1/* 2 * Copyright (c) 2000-2006 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 36#include <mach/vm_param.h> 37#include <mach/thread_status.h> 38 39#include <sys/param.h> 40#include <sys/systm.h> 41#include <sys/signalvar.h> 42#include <sys/resourcevar.h> 43#include <sys/namei.h> 44#include <sys/vnode_internal.h> 45#include <sys/proc_internal.h> 46#include <sys/kauth.h> 47#include <sys/timeb.h> 48#include <sys/times.h> 49#include <sys/acct.h> 50#include <sys/file_internal.h> 51#include <sys/uio.h> 52#include <sys/kernel.h> 53#include <sys/stat.h> 54 55#include <mach-o/loader.h> 56#include <mach/vm_region.h> 57#include <mach/vm_statistics.h> 58 59#include <vm/vm_kern.h> 60#include <vm/vm_protos.h> /* last */ 61#include <vm/vm_map.h> /* current_map() */ 62#include <mach/mach_vm.h> /* mach_vm_region_recurse() */ 63#include <mach/task.h> /* task_suspend() */ 64#include <kern/task.h> /* get_task_numacts() */ 65 66#include <security/audit/audit.h> 67 68typedef struct { 69 int flavor; /* the number for this flavor */ 70 mach_msg_type_number_t count; /* count of ints in this flavor */ 71} mythread_state_flavor_t; 72 73#if defined (__i386__) || defined (__x86_64__) 74mythread_state_flavor_t thread_flavor_array [] = { 75 {x86_THREAD_STATE, x86_THREAD_STATE_COUNT}, 76 {x86_FLOAT_STATE, x86_FLOAT_STATE_COUNT}, 77 {x86_EXCEPTION_STATE, x86_EXCEPTION_STATE_COUNT}, 78 }; 79int mynum_flavors=3; 80#else 81#error architecture not supported 82#endif 83 84 85typedef struct { 86 vm_offset_t header; 87 int hoffset; 88 mythread_state_flavor_t *flavors; 89 int tstate_size; 90 int flavor_count; 91} tir_t; 92 93/* XXX should be static */ 94void collectth_state(thread_t th_act, void *tirp); 95 96extern int freespace_mb(vnode_t vp); 97 98/* XXX not in a Mach header anywhere */ 99kern_return_t thread_getstatus(register thread_t act, int flavor, 100 thread_state_t tstate, mach_msg_type_number_t *count); 101void task_act_iterate_wth_args(task_t, void(*)(thread_t, void *), void *); 102extern kern_return_t task_suspend_internal(task_t); 103 104static cpu_type_t process_cpu_type(proc_t proc); 105static cpu_type_t process_cpu_subtype(proc_t proc); 106 107#ifdef SECURE_KERNEL 108__XNU_PRIVATE_EXTERN int do_coredump = 0; /* default: don't dump cores */ 109#else 110__XNU_PRIVATE_EXTERN int do_coredump = 1; /* default: dump cores */ 111#endif 112__XNU_PRIVATE_EXTERN int sugid_coredump = 0; /* default: but not SGUID binaries */ 113 114 115/* cpu_type returns only the most generic indication of the current CPU. */ 116/* in a core we want to know the kind of process. */ 117 118static cpu_type_t 119process_cpu_type(proc_t core_proc) 120{ 121 cpu_type_t what_we_think; 122#if defined (__i386__) || defined (__x86_64__) 123 if (IS_64BIT_PROCESS(core_proc)) { 124 what_we_think = CPU_TYPE_X86_64; 125 } else { 126 what_we_think = CPU_TYPE_I386; 127 } 128#endif 129 return what_we_think; 130} 131 132static cpu_type_t 133process_cpu_subtype(proc_t core_proc) 134{ 135 cpu_type_t what_we_think; 136#if defined (__i386__) || defined (__x86_64__) 137 if (IS_64BIT_PROCESS(core_proc)) { 138 what_we_think = CPU_SUBTYPE_X86_64_ALL; 139 } else { 140 what_we_think = CPU_SUBTYPE_I386_ALL; 141 } 142#endif 143 return what_we_think; 144} 145 146void 147collectth_state(thread_t th_act, void *tirp) 148{ 149 vm_offset_t header; 150 int hoffset, i ; 151 mythread_state_flavor_t *flavors; 152 struct thread_command *tc; 153 tir_t *t = (tir_t *)tirp; 154 155 /* 156 * Fill in thread command structure. 157 */ 158 header = t->header; 159 hoffset = t->hoffset; 160 flavors = t->flavors; 161 162 tc = (struct thread_command *) (header + hoffset); 163 tc->cmd = LC_THREAD; 164 tc->cmdsize = sizeof(struct thread_command) 165 + t->tstate_size; 166 hoffset += sizeof(struct thread_command); 167 /* 168 * Follow with a struct thread_state_flavor and 169 * the appropriate thread state struct for each 170 * thread state flavor. 171 */ 172 for (i = 0; i < t->flavor_count; i++) { 173 *(mythread_state_flavor_t *)(header+hoffset) = 174 flavors[i]; 175 hoffset += sizeof(mythread_state_flavor_t); 176 thread_getstatus(th_act, flavors[i].flavor, 177 (thread_state_t)(header+hoffset), 178 &flavors[i].count); 179 hoffset += flavors[i].count*sizeof(int); 180 } 181 182 t->hoffset = hoffset; 183} 184 185 186/* 187 * coredump 188 * 189 * Description: Create a core image on the file "core" for the process 190 * indicated 191 * 192 * Parameters: core_proc Process to dump core [*] 193 * reserve_mb If non-zero, leave filesystem with 194 * at least this much free space. 195 * ignore_ulimit If set, ignore the process's core file ulimit. 196 * 197 * Returns: 0 Success 198 * EFAULT Failed 199 * 200 * IMPORTANT: This function can only be called on the current process, due 201 * to assumptions below; see variable declaration section for 202 * details. 203 */ 204#define MAX_TSTATE_FLAVORS 10 205int 206coredump(proc_t core_proc, uint32_t reserve_mb, int ignore_ulimit) 207{ 208/* Begin assumptions that limit us to only the current process */ 209 vfs_context_t ctx = vfs_context_current(); 210 vm_map_t map = current_map(); 211 task_t task = current_task(); 212/* End assumptions */ 213 kauth_cred_t cred = vfs_context_ucred(ctx); 214 int error = 0; 215 struct vnode_attr va; 216 int thread_count, segment_count; 217 int command_size, header_size, tstate_size; 218 int hoffset; 219 off_t foffset; 220 mach_vm_offset_t vmoffset; 221 vm_offset_t header; 222 mach_vm_size_t vmsize; 223 vm_prot_t prot; 224 vm_prot_t maxprot; 225 vm_inherit_t inherit; 226 int error1 = 0; 227 char stack_name[MAXCOMLEN+6]; 228 char *alloced_name = NULL; 229 char *name; 230 mythread_state_flavor_t flavors[MAX_TSTATE_FLAVORS]; 231 vm_size_t mapsize; 232 int i; 233 uint32_t nesting_depth = 0; 234 kern_return_t kret; 235 struct vm_region_submap_info_64 vbr; 236 mach_msg_type_number_t vbrcount = 0; 237 tir_t tir1; 238 struct vnode * vp; 239 struct mach_header *mh = NULL; /* protected by is_64 */ 240 struct mach_header_64 *mh64 = NULL; /* protected by is_64 */ 241 int is_64 = 0; 242 size_t mach_header_sz = sizeof(struct mach_header); 243 size_t segment_command_sz = sizeof(struct segment_command); 244 245 if (do_coredump == 0 || /* Not dumping at all */ 246 ( (sugid_coredump == 0) && /* Not dumping SUID/SGID binaries */ 247 ( (kauth_cred_getsvuid(cred) != kauth_cred_getruid(cred)) || 248 (kauth_cred_getsvgid(cred) != kauth_cred_getrgid(cred))))) { 249 250#if CONFIG_AUDIT 251 audit_proc_coredump(core_proc, NULL, EFAULT); 252#endif 253 return (EFAULT); 254 } 255 256 if (IS_64BIT_PROCESS(core_proc)) { 257 is_64 = 1; 258 mach_header_sz = sizeof(struct mach_header_64); 259 segment_command_sz = sizeof(struct segment_command_64); 260 } 261 262 mapsize = get_vmmap_size(map); 263 264 if ((mapsize >= core_proc->p_rlimit[RLIMIT_CORE].rlim_cur) && (ignore_ulimit == 0)) 265 return (EFAULT); 266 (void) task_suspend_internal(task); 267 268 MALLOC(alloced_name, char *, MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 269 270 /* create name according to sysctl'able format string */ 271 /* if name creation fails, fall back to historical behaviour... */ 272 if (alloced_name == NULL || 273 proc_core_name(core_proc->p_comm, kauth_cred_getuid(cred), 274 core_proc->p_pid, alloced_name, MAXPATHLEN)) { 275 snprintf(stack_name, sizeof(stack_name), 276 "/cores/core.%d", core_proc->p_pid); 277 name = stack_name; 278 } else 279 name = alloced_name; 280 281 if ((error = vnode_open(name, (O_CREAT | FWRITE | O_NOFOLLOW), S_IRUSR, VNODE_LOOKUP_NOFOLLOW, &vp, ctx))) 282 goto out2; 283 284 VATTR_INIT(&va); 285 VATTR_WANTED(&va, va_nlink); 286 /* Don't dump to non-regular files or files with links. */ 287 if (vp->v_type != VREG || 288 vnode_getattr(vp, &va, ctx) || va.va_nlink != 1) { 289 error = EFAULT; 290 goto out; 291 } 292 293 VATTR_INIT(&va); /* better to do it here than waste more stack in vnode_setsize */ 294 VATTR_SET(&va, va_data_size, 0); 295 vnode_setattr(vp, &va, ctx); 296 core_proc->p_acflag |= ACORE; 297 298 if ((reserve_mb > 0) && 299 ((freespace_mb(vp) - (mapsize >> 20)) < reserve_mb)) { 300 error = ENOSPC; 301 goto out; 302 } 303 304 /* 305 * If the task is modified while dumping the file 306 * (e.g., changes in threads or VM, the resulting 307 * file will not necessarily be correct. 308 */ 309 310 thread_count = get_task_numacts(task); 311 segment_count = get_vmmap_entries(map); /* XXX */ 312 tir1.flavor_count = sizeof(thread_flavor_array)/sizeof(mythread_state_flavor_t); 313 bcopy(thread_flavor_array, flavors,sizeof(thread_flavor_array)); 314 tstate_size = 0; 315 for (i = 0; i < tir1.flavor_count; i++) 316 tstate_size += sizeof(mythread_state_flavor_t) + 317 (flavors[i].count * sizeof(int)); 318 command_size = segment_count * segment_command_sz + 319 thread_count*sizeof(struct thread_command) + 320 tstate_size*thread_count; 321 322 header_size = command_size + mach_header_sz; 323 324 if (kmem_alloc(kernel_map, &header, (vm_size_t)header_size) != KERN_SUCCESS) { 325 error = ENOMEM; 326 goto out; 327 } 328 329 /* 330 * Set up Mach-O header. 331 */ 332 if (is_64) { 333 mh64 = (struct mach_header_64 *)header; 334 mh64->magic = MH_MAGIC_64; 335 mh64->cputype = process_cpu_type(core_proc); 336 mh64->cpusubtype = process_cpu_subtype(core_proc); 337 mh64->filetype = MH_CORE; 338 mh64->ncmds = segment_count + thread_count; 339 mh64->sizeofcmds = command_size; 340 mh64->reserved = 0; /* 8 byte alignment */ 341 } else { 342 mh = (struct mach_header *)header; 343 mh->magic = MH_MAGIC; 344 mh->cputype = process_cpu_type(core_proc); 345 mh->cpusubtype = process_cpu_subtype(core_proc); 346 mh->filetype = MH_CORE; 347 mh->ncmds = segment_count + thread_count; 348 mh->sizeofcmds = command_size; 349 } 350 351 hoffset = mach_header_sz; /* offset into header */ 352 foffset = round_page(header_size); /* offset into file */ 353 vmoffset = MACH_VM_MIN_ADDRESS; /* offset into VM */ 354 355 /* 356 * We use to check for an error, here, now we try and get 357 * as much as we can 358 */ 359 while (segment_count > 0) { 360 struct segment_command *sc; 361 struct segment_command_64 *sc64; 362 363 /* 364 * Get region information for next region. 365 */ 366 367 while (1) { 368 vbrcount = VM_REGION_SUBMAP_INFO_COUNT_64; 369 if((kret = mach_vm_region_recurse(map, 370 &vmoffset, &vmsize, &nesting_depth, 371 (vm_region_recurse_info_t)&vbr, 372 &vbrcount)) != KERN_SUCCESS) { 373 break; 374 } 375 /* 376 * If we get a valid mapping back, but we're dumping 377 * a 32 bit process, and it's over the allowable 378 * address space of a 32 bit process, it's the same 379 * as if mach_vm_region_recurse() failed. 380 */ 381 if (!(is_64) && 382 (vmoffset + vmsize > VM_MAX_ADDRESS)) { 383 kret = KERN_INVALID_ADDRESS; 384 break; 385 } 386 if(vbr.is_submap) { 387 nesting_depth++; 388 continue; 389 } else { 390 break; 391 } 392 } 393 if(kret != KERN_SUCCESS) 394 break; 395 396 prot = vbr.protection; 397 maxprot = vbr.max_protection; 398 inherit = vbr.inheritance; 399 /* 400 * Fill in segment command structure. 401 */ 402 if (is_64) { 403 sc64 = (struct segment_command_64 *)(header + hoffset); 404 sc64->cmd = LC_SEGMENT_64; 405 sc64->cmdsize = sizeof(struct segment_command_64); 406 /* segment name is zeroed by kmem_alloc */ 407 sc64->segname[0] = 0; 408 sc64->vmaddr = vmoffset; 409 sc64->vmsize = vmsize; 410 sc64->fileoff = foffset; 411 sc64->filesize = vmsize; 412 sc64->maxprot = maxprot; 413 sc64->initprot = prot; 414 sc64->nsects = 0; 415 } else { 416 sc = (struct segment_command *) (header + hoffset); 417 sc->cmd = LC_SEGMENT; 418 sc->cmdsize = sizeof(struct segment_command); 419 /* segment name is zeroed by kmem_alloc */ 420 sc->segname[0] = 0; 421 sc->vmaddr = CAST_DOWN_EXPLICIT(vm_offset_t,vmoffset); 422 sc->vmsize = CAST_DOWN_EXPLICIT(vm_size_t,vmsize); 423 sc->fileoff = CAST_DOWN_EXPLICIT(uint32_t,foffset); /* will never truncate */ 424 sc->filesize = CAST_DOWN_EXPLICIT(uint32_t,vmsize); /* will never truncate */ 425 sc->maxprot = maxprot; 426 sc->initprot = prot; 427 sc->nsects = 0; 428 } 429 430 /* 431 * Write segment out. Try as hard as possible to 432 * get read access to the data. 433 */ 434 if ((prot & VM_PROT_READ) == 0) { 435 mach_vm_protect(map, vmoffset, vmsize, FALSE, 436 prot|VM_PROT_READ); 437 } 438 /* 439 * Only actually perform write if we can read. 440 * Note: if we can't read, then we end up with 441 * a hole in the file. 442 */ 443 if ((maxprot & VM_PROT_READ) == VM_PROT_READ 444 && vbr.user_tag != VM_MEMORY_IOKIT 445 && coredumpok(map,vmoffset)) { 446 447 error = vn_rdwr_64(UIO_WRITE, vp, vmoffset, vmsize, foffset, 448 (IS_64BIT_PROCESS(core_proc) ? UIO_USERSPACE64 : UIO_USERSPACE32), 449 IO_NOCACHE|IO_NODELOCKED|IO_UNIT, cred, (int64_t *) 0, core_proc); 450 451 } 452 453 hoffset += segment_command_sz; 454 foffset += vmsize; 455 vmoffset += vmsize; 456 segment_count--; 457 } 458 459 /* 460 * If there are remaining segments which have not been written 461 * out because break in the loop above, then they were not counted 462 * because they exceed the real address space of the executable 463 * type: remove them from the header's count. This is OK, since 464 * we are allowed to have a sparse area following the segments. 465 */ 466 if (is_64) { 467 mh64->ncmds -= segment_count; 468 mh64->sizeofcmds -= segment_count * segment_command_sz; 469 } else { 470 mh->ncmds -= segment_count; 471 mh->sizeofcmds -= segment_count * segment_command_sz; 472 } 473 474 tir1.header = header; 475 tir1.hoffset = hoffset; 476 tir1.flavors = flavors; 477 tir1.tstate_size = tstate_size; 478 task_act_iterate_wth_args(task, collectth_state,&tir1); 479 480 /* 481 * Write out the Mach header at the beginning of the 482 * file. OK to use a 32 bit write for this. 483 */ 484 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)header, header_size, (off_t)0, 485 UIO_SYSSPACE, IO_NOCACHE|IO_NODELOCKED|IO_UNIT, cred, (int *) 0, core_proc); 486 kmem_free(kernel_map, header, header_size); 487out: 488 error1 = vnode_close(vp, FWRITE, ctx); 489out2: 490#if CONFIG_AUDIT 491 audit_proc_coredump(core_proc, name, error); 492#endif 493 if (alloced_name != NULL) 494 FREE(alloced_name, M_TEMP); 495 if (error == 0) 496 error = error1; 497 498 return (error); 499} 500