lib/asan/asan_malloc_mac.cc

   1 //===-- asan_malloc_mac.cc ------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file is a part of AddressSanitizer, an address sanity checker.
  11 //
  12 // Mac-specific malloc interception.
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_common/sanitizer_platform.h"
  16 #if SANITIZER_MAC
  17
  18 #include <AvailabilityMacros.h>
  19 #include <CoreFoundation/CFBase.h>
  20 #include <dlfcn.h>
  21 #include <malloc/malloc.h>
  22 #include <sys/mman.h>
  23
  24 #include "asan_allocator.h"
  25 #include "asan_interceptors.h"
  26 #include "asan_internal.h"
  27 #include "asan_report.h"
  28 #include "asan_stack.h"
  29 #include "asan_stats.h"
  30 #include "sanitizer_common/sanitizer_mac.h"
  31
  32 // Similar code is used in Google Perftools,
  33 // http://code.google.com/p/google-perftools.
  34
  35 // ---------------------- Replacement functions ---------------- {{{1
  36 using namespace __asan;  // NOLINT
  37
  38 // TODO(glider): do we need both zones?
  39 static malloc_zone_t *system_malloc_zone = 0;
  40 static malloc_zone_t asan_zone;
  41
  42 INTERCEPTOR(malloc_zone_t *, malloc_create_zone,
  43                              vm_size_t start_size, unsigned zone_flags) {
  44   ENSURE_ASAN_INITED();
  45   GET_STACK_TRACE_MALLOC;
  46   uptr page_size = GetPageSizeCached();
  47   uptr allocated_size = RoundUpTo(sizeof(asan_zone), page_size);
  48   malloc_zone_t *new_zone =
  49       (malloc_zone_t*)asan_memalign(page_size, allocated_size,
  50                                     &stack, FROM_MALLOC);
  51   internal_memcpy(new_zone, &asan_zone, sizeof(asan_zone));
  52   new_zone->zone_name = NULL;  // The name will be changed anyway.
  53   if (GetMacosVersion() >= MACOS_VERSION_LION) {
  54     // Prevent the client app from overwriting the zone contents.
  55     // Library functions that need to modify the zone will set PROT_WRITE on it.
  56     // This matches the behavior of malloc_create_zone() on OSX 10.7 and higher.
  57     mprotect(new_zone, allocated_size, PROT_READ);
  58   }
  59   return new_zone;
  60 }
  61
  62 INTERCEPTOR(malloc_zone_t *, malloc_default_zone, void) {
  63   ENSURE_ASAN_INITED();
  64   return &asan_zone;
  65 }
  66
  67 INTERCEPTOR(malloc_zone_t *, malloc_default_purgeable_zone, void) {
  68   // FIXME: ASan should support purgeable allocations.
  69   // https://code.google.com/p/address-sanitizer/issues/detail?id=139
  70   ENSURE_ASAN_INITED();
  71   return &asan_zone;
  72 }
  73
  74 INTERCEPTOR(void, malloc_make_purgeable, void *ptr) {
  75   // FIXME: ASan should support purgeable allocations. Ignoring them is fine
  76   // for now.
  77   ENSURE_ASAN_INITED();
  78 }
  79
  80 INTERCEPTOR(int, malloc_make_nonpurgeable, void *ptr) {
  81   // FIXME: ASan should support purgeable allocations. Ignoring them is fine
  82   // for now.
  83   ENSURE_ASAN_INITED();
  84   // Must return 0 if the contents were not purged since the last call to
  85   // malloc_make_purgeable().
  86   return 0;
  87 }
  88
  89 INTERCEPTOR(void, malloc_set_zone_name, malloc_zone_t *zone, const char *name) {
  90   ENSURE_ASAN_INITED();
  91   // Allocate |strlen("asan-") + 1 + internal_strlen(name)| bytes.
  92   size_t buflen = 6 + (name ? internal_strlen(name) : 0);
  93   InternalScopedBuffer<char> new_name(buflen);
  94   if (name && zone->introspect == asan_zone.introspect) {
  95     internal_snprintf(new_name.data(), buflen, "asan-%s", name);
  96     name = new_name.data();
  97   }
  98
  99   // Call the system malloc's implementation for both external and our zones,
 100   // since that appropriately changes VM region protections on the zone.
 101   REAL(malloc_set_zone_name)(zone, name);
 102 }
 103
 104 INTERCEPTOR(void *, malloc, size_t size) {
 105   ENSURE_ASAN_INITED();
 106   GET_STACK_TRACE_MALLOC;
 107   void *res = asan_malloc(size, &stack);
 108   return res;
 109 }
 110
 111 INTERCEPTOR(void, free, void *ptr) {
 112   ENSURE_ASAN_INITED();
 113   if (!ptr) return;
 114   GET_STACK_TRACE_FREE;
 115   asan_free(ptr, &stack, FROM_MALLOC);
 116 }
 117
 118 INTERCEPTOR(void *, realloc, void *ptr, size_t size) {
 119   ENSURE_ASAN_INITED();
 120   GET_STACK_TRACE_MALLOC;
 121   return asan_realloc(ptr, size, &stack);
 122 }
 123
 124 INTERCEPTOR(void *, calloc, size_t nmemb, size_t size) {
 125   ENSURE_ASAN_INITED();
 126   GET_STACK_TRACE_MALLOC;
 127   return asan_calloc(nmemb, size, &stack);
 128 }
 129
 130 INTERCEPTOR(void *, valloc, size_t size) {
 131   ENSURE_ASAN_INITED();
 132   GET_STACK_TRACE_MALLOC;
 133   return asan_memalign(GetPageSizeCached(), size, &stack, FROM_MALLOC);
 134 }
 135
 136 INTERCEPTOR(size_t, malloc_good_size, size_t size) {
 137   ENSURE_ASAN_INITED();
 138   return asan_zone.introspect->good_size(&asan_zone, size);
 139 }
 140
 141 INTERCEPTOR(int, posix_memalign, void **memptr, size_t alignment, size_t size) {
 142   ENSURE_ASAN_INITED();
 143   CHECK(memptr);
 144   GET_STACK_TRACE_MALLOC;
 145   void *result = asan_memalign(alignment, size, &stack, FROM_MALLOC);
 146   if (result) {
 147     *memptr = result;
 148     return 0;
 149   }
 150   return -1;
 151 }
 152
 153 namespace {
 154
 155 // TODO(glider): the mz_* functions should be united with the Linux wrappers,
 156 // as they are basically copied from there.
 157 size_t mz_size(malloc_zone_t* zone, const void* ptr) {
 158   return asan_mz_size(ptr);
 159 }
 160
 161 void *mz_malloc(malloc_zone_t *zone, size_t size) {
 162   if (!asan_inited) {
 163     CHECK(system_malloc_zone);
 164     return malloc_zone_malloc(system_malloc_zone, size);
 165   }
 166   GET_STACK_TRACE_MALLOC;
 167   return asan_malloc(size, &stack);
 168 }
 169
 170 void *mz_calloc(malloc_zone_t *zone, size_t nmemb, size_t size) {
 171   if (!asan_inited) {
 172     // Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym.
 173     const size_t kCallocPoolSize = 1024;
 174     static uptr calloc_memory_for_dlsym[kCallocPoolSize];
 175     static size_t allocated;
 176     size_t size_in_words = ((nmemb * size) + kWordSize - 1) / kWordSize;
 177     void *mem = (void*)&calloc_memory_for_dlsym[allocated];
 178     allocated += size_in_words;
 179     CHECK(allocated < kCallocPoolSize);
 180     return mem;
 181   }
 182   GET_STACK_TRACE_MALLOC;
 183   return asan_calloc(nmemb, size, &stack);
 184 }
 185
 186 void *mz_valloc(malloc_zone_t *zone, size_t size) {
 187   if (!asan_inited) {
 188     CHECK(system_malloc_zone);
 189     return malloc_zone_valloc(system_malloc_zone, size);
 190   }
 191   GET_STACK_TRACE_MALLOC;
 192   return asan_memalign(GetPageSizeCached(), size, &stack, FROM_MALLOC);
 193 }
 194
 195 #define GET_ZONE_FOR_PTR(ptr) \
 196   malloc_zone_t *zone_ptr = malloc_zone_from_ptr(ptr); \
 197   const char *zone_name = (zone_ptr == 0) ? 0 : zone_ptr->zone_name
 198
 199 void ALWAYS_INLINE free_common(void *context, void *ptr) {
 200   if (!ptr) return;
 201   GET_STACK_TRACE_FREE;
 202   // FIXME: need to retire this flag.
 203   if (!flags()->mac_ignore_invalid_free) {
 204     asan_free(ptr, &stack, FROM_MALLOC);
 205   } else {
 206     GET_ZONE_FOR_PTR(ptr);
 207     WarnMacFreeUnallocated((uptr)ptr, (uptr)zone_ptr, zone_name, &stack);
 208     return;
 209   }
 210 }
 211
 212 // TODO(glider): the allocation callbacks need to be refactored.
 213 void mz_free(malloc_zone_t *zone, void *ptr) {
 214   free_common(zone, ptr);
 215 }
 216
 217 void *mz_realloc(malloc_zone_t *zone, void *ptr, size_t size) {
 218   if (!ptr) {
 219     GET_STACK_TRACE_MALLOC;
 220     return asan_malloc(size, &stack);
 221   } else {
 222     if (asan_mz_size(ptr)) {
 223       GET_STACK_TRACE_MALLOC;
 224       return asan_realloc(ptr, size, &stack);
 225     } else {
 226       // We can't recover from reallocating an unknown address, because
 227       // this would require reading at most |size| bytes from
 228       // potentially unaccessible memory.
 229       GET_STACK_TRACE_FREE;
 230       GET_ZONE_FOR_PTR(ptr);
 231       ReportMacMzReallocUnknown((uptr)ptr, (uptr)zone_ptr, zone_name, &stack);
 232     }
 233   }
 234 }
 235
 236 void mz_destroy(malloc_zone_t* zone) {
 237   // A no-op -- we will not be destroyed!
 238   Report("mz_destroy() called -- ignoring\n");
 239 }
 240
 241   // from AvailabilityMacros.h
 242 #if defined(MAC_OS_X_VERSION_10_6) && \
 243     MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_6
 244 void *mz_memalign(malloc_zone_t *zone, size_t align, size_t size) {
 245   if (!asan_inited) {
 246     CHECK(system_malloc_zone);
 247     return malloc_zone_memalign(system_malloc_zone, align, size);
 248   }
 249   GET_STACK_TRACE_MALLOC;
 250   return asan_memalign(align, size, &stack, FROM_MALLOC);
 251 }
 252
 253 // This function is currently unused, and we build with -Werror.
 254 #if 0
 255 void mz_free_definite_size(malloc_zone_t* zone, void *ptr, size_t size) {
 256   // TODO(glider): check that |size| is valid.
 257   UNIMPLEMENTED();
 258 }
 259 #endif
 260 #endif
 261
 262 kern_return_t mi_enumerator(task_t task, void *,
 263                             unsigned type_mask, vm_address_t zone_address,
 264                             memory_reader_t reader,
 265                             vm_range_recorder_t recorder) {
 266   // Should enumerate all the pointers we have.  Seems like a lot of work.
 267   return KERN_FAILURE;
 268 }
 269
 270 size_t mi_good_size(malloc_zone_t *zone, size_t size) {
 271   // I think it's always safe to return size, but we maybe could do better.
 272   return size;
 273 }
 274
 275 boolean_t mi_check(malloc_zone_t *zone) {
 276   UNIMPLEMENTED();
 277 }
 278
 279 void mi_print(malloc_zone_t *zone, boolean_t verbose) {
 280   UNIMPLEMENTED();
 281 }
 282
 283 void mi_log(malloc_zone_t *zone, void *address) {
 284   // I don't think we support anything like this
 285 }
 286
 287 void mi_force_lock(malloc_zone_t *zone) {
 288   asan_mz_force_lock();
 289 }
 290
 291 void mi_force_unlock(malloc_zone_t *zone) {
 292   asan_mz_force_unlock();
 293 }
 294
 295 void mi_statistics(malloc_zone_t *zone, malloc_statistics_t *stats) {
 296   AsanMallocStats malloc_stats;
 297   FillMallocStatistics(&malloc_stats);
 298   CHECK(sizeof(malloc_statistics_t) == sizeof(AsanMallocStats));
 299   internal_memcpy(stats, &malloc_stats, sizeof(malloc_statistics_t));
 300 }
 301
 302 #if defined(MAC_OS_X_VERSION_10_6) && \
 303     MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_6
 304 boolean_t mi_zone_locked(malloc_zone_t *zone) {
 305   // UNIMPLEMENTED();
 306   return false;
 307 }
 308 #endif
 309
 310 }  // unnamed namespace
 311
 312 namespace __asan {
 313
 314 void ReplaceSystemMalloc() {
 315   static malloc_introspection_t asan_introspection;
 316   // Ok to use internal_memset, these places are not performance-critical.
 317   internal_memset(&asan_introspection, 0, sizeof(asan_introspection));
 318
 319   asan_introspection.enumerator = &mi_enumerator;
 320   asan_introspection.good_size = &mi_good_size;
 321   asan_introspection.check = &mi_check;
 322   asan_introspection.print = &mi_print;
 323   asan_introspection.log = &mi_log;
 324   asan_introspection.force_lock = &mi_force_lock;
 325   asan_introspection.force_unlock = &mi_force_unlock;
 326   asan_introspection.statistics = &mi_statistics;
 327
 328   internal_memset(&asan_zone, 0, sizeof(malloc_zone_t));
 329
 330   // Start with a version 4 zone which is used for OS X 10.4 and 10.5.
 331   asan_zone.version = 4;
 332   asan_zone.zone_name = "asan";
 333   asan_zone.size = &mz_size;
 334   asan_zone.malloc = &mz_malloc;
 335   asan_zone.calloc = &mz_calloc;
 336   asan_zone.valloc = &mz_valloc;
 337   asan_zone.free = &mz_free;
 338   asan_zone.realloc = &mz_realloc;
 339   asan_zone.destroy = &mz_destroy;
 340   asan_zone.batch_malloc = 0;
 341   asan_zone.batch_free = 0;
 342   asan_zone.introspect = &asan_introspection;
 343
 344   // from AvailabilityMacros.h
 345 #if defined(MAC_OS_X_VERSION_10_6) && \
 346     MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_6
 347   // Switch to version 6 on OSX 10.6 to support memalign.
 348   asan_zone.version = 6;
 349   asan_zone.free_definite_size = 0;
 350   asan_zone.memalign = &mz_memalign;
 351   asan_introspection.zone_locked = &mi_zone_locked;
 352 #endif
 353
 354   // Register the ASan zone.
 355   malloc_zone_register(&asan_zone);
 356 }
 357 }  // namespace __asan
 358
 359 #endif  // SANITIZER_MAC