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 297
