asan_rtl.cc revision 5a9938d4de74d41cb5f167f751a621dfb7545b64
1//===-- asan_rtl.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// Main file of the ASan run-time library. 13//===----------------------------------------------------------------------===// 14#include "asan_allocator.h" 15#include "asan_interceptors.h" 16#include "asan_interface.h" 17#include "asan_internal.h" 18#include "asan_lock.h" 19#include "asan_mapping.h" 20#include "asan_report.h" 21#include "asan_stack.h" 22#include "asan_stats.h" 23#include "asan_thread.h" 24#include "asan_thread_registry.h" 25#include "sanitizer_common/sanitizer_atomic.h" 26#include "sanitizer_common/sanitizer_flags.h" 27#include "sanitizer_common/sanitizer_libc.h" 28 29namespace __sanitizer { 30using namespace __asan; 31 32void Die() { 33 static atomic_uint32_t num_calls; 34 if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) { 35 // Don't die twice - run a busy loop. 36 while (1) { } 37 } 38 if (flags()->sleep_before_dying) { 39 Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying); 40 SleepForSeconds(flags()->sleep_before_dying); 41 } 42 if (flags()->unmap_shadow_on_exit) 43 UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg); 44 if (death_callback) 45 death_callback(); 46 if (flags()->abort_on_error) 47 Abort(); 48 Exit(flags()->exitcode); 49} 50 51void CheckFailed(const char *file, int line, const char *cond, u64 v1, u64 v2) { 52 AsanReport("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", 53 file, line, cond, (uptr)v1, (uptr)v2); 54 PRINT_CURRENT_STACK(); 55 ShowStatsAndAbort(); 56} 57 58} // namespace __sanitizer 59 60namespace __asan { 61 62// -------------------------- Flags ------------------------- {{{1 63static const int kMallocContextSize = 30; 64 65static Flags asan_flags; 66 67Flags *flags() { 68 return &asan_flags; 69} 70 71static void ParseFlagsFromString(Flags *f, const char *str) { 72 ParseFlag(str, &f->quarantine_size, "quarantine_size"); 73 ParseFlag(str, &f->symbolize, "symbolize"); 74 ParseFlag(str, &f->verbosity, "verbosity"); 75 ParseFlag(str, &f->redzone, "redzone"); 76 CHECK(f->redzone >= 16); 77 CHECK(IsPowerOfTwo(f->redzone)); 78 79 ParseFlag(str, &f->debug, "debug"); 80 ParseFlag(str, &f->report_globals, "report_globals"); 81 ParseFlag(str, &f->malloc_context_size, "malloc_context_size"); 82 CHECK(f->malloc_context_size <= kMallocContextSize); 83 84 ParseFlag(str, &f->replace_str, "replace_str"); 85 ParseFlag(str, &f->replace_intrin, "replace_intrin"); 86 ParseFlag(str, &f->replace_cfallocator, "replace_cfallocator"); 87 ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free"); 88 ParseFlag(str, &f->use_fake_stack, "use_fake_stack"); 89 ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size"); 90 ParseFlag(str, &f->exitcode, "exitcode"); 91 ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning"); 92 ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying"); 93 ParseFlag(str, &f->handle_segv, "handle_segv"); 94 ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack"); 95 ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size"); 96 ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit"); 97 ParseFlag(str, &f->abort_on_error, "abort_on_error"); 98 ParseFlag(str, &f->atexit, "atexit"); 99 ParseFlag(str, &f->disable_core, "disable_core"); 100 ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix"); 101} 102 103extern "C" { 104const char* WEAK __asan_default_options() { return ""; } 105} // extern "C" 106 107void InitializeFlags(Flags *f, const char *env) { 108 internal_memset(f, 0, sizeof(*f)); 109 110 f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 24 : 1UL << 28; 111 f->symbolize = false; 112 f->verbosity = 0; 113 f->redzone = (ASAN_LOW_MEMORY) ? 64 : 128; 114 f->debug = false; 115 f->report_globals = 1; 116 f->malloc_context_size = kMallocContextSize; 117 f->replace_str = true; 118 f->replace_intrin = true; 119 f->replace_cfallocator = true; 120 f->mac_ignore_invalid_free = false; 121 f->use_fake_stack = true; 122 f->max_malloc_fill_size = 0; 123 f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE; 124 f->allow_user_poisoning = true; 125 f->sleep_before_dying = 0; 126 f->handle_segv = ASAN_NEEDS_SEGV; 127 f->use_sigaltstack = false; 128 f->check_malloc_usable_size = true; 129 f->unmap_shadow_on_exit = false; 130 f->abort_on_error = false; 131 f->atexit = false; 132 f->disable_core = (__WORDSIZE == 64); 133 f->strip_path_prefix = ""; 134 135 // Override from user-specified string. 136 ParseFlagsFromString(f, __asan_default_options()); 137 if (flags()->verbosity) { 138 Report("Using the defaults from __asan_default_options: %s\n", 139 __asan_default_options()); 140 } 141 142 // Override from command line. 143 ParseFlagsFromString(f, env); 144} 145 146// -------------------------- Globals --------------------- {{{1 147int asan_inited; 148bool asan_init_is_running; 149void (*death_callback)(void); 150 151// -------------------------- Misc ---------------- {{{1 152void ShowStatsAndAbort() { 153 __asan_print_accumulated_stats(); 154 Die(); 155} 156 157// ---------------------- mmap -------------------- {{{1 158// Reserve memory range [beg, end]. 159static void ReserveShadowMemoryRange(uptr beg, uptr end) { 160 CHECK((beg % kPageSize) == 0); 161 CHECK(((end + 1) % kPageSize) == 0); 162 uptr size = end - beg + 1; 163 void *res = MmapFixedNoReserve(beg, size); 164 CHECK(res == (void*)beg && "ReserveShadowMemoryRange failed"); 165} 166 167// ---------------------- LowLevelAllocator ------------- {{{1 168void *LowLevelAllocator::Allocate(uptr size) { 169 CHECK((size & (size - 1)) == 0 && "size must be a power of two"); 170 if (allocated_end_ - allocated_current_ < (sptr)size) { 171 uptr size_to_allocate = Max(size, kPageSize); 172 allocated_current_ = 173 (char*)MmapOrDie(size_to_allocate, __FUNCTION__); 174 allocated_end_ = allocated_current_ + size_to_allocate; 175 PoisonShadow((uptr)allocated_current_, size_to_allocate, 176 kAsanInternalHeapMagic); 177 } 178 CHECK(allocated_end_ - allocated_current_ >= (sptr)size); 179 void *res = allocated_current_; 180 allocated_current_ += size; 181 return res; 182} 183 184// -------------------------- Run-time entry ------------------- {{{1 185// exported functions 186#define ASAN_REPORT_ERROR(type, is_write, size) \ 187extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 188void __asan_report_ ## type ## size(uptr addr); \ 189void __asan_report_ ## type ## size(uptr addr) { \ 190 GET_CALLER_PC_BP_SP; \ 191 __asan_report_error(pc, bp, sp, addr, is_write, size); \ 192} 193 194ASAN_REPORT_ERROR(load, false, 1) 195ASAN_REPORT_ERROR(load, false, 2) 196ASAN_REPORT_ERROR(load, false, 4) 197ASAN_REPORT_ERROR(load, false, 8) 198ASAN_REPORT_ERROR(load, false, 16) 199ASAN_REPORT_ERROR(store, true, 1) 200ASAN_REPORT_ERROR(store, true, 2) 201ASAN_REPORT_ERROR(store, true, 4) 202ASAN_REPORT_ERROR(store, true, 8) 203ASAN_REPORT_ERROR(store, true, 16) 204 205// Force the linker to keep the symbols for various ASan interface functions. 206// We want to keep those in the executable in order to let the instrumented 207// dynamic libraries access the symbol even if it is not used by the executable 208// itself. This should help if the build system is removing dead code at link 209// time. 210static NOINLINE void force_interface_symbols() { 211 volatile int fake_condition = 0; // prevent dead condition elimination. 212 // __asan_report_* functions are noreturn, so we need a switch to prevent 213 // the compiler from removing any of them. 214 switch (fake_condition) { 215 case 1: __asan_report_load1(0); break; 216 case 2: __asan_report_load2(0); break; 217 case 3: __asan_report_load4(0); break; 218 case 4: __asan_report_load8(0); break; 219 case 5: __asan_report_load16(0); break; 220 case 6: __asan_report_store1(0); break; 221 case 7: __asan_report_store2(0); break; 222 case 8: __asan_report_store4(0); break; 223 case 9: __asan_report_store8(0); break; 224 case 10: __asan_report_store16(0); break; 225 case 11: __asan_register_global(0, 0, 0); break; 226 case 12: __asan_register_globals(0, 0); break; 227 case 13: __asan_unregister_globals(0, 0); break; 228 case 14: __asan_set_death_callback(0); break; 229 case 15: __asan_set_error_report_callback(0); break; 230 case 16: __asan_handle_no_return(); break; 231 case 17: __asan_address_is_poisoned(0); break; 232 case 18: __asan_get_allocated_size(0); break; 233 case 19: __asan_get_current_allocated_bytes(); break; 234 case 20: __asan_get_estimated_allocated_size(0); break; 235 case 21: __asan_get_free_bytes(); break; 236 case 22: __asan_get_heap_size(); break; 237 case 23: __asan_get_ownership(0); break; 238 case 24: __asan_get_unmapped_bytes(); break; 239 case 25: __asan_poison_memory_region(0, 0); break; 240 case 26: __asan_unpoison_memory_region(0, 0); break; 241 case 27: __asan_set_error_exit_code(0); break; 242 case 28: __asan_stack_free(0, 0, 0); break; 243 case 29: __asan_stack_malloc(0, 0); break; 244 } 245} 246 247static void asan_atexit() { 248 AsanPrintf("AddressSanitizer exit stats:\n"); 249 __asan_print_accumulated_stats(); 250} 251 252} // namespace __asan 253 254// ---------------------- Interface ---------------- {{{1 255using namespace __asan; // NOLINT 256 257int NOINLINE __asan_set_error_exit_code(int exit_code) { 258 int old = flags()->exitcode; 259 flags()->exitcode = exit_code; 260 return old; 261} 262 263void NOINLINE __asan_handle_no_return() { 264 int local_stack; 265 AsanThread *curr_thread = asanThreadRegistry().GetCurrent(); 266 CHECK(curr_thread); 267 uptr top = curr_thread->stack_top(); 268 uptr bottom = ((uptr)&local_stack - kPageSize) & ~(kPageSize-1); 269 PoisonShadow(bottom, top - bottom, 0); 270} 271 272void NOINLINE __asan_set_death_callback(void (*callback)(void)) { 273 death_callback = callback; 274} 275 276void __asan_init() { 277 if (asan_inited) return; 278 asan_init_is_running = true; 279 280 // Make sure we are not statically linked. 281 AsanDoesNotSupportStaticLinkage(); 282 283 // Initialize flags. 284 const char *options = GetEnv("ASAN_OPTIONS"); 285 InitializeFlags(flags(), options); 286 287 if (flags()->verbosity && options) { 288 Report("Parsed ASAN_OPTIONS: %s\n", options); 289 } 290 291 if (flags()->atexit) { 292 Atexit(asan_atexit); 293 } 294 295 // interceptors 296 InitializeAsanInterceptors(); 297 298 ReplaceSystemMalloc(); 299 ReplaceOperatorsNewAndDelete(); 300 301 if (flags()->verbosity) { 302 Printf("|| `[%p, %p]` || HighMem ||\n", 303 (void*)kHighMemBeg, (void*)kHighMemEnd); 304 Printf("|| `[%p, %p]` || HighShadow ||\n", 305 (void*)kHighShadowBeg, (void*)kHighShadowEnd); 306 Printf("|| `[%p, %p]` || ShadowGap ||\n", 307 (void*)kShadowGapBeg, (void*)kShadowGapEnd); 308 Printf("|| `[%p, %p]` || LowShadow ||\n", 309 (void*)kLowShadowBeg, (void*)kLowShadowEnd); 310 Printf("|| `[%p, %p]` || LowMem ||\n", 311 (void*)kLowMemBeg, (void*)kLowMemEnd); 312 Printf("MemToShadow(shadow): %p %p %p %p\n", 313 (void*)MEM_TO_SHADOW(kLowShadowBeg), 314 (void*)MEM_TO_SHADOW(kLowShadowEnd), 315 (void*)MEM_TO_SHADOW(kHighShadowBeg), 316 (void*)MEM_TO_SHADOW(kHighShadowEnd)); 317 Printf("red_zone=%zu\n", (uptr)flags()->redzone); 318 Printf("malloc_context_size=%zu\n", (uptr)flags()->malloc_context_size); 319 320 Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE); 321 Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY); 322 Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET); 323 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7); 324 } 325 326 if (flags()->disable_core) { 327 DisableCoreDumper(); 328 } 329 330 uptr shadow_start = kLowShadowBeg; 331 if (kLowShadowBeg > 0) shadow_start -= kMmapGranularity; 332 uptr shadow_end = kHighShadowEnd; 333 if (MemoryRangeIsAvailable(shadow_start, shadow_end)) { 334 if (kLowShadowBeg != kLowShadowEnd) { 335 // mmap the low shadow plus at least one page. 336 ReserveShadowMemoryRange(kLowShadowBeg - kMmapGranularity, kLowShadowEnd); 337 } 338 // mmap the high shadow. 339 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd); 340 // protect the gap 341 void *prot = Mprotect(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1); 342 CHECK(prot == (void*)kShadowGapBeg); 343 } else { 344 Report("Shadow memory range interleaves with an existing memory mapping. " 345 "ASan cannot proceed correctly. ABORTING.\n"); 346 DumpProcessMap(); 347 Die(); 348 } 349 350 InstallSignalHandlers(); 351 352 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited 353 // should be set to 1 prior to initializing the threads. 354 asan_inited = 1; 355 asan_init_is_running = false; 356 357 asanThreadRegistry().Init(); 358 asanThreadRegistry().GetMain()->ThreadStart(); 359 force_interface_symbols(); // no-op. 360 361 if (flags()->verbosity) { 362 Report("AddressSanitizer Init done\n"); 363 } 364} 365 366#if defined(ASAN_USE_PREINIT_ARRAY) 367 // On Linux, we force __asan_init to be called before anyone else 368 // by placing it into .preinit_array section. 369 // FIXME: do we have anything like this on Mac? 370 __attribute__((section(".preinit_array"))) 371 typeof(__asan_init) *__asan_preinit =__asan_init; 372#elif defined(_WIN32) && defined(_DLL) 373 // On Windows, when using dynamic CRT (/MD), we can put a pointer 374 // to __asan_init into the global list of C initializers. 375 // See crt0dat.c in the CRT sources for the details. 376 #pragma section(".CRT$XIB", long, read) // NOLINT 377 __declspec(allocate(".CRT$XIB")) void (*__asan_preinit)() = __asan_init; 378#endif 379