 | return KERN_NOT_SUPPORTED; |
| 535 | } |
| 536 | |
| 537 | if (etype == EXC_GUARD && EXC_GUARD_DECODE_GUARD_TYPE(code) == GUARD_TYPE_USER) { |
| 538 | kc_u_flags |= CORPSE_CRASHINFO_USER_FAULT; |
| 539 | } |
| 540 | |
| 541 | kr = task_crashinfo_get_ref(kc_u_flags); |
| 542 | if (kr != KERN_SUCCESS) { |
| 543 | return kr; |
| 544 | } |
| 545 | |
| 546 | /* Having a task reference does not guarantee a proc reference */ |
| 547 | p = proc_find(task_pid(task)); |
| 548 | if (p == NULL) { |
| 549 | kr = KERN_INVALID_TASK; |
| 550 | goto error_task_generate_corpse; |
| 551 | } |
| 552 | |
| 553 | is_64bit_addr = IS_64BIT_PROCESS(p); |
| 554 | is_64bit_data = (task == TASK_NULL) ? is_64bit_addr : task_get_64bit_data(task); |
| 555 | t_flags = TF_CORPSE_FORK | |
| 556 | TF_PENDING_CORPSE | |
| 557 | TF_CORPSE | |
| 558 | (is_64bit_addr ? TF_64B_ADDR : TF_NONE) | |
| 559 | (is_64bit_data ? TF_64B_DATA : TF_NONE); |
| 560 | |
| 561 | #if CONFIG_MACF |
| 562 | /* Create the corpse label credentials from the process. */ |
| 563 | label = mac_exc_create_label_for_proc(p); |
| 564 | #endif |
| 565 | |
| 566 | /* Create a task for corpse */ |
| 567 | kr = task_create_internal(task, |
| 568 | NULL, |
| 569 | TRUE, |
| 570 | is_64bit_addr, |
| 571 | is_64bit_data, |
| 572 | t_flags, |
| 573 | TPF_NONE, |
| 574 | &new_task); |
| 575 | if (kr != KERN_SUCCESS) { |
| 576 | goto error_task_generate_corpse; |
| 577 | } |
| 578 | |
| 579 | /* Create and copy threads from task, returns a ref to thread */ |
| 580 | kr = task_duplicate_map_and_threads(task, p, new_task, &thread, |
| 581 | &udata_buffer, &size, &num_udata); |
| 582 | if (kr != KERN_SUCCESS) { |
| 583 | goto error_task_generate_corpse; |
| 584 | } |
| 585 | |
| 586 | kr = task_collect_crash_info(new_task, |
| 587 | #if CONFIG_MACF |
| 588 | label, |
| 589 | #endif |
| 590 | TRUE); |
| 591 | if (kr != KERN_SUCCESS) { |
| 592 | goto error_task_generate_corpse; |
| 593 | } |
| 594 | |
| 595 | /* transfer our references to the corpse info */ |
| 596 | assert(new_task->corpse_info->kcd_user_flags == 0); |
| 597 | new_task->corpse_info->kcd_user_flags = kc_u_flags; |
| 598 | kc_u_flags = 0; |
| 599 | |
| 600 | kr = task_start_halt(new_task); |
| 601 | if (kr != KERN_SUCCESS) { |
| 602 | goto error_task_generate_corpse; |
| 603 | } |
| 604 | |
| 605 | /* terminate the ipc space */ |
| 606 | ipc_space_terminate(new_task->itk_space); |
| 607 | |
| 608 | /* Populate the corpse blob, use the proc struct of task instead of corpse task */ |
| 609 | gather_populate_corpse_crashinfo(p, new_task, |
| 610 | code, subcode, udata_buffer, num_udata, reason); |
| 611 | |
| 612 | /* Add it to global corpse task list */ |
| 613 | task_add_to_corpse_task_list(new_task); |
| 614 | |
| 615 | *corpse_task = new_task; |
| 616 | *exc_thread = thread; |
| 617 | |
| 618 | error_task_generate_corpse: |
| 619 | #if CONFIG_MACF |
| 620 | if (label) { |
| 621 | mac_exc_free_label(label); |
| 622 | } |
| 623 | #endif |
| 624 | |
| 625 | /* Release the proc reference */ |
| 626 | if (p != NULL) { |
| 627 | proc_rele(p); |
| 628 | } |
| 629 | |
| 630 | if (kr != KERN_SUCCESS) { |
| 631 | if (thread != THREAD_NULL) { |
| 632 | thread_deallocate(thread); |
| 633 | } |
| 634 | if (new_task != TASK_NULL) { |
| 635 | task_lock(new_task); |
| 636 | /* Terminate all the other threads in the task. */ |
| 637 | queue_iterate(&new_task->threads, thread_next, thread_t, task_threads) |
| 638 | { |
| 639 | thread_terminate_internal(thread_next); |
| 640 | } |
| 641 | /* wait for all the threads in the task to terminate */ |
| 642 | task_wait_till_threads_terminate_locked(new_task); |
| 643 | task_unlock(new_task); |
| 644 | |
| 645 | task_clear_corpse(new_task); |
| 646 | task_terminate_internal(new_task); |
| 647 | task_deallocate(new_task); |
| 648 | } |
| 649 | if (kc_u_flags) { |
| 650 | task_crashinfo_release_ref(kc_u_flags); |
| 651 | } |
| 652 | } |
| 653 | /* Free the udata buffer allocated in task_duplicate_map_and_threads */ |
| 654 | if (udata_buffer != NULL) { |
| 655 | kfree(udata_buffer, size); |
| 656 | } |
| 657 | |
| 658 | return kr; |
| 659 | } |
| 660 | |
| 661 | /* |
| 662 | * Routine: task_map_corpse_info |
| 663 | * params: task - Map the corpse info in task's address space |
| 664 | * corpse_task - task port of the corpse |
| 665 | * kcd_addr_begin - address of the mapped corpse info |
| 666 | * kcd_addr_begin - size of the mapped corpse info |
| 667 | * returns: KERN_SUCCESS on Success. |
| 668 | * KERN_FAILURE on Failure. |
| 669 | * KERN_INVALID_ARGUMENT on invalid arguments. |
| 670 | * Note: Temporary function, will be deleted soon. |
| 671 | */ |
| 672 | kern_return_t |
| 673 | task_map_corpse_info( |
| 674 | task_t task, |
| 675 | task_t corpse_task, |
| 676 | vm_address_t *kcd_addr_begin, |
| 677 | uint32_t *kcd_size) |
| 678 | { |
| 679 | kern_return_t kr; |
| 680 | mach_vm_address_t kcd_addr_begin_64; |
| 681 | mach_vm_size_t size_64; |
| 682 | |
| 683 | kr = task_map_corpse_info_64(task, corpse_task, &kcd_addr_begin_64, &size_64); |
| 684 | if (kr != KERN_SUCCESS) { |
| 685 | return kr; |
| 686 | } |
| 687 | |
| 688 | *kcd_addr_begin = (vm_address_t)kcd_addr_begin_64; |
| 689 | *kcd_size = (uint32_t) size_64; |
| 690 | return KERN_SUCCESS; |
| 691 | } |
| 692 | |
| 693 | /* |
| 694 | * Routine: task_map_corpse_info_64 |
| 695 | * params: task - Map the corpse info in task's address space |
| 696 | * corpse_task - task port of the corpse |
| 697 | * kcd_addr_begin - address of the mapped corpse info (takes mach_vm_addess_t *) |
| 698 | * kcd_addr_begin - size of the mapped corpse info (takes mach_vm_size_t *) |
| 699 | * returns: KERN_SUCCESS on Success. |
| 700 | * KERN_FAILURE on Failure. |
| 701 | * KERN_INVALID_ARGUMENT on invalid arguments. |
| 702 | */ |
| 703 | kern_return_t |
| 704 | task_map_corpse_info_64( |
| 705 | task_t task, |
| 706 | task_t corpse_task, |
| 707 | mach_vm_address_t *kcd_addr_begin, |
| 708 | mach_vm_size_t *kcd_size) |
| 709 | { |
| 710 | kern_return_t kr; |
| 711 | mach_vm_offset_t crash_data_ptr = 0; |
| 712 | mach_vm_size_t size = CORPSEINFO_ALLOCATION_SIZE; |
| 713 | void *corpse_info_kernel = NULL; |
| 714 | |
| 715 | if (task == TASK_NULL || task_is_a_corpse_fork(task)) { |
| 716 | return KERN_INVALID_ARGUMENT; |
| 717 | } |
| 718 | |
| 719 | if (corpse_task == TASK_NULL || !task_is_a_corpse(corpse_task) || |
| 720 | kcdata_memory_get_begin_addr(corpse_task->corpse_info) == NULL) { |
| 721 | return KERN_INVALID_ARGUMENT; |
| 722 | } |
| 723 | corpse_info_kernel = kcdata_memory_get_begin_addr(corpse_task->corpse_info); |
| 724 | kr = mach_vm_allocate_kernel(task->map, &crash_data_ptr, size, |
| 725 | VM_FLAGS_ANYWHERE, VM_MEMORY_CORPSEINFO); |
| 726 | if (kr != KERN_SUCCESS) { |
| 727 | return kr; |
| 728 | } |
| 729 | copyout(corpse_info_kernel, crash_data_ptr, size); |
| 730 | *kcd_addr_begin = crash_data_ptr; |
| 731 | *kcd_size = size; |
| 732 | |
| 733 | return KERN_SUCCESS; |
| 734 | } |
| 735 | |
| 736 | uint64_t |
| 737 | task_corpse_get_crashed_thread_id(task_t corpse_task) |
| 738 | { |
| 739 | return corpse_task->crashed_thread_id; |
| 740 | } |
| 741 | |