libsanitizer/asan/asan_mac.cc

   1 //===-- asan_mac.cc -------------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of AddressSanitizer, an address sanity checker.
   9 //
  10 // Mac-specific details.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_common/sanitizer_platform.h"
  14 #if SANITIZER_MAC
  15
  16 #include "asan_interceptors.h"
  17 #include "asan_internal.h"
  18 #include "asan_mapping.h"
  19 #include "asan_stack.h"
  20 #include "asan_thread.h"
  21 #include "sanitizer_common/sanitizer_atomic.h"
  22 #include "sanitizer_common/sanitizer_libc.h"
  23 #include "sanitizer_common/sanitizer_mac.h"
  24
  25 #include <dlfcn.h>
  26 #include <fcntl.h>
  27 #include <libkern/OSAtomic.h>
  28 #include <mach-o/dyld.h>
  29 #include <mach-o/getsect.h>
  30 #include <mach-o/loader.h>
  31 #include <pthread.h>
  32 #include <stdlib.h>  // for free()
  33 #include <sys/mman.h>
  34 #include <sys/resource.h>
  35 #include <sys/sysctl.h>
  36 #include <sys/ucontext.h>
  37 #include <unistd.h>
  38
  39 // from <crt_externs.h>, but we don't have that file on iOS
  40 extern "C" {
  41   extern char ***_NSGetArgv(void);
  42   extern char ***_NSGetEnviron(void);
  43 }
  44
  45 namespace __asan {
  46
  47 void InitializePlatformInterceptors() {}
  48 void InitializePlatformExceptionHandlers() {}
  49
  50 bool PlatformHasDifferentMemcpyAndMemmove() {
  51   // On OS X 10.7 memcpy() and memmove() are both resolved
  52   // into memmove$VARIANT$sse42.
  53   // See also https://github.com/google/sanitizers/issues/34.
  54   // TODO(glider): need to check dynamically that memcpy() and memmove() are
  55   // actually the same function.
  56   return GetMacosVersion() == MACOS_VERSION_SNOW_LEOPARD;
  57 }
  58
  59 // No-op. Mac does not support static linkage anyway.
  60 void *AsanDoesNotSupportStaticLinkage() {
  61   return 0;
  62 }
  63
  64 // No-op. Mac does not support static linkage anyway.
  65 void AsanCheckDynamicRTPrereqs() {}
  66
  67 // No-op. Mac does not support static linkage anyway.
  68 void AsanCheckIncompatibleRT() {}
  69
  70 void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
  71   // Find the Mach-O header for the image containing the needle
  72   Dl_info info;
  73   int err = dladdr(needle, &info);
  74   if (err == 0) return;
  75
  76 #if __LP64__
  77   const struct mach_header_64 *mh = (struct mach_header_64 *)info.dli_fbase;
  78 #else
  79   const struct mach_header *mh = (struct mach_header *)info.dli_fbase;
  80 #endif
  81
  82   // Look up the __asan_globals section in that image and register its globals
  83   unsigned long size = 0;
  84   __asan_global *globals = (__asan_global *)getsectiondata(
  85       mh,
  86       "__DATA", "__asan_globals",
  87       &size);
  88
  89   if (!globals) return;
  90   if (size % sizeof(__asan_global) != 0) return;
  91   op(globals, size / sizeof(__asan_global));
  92 }
  93
  94 void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
  95   UNIMPLEMENTED();
  96 }
  97
  98 // Support for the following functions from libdispatch on Mac OS:
  99 //   dispatch_async_f()
 100 //   dispatch_async()
 101 //   dispatch_sync_f()
 102 //   dispatch_sync()
 103 //   dispatch_after_f()
 104 //   dispatch_after()
 105 //   dispatch_group_async_f()
 106 //   dispatch_group_async()
 107 // TODO(glider): libdispatch API contains other functions that we don't support
 108 // yet.
 109 //
 110 // dispatch_sync() and dispatch_sync_f() are synchronous, although chances are
 111 // they can cause jobs to run on a thread different from the current one.
 112 // TODO(glider): if so, we need a test for this (otherwise we should remove
 113 // them).
 114 //
 115 // The following functions use dispatch_barrier_async_f() (which isn't a library
 116 // function but is exported) and are thus supported:
 117 //   dispatch_source_set_cancel_handler_f()
 118 //   dispatch_source_set_cancel_handler()
 119 //   dispatch_source_set_event_handler_f()
 120 //   dispatch_source_set_event_handler()
 121 //
 122 // The reference manual for Grand Central Dispatch is available at
 123 //   http://developer.apple.com/library/mac/#documentation/Performance/Reference/GCD_libdispatch_Ref/Reference/reference.html
 124 // The implementation details are at
 125 //   http://libdispatch.macosforge.org/trac/browser/trunk/src/queue.c
 126
 127 typedef void* dispatch_group_t;
 128 typedef void* dispatch_queue_t;
 129 typedef void* dispatch_source_t;
 130 typedef u64 dispatch_time_t;
 131 typedef void (*dispatch_function_t)(void *block);
 132 typedef void* (*worker_t)(void *block);
 133
 134 // A wrapper for the ObjC blocks used to support libdispatch.
 135 typedef struct {
 136   void *block;
 137   dispatch_function_t func;
 138   u32 parent_tid;
 139 } asan_block_context_t;
 140
 141 ALWAYS_INLINE
 142 void asan_register_worker_thread(int parent_tid, StackTrace *stack) {
 143   AsanThread *t = GetCurrentThread();
 144   if (!t) {
 145     t = AsanThread::Create(/* start_routine */ nullptr, /* arg */ nullptr,
 146                            parent_tid, stack, /* detached */ true);
 147     t->Init();
 148     asanThreadRegistry().StartThread(t->tid(), 0, 0);
 149     SetCurrentThread(t);
 150   }
 151 }
 152
 153 // For use by only those functions that allocated the context via
 154 // alloc_asan_context().
 155 extern "C"
 156 void asan_dispatch_call_block_and_release(void *block) {
 157   GET_STACK_TRACE_THREAD;
 158   asan_block_context_t *context = (asan_block_context_t*)block;
 159   VReport(2,
 160           "asan_dispatch_call_block_and_release(): "
 161           "context: %p, pthread_self: %p\n",
 162           block, pthread_self());
 163   asan_register_worker_thread(context->parent_tid, &stack);
 164   // Call the original dispatcher for the block.
 165   context->func(context->block);
 166   asan_free(context, &stack, FROM_MALLOC);
 167 }
 168
 169 }  // namespace __asan
 170
 171 using namespace __asan;  // NOLINT
 172
 173 // Wrap |ctxt| and |func| into an asan_block_context_t.
 174 // The caller retains control of the allocated context.
 175 extern "C"
 176 asan_block_context_t *alloc_asan_context(void *ctxt, dispatch_function_t func,
 177                                          BufferedStackTrace *stack) {
 178   asan_block_context_t *asan_ctxt =
 179       (asan_block_context_t*) asan_malloc(sizeof(asan_block_context_t), stack);
 180   asan_ctxt->block = ctxt;
 181   asan_ctxt->func = func;
 182   asan_ctxt->parent_tid = GetCurrentTidOrInvalid();
 183   return asan_ctxt;
 184 }
 185
 186 // Define interceptor for dispatch_*_f function with the three most common
 187 // parameters: dispatch_queue_t, context, dispatch_function_t.
 188 #define INTERCEPT_DISPATCH_X_F_3(dispatch_x_f)                                \
 189   INTERCEPTOR(void, dispatch_x_f, dispatch_queue_t dq, void *ctxt,            \
 190                                   dispatch_function_t func) {                 \
 191     GET_STACK_TRACE_THREAD;                                                   \
 192     asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); \
 193     if (Verbosity() >= 2) {                                     \
 194       Report(#dispatch_x_f "(): context: %p, pthread_self: %p\n",             \
 195              asan_ctxt, pthread_self());                                      \
 196       PRINT_CURRENT_STACK();                                                  \
 197     }                                                                         \
 198     return REAL(dispatch_x_f)(dq, (void*)asan_ctxt,                           \
 199                               asan_dispatch_call_block_and_release);          \
 200   }
 201
 202 INTERCEPT_DISPATCH_X_F_3(dispatch_async_f)
 203 INTERCEPT_DISPATCH_X_F_3(dispatch_sync_f)
 204 INTERCEPT_DISPATCH_X_F_3(dispatch_barrier_async_f)
 205
 206 INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when,
 207                                     dispatch_queue_t dq, void *ctxt,
 208                                     dispatch_function_t func) {
 209   GET_STACK_TRACE_THREAD;
 210   asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack);
 211   if (Verbosity() >= 2) {
 212     Report("dispatch_after_f: %p\n", asan_ctxt);
 213     PRINT_CURRENT_STACK();
 214   }
 215   return REAL(dispatch_after_f)(when, dq, (void*)asan_ctxt,
 216                                 asan_dispatch_call_block_and_release);
 217 }
 218
 219 INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group,
 220                                           dispatch_queue_t dq, void *ctxt,
 221                                           dispatch_function_t func) {
 222   GET_STACK_TRACE_THREAD;
 223   asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack);
 224   if (Verbosity() >= 2) {
 225     Report("dispatch_group_async_f(): context: %p, pthread_self: %p\n",
 226            asan_ctxt, pthread_self());
 227     PRINT_CURRENT_STACK();
 228   }
 229   REAL(dispatch_group_async_f)(group, dq, (void*)asan_ctxt,
 230                                asan_dispatch_call_block_and_release);
 231 }
 232
 233 #if !defined(MISSING_BLOCKS_SUPPORT)
 234 extern "C" {
 235 void dispatch_async(dispatch_queue_t dq, void(^work)(void));
 236 void dispatch_group_async(dispatch_group_t dg, dispatch_queue_t dq,
 237                           void(^work)(void));
 238 void dispatch_after(dispatch_time_t when, dispatch_queue_t queue,
 239                     void(^work)(void));
 240 void dispatch_source_set_cancel_handler(dispatch_source_t ds,
 241                                         void(^work)(void));
 242 void dispatch_source_set_event_handler(dispatch_source_t ds, void(^work)(void));
 243 }
 244
 245 #define GET_ASAN_BLOCK(work) \
 246   void (^asan_block)(void);  \
 247   int parent_tid = GetCurrentTidOrInvalid(); \
 248   asan_block = ^(void) { \
 249     GET_STACK_TRACE_THREAD; \
 250     asan_register_worker_thread(parent_tid, &stack); \
 251     work(); \
 252   }
 253
 254 INTERCEPTOR(void, dispatch_async,
 255             dispatch_queue_t dq, void(^work)(void)) {
 256   ENABLE_FRAME_POINTER;
 257   GET_ASAN_BLOCK(work);
 258   REAL(dispatch_async)(dq, asan_block);
 259 }
 260
 261 INTERCEPTOR(void, dispatch_group_async,
 262             dispatch_group_t dg, dispatch_queue_t dq, void(^work)(void)) {
 263   ENABLE_FRAME_POINTER;
 264   GET_ASAN_BLOCK(work);
 265   REAL(dispatch_group_async)(dg, dq, asan_block);
 266 }
 267
 268 INTERCEPTOR(void, dispatch_after,
 269             dispatch_time_t when, dispatch_queue_t queue, void(^work)(void)) {
 270   ENABLE_FRAME_POINTER;
 271   GET_ASAN_BLOCK(work);
 272   REAL(dispatch_after)(when, queue, asan_block);
 273 }
 274
 275 INTERCEPTOR(void, dispatch_source_set_cancel_handler,
 276             dispatch_source_t ds, void(^work)(void)) {
 277   if (!work) {
 278     REAL(dispatch_source_set_cancel_handler)(ds, work);
 279     return;
 280   }
 281   ENABLE_FRAME_POINTER;
 282   GET_ASAN_BLOCK(work);
 283   REAL(dispatch_source_set_cancel_handler)(ds, asan_block);
 284 }
 285
 286 INTERCEPTOR(void, dispatch_source_set_event_handler,
 287             dispatch_source_t ds, void(^work)(void)) {
 288   ENABLE_FRAME_POINTER;
 289   GET_ASAN_BLOCK(work);
 290   REAL(dispatch_source_set_event_handler)(ds, asan_block);
 291 }
 292 #endif
 293
 294 #endif  // SANITIZER_MAC