//===-- asan_rtl.cpp ------------------------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // // This file is a part of AddressSanitizer, an address sanity checker. // // Main file of the ASan run-time library. //===----------------------------------------------------------------------===// #include "asan_activation.h" #include "asan_allocator.h" #include "asan_fake_stack.h" #include "asan_interceptors.h" #include "asan_interface_internal.h" #include "asan_internal.h" #include "asan_mapping.h" #include "asan_poisoning.h" #include "asan_report.h" #include "asan_stack.h" #include "asan_stats.h" #include "asan_suppressions.h" #include "asan_thread.h" #include "lsan/lsan_common.h" #include "sanitizer_common/sanitizer_atomic.h" #include "sanitizer_common/sanitizer_flags.h" #include "sanitizer_common/sanitizer_interface_internal.h" #include "sanitizer_common/sanitizer_libc.h" #include "sanitizer_common/sanitizer_symbolizer.h" #include "ubsan/ubsan_init.h" #include "ubsan/ubsan_platform.h" uptr __asan_shadow_memory_dynamic_address; // Global interface symbol. int __asan_option_detect_stack_use_after_return; // Global interface symbol. uptr *__asan_test_only_reported_buggy_pointer; // Used only for testing asan. namespace __asan { uptr AsanMappingProfile[kAsanMappingProfileSize]; static void AsanDie() { static atomic_uint32_t num_calls; if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) { // Don't die twice - run a busy loop. while (1) { internal_sched_yield(); } } if (common_flags()->print_module_map >= 1) DumpProcessMap(); WaitForDebugger(flags()->sleep_before_dying, "before dying"); if (flags()->unmap_shadow_on_exit) { if (kMidMemBeg) { UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg); UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd); } else { if (kHighShadowEnd) UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg); } } } static void CheckUnwind() { GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_check); stack.Print(); } // -------------------------- Globals --------------------- {{{1 int asan_inited; bool asan_init_is_running; bool replace_intrin_cached; #if !ASAN_FIXED_MAPPING uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; #endif // -------------------------- Misc ---------------- {{{1 void ShowStatsAndAbort() { __asan_print_accumulated_stats(); Die(); } NOINLINE static void ReportGenericErrorWrapper(uptr addr, bool is_write, int size, int exp_arg, bool fatal) { GET_CALLER_PC_BP_SP; ReportGenericError(pc, bp, sp, addr, is_write, size, exp_arg, fatal); } // --------------- LowLevelAllocateCallbac ---------- {{{1 static void OnLowLevelAllocate(uptr ptr, uptr size) { PoisonShadow(ptr, size, kAsanInternalHeapMagic); } // -------------------------- Run-time entry ------------------- {{{1 // exported functions #define ASAN_REPORT_ERROR(type, is_write, size) \ extern "C" NOINLINE INTERFACE_ATTRIBUTE \ void __asan_report_ ## type ## size(uptr addr) { \ GET_CALLER_PC_BP_SP; \ ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true); \ } \ extern "C" NOINLINE INTERFACE_ATTRIBUTE \ void __asan_report_exp_ ## type ## size(uptr addr, u32 exp) { \ GET_CALLER_PC_BP_SP; \ ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true); \ } \ extern "C" NOINLINE INTERFACE_ATTRIBUTE \ void __asan_report_ ## type ## size ## _noabort(uptr addr) { \ GET_CALLER_PC_BP_SP; \ ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false); \ } \ ASAN_REPORT_ERROR(load, false, 1) ASAN_REPORT_ERROR(load, false, 2) ASAN_REPORT_ERROR(load, false, 4) ASAN_REPORT_ERROR(load, false, 8) ASAN_REPORT_ERROR(load, false, 16) ASAN_REPORT_ERROR(store, true, 1) ASAN_REPORT_ERROR(store, true, 2) ASAN_REPORT_ERROR(store, true, 4) ASAN_REPORT_ERROR(store, true, 8) ASAN_REPORT_ERROR(store, true, 16) #define ASAN_REPORT_ERROR_N(type, is_write) \ extern "C" NOINLINE INTERFACE_ATTRIBUTE \ void __asan_report_ ## type ## _n(uptr addr, uptr size) { \ GET_CALLER_PC_BP_SP; \ ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true); \ } \ extern "C" NOINLINE INTERFACE_ATTRIBUTE \ void __asan_report_exp_ ## type ## _n(uptr addr, uptr size, u32 exp) { \ GET_CALLER_PC_BP_SP; \ ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true); \ } \ extern "C" NOINLINE INTERFACE_ATTRIBUTE \ void __asan_report_ ## type ## _n_noabort(uptr addr, uptr size) { \ GET_CALLER_PC_BP_SP; \ ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false); \ } \ ASAN_REPORT_ERROR_N(load, false) ASAN_REPORT_ERROR_N(store, true) #define ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp_arg, fatal) \ uptr sp = MEM_TO_SHADOW(addr); \ uptr s = size <= ASAN_SHADOW_GRANULARITY ? *reinterpret_cast(sp) \ : *reinterpret_cast(sp); \ if (UNLIKELY(s)) { \ if (UNLIKELY(size >= ASAN_SHADOW_GRANULARITY || \ ((s8)((addr & (ASAN_SHADOW_GRANULARITY - 1)) + size - 1)) >= \ (s8)s)) { \ ReportGenericErrorWrapper(addr, is_write, size, exp_arg, fatal); \ } \ } #define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size) \ extern "C" NOINLINE INTERFACE_ATTRIBUTE \ void __asan_##type##size(uptr addr) { \ ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, true) \ } \ extern "C" NOINLINE INTERFACE_ATTRIBUTE \ void __asan_exp_##type##size(uptr addr, u32 exp) { \ ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp, true) \ } \ extern "C" NOINLINE INTERFACE_ATTRIBUTE \ void __asan_##type##size ## _noabort(uptr addr) { \ ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, false) \ } \ ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1) ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2) ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4) ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8) ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16) ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1) ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2) ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4) ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8) ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16) extern "C" NOINLINE INTERFACE_ATTRIBUTE void __asan_loadN(uptr addr, uptr size) { if ((addr = __asan_region_is_poisoned(addr, size))) { GET_CALLER_PC_BP_SP; ReportGenericError(pc, bp, sp, addr, false, size, 0, true); } } extern "C" NOINLINE INTERFACE_ATTRIBUTE void __asan_exp_loadN(uptr addr, uptr size, u32 exp) { if ((addr = __asan_region_is_poisoned(addr, size))) { GET_CALLER_PC_BP_SP; ReportGenericError(pc, bp, sp, addr, false, size, exp, true); } } extern "C" NOINLINE INTERFACE_ATTRIBUTE void __asan_loadN_noabort(uptr addr, uptr size) { if ((addr = __asan_region_is_poisoned(addr, size))) { GET_CALLER_PC_BP_SP; ReportGenericError(pc, bp, sp, addr, false, size, 0, false); } } extern "C" NOINLINE INTERFACE_ATTRIBUTE void __asan_storeN(uptr addr, uptr size) { if ((addr = __asan_region_is_poisoned(addr, size))) { GET_CALLER_PC_BP_SP; ReportGenericError(pc, bp, sp, addr, true, size, 0, true); } } extern "C" NOINLINE INTERFACE_ATTRIBUTE void __asan_exp_storeN(uptr addr, uptr size, u32 exp) { if ((addr = __asan_region_is_poisoned(addr, size))) { GET_CALLER_PC_BP_SP; ReportGenericError(pc, bp, sp, addr, true, size, exp, true); } } extern "C" NOINLINE INTERFACE_ATTRIBUTE void __asan_storeN_noabort(uptr addr, uptr size) { if ((addr = __asan_region_is_poisoned(addr, size))) { GET_CALLER_PC_BP_SP; ReportGenericError(pc, bp, sp, addr, true, size, 0, false); } } // Force the linker to keep the symbols for various ASan interface functions. // We want to keep those in the executable in order to let the instrumented // dynamic libraries access the symbol even if it is not used by the executable // itself. This should help if the build system is removing dead code at link // time. static NOINLINE void force_interface_symbols() { volatile int fake_condition = 0; // prevent dead condition elimination. // __asan_report_* functions are noreturn, so we need a switch to prevent // the compiler from removing any of them. // clang-format off switch (fake_condition) { case 1: __asan_report_load1(0); break; case 2: __asan_report_load2(0); break; case 3: __asan_report_load4(0); break; case 4: __asan_report_load8(0); break; case 5: __asan_report_load16(0); break; case 6: __asan_report_load_n(0, 0); break; case 7: __asan_report_store1(0); break; case 8: __asan_report_store2(0); break; case 9: __asan_report_store4(0); break; case 10: __asan_report_store8(0); break; case 11: __asan_report_store16(0); break; case 12: __asan_report_store_n(0, 0); break; case 13: __asan_report_exp_load1(0, 0); break; case 14: __asan_report_exp_load2(0, 0); break; case 15: __asan_report_exp_load4(0, 0); break; case 16: __asan_report_exp_load8(0, 0); break; case 17: __asan_report_exp_load16(0, 0); break; case 18: __asan_report_exp_load_n(0, 0, 0); break; case 19: __asan_report_exp_store1(0, 0); break; case 20: __asan_report_exp_store2(0, 0); break; case 21: __asan_report_exp_store4(0, 0); break; case 22: __asan_report_exp_store8(0, 0); break; case 23: __asan_report_exp_store16(0, 0); break; case 24: __asan_report_exp_store_n(0, 0, 0); break; case 25: __asan_register_globals(nullptr, 0); break; case 26: __asan_unregister_globals(nullptr, 0); break; case 27: __asan_set_death_callback(nullptr); break; case 28: __asan_set_error_report_callback(nullptr); break; case 29: __asan_handle_no_return(); break; case 30: __asan_address_is_poisoned(nullptr); break; case 31: __asan_poison_memory_region(nullptr, 0); break; case 32: __asan_unpoison_memory_region(nullptr, 0); break; case 34: __asan_before_dynamic_init(nullptr); break; case 35: __asan_after_dynamic_init(); break; case 36: __asan_poison_stack_memory(0, 0); break; case 37: __asan_unpoison_stack_memory(0, 0); break; case 38: __asan_region_is_poisoned(0, 0); break; case 39: __asan_describe_address(0); break; case 40: __asan_set_shadow_00(0, 0); break; case 41: __asan_set_shadow_01(0, 0); break; case 42: __asan_set_shadow_02(0, 0); break; case 43: __asan_set_shadow_03(0, 0); break; case 44: __asan_set_shadow_04(0, 0); break; case 45: __asan_set_shadow_05(0, 0); break; case 46: __asan_set_shadow_06(0, 0); break; case 47: __asan_set_shadow_07(0, 0); break; case 48: __asan_set_shadow_f1(0, 0); break; case 49: __asan_set_shadow_f2(0, 0); break; case 50: __asan_set_shadow_f3(0, 0); break; case 51: __asan_set_shadow_f5(0, 0); break; case 52: __asan_set_shadow_f8(0, 0); break; } // clang-format on } static void asan_atexit() { Printf("AddressSanitizer exit stats:\n"); __asan_print_accumulated_stats(); // Print AsanMappingProfile. for (uptr i = 0; i < kAsanMappingProfileSize; i++) { if (AsanMappingProfile[i] == 0) continue; Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]); } } static void InitializeHighMemEnd() { #if !ASAN_FIXED_MAPPING kHighMemEnd = GetMaxUserVirtualAddress(); // Increase kHighMemEnd to make sure it's properly // aligned together with kHighMemBeg: kHighMemEnd |= (GetMmapGranularity() << ASAN_SHADOW_SCALE) - 1; #endif // !ASAN_FIXED_MAPPING CHECK_EQ((kHighMemBeg % GetMmapGranularity()), 0); } void PrintAddressSpaceLayout() { if (kHighMemBeg) { Printf("|| `[%p, %p]` || HighMem ||\n", (void*)kHighMemBeg, (void*)kHighMemEnd); Printf("|| `[%p, %p]` || HighShadow ||\n", (void*)kHighShadowBeg, (void*)kHighShadowEnd); } if (kMidMemBeg) { Printf("|| `[%p, %p]` || ShadowGap3 ||\n", (void*)kShadowGap3Beg, (void*)kShadowGap3End); Printf("|| `[%p, %p]` || MidMem ||\n", (void*)kMidMemBeg, (void*)kMidMemEnd); Printf("|| `[%p, %p]` || ShadowGap2 ||\n", (void*)kShadowGap2Beg, (void*)kShadowGap2End); Printf("|| `[%p, %p]` || MidShadow ||\n", (void*)kMidShadowBeg, (void*)kMidShadowEnd); } Printf("|| `[%p, %p]` || ShadowGap ||\n", (void*)kShadowGapBeg, (void*)kShadowGapEnd); if (kLowShadowBeg) { Printf("|| `[%p, %p]` || LowShadow ||\n", (void*)kLowShadowBeg, (void*)kLowShadowEnd); Printf("|| `[%p, %p]` || LowMem ||\n", (void*)kLowMemBeg, (void*)kLowMemEnd); } Printf("MemToShadow(shadow): %p %p", (void*)MEM_TO_SHADOW(kLowShadowBeg), (void*)MEM_TO_SHADOW(kLowShadowEnd)); if (kHighMemBeg) { Printf(" %p %p", (void*)MEM_TO_SHADOW(kHighShadowBeg), (void*)MEM_TO_SHADOW(kHighShadowEnd)); } if (kMidMemBeg) { Printf(" %p %p", (void*)MEM_TO_SHADOW(kMidShadowBeg), (void*)MEM_TO_SHADOW(kMidShadowEnd)); } Printf("\n"); Printf("redzone=%zu\n", (uptr)flags()->redzone); Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone); Printf("quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb); Printf("thread_local_quarantine_size_kb=%zuK\n", (uptr)flags()->thread_local_quarantine_size_kb); Printf("malloc_context_size=%zu\n", (uptr)common_flags()->malloc_context_size); Printf("SHADOW_SCALE: %d\n", (int)ASAN_SHADOW_SCALE); Printf("SHADOW_GRANULARITY: %d\n", (int)ASAN_SHADOW_GRANULARITY); Printf("SHADOW_OFFSET: 0x%zx\n", (uptr)ASAN_SHADOW_OFFSET); CHECK(ASAN_SHADOW_SCALE >= 3 && ASAN_SHADOW_SCALE <= 7); if (kMidMemBeg) CHECK(kMidShadowBeg > kLowShadowEnd && kMidMemBeg > kMidShadowEnd && kHighShadowBeg > kMidMemEnd); } static void AsanInitInternal() { if (LIKELY(asan_inited)) return; SanitizerToolName = "AddressSanitizer"; CHECK(!asan_init_is_running && "ASan init calls itself!"); asan_init_is_running = true; CacheBinaryName(); // Initialize flags. This must be done early, because most of the // initialization steps look at flags(). InitializeFlags(); WaitForDebugger(flags()->sleep_before_init, "before init"); // Stop performing init at this point if we are being loaded via // dlopen() and the platform supports it. if (SANITIZER_SUPPORTS_INIT_FOR_DLOPEN && UNLIKELY(HandleDlopenInit())) { asan_init_is_running = false; VReport(1, "AddressSanitizer init is being performed for dlopen().\n"); return; } AsanCheckIncompatibleRT(); AsanCheckDynamicRTPrereqs(); AvoidCVE_2016_2143(); SetCanPoisonMemory(flags()->poison_heap); SetMallocContextSize(common_flags()->malloc_context_size); InitializePlatformExceptionHandlers(); InitializeHighMemEnd(); // Make sure we are not statically linked. AsanDoesNotSupportStaticLinkage(); // Install tool-specific callbacks in sanitizer_common. AddDieCallback(AsanDie); SetCheckUnwindCallback(CheckUnwind); SetPrintfAndReportCallback(AppendToErrorMessageBuffer); __sanitizer_set_report_path(common_flags()->log_path); __asan_option_detect_stack_use_after_return = flags()->detect_stack_use_after_return; __sanitizer::InitializePlatformEarly(); // Setup internal allocator callback. SetLowLevelAllocateMinAlignment(ASAN_SHADOW_GRANULARITY); SetLowLevelAllocateCallback(OnLowLevelAllocate); InitializeAsanInterceptors(); CheckASLR(); // Enable system log ("adb logcat") on Android. // Doing this before interceptors are initialized crashes in: // AsanInitInternal -> android_log_write -> __interceptor_strcmp AndroidLogInit(); ReplaceSystemMalloc(); DisableCoreDumperIfNecessary(); InitializeShadowMemory(); AsanTSDInit(PlatformTSDDtor); InstallDeadlySignalHandlers(AsanOnDeadlySignal); AllocatorOptions allocator_options; allocator_options.SetFrom(flags(), common_flags()); InitializeAllocator(allocator_options); if (SANITIZER_START_BACKGROUND_THREAD_IN_ASAN_INTERNAL) MaybeStartBackgroudThread(); // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited // should be set to 1 prior to initializing the threads. replace_intrin_cached = flags()->replace_intrin; asan_inited = 1; asan_init_is_running = false; if (flags()->atexit) Atexit(asan_atexit); InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir); // Now that ASan runtime is (mostly) initialized, deactivate it if // necessary, so that it can be re-activated when requested. if (flags()->start_deactivated) AsanDeactivate(); // interceptors InitTlsSize(); // Create main thread. AsanThread *main_thread = CreateMainThread(); CHECK_EQ(0, main_thread->tid()); force_interface_symbols(); // no-op. SanitizerInitializeUnwinder(); if (CAN_SANITIZE_LEAKS) { __lsan::InitCommonLsan(); InstallAtExitCheckLeaks(); } #if CAN_SANITIZE_UB __ubsan::InitAsPlugin(); #endif InitializeSuppressions(); if (CAN_SANITIZE_LEAKS) { // LateInitialize() calls dlsym, which can allocate an error string buffer // in the TLS. Let's ignore the allocation to avoid reporting a leak. __lsan::ScopedInterceptorDisabler disabler; Symbolizer::LateInitialize(); } else { Symbolizer::LateInitialize(); } VReport(1, "AddressSanitizer Init done\n"); WaitForDebugger(flags()->sleep_after_init, "after init"); } // Initialize as requested from some part of ASan runtime library (interceptors, // allocator, etc). void AsanInitFromRtl() { AsanInitInternal(); } #if ASAN_DYNAMIC // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable // (and thus normal initializers from .preinit_array or modules haven't run). class AsanInitializer { public: AsanInitializer() { AsanInitFromRtl(); } }; static AsanInitializer asan_initializer; #endif // ASAN_DYNAMIC void UnpoisonStack(uptr bottom, uptr top, const char *type) { static const uptr kMaxExpectedCleanupSize = 64 << 20; // 64M if (top - bottom > kMaxExpectedCleanupSize) { static bool reported_warning = false; if (reported_warning) return; reported_warning = true; Report( "WARNING: ASan is ignoring requested __asan_handle_no_return: " "stack type: %s top: %p; bottom %p; size: %p (%zd)\n" "False positive error reports may follow\n" "For details see " "https://github.com/google/sanitizers/issues/189\n", type, (void *)top, (void *)bottom, (void *)(top - bottom), top - bottom); return; } PoisonShadow(bottom, RoundUpTo(top - bottom, ASAN_SHADOW_GRANULARITY), 0); } static void UnpoisonDefaultStack() { uptr bottom, top; if (AsanThread *curr_thread = GetCurrentThread()) { int local_stack; const uptr page_size = GetPageSizeCached(); top = curr_thread->stack_top(); bottom = ((uptr)&local_stack - page_size) & ~(page_size - 1); } else { CHECK(!SANITIZER_FUCHSIA); // If we haven't seen this thread, try asking the OS for stack bounds. uptr tls_addr, tls_size, stack_size; GetThreadStackAndTls(/*main=*/false, &bottom, &stack_size, &tls_addr, &tls_size); top = bottom + stack_size; } UnpoisonStack(bottom, top, "default"); } static void UnpoisonFakeStack() { AsanThread *curr_thread = GetCurrentThread(); if (!curr_thread) return; FakeStack *stack = curr_thread->get_fake_stack(); if (!stack) return; stack->HandleNoReturn(); } } // namespace __asan // ---------------------- Interface ---------------- {{{1 using namespace __asan; void NOINLINE __asan_handle_no_return() { if (asan_init_is_running) return; if (!PlatformUnpoisonStacks()) UnpoisonDefaultStack(); UnpoisonFakeStack(); } extern "C" void *__asan_extra_spill_area() { AsanThread *t = GetCurrentThread(); CHECK(t); return t->extra_spill_area(); } void __asan_handle_vfork(void *sp) { AsanThread *t = GetCurrentThread(); CHECK(t); uptr bottom = t->stack_bottom(); PoisonShadow(bottom, (uptr)sp - bottom, 0); } void NOINLINE __asan_set_death_callback(void (*callback)(void)) { SetUserDieCallback(callback); } // Initialize as requested from instrumented application code. // We use this call as a trigger to wake up ASan from deactivated state. void __asan_init() { AsanActivate(); AsanInitInternal(); } void __asan_version_mismatch_check() { // Do nothing. }