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