1 //===-- asan_flags.cpp ------------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of AddressSanitizer, an address sanity checker. 10 // 11 // ASan flag parsing logic. 12 //===----------------------------------------------------------------------===// 13 14 #include "asan_activation.h" 15 #include "asan_flags.h" 16 #include "asan_interface_internal.h" 17 #include "asan_stack.h" 18 #include "lsan/lsan_common.h" 19 #include "sanitizer_common/sanitizer_common.h" 20 #include "sanitizer_common/sanitizer_flags.h" 21 #include "sanitizer_common/sanitizer_flag_parser.h" 22 #include "ubsan/ubsan_flags.h" 23 #include "ubsan/ubsan_platform.h" 24 25 namespace __asan { 26 27 Flags asan_flags_dont_use_directly; // use via flags(). 28 29 static const char *MaybeCallAsanDefaultOptions() { 30 return (&__asan_default_options) ? __asan_default_options() : ""; 31 } 32 33 static const char *MaybeUseAsanDefaultOptionsCompileDefinition() { 34 #ifdef ASAN_DEFAULT_OPTIONS 35 return SANITIZER_STRINGIFY(ASAN_DEFAULT_OPTIONS); 36 #else 37 return ""; 38 #endif 39 } 40 41 void Flags::SetDefaults() { 42 #define ASAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue; 43 #include "asan_flags.inc" 44 #undef ASAN_FLAG 45 } 46 47 static void RegisterAsanFlags(FlagParser *parser, Flags *f) { 48 #define ASAN_FLAG(Type, Name, DefaultValue, Description) \ 49 RegisterFlag(parser, #Name, Description, &f->Name); 50 #include "asan_flags.inc" 51 #undef ASAN_FLAG 52 } 53 54 void InitializeFlags() { 55 // Set the default values and prepare for parsing ASan and common flags. 56 SetCommonFlagsDefaults(); 57 { 58 CommonFlags cf; 59 cf.CopyFrom(*common_flags()); 60 cf.detect_leaks = cf.detect_leaks && CAN_SANITIZE_LEAKS; 61 cf.external_symbolizer_path = GetEnv("ASAN_SYMBOLIZER_PATH"); 62 cf.malloc_context_size = kDefaultMallocContextSize; 63 cf.intercept_tls_get_addr = true; 64 cf.exitcode = 1; 65 OverrideCommonFlags(cf); 66 } 67 Flags *f = flags(); 68 f->SetDefaults(); 69 70 FlagParser asan_parser; 71 RegisterAsanFlags(&asan_parser, f); 72 RegisterCommonFlags(&asan_parser); 73 74 // Set the default values and prepare for parsing LSan and UBSan flags 75 // (which can also overwrite common flags). 76 #if CAN_SANITIZE_LEAKS 77 __lsan::Flags *lf = __lsan::flags(); 78 lf->SetDefaults(); 79 80 FlagParser lsan_parser; 81 __lsan::RegisterLsanFlags(&lsan_parser, lf); 82 RegisterCommonFlags(&lsan_parser); 83 #endif 84 85 #if CAN_SANITIZE_UB 86 __ubsan::Flags *uf = __ubsan::flags(); 87 uf->SetDefaults(); 88 89 FlagParser ubsan_parser; 90 __ubsan::RegisterUbsanFlags(&ubsan_parser, uf); 91 RegisterCommonFlags(&ubsan_parser); 92 #endif 93 94 if (SANITIZER_MAC) { 95 // Support macOS MallocScribble and MallocPreScribble: 96 // <https://developer.apple.com/library/content/documentation/Performance/ 97 // Conceptual/ManagingMemory/Articles/MallocDebug.html> 98 if (GetEnv("MallocScribble")) { 99 f->max_free_fill_size = 0x1000; 100 } 101 if (GetEnv("MallocPreScribble")) { 102 f->malloc_fill_byte = 0xaa; 103 } 104 } 105 106 // Override from ASan compile definition. 107 const char *asan_compile_def = MaybeUseAsanDefaultOptionsCompileDefinition(); 108 asan_parser.ParseString(asan_compile_def); 109 110 // Override from user-specified string. 111 const char *asan_default_options = MaybeCallAsanDefaultOptions(); 112 asan_parser.ParseString(asan_default_options); 113 #if CAN_SANITIZE_UB 114 const char *ubsan_default_options = __ubsan::MaybeCallUbsanDefaultOptions(); 115 ubsan_parser.ParseString(ubsan_default_options); 116 #endif 117 #if CAN_SANITIZE_LEAKS 118 const char *lsan_default_options = __lsan::MaybeCallLsanDefaultOptions(); 119 lsan_parser.ParseString(lsan_default_options); 120 #endif 121 122 // Override from command line. 123 asan_parser.ParseStringFromEnv("ASAN_OPTIONS"); 124 #if CAN_SANITIZE_LEAKS 125 lsan_parser.ParseStringFromEnv("LSAN_OPTIONS"); 126 #endif 127 #if CAN_SANITIZE_UB 128 ubsan_parser.ParseStringFromEnv("UBSAN_OPTIONS"); 129 #endif 130 131 InitializeCommonFlags(); 132 133 // TODO(eugenis): dump all flags at verbosity>=2? 134 if (Verbosity()) ReportUnrecognizedFlags(); 135 136 if (common_flags()->help) { 137 // TODO(samsonov): print all of the flags (ASan, LSan, common). 138 asan_parser.PrintFlagDescriptions(); 139 } 140 141 // Flag validation: 142 if (!CAN_SANITIZE_LEAKS && common_flags()->detect_leaks) { 143 Report("%s: detect_leaks is not supported on this platform.\n", 144 SanitizerToolName); 145 Die(); 146 } 147 // Ensure that redzone is at least SHADOW_GRANULARITY. 148 if (f->redzone < (int)SHADOW_GRANULARITY) 149 f->redzone = SHADOW_GRANULARITY; 150 // Make "strict_init_order" imply "check_initialization_order". 151 // TODO(samsonov): Use a single runtime flag for an init-order checker. 152 if (f->strict_init_order) { 153 f->check_initialization_order = true; 154 } 155 CHECK_LE((uptr)common_flags()->malloc_context_size, kStackTraceMax); 156 CHECK_LE(f->min_uar_stack_size_log, f->max_uar_stack_size_log); 157 CHECK_GE(f->redzone, 16); 158 CHECK_GE(f->max_redzone, f->redzone); 159 CHECK_LE(f->max_redzone, 2048); 160 CHECK(IsPowerOfTwo(f->redzone)); 161 CHECK(IsPowerOfTwo(f->max_redzone)); 162 if (SANITIZER_RTEMS) { 163 CHECK(!f->unmap_shadow_on_exit); 164 CHECK(!f->protect_shadow_gap); 165 } 166 167 // quarantine_size is deprecated but we still honor it. 168 // quarantine_size can not be used together with quarantine_size_mb. 169 if (f->quarantine_size >= 0 && f->quarantine_size_mb >= 0) { 170 Report("%s: please use either 'quarantine_size' (deprecated) or " 171 "quarantine_size_mb, but not both\n", SanitizerToolName); 172 Die(); 173 } 174 if (f->quarantine_size >= 0) 175 f->quarantine_size_mb = f->quarantine_size >> 20; 176 if (f->quarantine_size_mb < 0) { 177 const int kDefaultQuarantineSizeMb = 178 (ASAN_LOW_MEMORY) ? 1UL << 4 : 1UL << 8; 179 f->quarantine_size_mb = kDefaultQuarantineSizeMb; 180 } 181 if (f->thread_local_quarantine_size_kb < 0) { 182 const u32 kDefaultThreadLocalQuarantineSizeKb = 183 // It is not advised to go lower than 64Kb, otherwise quarantine batches 184 // pushed from thread local quarantine to global one will create too 185 // much overhead. One quarantine batch size is 8Kb and it holds up to 186 // 1021 chunk, which amounts to 1/8 memory overhead per batch when 187 // thread local quarantine is set to 64Kb. 188 (ASAN_LOW_MEMORY) ? 1 << 6 : FIRST_32_SECOND_64(1 << 8, 1 << 10); 189 f->thread_local_quarantine_size_kb = kDefaultThreadLocalQuarantineSizeKb; 190 } 191 if (f->thread_local_quarantine_size_kb == 0 && f->quarantine_size_mb > 0) { 192 Report("%s: thread_local_quarantine_size_kb can be set to 0 only when " 193 "quarantine_size_mb is set to 0\n", SanitizerToolName); 194 Die(); 195 } 196 if (!f->replace_str && common_flags()->intercept_strlen) { 197 Report("WARNING: strlen interceptor is enabled even though replace_str=0. " 198 "Use intercept_strlen=0 to disable it."); 199 } 200 if (!f->replace_str && common_flags()->intercept_strchr) { 201 Report("WARNING: strchr* interceptors are enabled even though " 202 "replace_str=0. Use intercept_strchr=0 to disable them."); 203 } 204 if (!f->replace_str && common_flags()->intercept_strndup) { 205 Report("WARNING: strndup* interceptors are enabled even though " 206 "replace_str=0. Use intercept_strndup=0 to disable them."); 207 } 208 } 209 210 } // namespace __asan 211 212 SANITIZER_INTERFACE_WEAK_DEF(const char*, __asan_default_options, void) { 213 return ""; 214 } 215