libsanitizer/asan/asan_flags.cpp

   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 }