src/compiler-rt/lib/asan/asan_mac.cc

   1 //===-- asan_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 details.
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_common/sanitizer_platform.h"
  16 #if SANITIZER_MAC
  17
  18 #include "asan_interceptors.h"
  19 #include "asan_internal.h"
  20 #include "asan_mapping.h"
  21 #include "asan_stack.h"
  22 #include "asan_thread.h"
  23 #include "sanitizer_common/sanitizer_atomic.h"
  24 #include "sanitizer_common/sanitizer_libc.h"
  25 #include "sanitizer_common/sanitizer_mac.h"
  26
  27 #include <dlfcn.h>
  28 #include <fcntl.h>
  29 #include <libkern/OSAtomic.h>
  30 #include <mach-o/dyld.h>
  31 #include <mach-o/getsect.h>
  32 #include <mach-o/loader.h>
  33 #include <pthread.h>
  34 #include <stdlib.h>  // for free()
  35 #include <sys/mman.h>
  36 #include <sys/resource.h>
  37 #include <sys/sysctl.h>
  38 #include <sys/ucontext.h>
  39 #include <unistd.h>
  40
  41 // from <crt_externs.h>, but we don't have that file on iOS
  42 extern "C" {
  43   extern char ***_NSGetArgv(void);
  44   extern char ***_NSGetEnviron(void);
  45 }
  46
  47 namespace __asan {
  48
  49 void InitializePlatformInterceptors() {}
  50 void InitializePlatformExceptionHandlers() {}
  51
  52 bool PlatformHasDifferentMemcpyAndMemmove() {
  53   // On OS X 10.7 memcpy() and memmove() are both resolved
  54   // into memmove$VARIANT$sse42.
  55   // See also https://github.com/google/sanitizers/issues/34.
  56   // TODO(glider): need to check dynamically that memcpy() and memmove() are
  57   // actually the same function.
  58   return GetMacosVersion() == MACOS_VERSION_SNOW_LEOPARD;
  59 }
  60
  61 // No-op. Mac does not support static linkage anyway.
  62 void *AsanDoesNotSupportStaticLinkage() {
  63   return 0;
  64 }
  65
  66 // No-op. Mac does not support static linkage anyway.
  67 void AsanCheckDynamicRTPrereqs() {}
  68
  69 // No-op. Mac does not support static linkage anyway.
  70 void AsanCheckIncompatibleRT() {}
  71
  72 void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
  73   // Find the Mach-O header for the image containing the needle
  74   Dl_info info;
  75   int err = dladdr(needle, &info);
  76   if (err == 0) return;
  77
  78 #if __LP64__
  79   const struct mach_header_64 *mh = (struct mach_header_64 *)info.dli_fbase;
  80 #else
  81   const struct mach_header *mh = (struct mach_header *)info.dli_fbase;
  82 #endif
  83
  84   // Look up the __asan_globals section in that image and register its globals
  85   unsigned long size = 0;
  86   __asan_global *globals = (__asan_global *)getsectiondata(
  87       mh,
  88       "__DATA", "__asan_globals",
  89       &size);
  90
  91   if (!globals) return;
  92   if (size % sizeof(__asan_global) != 0) return;
  93   op(globals, size / sizeof(__asan_global));
  94 }
  95
  96 void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
  97   UNIMPLEMENTED();
  98 }
  99
 100 // Support for the following functions from libdispatch on Mac OS:
 101 //   dispatch_async_f()
 102 //   dispatch_async()
 103 //   dispatch_sync_f()
 104 //   dispatch_sync()
 105 //   dispatch_after_f()
 106 //   dispatch_after()
 107 //   dispatch_group_async_f()
 108 //   dispatch_group_async()
 109 // TODO(glider): libdispatch API contains other functions that we don't support
 110 // yet.
 111 //
 112 // dispatch_sync() and dispatch_sync_f() are synchronous, although chances are
 113 // they can cause jobs to run on a thread different from the current one.
 114 // TODO(glider): if so, we need a test for this (otherwise we should remove
 115 // them).
 116 //
 117 // The following functions use dispatch_barrier_async_f() (which isn't a library
 118 // function but is exported) and are thus supported:
 119 //   dispatch_source_set_cancel_handler_f()
 120 //   dispatch_source_set_cancel_handler()
 121 //   dispatch_source_set_event_handler_f()
 122 //   dispatch_source_set_event_handler()
 123 //
 124 // The reference manual for Grand Central Dispatch is available at
 125 //   http://developer.apple.com/library/mac/#documentation/Performance/Reference/GCD_libdispatch_Ref/Reference/reference.html
 126 // The implementation details are at
 127 //   http://libdispatch.macosforge.org/trac/browser/trunk/src/queue.c
 128
 129 typedef void* dispatch_group_t;
 130 typedef void* dispatch_queue_t;
 131 typedef void* dispatch_source_t;
 132 typedef u64 dispatch_time_t;
 133 typedef void (*dispatch_function_t)(void *block);
 134 typedef void* (*worker_t)(void *block);
 135
 136 // A wrapper for the ObjC blocks used to support libdispatch.
 137 typedef struct {
 138   void *block;
 139   dispatch_function_t func;
 140   u32 parent_tid;
 141 } asan_block_context_t;
 142
 143 ALWAYS_INLINE
 144 void asan_register_worker_thread(int parent_tid, StackTrace *stack) {
 145   AsanThread *t = GetCurrentThread();
 146   if (!t) {
 147     t = AsanThread::Create(/* start_routine */ nullptr, /* arg */ nullptr,
 148                            parent_tid, stack, /* detached */ true);
 149     t->Init();
 150     asanThreadRegistry().StartThread(t->tid(), 0, 0);
 151     SetCurrentThread(t);
 152   }
 153 }
 154
 155 // For use by only those functions that allocated the context via
 156 // alloc_asan_context().
 157 extern "C"
 158 void asan_dispatch_call_block_and_release(void *block) {
 159   GET_STACK_TRACE_THREAD;
 160   asan_block_context_t *context = (asan_block_context_t*)block;
 161   VReport(2,
 162           "asan_dispatch_call_block_and_release(): "
 163           "context: %p, pthread_self: %p\n",
 164           block, pthread_self());
 165   asan_register_worker_thread(context->parent_tid, &stack);
 166   // Call the original dispatcher for the block.
 167   context->func(context->block);
 168   asan_free(context, &stack, FROM_MALLOC);
 169 }
 170
 171 }  // namespace __asan
 172
 173 using namespace __asan;  // NOLINT
 174
 175 // Wrap |ctxt| and |func| into an asan_block_context_t.
 176 // The caller retains control of the allocated context.
 177 extern "C"
 178 asan_block_context_t *alloc_asan_context(void *ctxt, dispatch_function_t func,
 179                                          BufferedStackTrace *stack) {
 180   asan_block_context_t *asan_ctxt =
 181       (asan_block_context_t*) asan_malloc(sizeof(asan_block_context_t), stack);
 182   asan_ctxt->block = ctxt;
 183   asan_ctxt->func = func;
 184   asan_ctxt->parent_tid = GetCurrentTidOrInvalid();
 185   return asan_ctxt;
 186 }
 187
 188 // Define interceptor for dispatch_*_f function with the three most common
 189 // parameters: dispatch_queue_t, context, dispatch_function_t.
 190 #define INTERCEPT_DISPATCH_X_F_3(dispatch_x_f)                                \
 191   INTERCEPTOR(void, dispatch_x_f, dispatch_queue_t dq, void *ctxt,            \
 192                                   dispatch_function_t func) {                 \
 193     GET_STACK_TRACE_THREAD;                                                   \
 194     asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); \
 195     if (Verbosity() >= 2) {                                     \
 196       Report(#dispatch_x_f "(): context: %p, pthread_self: %p\n",             \
 197              asan_ctxt, pthread_self());                                      \
 198       PRINT_CURRENT_STACK();                                                  \
 199     }                                                                         \
 200     return REAL(dispatch_x_f)(dq, (void*)asan_ctxt,                           \
 201                               asan_dispatch_call_block_and_release);          \
 202   }
 203
 204 INTERCEPT_DISPATCH_X_F_3(dispatch_async_f)
 205 INTERCEPT_DISPATCH_X_F_3(dispatch_sync_f)
 206 INTERCEPT_DISPATCH_X_F_3(dispatch_barrier_async_f)
 207
 208 INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when,
 209                                     dispatch_queue_t dq, void *ctxt,
 210                                     dispatch_function_t func) {
 211   GET_STACK_TRACE_THREAD;
 212   asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack);
 213   if (Verbosity() >= 2) {
 214     Report("dispatch_after_f: %p\n", asan_ctxt);
 215     PRINT_CURRENT_STACK();
 216   }
 217   return REAL(dispatch_after_f)(when, dq, (void*)asan_ctxt,
 218                                 asan_dispatch_call_block_and_release);
 219 }
 220
 221 INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group,
 222                                           dispatch_queue_t dq, void *ctxt,
 223                                           dispatch_function_t func) {
 224   GET_STACK_TRACE_THREAD;
 225   asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack);
 226   if (Verbosity() >= 2) {
 227     Report("dispatch_group_async_f(): context: %p, pthread_self: %p\n",
 228            asan_ctxt, pthread_self());
 229     PRINT_CURRENT_STACK();
 230   }
 231   REAL(dispatch_group_async_f)(group, dq, (void*)asan_ctxt,
 232                                asan_dispatch_call_block_and_release);
 233 }
 234
 235 #if !defined(MISSING_BLOCKS_SUPPORT)
 236 extern "C" {
 237 void dispatch_async(dispatch_queue_t dq, void(^work)(void));
 238 void dispatch_group_async(dispatch_group_t dg, dispatch_queue_t dq,
 239                           void(^work)(void));
 240 void dispatch_after(dispatch_time_t when, dispatch_queue_t queue,
 241                     void(^work)(void));
 242 void dispatch_source_set_cancel_handler(dispatch_source_t ds,
 243                                         void(^work)(void));
 244 void dispatch_source_set_event_handler(dispatch_source_t ds, void(^work)(void));
 245 }
 246
 247 #define GET_ASAN_BLOCK(work) \
 248   void (^asan_block)(void);  \
 249   int parent_tid = GetCurrentTidOrInvalid(); \
 250   asan_block = ^(void) { \
 251     GET_STACK_TRACE_THREAD; \
 252     asan_register_worker_thread(parent_tid, &stack); \
 253     work(); \
 254   }
 255
 256 INTERCEPTOR(void, dispatch_async,
 257             dispatch_queue_t dq, void(^work)(void)) {
 258   ENABLE_FRAME_POINTER;
 259   GET_ASAN_BLOCK(work);
 260   REAL(dispatch_async)(dq, asan_block);
 261 }
 262
 263 INTERCEPTOR(void, dispatch_group_async,
 264             dispatch_group_t dg, dispatch_queue_t dq, void(^work)(void)) {
 265   ENABLE_FRAME_POINTER;
 266   GET_ASAN_BLOCK(work);
 267   REAL(dispatch_group_async)(dg, dq, asan_block);
 268 }
 269
 270 INTERCEPTOR(void, dispatch_after,
 271             dispatch_time_t when, dispatch_queue_t queue, void(^work)(void)) {
 272   ENABLE_FRAME_POINTER;
 273   GET_ASAN_BLOCK(work);
 274   REAL(dispatch_after)(when, queue, asan_block);
 275 }
 276
 277 INTERCEPTOR(void, dispatch_source_set_cancel_handler,
 278             dispatch_source_t ds, void(^work)(void)) {
 279   if (!work) {
 280     REAL(dispatch_source_set_cancel_handler)(ds, work);
 281     return;
 282   }
 283   ENABLE_FRAME_POINTER;
 284   GET_ASAN_BLOCK(work);
 285   REAL(dispatch_source_set_cancel_handler)(ds, asan_block);
 286 }
 287
 288 INTERCEPTOR(void, dispatch_source_set_event_handler,
 289             dispatch_source_t ds, void(^work)(void)) {
 290   ENABLE_FRAME_POINTER;
 291   GET_ASAN_BLOCK(work);
 292   REAL(dispatch_source_set_event_handler)(ds, asan_block);
 293 }
 294 #endif
 295
 296 #endif  // SANITIZER_MAC