asan_mac.cc revision eb5f427c10c5d23e520def5f921cbbed831526be
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#ifdef __APPLE__ 16 17#include "asan_interceptors.h" 18#include "asan_internal.h" 19#include "asan_mac.h" 20#include "asan_mapping.h" 21#include "asan_stack.h" 22#include "asan_thread.h" 23#include "asan_thread_registry.h" 24#include "sanitizer_common/sanitizer_libc.h" 25 26#include <crt_externs.h> // for _NSGetArgv 27#include <dlfcn.h> // for dladdr() 28#include <mach-o/dyld.h> 29#include <mach-o/loader.h> 30#include <sys/mman.h> 31#include <sys/resource.h> 32#include <sys/sysctl.h> 33#include <sys/ucontext.h> 34#include <fcntl.h> 35#include <pthread.h> 36#include <stdlib.h> // for free() 37#include <unistd.h> 38#include <libkern/OSAtomic.h> 39 40namespace __asan { 41 42void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) { 43 ucontext_t *ucontext = (ucontext_t*)context; 44# if SANITIZER_WORDSIZE == 64 45 *pc = ucontext->uc_mcontext->__ss.__rip; 46 *bp = ucontext->uc_mcontext->__ss.__rbp; 47 *sp = ucontext->uc_mcontext->__ss.__rsp; 48# else 49 *pc = ucontext->uc_mcontext->__ss.__eip; 50 *bp = ucontext->uc_mcontext->__ss.__ebp; 51 *sp = ucontext->uc_mcontext->__ss.__esp; 52# endif // SANITIZER_WORDSIZE 53} 54 55int GetMacosVersion() { 56 int mib[2] = { CTL_KERN, KERN_OSRELEASE }; 57 char version[100]; 58 uptr len = 0, maxlen = sizeof(version) / sizeof(version[0]); 59 for (uptr i = 0; i < maxlen; i++) version[i] = '\0'; 60 // Get the version length. 61 CHECK(sysctl(mib, 2, 0, &len, 0, 0) != -1); 62 CHECK(len < maxlen); 63 CHECK(sysctl(mib, 2, version, &len, 0, 0) != -1); 64 switch (version[0]) { 65 case '9': return MACOS_VERSION_LEOPARD; 66 case '1': { 67 switch (version[1]) { 68 case '0': return MACOS_VERSION_SNOW_LEOPARD; 69 case '1': return MACOS_VERSION_LION; 70 case '2': return MACOS_VERSION_MOUNTAIN_LION; 71 default: return MACOS_VERSION_UNKNOWN; 72 } 73 } 74 default: return MACOS_VERSION_UNKNOWN; 75 } 76} 77 78bool PlatformHasDifferentMemcpyAndMemmove() { 79 // On OS X 10.7 memcpy() and memmove() are both resolved 80 // into memmove$VARIANT$sse42. 81 // See also http://code.google.com/p/address-sanitizer/issues/detail?id=34. 82 // TODO(glider): need to check dynamically that memcpy() and memmove() are 83 // actually the same function. 84 return GetMacosVersion() == MACOS_VERSION_SNOW_LEOPARD; 85} 86 87extern "C" 88void __asan_init(); 89 90static const char kDyldInsertLibraries[] = "DYLD_INSERT_LIBRARIES"; 91 92void MaybeReexec() { 93 if (!flags()->allow_reexec) return; 94 // Make sure the dynamic ASan runtime library is preloaded so that the 95 // wrappers work. If it is not, set DYLD_INSERT_LIBRARIES and re-exec 96 // ourselves. 97 Dl_info info; 98 CHECK(dladdr((void*)((uptr)__asan_init), &info)); 99 const char *dyld_insert_libraries = GetEnv(kDyldInsertLibraries); 100 if (!dyld_insert_libraries || 101 !REAL(strstr)(dyld_insert_libraries, info.dli_fname)) { 102 // DYLD_INSERT_LIBRARIES is not set or does not contain the runtime 103 // library. 104 char program_name[1024]; 105 uint32_t buf_size = sizeof(program_name); 106 _NSGetExecutablePath(program_name, &buf_size); 107 // Ok to use setenv() since the wrappers don't depend on the value of 108 // asan_inited. 109 if (dyld_insert_libraries) { 110 // Append the runtime dylib name to the existing value of 111 // DYLD_INSERT_LIBRARIES. 112 uptr old_env_len = internal_strlen(dyld_insert_libraries); 113 uptr fname_len = internal_strlen(info.dli_fname); 114 LowLevelAllocator allocator_for_env; 115 char *new_env = 116 (char*)allocator_for_env.Allocate(old_env_len + fname_len + 2); 117 internal_strncpy(new_env, dyld_insert_libraries, old_env_len); 118 new_env[old_env_len] = ':'; 119 // Copy fname_len and add a trailing zero. 120 internal_strncpy(new_env + old_env_len + 1, info.dli_fname, fname_len + 1); 121 setenv(kDyldInsertLibraries, new_env, /*overwrite*/1); 122 } else { 123 // Set DYLD_INSERT_LIBRARIES equal to the runtime dylib name. 124 setenv(kDyldInsertLibraries, info.dli_fname, /*overwrite*/0); 125 } 126 if (flags()->verbosity >= 1) { 127 Report("exec()-ing the program with\n"); 128 Report("%s=%s\n", kDyldInsertLibraries, info.dli_fname); 129 Report("to enable ASan wrappers.\n"); 130 Report("Set ASAN_OPTIONS=allow_reexec=0 to disable this.\n"); 131 } 132 execv(program_name, *_NSGetArgv()); 133 } 134} 135 136// No-op. Mac does not support static linkage anyway. 137void *AsanDoesNotSupportStaticLinkage() { 138 return 0; 139} 140 141bool AsanInterceptsSignal(int signum) { 142 return (signum == SIGSEGV || signum == SIGBUS) && flags()->handle_segv; 143} 144 145void AsanPlatformThreadInit() { 146} 147 148void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp, bool fast) { 149 (void)fast; 150 stack->size = 0; 151 stack->trace[0] = pc; 152 if ((max_s) > 1) { 153 stack->max_size = max_s; 154 if (!asan_inited) return; 155 if (AsanThread *t = asanThreadRegistry().GetCurrent()) 156 stack->FastUnwindStack(pc, bp, t->stack_top(), t->stack_bottom()); 157 } 158} 159 160void ReadContextStack(void *context, uptr *stack, uptr *ssize) { 161 UNIMPLEMENTED(); 162} 163 164// Support for the following functions from libdispatch on Mac OS: 165// dispatch_async_f() 166// dispatch_async() 167// dispatch_sync_f() 168// dispatch_sync() 169// dispatch_after_f() 170// dispatch_after() 171// dispatch_group_async_f() 172// dispatch_group_async() 173// TODO(glider): libdispatch API contains other functions that we don't support 174// yet. 175// 176// dispatch_sync() and dispatch_sync_f() are synchronous, although chances are 177// they can cause jobs to run on a thread different from the current one. 178// TODO(glider): if so, we need a test for this (otherwise we should remove 179// them). 180// 181// The following functions use dispatch_barrier_async_f() (which isn't a library 182// function but is exported) and are thus supported: 183// dispatch_source_set_cancel_handler_f() 184// dispatch_source_set_cancel_handler() 185// dispatch_source_set_event_handler_f() 186// dispatch_source_set_event_handler() 187// 188// The reference manual for Grand Central Dispatch is available at 189// http://developer.apple.com/library/mac/#documentation/Performance/Reference/GCD_libdispatch_Ref/Reference/reference.html 190// The implementation details are at 191// http://libdispatch.macosforge.org/trac/browser/trunk/src/queue.c 192 193typedef void* dispatch_group_t; 194typedef void* dispatch_queue_t; 195typedef void* dispatch_source_t; 196typedef u64 dispatch_time_t; 197typedef void (*dispatch_function_t)(void *block); 198typedef void* (*worker_t)(void *block); 199 200// A wrapper for the ObjC blocks used to support libdispatch. 201typedef struct { 202 void *block; 203 dispatch_function_t func; 204 u32 parent_tid; 205} asan_block_context_t; 206 207// We use extern declarations of libdispatch functions here instead 208// of including <dispatch/dispatch.h>. This header is not present on 209// Mac OS X Leopard and eariler, and although we don't expect ASan to 210// work on legacy systems, it's bad to break the build of 211// LLVM compiler-rt there. 212extern "C" { 213void dispatch_async_f(dispatch_queue_t dq, void *ctxt, 214 dispatch_function_t func); 215void dispatch_sync_f(dispatch_queue_t dq, void *ctxt, 216 dispatch_function_t func); 217void dispatch_after_f(dispatch_time_t when, dispatch_queue_t dq, void *ctxt, 218 dispatch_function_t func); 219void dispatch_barrier_async_f(dispatch_queue_t dq, void *ctxt, 220 dispatch_function_t func); 221void dispatch_group_async_f(dispatch_group_t group, dispatch_queue_t dq, 222 void *ctxt, dispatch_function_t func); 223} // extern "C" 224 225static ALWAYS_INLINE 226void asan_register_worker_thread(int parent_tid, StackTrace *stack) { 227 AsanThread *t = asanThreadRegistry().GetCurrent(); 228 if (!t) { 229 t = AsanThread::Create(parent_tid, 0, 0, stack); 230 asanThreadRegistry().RegisterThread(t); 231 t->Init(); 232 asanThreadRegistry().SetCurrent(t); 233 } 234} 235 236// For use by only those functions that allocated the context via 237// alloc_asan_context(). 238extern "C" 239void asan_dispatch_call_block_and_release(void *block) { 240 GET_STACK_TRACE_THREAD; 241 asan_block_context_t *context = (asan_block_context_t*)block; 242 if (flags()->verbosity >= 2) { 243 Report("asan_dispatch_call_block_and_release(): " 244 "context: %p, pthread_self: %p\n", 245 block, pthread_self()); 246 } 247 asan_register_worker_thread(context->parent_tid, &stack); 248 // Call the original dispatcher for the block. 249 context->func(context->block); 250 asan_free(context, &stack, FROM_MALLOC); 251} 252 253} // namespace __asan 254 255using namespace __asan; // NOLINT 256 257// Wrap |ctxt| and |func| into an asan_block_context_t. 258// The caller retains control of the allocated context. 259extern "C" 260asan_block_context_t *alloc_asan_context(void *ctxt, dispatch_function_t func, 261 StackTrace *stack) { 262 asan_block_context_t *asan_ctxt = 263 (asan_block_context_t*) asan_malloc(sizeof(asan_block_context_t), stack); 264 asan_ctxt->block = ctxt; 265 asan_ctxt->func = func; 266 asan_ctxt->parent_tid = asanThreadRegistry().GetCurrentTidOrInvalid(); 267 return asan_ctxt; 268} 269 270// Define interceptor for dispatch_*_f function with the three most common 271// parameters: dispatch_queue_t, context, dispatch_function_t. 272#define INTERCEPT_DISPATCH_X_F_3(dispatch_x_f) \ 273 INTERCEPTOR(void, dispatch_x_f, dispatch_queue_t dq, void *ctxt, \ 274 dispatch_function_t func) { \ 275 GET_STACK_TRACE_THREAD; \ 276 asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); \ 277 if (flags()->verbosity >= 2) { \ 278 Report(#dispatch_x_f "(): context: %p, pthread_self: %p\n", \ 279 asan_ctxt, pthread_self()); \ 280 PRINT_CURRENT_STACK(); \ 281 } \ 282 return REAL(dispatch_x_f)(dq, (void*)asan_ctxt, \ 283 asan_dispatch_call_block_and_release); \ 284 } 285 286INTERCEPT_DISPATCH_X_F_3(dispatch_async_f) 287INTERCEPT_DISPATCH_X_F_3(dispatch_sync_f) 288INTERCEPT_DISPATCH_X_F_3(dispatch_barrier_async_f) 289 290INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when, 291 dispatch_queue_t dq, void *ctxt, 292 dispatch_function_t func) { 293 GET_STACK_TRACE_THREAD; 294 asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); 295 if (flags()->verbosity >= 2) { 296 Report("dispatch_after_f: %p\n", asan_ctxt); 297 PRINT_CURRENT_STACK(); 298 } 299 return REAL(dispatch_after_f)(when, dq, (void*)asan_ctxt, 300 asan_dispatch_call_block_and_release); 301} 302 303INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group, 304 dispatch_queue_t dq, void *ctxt, 305 dispatch_function_t func) { 306 GET_STACK_TRACE_THREAD; 307 asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); 308 if (flags()->verbosity >= 2) { 309 Report("dispatch_group_async_f(): context: %p, pthread_self: %p\n", 310 asan_ctxt, pthread_self()); 311 PRINT_CURRENT_STACK(); 312 } 313 REAL(dispatch_group_async_f)(group, dq, (void*)asan_ctxt, 314 asan_dispatch_call_block_and_release); 315} 316 317#if !defined(MISSING_BLOCKS_SUPPORT) 318extern "C" { 319// FIXME: consolidate these declarations with asan_intercepted_functions.h. 320void dispatch_async(dispatch_queue_t dq, void(^work)(void)); 321void dispatch_group_async(dispatch_group_t dg, dispatch_queue_t dq, 322 void(^work)(void)); 323void dispatch_after(dispatch_time_t when, dispatch_queue_t queue, 324 void(^work)(void)); 325void dispatch_source_set_cancel_handler(dispatch_source_t ds, 326 void(^work)(void)); 327void dispatch_source_set_event_handler(dispatch_source_t ds, void(^work)(void)); 328} 329 330#define GET_ASAN_BLOCK(work) \ 331 void (^asan_block)(void); \ 332 int parent_tid = asanThreadRegistry().GetCurrentTidOrInvalid(); \ 333 asan_block = ^(void) { \ 334 GET_STACK_TRACE_THREAD; \ 335 asan_register_worker_thread(parent_tid, &stack); \ 336 work(); \ 337 } 338 339INTERCEPTOR(void, dispatch_async, 340 dispatch_queue_t dq, void(^work)(void)) { 341 GET_ASAN_BLOCK(work); 342 REAL(dispatch_async)(dq, asan_block); 343} 344 345INTERCEPTOR(void, dispatch_group_async, 346 dispatch_group_t dg, dispatch_queue_t dq, void(^work)(void)) { 347 GET_ASAN_BLOCK(work); 348 REAL(dispatch_group_async)(dg, dq, asan_block); 349} 350 351INTERCEPTOR(void, dispatch_after, 352 dispatch_time_t when, dispatch_queue_t queue, void(^work)(void)) { 353 GET_ASAN_BLOCK(work); 354 REAL(dispatch_after)(when, queue, asan_block); 355} 356 357INTERCEPTOR(void, dispatch_source_set_cancel_handler, 358 dispatch_source_t ds, void(^work)(void)) { 359 GET_ASAN_BLOCK(work); 360 REAL(dispatch_source_set_cancel_handler)(ds, asan_block); 361} 362 363INTERCEPTOR(void, dispatch_source_set_event_handler, 364 dispatch_source_t ds, void(^work)(void)) { 365 GET_ASAN_BLOCK(work); 366 REAL(dispatch_source_set_event_handler)(ds, asan_block); 367} 368#endif 369 370#endif // __APPLE__ 371