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