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