libkern/c++/OSRuntime.cpp

   1 /*
   2  * Copyright (c) 2000,2008-2009 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  * Copyright (c) 1997 Apple Inc.
  30  *
  31  */
  32 #include <libkern/c++/OSMetaClass.h>
  33 #include <libkern/c++/OSKext.h>
  34 #include <libkern/c++/OSLib.h>
  35 #include <libkern/c++/OSSymbol.h>
  36
  37 #include <sys/cdefs.h>
  38
  39 __BEGIN_DECLS
  40
  41 #include <string.h>
  42 #include <mach/mach_types.h>
  43 #include <libkern/kernel_mach_header.h>
  44 #include <stdarg.h>
  45
  46 #if PRAGMA_MARK
  47 #pragma mark Constants &c.
  48 #endif /* PRAGMA_MARK */
  49 OSKextLogSpec kOSRuntimeLogSpec =
  50     kOSKextLogErrorLevel |
  51     kOSKextLogLoadFlag |
  52     kOSKextLogKextBookkeepingFlag;
  53
  54 #if PRAGMA_MARK
  55 #pragma mark Logging Bootstrap
  56 #endif /* PRAGMA_MARK */
  57 /*********************************************************************
  58 * kern_os Logging Bootstrap
  59 *
  60 * We can't call in to OSKext until the kernel's C++ environment is up
  61 * and running, so let's mask those references with a check variable.
  62 * We print unconditionally if C++ isn't up, but if that's the case
  63 * we've generally hit a serious error in kernel init!
  64 *********************************************************************/
  65 static bool gKernelCPPInitialized = false;
  66
  67 #define OSRuntimeLog(kext, flags, format, args...)            \
  68     do {                                                      \
  69         if (gKernelCPPInitialized) {                          \
  70             OSKextLog((kext), (flags), (format), ## args);  \
  71         } else {                                              \
  72             printf((format), ## args);                        \
  73         }                                                     \
  74     } while (0)
  75
  76
  77 #if PRAGMA_MARK
  78 #pragma mark kern_os Allocator Package
  79 #endif /* PRAGMA_MARK */
  80 /*********************************************************************
  81 * kern_os Allocator Package
  82 *********************************************************************/
  83
  84 /*********************************************************************
  85 *********************************************************************/
  86 #if OSALLOCDEBUG
  87 extern int debug_iomalloc_size;
  88 #endif
  89
  90 struct _mhead {
  91     size_t  mlen;
  92     char    dat[0];
  93 };
  94
  95 /*********************************************************************
  96 *********************************************************************/
  97 void *
  98 kern_os_malloc(size_t size)
  99 {
 100     struct _mhead * mem;
 101     size_t          memsize = sizeof (*mem) + size ;
 102
 103     if (size == 0) {
 104         return (0);
 105     }
 106
 107     mem = (struct _mhead *)kalloc(memsize);
 108     if (!mem) {
 109         return (0);
 110     }
 111
 112 #if OSALLOCDEBUG
 113     debug_iomalloc_size += memsize;
 114 #endif
 115
 116     mem->mlen = memsize;
 117     bzero(mem->dat, size);
 118
 119     return mem->dat;
 120 }
 121
 122 /*********************************************************************
 123 *********************************************************************/
 124 void
 125 kern_os_free(void * addr)
 126 {
 127     struct _mhead * hdr;
 128
 129     if (!addr) {
 130         return;
 131     }
 132
 133     hdr = (struct _mhead *)addr;
 134     hdr--;
 135
 136 #if OSALLOCDEBUG
 137     debug_iomalloc_size -= hdr->mlen;
 138 #endif
 139
 140 #if 0
 141     memset((vm_offset_t)hdr, 0xbb, hdr->mlen);
 142 #else
 143     kfree(hdr, hdr->mlen);
 144 #endif
 145 }
 146
 147 /*********************************************************************
 148 *********************************************************************/
 149 void *
 150 kern_os_realloc(
 151     void   * addr,
 152     size_t   nsize)
 153 {
 154     struct _mhead * ohdr;
 155     struct _mhead * nmem;
 156     size_t          nmemsize, osize;
 157
 158     if (!addr) {
 159         return (kern_os_malloc(nsize));
 160     }
 161
 162     ohdr = (struct _mhead *)addr;
 163     ohdr--;
 164     osize = ohdr->mlen - sizeof(*ohdr);
 165     if (nsize == osize) {
 166         return (addr);
 167     }
 168
 169     if (nsize == 0) {
 170         kern_os_free(addr);
 171         return (0);
 172     }
 173
 174     nmemsize = sizeof (*nmem) + nsize ;
 175     nmem = (struct _mhead *) kalloc(nmemsize);
 176     if (!nmem){
 177         kern_os_free(addr);
 178         return (0);
 179     }
 180
 181 #if OSALLOCDEBUG
 182     debug_iomalloc_size += (nmemsize - ohdr->mlen);
 183 #endif
 184
 185     nmem->mlen = nmemsize;
 186     if (nsize > osize) {
 187         (void) memset(&nmem->dat[osize], 0, nsize - osize);
 188     }
 189     (void)memcpy(nmem->dat, ohdr->dat, (nsize > osize) ? osize : nsize);
 190     kfree(ohdr, ohdr->mlen);
 191
 192     return (nmem->dat);
 193 }
 194
 195 /*********************************************************************
 196 *********************************************************************/
 197 size_t
 198 kern_os_malloc_size(void * addr)
 199 {
 200     struct _mhead * hdr;
 201
 202     if (!addr) {
 203         return(0);
 204     }
 205
 206     hdr = (struct _mhead *) addr; hdr--;
 207     return hdr->mlen - sizeof (struct _mhead);
 208 }
 209
 210 #if PRAGMA_MARK
 211 #pragma mark C++ Runtime Load/Unload
 212 #endif /* PRAGMA_MARK */
 213 /*********************************************************************
 214 * kern_os C++ Runtime Load/Unload
 215 *********************************************************************/
 216
 217 /*********************************************************************
 218 *********************************************************************/
 219 #if __GNUC__ >= 3
 220 void __cxa_pure_virtual( void )    { panic("%s", __FUNCTION__); }
 221 #else
 222 void __pure_virtual( void )        { panic("%s", __FUNCTION__); }
 223 #endif
 224
 225 typedef void (*structor_t)(void);
 226
 227 /*********************************************************************
 228 * OSRuntimeUnloadCPPForSegment()
 229 *
 230 * Given a pointer to a mach object segment, iterate the segment to
 231 * obtain a destructor section for C++ objects, and call each of the
 232 * destructors there.
 233 *********************************************************************/
 234
 235 void
 236 OSRuntimeUnloadCPPForSegmentInKmod(
 237     kernel_segment_command_t * segment,
 238     kmod_info_t              * kmodInfo)
 239 {
 240
 241     kernel_section_t * section = NULL;  // do not free
 242     OSKext           * theKext = NULL;  // must release
 243
 244     if (gKernelCPPInitialized && kmodInfo) {
 245         theKext = OSKext::lookupKextWithIdentifier(kmodInfo->name);
 246     }
 247
 248     for (section = firstsect(segment);
 249          section != 0;
 250          section = nextsect(segment, section)) {
 251
 252         if (strncmp(section->sectname, SECT_DESTRUCTOR,
 253             sizeof(SECT_DESTRUCTOR)) == 0) {
 254
 255             structor_t * destructors = (structor_t *)section->addr;
 256
 257             if (destructors) {
 258                 int num_destructors = section->size / sizeof(structor_t);
 259                 int hit_null_destructor = 0;
 260
 261                 for (int i = 0; i < num_destructors; i++) {
 262                     if (destructors[i]) {
 263                         (*destructors[i])();
 264                     } else if (!hit_null_destructor) {
 265                         hit_null_destructor = 1;
 266                         OSRuntimeLog(theKext, kOSRuntimeLogSpec,
 267                             "Null destructor in kext %s segment %s!",
 268                             kmodInfo ? kmodInfo->name : "(unknown)",
 269                             section->segname);
 270                     }
 271                 }
 272             } /* if (destructors) */
 273         } /* if (strncmp...) */
 274     } /* for (section...) */
 275
 276     OSSafeRelease(theKext);
 277     return;
 278 }
 279
 280 void
 281 OSRuntimeUnloadCPPForSegment(kernel_segment_command_t * segment) {
 282     OSRuntimeUnloadCPPForSegmentInKmod(segment, NULL);
 283 }
 284
 285 /*********************************************************************
 286 *********************************************************************/
 287 void
 288 OSRuntimeUnloadCPP(
 289     kmod_info_t * kmodInfo,
 290     void        * data __unused)
 291 {
 292     if (kmodInfo && kmodInfo->address) {
 293
 294         kernel_segment_command_t * segment;
 295         kernel_mach_header_t * header;
 296
 297         OSSymbol::checkForPageUnload((void *)kmodInfo->address,
 298             (void *)(kmodInfo->address + kmodInfo->size));
 299
 300         header = (kernel_mach_header_t *)kmodInfo->address;
 301         segment = firstsegfromheader(header);
 302
 303         for (segment = firstsegfromheader(header);
 304              segment != 0;
 305              segment = nextsegfromheader(header, segment)) {
 306
 307             OSRuntimeUnloadCPPForSegmentInKmod(segment, kmodInfo);
 308         }
 309     }
 310
 311     return;
 312 }
 313
 314 /*********************************************************************
 315 *********************************************************************/
 316 kern_return_t
 317 OSRuntimeFinalizeCPP(
 318     kmod_info_t * kmodInfo,
 319     void        * data __unused)
 320 {
 321     kern_return_t   result = KMOD_RETURN_FAILURE;
 322     void          * metaHandle = NULL;  // do not free
 323     OSKext        * theKext    = NULL;  // must release
 324
 325     if (gKernelCPPInitialized) {
 326         theKext = OSKext::lookupKextWithIdentifier(kmodInfo->name);
 327     }
 328
 329     if (theKext && !theKext->isCPPInitialized()) {
 330         result = KMOD_RETURN_SUCCESS;
 331         goto finish;
 332     }
 333
 334    /* OSKext checks for this condition now, but somebody might call
 335     * this function directly (the symbol is exported....).
 336     */
 337     if (OSMetaClass::modHasInstance(kmodInfo->name)) {
 338         // xxx - Don't log under errors? this is more of an info thing
 339         OSRuntimeLog(theKext, kOSRuntimeLogSpec,
 340             "Can't tear down kext %s C++; classes have instances:",
 341             kmodInfo->name);
 342         OSKext::reportOSMetaClassInstances(kmodInfo->name, kOSRuntimeLogSpec);
 343         result = kOSMetaClassHasInstances;
 344         goto finish;
 345     }
 346
 347    /* Tell the meta class system that we are starting to unload.
 348     * metaHandle isn't actually needed on the finalize path,
 349     * so we don't check it here, even though OSMetaClass::postModLoad() will
 350     * return a failure (it only does actual work on the init path anyhow).
 351     */
 352     metaHandle = OSMetaClass::preModLoad(kmodInfo->name);
 353     OSRuntimeUnloadCPP(kmodInfo, 0);
 354     (void)OSMetaClass::postModLoad(metaHandle);
 355
 356     if (theKext) {
 357         theKext->setCPPInitialized(false);
 358     }
 359     result = KMOD_RETURN_SUCCESS;
 360 finish:
 361     OSSafeRelease(theKext);
 362     return result;
 363 }
 364
 365 // Functions used by the extenTools/kmod library project
 366
 367 /*********************************************************************
 368 *********************************************************************/
 369 kern_return_t
 370 OSRuntimeInitializeCPP(
 371     kmod_info_t * kmodInfo,
 372     void *        data __unused)
 373 {
 374     kern_return_t              result          = KMOD_RETURN_FAILURE;
 375     OSKext                   * theKext         = NULL;  // must release
 376     kernel_mach_header_t     * header          = NULL;
 377     void                     * metaHandle      = NULL;  // do not free
 378     bool                       load_success    = true;
 379     kernel_segment_command_t * segment         = NULL;  // do not free
 380     kernel_segment_command_t * failure_segment = NULL;  // do not free
 381
 382     if (!kmodInfo || !kmodInfo->address || !kmodInfo->name) {
 383         result = kOSKextReturnInvalidArgument;
 384         goto finish;
 385     }
 386
 387     if (gKernelCPPInitialized) {
 388         theKext = OSKext::lookupKextWithIdentifier(kmodInfo->name);
 389     }
 390
 391     if (theKext && theKext->isCPPInitialized()) {
 392         result = KMOD_RETURN_SUCCESS;
 393         goto finish;
 394     }
 395
 396     header = (kernel_mach_header_t *)kmodInfo->address;
 397
 398    /* Tell the meta class system that we are starting the load
 399     */
 400     metaHandle = OSMetaClass::preModLoad(kmodInfo->name);
 401     assert(metaHandle);
 402     if (!metaHandle) {
 403         goto finish;
 404     }
 405
 406    /* NO GOTO PAST HERE. */
 407
 408    /* Scan the header for all constructor sections, in any
 409     * segment, and invoke the constructors within those sections.
 410     */
 411     for (segment = firstsegfromheader(header);
 412          segment != NULL && load_success;
 413          segment = nextsegfromheader(header, segment)) {
 414
 415         kernel_section_t * section;
 416
 417        /* Record the current segment in the event of a failure.
 418         */
 419         failure_segment = segment;
 420
 421         for (section = firstsect(segment);
 422              section != NULL;
 423              section = nextsect(segment, section)) {
 424
 425             if (strncmp(section->sectname, SECT_CONSTRUCTOR,
 426                 sizeof(SECT_CONSTRUCTOR)) == 0) {
 427
 428                 structor_t * constructors = (structor_t *)section->addr;
 429
 430                 if (constructors) {
 431                     int num_constructors = section->size / sizeof(structor_t);
 432                     int hit_null_constructor = 0;
 433
 434                     for (int i = 0;
 435                          i < num_constructors &&
 436                          OSMetaClass::checkModLoad(metaHandle);
 437                          i++) {
 438
 439                         if (constructors[i]) {
 440                             (*constructors[i])();
 441                         } else if (!hit_null_constructor) {
 442                             hit_null_constructor = 1;
 443                             OSRuntimeLog(theKext, kOSRuntimeLogSpec,
 444                                 "Null constructor in kext %s segment %s!",
 445                                 kmodInfo->name, section->segname);
 446                         }
 447                     }
 448                     load_success = OSMetaClass::checkModLoad(metaHandle);
 449
 450                     break;
 451                 } /* if (constructors) */
 452             } /* if (strncmp...) */
 453         } /* for (section...) */
 454     } /* for (segment...) */
 455
 456    /* We failed so call all of the destructors. We must do this before
 457     * calling OSMetaClass::postModLoad() as the OSMetaClass destructors
 458     * will alter state (in the metaHandle) used by that function.
 459     */
 460     if (!load_success) {
 461
 462        /* Scan the header for all destructor sections, in any
 463         * segment, and invoke the constructors within those sections.
 464         */
 465         for (segment = firstsegfromheader(header);
 466              segment != failure_segment && segment != 0;
 467              segment = nextsegfromheader(header, segment)) {
 468
 469             OSRuntimeUnloadCPPForSegment(segment);
 470
 471         } /* for (segment...) */
 472     }
 473
 474    /* Now, regardless of success so far, do the post-init registration
 475     * and cleanup. If we had to call the unloadCPP function, static
 476     * destructors have removed classes from the stalled list so no
 477     * metaclasses will actually be registered.
 478     */
 479     result = OSMetaClass::postModLoad(metaHandle);
 480
 481    /* If we've otherwise been fine up to now, but OSMetaClass::postModLoad()
 482     * fails (typically due to a duplicate class), tear down all the C++
 483     * stuff from the kext. This isn't necessary for libkern/OSMetaClass stuff,
 484     * but may be necessary for other C++ code. We ignore the return value
 485     * because it's only a fail when there are existing instances of libkern
 486     * classes, and there had better not be any created on the C++ init path.
 487     */
 488     if (load_success && result != KMOD_RETURN_SUCCESS) {
 489         (void)OSRuntimeFinalizeCPP(kmodInfo, NULL);
 490     }
 491
 492     if (theKext && load_success && result == KMOD_RETURN_SUCCESS) {
 493         theKext->setCPPInitialized(true);
 494     }
 495 finish:
 496     OSSafeRelease(theKext);
 497     return result;
 498 }
 499
 500 #if PRAGMA_MARK
 501 #pragma mark Libkern Init
 502 #endif /* PRAGMA_MARK */
 503 /*********************************************************************
 504 * Libkern Init
 505 *********************************************************************/
 506
 507 /*********************************************************************
 508 *********************************************************************/
 509 extern lck_spin_t  gOSObjectTrackLock;
 510 extern lck_grp_t * IOLockGroup;
 511 extern kmod_info_t g_kernel_kmod_info;
 512
 513 void OSlibkernInit(void)
 514 {
 515     lck_spin_init(&gOSObjectTrackLock, IOLockGroup, LCK_ATTR_NULL);
 516
 517     // This must be called before calling OSRuntimeInitializeCPP.
 518     OSMetaClassBase::initialize();
 519
 520     if (kOSReturnSuccess != OSRuntimeInitializeCPP(&g_kernel_kmod_info, 0)) {
 521         panic("OSRuntime: C++ runtime failed to initialize.");
 522     }
 523
 524     gKernelCPPInitialized = true;
 525
 526     return;
 527 }
 528
 529 __END_DECLS
 530
 531 #if PRAGMA_MARK
 532 #pragma mark C++ Allocators & Deallocators
 533 #endif /* PRAGMA_MARK */
 534 /*********************************************************************
 535 * C++ Allocators & Deallocators
 536 *********************************************************************/
 537 void *
 538 operator new(size_t size)
 539 {
 540     void * result;
 541
 542     result = (void *) kern_os_malloc(size);
 543     return result;
 544 }
 545
 546 void
 547 operator delete(void * addr)
 548 {
 549     kern_os_free(addr);
 550     return;
 551 }
 552
 553 void *
 554 operator new[](unsigned long sz)
 555 {
 556     if (sz == 0) sz = 1;
 557     return kern_os_malloc(sz);
 558 }
 559
 560 void
 561 operator delete[](void * ptr)
 562 {
 563     if (ptr) {
 564         kern_os_free(ptr);
 565     }
 566     return;
 567 }
 568
 569 /* PR-6481964 - The compiler is going to check for size overflows in calls to
 570  * new[], and if there is an overflow, it will call __throw_length_error.
 571  * This is an unrecoverable error by the C++ standard, so we must panic here.
 572  *
 573  * We have to put the function inside the std namespace because of how the
 574  * compiler expects the name to be mangled.
 575  */
 576 namespace std {
 577
 578 void
 579 __throw_length_error(const char *msg __unused)
 580 {
 581     panic("Size of array created by new[] has overflowed");
 582 }
 583
 584 };
 585