1 /*
2 * Copyright (c) 2000-2025 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 /* Copyright (c) 1991 NeXT Computer, Inc. All rights reserved.
29 *
30 * File: bsd/kern/kern_core.c
31 *
32 * This file contains machine independent code for performing core dumps.
33 *
34 */
35 #if CONFIG_COREDUMP || CONFIG_UCOREDUMP
36
37 #include <mach/vm_param.h>
38 #include <mach/thread_status.h>
39 #include <sys/content_protection.h>
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/signalvar.h>
43 #include <sys/resourcevar.h>
44 #include <sys/namei.h>
45 #include <sys/vnode_internal.h>
46 #include <sys/proc_internal.h>
47 #include <sys/kauth.h>
48 #include <sys/timeb.h>
49 #include <sys/times.h>
50 #include <sys/acct.h>
51 #include <sys/file_internal.h>
52 #include <sys/uio.h>
53 #include <sys/kernel.h>
54 #include <sys/stat.h>
55
56 #include <mach-o/loader.h>
57 #include <mach/vm_region.h>
58 #include <mach/vm_statistics.h>
59
60 #include <IOKit/IOBSD.h>
61
62 #include <vm/vm_kern_xnu.h>
63 #include <vm/vm_protos.h> /* last */
64 #include <vm/vm_map_xnu.h> /* current_map() */
65 #include <vm/pmap.h> /* pmap_user_va_bits() */
66 #include <mach/mach_vm.h> /* mach_vm_region_recurse() */
67 #include <mach/task.h> /* task_suspend() */
68 #include <kern/task.h> /* get_task_numacts() */
69
70 #include <security/audit/audit.h>
71
72 #if CONFIG_MACF
73 #include <security/mac_framework.h>
74 #endif /* CONFIG_MACF */
75
76 #if HAS_MTE
77 #include <arm64/mte_xnu.h>
78 #endif /* HAS_MTE */
79
80 #include <kdp/core_notes.h>
81
82 extern int freespace_mb(vnode_t vp);
83
84 /* XXX not in a Mach header anywhere */
85 kern_return_t thread_getstatus(thread_t act, int flavor,
86 thread_state_t tstate, mach_msg_type_number_t *count);
87 void task_act_iterate_wth_args(task_t, void (*)(thread_t, void *), void *);
88
89 #ifdef SECURE_KERNEL
90 __XNU_PRIVATE_EXTERN int do_coredump = 0; /* default: don't dump cores */
91 #else
92 __XNU_PRIVATE_EXTERN int do_coredump = 1; /* default: dump cores */
93 #endif /* SECURE_KERNEL */
94 __XNU_PRIVATE_EXTERN int sugid_coredump = 0; /* default: but not SGUID binaries */
95
96 #if CONFIG_UCOREDUMP
97 __XNU_PRIVATE_EXTERN int do_ucoredump = 0; /* default: kernel does dumps */
98 #endif
99
100 /*
101 * is_coredump_eligible
102 *
103 * Determine if a core should even be dumped at all (by any mechanism)
104 *
105 * Does NOT include disk permission or space constraints
106 *
107 * core_proc Process to dump core [*] must be current proc!
108 *
109 * Return: 0 Success
110 * !0 Failure errno
111 */
112 int
is_coredump_eligible(proc_t core_proc)113 is_coredump_eligible(proc_t core_proc)
114 {
115 if (current_proc() != core_proc && (
116 core_proc->p_exit_reason &&
117 core_proc->p_exit_reason->osr_namespace == OS_REASON_JETSAM)) {
118 return EPERM;
119 }
120 if (current_proc() != core_proc) {
121 panic("coredump for proc that is not current: %p)", core_proc);
122 }
123
124 vfs_context_t ctx = vfs_context_current();
125 kauth_cred_t cred = vfs_context_ucred(ctx);
126
127 if (do_coredump == 0 || /* Not dumping at all */
128 ((sugid_coredump == 0) && /* Not dumping SUID/SGID binaries */
129 ((kauth_cred_getsvuid(cred) != kauth_cred_getruid(cred)) ||
130 (kauth_cred_getsvgid(cred) != kauth_cred_getrgid(cred))))) {
131 return EPERM;
132 }
133
134 #if CONFIG_MACF
135 const int error = mac_proc_check_dump_core(core_proc);
136 if (error != 0) {
137 return error;
138 }
139 #endif
140 return 0;
141 }
142
143 #else /* CONFIG_COREDUMP || CONFIG_UCOREDUMP */
144
145 /* When core dumps aren't needed, no need to compile this file at all */
146
147 #error assertion failed: this section is not compiled
148
149 #endif /* CONFIG_COREDUMP || CONFIG_UCOREDUMP */
150
151 #if CONFIG_COREDUMP
152
153 #define COREDUMP_CUSTOM_LOCATION_ENTITLEMENT "com.apple.private.custom-coredump-location"
154
155 typedef struct {
156 int flavor; /* the number for this flavor */
157 mach_msg_type_number_t count; /* count of ints in this flavor */
158 } mythread_state_flavor_t;
159
160 #if defined (__i386__) || defined (__x86_64__)
161 mythread_state_flavor_t thread_flavor_array[] = {
162 {x86_THREAD_STATE, x86_THREAD_STATE_COUNT},
163 {x86_FLOAT_STATE, x86_FLOAT_STATE_COUNT},
164 {x86_EXCEPTION_STATE, x86_EXCEPTION_STATE_COUNT},
165 };
166 int mynum_flavors = 3;
167 #elif defined (__arm64__)
168 mythread_state_flavor_t thread_flavor_array[] = {
169 {ARM_THREAD_STATE64, ARM_THREAD_STATE64_COUNT},
170 /* ARM64_TODO: VFP */
171 {ARM_EXCEPTION_STATE64, ARM_EXCEPTION_STATE64_COUNT}
172 };
173 int mynum_flavors = 2;
174 #else
175 #error architecture not supported
176 #endif
177
178
179 typedef struct {
180 vm_offset_t header;
181 size_t hoffset;
182 mythread_state_flavor_t *flavors;
183 size_t tstate_size;
184 size_t flavor_count;
185 } tir_t;
186
187 /* cpu_type returns only the most generic indication of the current CPU. */
188 /* in a core we want to know the kind of process. */
189
190 cpu_type_t
process_cpu_type(proc_t core_proc)191 process_cpu_type(proc_t core_proc)
192 {
193 cpu_type_t what_we_think;
194 #if defined (__i386__) || defined (__x86_64__)
195 if (IS_64BIT_PROCESS(core_proc)) {
196 what_we_think = CPU_TYPE_X86_64;
197 } else {
198 what_we_think = CPU_TYPE_I386;
199 }
200 #elif defined(__arm64__)
201 if (IS_64BIT_PROCESS(core_proc)) {
202 what_we_think = CPU_TYPE_ARM64;
203 } else {
204 what_we_think = CPU_TYPE_ARM;
205 }
206 #endif
207
208 return what_we_think;
209 }
210
211 cpu_type_t
process_cpu_subtype(proc_t core_proc)212 process_cpu_subtype(proc_t core_proc)
213 {
214 cpu_type_t what_we_think;
215 #if defined (__i386__) || defined (__x86_64__)
216 if (IS_64BIT_PROCESS(core_proc)) {
217 what_we_think = CPU_SUBTYPE_X86_64_ALL;
218 } else {
219 what_we_think = CPU_SUBTYPE_I386_ALL;
220 }
221 #elif defined(__arm64__)
222 if (IS_64BIT_PROCESS(core_proc)) {
223 what_we_think = CPU_SUBTYPE_ARM64_ALL;
224 } else {
225 what_we_think = CPU_SUBTYPE_ARM_ALL;
226 }
227 #endif
228 return what_we_think;
229 }
230
231 static void
collectth_state(thread_t th_act,void * tirp)232 collectth_state(thread_t th_act, void *tirp)
233 {
234 vm_offset_t header;
235 size_t hoffset, i;
236 mythread_state_flavor_t *flavors;
237 struct thread_command *tc;
238 tir_t *t = (tir_t *)tirp;
239
240 /*
241 * Fill in thread command structure.
242 */
243 header = t->header;
244 hoffset = t->hoffset;
245 flavors = t->flavors;
246
247 tc = (struct thread_command *) (header + hoffset);
248 tc->cmd = LC_THREAD;
249 tc->cmdsize = (uint32_t)(sizeof(struct thread_command)
250 + t->tstate_size);
251 hoffset += sizeof(struct thread_command);
252 /*
253 * Follow with a struct thread_state_flavor and
254 * the appropriate thread state struct for each
255 * thread state flavor.
256 */
257 for (i = 0; i < t->flavor_count; i++) {
258 *(mythread_state_flavor_t *)(header + hoffset) =
259 flavors[i];
260 hoffset += sizeof(mythread_state_flavor_t);
261 thread_getstatus(th_act, flavors[i].flavor,
262 (thread_state_t)(header + hoffset),
263 &flavors[i].count);
264 hoffset += flavors[i].count * sizeof(int);
265 }
266
267 t->hoffset = hoffset;
268 }
269
270 #if DEVELOPMENT || DEBUG
271 #define COREDUMPLOG(fmt, args...) printf("coredump (%s, pid %d): " fmt "\n", core_proc->p_comm, proc_getpid(core_proc), ## args)
272 #else
273 #define COREDUMPLOG(fmt, args...)
274 #endif
275
276 /*
277 * LC_NOTE support for userspace coredumps.
278 */
279
280 typedef int (write_note_cb_t)(struct vnode *vp, off_t foffset);
281
282 static int
note_addrable_bits(struct vnode * vp,off_t foffset)283 note_addrable_bits(struct vnode *vp, off_t foffset)
284 {
285 task_t t = current_task();
286 vfs_context_t ctx = vfs_context_current();
287 kauth_cred_t cred = vfs_context_ucred(ctx);
288
289 addrable_bits_note_t note = {
290 .version = ADDRABLE_BITS_VER,
291 .addressing_bits = pmap_user_va_bits(get_task_pmap(t)),
292 .unused = 0
293 };
294
295 return vn_rdwr_64(UIO_WRITE, vp, (vm_offset_t)¬e, sizeof(note), foffset, UIO_SYSSPACE,
296 IO_NODELOCKED | IO_UNIT, cred, 0, current_proc());
297 }
298
299 /*
300 * note handling
301 */
302
303 struct core_note {
304 size_t cn_size;
305 const char *cn_owner;
306 write_note_cb_t *cn_write_cb;
307 } const core_notes[] = {
308 {
309 .cn_size = sizeof(addrable_bits_note_t),
310 .cn_owner = ADDRABLE_BITS_DATA_OWNER,
311 .cn_write_cb = note_addrable_bits,
312 }
313 };
314
315 const size_t notes_count = sizeof(core_notes) / sizeof(struct core_note);
316
317 /*
318 * LC_NOTE commands are allocated as a part of Mach-O header and are written to
319 * disk at the end of coredump. LC_NOTE's payload has to be written in callbacks here.
320 */
321 static int
dump_notes(proc_t __unused core_proc,vm_offset_t header,size_t hoffset,struct vnode * vp,off_t foffset)322 dump_notes(proc_t __unused core_proc, vm_offset_t header, size_t hoffset, struct vnode *vp, off_t foffset)
323 {
324 for (size_t i = 0; i < notes_count; i++) {
325 int error = 0;
326
327 if (core_notes[i].cn_write_cb == NULL) {
328 continue;
329 }
330
331 /* Generate LC_NOTE command. */
332 struct note_command *nc = (struct note_command *)(header + hoffset);
333
334 nc->cmd = LC_NOTE;
335 nc->cmdsize = sizeof(struct note_command);
336 nc->offset = foffset;
337 nc->size = core_notes[i].cn_size;
338 strlcpy(nc->data_owner, core_notes[i].cn_owner, sizeof(nc->data_owner));
339
340 hoffset += sizeof(struct note_command);
341
342 /* Add note's payload. */
343 error = core_notes[i].cn_write_cb(vp, foffset);
344 if (error != KERN_SUCCESS) {
345 COREDUMPLOG("failed to write LC_NOTE %s: error %d", core_notes[i].cn_owner, error);
346 return error;
347 }
348
349 foffset += core_notes[i].cn_size;
350 }
351
352 return 0;
353 }
354
355 /*
356 * coredump
357 *
358 * Description: Create a core image on the file "core" for the process
359 * indicated
360 *
361 * Parameters: core_proc Process to dump core [*]
362 * reserve_mb If non-zero, leave filesystem with
363 * at least this much free space.
364 * coredump_flags Extra options (ignore rlimit, run fsync)
365 *
366 * Returns: 0 Success
367 * !0 Failure errno
368 *
369 * IMPORTANT: This function can only be called on the current process, due
370 * to assumptions below; see variable declaration section for
371 * details.
372 */
373 #define MAX_TSTATE_FLAVORS 10
374 int
coredump(proc_t core_proc,uint32_t reserve_mb,int coredump_flags)375 coredump(proc_t core_proc, uint32_t reserve_mb, int coredump_flags)
376 {
377 /* Begin assumptions that limit us to only the current process */
378 vfs_context_t ctx = vfs_context_current();
379 vm_map_t map = current_map();
380 task_t task = current_task();
381 /* End assumptions */
382 kauth_cred_t cred = vfs_context_ucred(ctx);
383 int error = 0;
384 struct vnode_attr *vap = NULL;
385 size_t thread_count, segment_count;
386 size_t command_size, header_size, tstate_size;
387 size_t hoffset;
388 off_t foffset;
389 mach_vm_offset_t vmoffset;
390 vm_offset_t header;
391 mach_vm_size_t vmsize;
392 vm_prot_t prot;
393 vm_prot_t maxprot;
394 int error1 = 0;
395 char stack_name[MAXCOMLEN + 6];
396 char *alloced_name = NULL;
397 char *name = NULL;
398 mythread_state_flavor_t flavors[MAX_TSTATE_FLAVORS];
399 vm_size_t mapsize;
400 size_t i;
401 uint32_t nesting_depth = 0;
402 kern_return_t kret;
403 struct vm_region_submap_info_64 vbr;
404 mach_msg_type_number_t vbrcount = 0;
405 tir_t tir1;
406 struct vnode * vp;
407 struct mach_header *mh = NULL; /* protected by is_64 */
408 struct mach_header_64 *mh64 = NULL; /* protected by is_64 */
409 int is_64 = 0;
410 size_t mach_header_sz = sizeof(struct mach_header);
411 size_t segment_command_sz = sizeof(struct segment_command);
412 size_t notes_size = 0;
413 const char *format = NULL;
414 char *custom_location_entitlement = NULL;
415 size_t custom_location_entitlement_len = 0;
416 char *alloced_format = NULL;
417 size_t alloced_format_len = 0;
418 bool include_iokit_memory = task_is_driver(task);
419 bool coredump_attempted = false;
420
421 if ((error = is_coredump_eligible(core_proc)) != 0) {
422 goto out2;
423 }
424
425 if (IS_64BIT_PROCESS(core_proc)) {
426 is_64 = 1;
427 mach_header_sz = sizeof(struct mach_header_64);
428 segment_command_sz = sizeof(struct segment_command_64);
429 }
430
431 mapsize = get_vmmap_size(map);
432
433 custom_location_entitlement = IOCurrentTaskGetEntitlement(COREDUMP_CUSTOM_LOCATION_ENTITLEMENT);
434 if (custom_location_entitlement != NULL) {
435 custom_location_entitlement_len = strlen(custom_location_entitlement);
436 const char * dirname;
437 if (proc_is_driver(core_proc)) {
438 dirname = defaultdrivercorefiledir;
439 } else {
440 dirname = defaultcorefiledir;
441 }
442 size_t dirname_len = strlen(dirname);
443 size_t printed_len;
444
445 /* new format is dirname + "/" + string from entitlement */
446 alloced_format_len = dirname_len + 1 + custom_location_entitlement_len;
447 alloced_format = kalloc_data(alloced_format_len + 1, Z_ZERO | Z_WAITOK | Z_NOFAIL);
448 printed_len = snprintf(alloced_format, alloced_format_len + 1, "%s/%s", dirname, custom_location_entitlement);
449 assert(printed_len == alloced_format_len);
450
451 format = alloced_format;
452 } else {
453 if (proc_is_driver(core_proc)) {
454 format = drivercorefilename;
455 } else {
456 format = corefilename;
457 }
458 }
459
460 if (((coredump_flags & COREDUMP_IGNORE_ULIMIT) == 0) &&
461 (mapsize >= proc_limitgetcur(core_proc, RLIMIT_CORE))) {
462 error = EFAULT;
463 goto out2;
464 }
465
466 /* log coredump failures from here */
467 coredump_attempted = true;
468
469 (void) task_suspend_internal(task);
470
471 #if HAS_MTE
472 /*
473 * At this point we have suspended all proc threads, so we are
474 * safe disabling tag checking for an MTE enabled process.
475 * This will be necessary later when we loop through the process
476 * memory segment and copy them in, as we would inevitably generate
477 * a tag check fault.
478 */
479
480 /*
481 * Do not disable tag checking and take the "faulty" path if high watermaks
482 * cores are enabled. We want a better fix here, but for the time being
483 * that's a debugging feature that can run under -disable_mte.
484 */
485 extern int hwm_user_cores;
486
487 if (task_has_sec(task) && hwm_user_cores == 0) {
488 mte_disable_user_checking(task);
489 }
490 #endif /* HAS_MTE */
491
492 alloced_name = zalloc_flags(ZV_NAMEI, Z_NOWAIT | Z_ZERO);
493
494 /* create name according to sysctl'able format string */
495 /* if name creation fails, fall back to historical behaviour... */
496 if (alloced_name == NULL ||
497 proc_core_name(format, core_proc->p_comm, kauth_cred_getuid(cred),
498 proc_getpid(core_proc), alloced_name, MAXPATHLEN)) {
499 snprintf(stack_name, sizeof(stack_name),
500 "/cores/core.%d", proc_getpid(core_proc));
501 name = stack_name;
502 } else {
503 name = alloced_name;
504 }
505
506 COREDUMPLOG("writing core to %s", name);
507 if ((error = vnode_open(name, (O_CREAT | FWRITE | O_NOFOLLOW), S_IRUSR, VNODE_LOOKUP_NOFOLLOW, &vp, ctx))) {
508 COREDUMPLOG("failed to open core dump file %s: error %d", name, error);
509 goto out2;
510 }
511
512 vap = kalloc_type(struct vnode_attr, Z_WAITOK | Z_ZERO);
513 VATTR_INIT(vap);
514 VATTR_WANTED(vap, va_nlink);
515 /* Don't dump to non-regular files or files with links. */
516 if (vp->v_type != VREG ||
517 vnode_getattr(vp, vap, ctx) || vap->va_nlink != 1) {
518 COREDUMPLOG("failed to write core to non-regular file");
519 error = EFAULT;
520 goto out;
521 }
522
523 VATTR_INIT(vap); /* better to do it here than waste more stack in vnode_setsize */
524 VATTR_SET(vap, va_data_size, 0);
525 if (core_proc == initproc) {
526 VATTR_SET(vap, va_dataprotect_class, PROTECTION_CLASS_D);
527 }
528 vnode_setattr(vp, vap, ctx);
529 core_proc->p_acflag |= ACORE;
530
531 COREDUMPLOG("map size: %lu", mapsize);
532 if ((reserve_mb > 0) &&
533 ((freespace_mb(vp) - (mapsize >> 20)) < reserve_mb)) {
534 COREDUMPLOG("insufficient free space (free=%d MB, needed=%lu MB, reserve=%d MB)", freespace_mb(vp), (mapsize >> 20), reserve_mb);
535 error = ENOSPC;
536 goto out;
537 }
538
539 /*
540 * If the task is modified while dumping the file
541 * (e.g., changes in threads or VM, the resulting
542 * file will not necessarily be correct.
543 */
544
545 thread_count = get_task_numacts(task);
546 segment_count = get_vmmap_entries(map); /* XXX */
547 tir1.flavor_count = sizeof(thread_flavor_array) / sizeof(mythread_state_flavor_t);
548 bcopy(thread_flavor_array, flavors, sizeof(thread_flavor_array));
549 tstate_size = 0;
550 for (i = 0; i < tir1.flavor_count; i++) {
551 tstate_size += sizeof(mythread_state_flavor_t) +
552 (flavors[i].count * sizeof(int));
553 }
554
555 {
556 size_t lhs;
557 size_t rhs;
558
559 /* lhs = segment_count * segment_command_sz */
560 if (os_mul_overflow(segment_count, segment_command_sz, &lhs)) {
561 COREDUMPLOG("error: segment size overflow: segment_count=%lu, segment_command_sz=%lu", segment_count, segment_command_sz);
562 error = ENOMEM;
563 goto out;
564 }
565
566 /* rhs = (tstate_size + sizeof(struct thread_command)) * thread_count */
567 if (os_add_and_mul_overflow(tstate_size, sizeof(struct thread_command), thread_count, &rhs)) {
568 COREDUMPLOG("error: thread state size overflow: tstate_size=%lu, thread_count=%lu", tstate_size, thread_count);
569 error = ENOMEM;
570 goto out;
571 }
572
573 /* command_size = lhs + rhs */
574 if (os_add_overflow(lhs, rhs, &command_size)) {
575 COREDUMPLOG("error: command size overflow: lhs=%lu, rhs=%lu", lhs, rhs);
576 error = ENOMEM;
577 goto out;
578 }
579
580 /* Add notes payload. */
581 if (os_mul_overflow(notes_count, sizeof(struct note_command), ¬es_size)) {
582 COREDUMPLOG("error: note command size overflow: note=%lu", i);
583 error = ENOMEM;
584 goto out;
585 }
586
587 if (os_add_overflow(command_size, notes_size, &command_size)) {
588 COREDUMPLOG("error: notes overflow: notes_size=%lu", notes_size);
589 error = ENOMEM;
590 goto out;
591 }
592 }
593
594 if (os_add_overflow(command_size, mach_header_sz, &header_size)) {
595 COREDUMPLOG("error: header size overflow: command_size=%lu, mach_header_sz=%lu", command_size, mach_header_sz);
596 error = ENOMEM;
597 goto out;
598 }
599
600 if (kmem_alloc(kernel_map, &header, (vm_size_t)header_size,
601 KMA_DATA | KMA_ZERO, VM_KERN_MEMORY_DIAG) != KERN_SUCCESS) {
602 COREDUMPLOG("error: failed to allocate memory for header (size=%lu)", header_size);
603 error = ENOMEM;
604 goto out;
605 }
606
607 /*
608 * Set up Mach-O header.
609 */
610 if (is_64) {
611 mh64 = (struct mach_header_64 *)header;
612 mh64->magic = MH_MAGIC_64;
613 mh64->cputype = process_cpu_type(core_proc);
614 mh64->cpusubtype = process_cpu_subtype(core_proc);
615 mh64->filetype = MH_CORE;
616 mh64->ncmds = (uint32_t)(segment_count + notes_count + thread_count);
617 mh64->sizeofcmds = (uint32_t)command_size;
618 } else {
619 mh = (struct mach_header *)header;
620 mh->magic = MH_MAGIC;
621 mh->cputype = process_cpu_type(core_proc);
622 mh->cpusubtype = process_cpu_subtype(core_proc);
623 mh->filetype = MH_CORE;
624 mh->ncmds = (uint32_t)(segment_count + notes_count + thread_count);
625 mh->sizeofcmds = (uint32_t)command_size;
626 }
627
628 hoffset = mach_header_sz; /* offset into header */
629 foffset = round_page(header_size); /* offset into file */
630 vmoffset = MACH_VM_MIN_ADDRESS; /* offset into VM */
631 COREDUMPLOG("mach header size: %zu", header_size);
632
633 /*
634 * We use to check for an error, here, now we try and get
635 * as much as we can
636 */
637 COREDUMPLOG("dumping %zu segments", segment_count);
638 while (segment_count > 0) {
639 struct segment_command *sc;
640 struct segment_command_64 *sc64;
641
642 /*
643 * Get region information for next region.
644 */
645
646 while (1) {
647 vbrcount = VM_REGION_SUBMAP_INFO_COUNT_64;
648 if ((kret = mach_vm_region_recurse(map,
649 &vmoffset, &vmsize, &nesting_depth,
650 (vm_region_recurse_info_t)&vbr,
651 &vbrcount)) != KERN_SUCCESS) {
652 break;
653 }
654 /*
655 * If we get a valid mapping back, but we're dumping
656 * a 32 bit process, and it's over the allowable
657 * address space of a 32 bit process, it's the same
658 * as if mach_vm_region_recurse() failed.
659 */
660 if (!(is_64) &&
661 (vmoffset + vmsize > VM_MAX_ADDRESS)) {
662 kret = KERN_INVALID_ADDRESS;
663 COREDUMPLOG("exceeded allowable region for 32-bit process");
664 break;
665 }
666 if (vbr.is_submap) {
667 nesting_depth++;
668 continue;
669 } else {
670 break;
671 }
672 }
673 if (kret != KERN_SUCCESS) {
674 COREDUMPLOG("ending segment dump, kret=%d", kret);
675 break;
676 }
677
678 prot = vbr.protection;
679 maxprot = vbr.max_protection;
680
681 if ((prot | maxprot) == VM_PROT_NONE) {
682 /*
683 * Elide unreadable (likely reserved) segments
684 */
685 COREDUMPLOG("eliding unreadable segment %llx->%llx", vmoffset, vmoffset + vmsize);
686 vmoffset += vmsize;
687 continue;
688 }
689
690 /*
691 * Try as hard as possible to get read access to the data.
692 */
693 if ((prot & VM_PROT_READ) == 0) {
694 mach_vm_protect(map, vmoffset, vmsize, FALSE,
695 prot | VM_PROT_READ);
696 }
697
698 /*
699 * But only try and perform the write if we can read it.
700 */
701 int64_t fsize = ((maxprot & VM_PROT_READ) == VM_PROT_READ
702 && (include_iokit_memory || vbr.user_tag != VM_MEMORY_IOKIT)
703 && coredumpok(map, vmoffset)) ? vmsize : 0;
704
705 if (fsize) {
706 int64_t resid = 0;
707 const enum uio_seg sflg = IS_64BIT_PROCESS(core_proc) ?
708 UIO_USERSPACE64 : UIO_USERSPACE32;
709
710 error = vn_rdwr_64(UIO_WRITE, vp, vmoffset, fsize,
711 foffset, sflg, IO_NODELOCKED | IO_UNIT,
712 cred, &resid, core_proc);
713
714 if (error) {
715 /*
716 * Mark segment as empty
717 */
718 fsize = 0;
719 COREDUMPLOG("failed to write segment %llx->%llx: error %d", vmoffset, vmoffset + vmsize, error);
720 } else if (resid) {
721 /*
722 * Partial write. Extend the file size so
723 * that the segment command contains a valid
724 * range of offsets, possibly creating a hole.
725 */
726 VATTR_INIT(vap);
727 VATTR_SET(vap, va_data_size, foffset + fsize);
728 vnode_setattr(vp, vap, ctx);
729 COREDUMPLOG("partially wrote segment %llx->%llx, resid %lld", vmoffset, vmoffset + vmsize, resid);
730 }
731 } else {
732 COREDUMPLOG("skipping unreadable segment %llx->%llx", vmoffset, vmoffset + vmsize);
733 }
734
735 /*
736 * Fill in segment command structure.
737 */
738
739 if (is_64) {
740 sc64 = (struct segment_command_64 *)(header + hoffset);
741 sc64->cmd = LC_SEGMENT_64;
742 sc64->cmdsize = sizeof(struct segment_command_64);
743 /* segment name is zeroed by kmem_alloc */
744 sc64->segname[0] = 0;
745 sc64->vmaddr = vmoffset;
746 sc64->vmsize = vmsize;
747 sc64->fileoff = foffset;
748 sc64->filesize = fsize;
749 sc64->maxprot = maxprot;
750 sc64->initprot = prot;
751 sc64->nsects = 0;
752 sc64->flags = 0;
753 } else {
754 sc = (struct segment_command *) (header + hoffset);
755 sc->cmd = LC_SEGMENT;
756 sc->cmdsize = sizeof(struct segment_command);
757 /* segment name is zeroed by kmem_alloc */
758 sc->segname[0] = 0;
759 sc->vmaddr = CAST_DOWN_EXPLICIT(uint32_t, vmoffset);
760 sc->vmsize = CAST_DOWN_EXPLICIT(uint32_t, vmsize);
761 sc->fileoff = CAST_DOWN_EXPLICIT(uint32_t, foffset); /* will never truncate */
762 sc->filesize = CAST_DOWN_EXPLICIT(uint32_t, fsize); /* will never truncate */
763 sc->maxprot = maxprot;
764 sc->initprot = prot;
765 sc->nsects = 0;
766 sc->flags = 0;
767 }
768
769 hoffset += segment_command_sz;
770 foffset += fsize;
771 vmoffset += vmsize;
772 segment_count--;
773 }
774 COREDUMPLOG("max file offset: %lld", foffset);
775
776 /*
777 * If there are remaining segments which have not been written
778 * out because break in the loop above, then they were not counted
779 * because they exceed the real address space of the executable
780 * type: remove them from the header's count. This is OK, since
781 * we are allowed to have a sparse area following the segments.
782 */
783 if (is_64) {
784 mh64->ncmds -= segment_count;
785 mh64->sizeofcmds -= segment_count * segment_command_sz;
786 } else {
787 mh->ncmds -= segment_count;
788 mh->sizeofcmds -= segment_count * segment_command_sz;
789 }
790
791 /* Add LC_NOTES */
792 COREDUMPLOG("dumping %zu notes", notes_count);
793 if (dump_notes(core_proc, header, hoffset, vp, foffset) != 0) {
794 error = EFAULT;
795 goto out;
796 }
797
798 tir1.header = header;
799 tir1.hoffset = hoffset + notes_size;
800 tir1.flavors = flavors;
801 tir1.tstate_size = tstate_size;
802 COREDUMPLOG("dumping %zu threads", thread_count);
803 task_act_iterate_wth_args(task, collectth_state, &tir1);
804
805 /*
806 * Write out the Mach header at the beginning of the
807 * file. OK to use a 32 bit write for this.
808 */
809 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)header, (int)MIN(header_size, INT_MAX), (off_t)0,
810 UIO_SYSSPACE, IO_NODELOCKED | IO_UNIT, cred, (int *) 0, core_proc);
811 if (error != KERN_SUCCESS) {
812 COREDUMPLOG("failed to write mach header: error %d", error);
813 }
814 kmem_free(kernel_map, header, header_size);
815
816 if ((coredump_flags & COREDUMP_FULLFSYNC) && error == 0) {
817 error = VNOP_IOCTL(vp, F_FULLFSYNC, (caddr_t)NULL, 0, ctx);
818 if (error != KERN_SUCCESS) {
819 COREDUMPLOG("failed to FULLFSYNC core: error %d", error);
820 }
821 }
822 out:
823 if (vap) {
824 kfree_type(struct vnode_attr, vap);
825 }
826 error1 = vnode_close(vp, FWRITE, ctx);
827 if (error1 != KERN_SUCCESS) {
828 COREDUMPLOG("failed to close core file: error %d", error1);
829 }
830 out2:
831 #if CONFIG_AUDIT
832 audit_proc_coredump(core_proc, name, error);
833 #endif
834 if (alloced_name != NULL) {
835 zfree(ZV_NAMEI, alloced_name);
836 }
837 if (alloced_format != NULL) {
838 kfree_data(alloced_format, alloced_format_len + 1);
839 }
840 if (custom_location_entitlement != NULL) {
841 kfree_data(custom_location_entitlement, custom_location_entitlement_len + 1);
842 }
843 if (error == 0) {
844 error = error1;
845 }
846
847 if (coredump_attempted) {
848 if (error != 0) {
849 COREDUMPLOG("core dump failed: error %d\n", error);
850 } else {
851 COREDUMPLOG("core dump succeeded");
852 }
853 }
854
855 return error;
856 }
857
858 #endif /* CONFIG_COREDUMP */
859