libsanitizer/asan/asan_flags.cc

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