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 
MaybeCallAsanDefaultOptions()28 static const char *MaybeCallAsanDefaultOptions() {
29   return (&__asan_default_options) ? __asan_default_options() : "";
30 }
31 
MaybeUseAsanDefaultOptionsCompileDefinition()32 static const char *MaybeUseAsanDefaultOptionsCompileDefinition() {
33 #ifdef ASAN_DEFAULT_OPTIONS
34 // Stringize the macro value.
35 # define ASAN_STRINGIZE(x) #x
36 # define ASAN_STRINGIZE_OPTIONS(options) ASAN_STRINGIZE(options)
37   return ASAN_STRINGIZE_OPTIONS(ASAN_DEFAULT_OPTIONS);
38 #else
39   return "";
40 #endif
41 }
42 
SetDefaults()43 void Flags::SetDefaults() {
44 #define ASAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
45 #include "asan_flags.inc"
46 #undef ASAN_FLAG
47 }
48 
RegisterAsanFlags(FlagParser * parser,Flags * f)49 static void RegisterAsanFlags(FlagParser *parser, Flags *f) {
50 #define ASAN_FLAG(Type, Name, DefaultValue, Description) \
51   RegisterFlag(parser, #Name, Description, &f->Name);
52 #include "asan_flags.inc"
53 #undef ASAN_FLAG
54 }
55 
InitializeFlags()56 void InitializeFlags() {
57   // Set the default values and prepare for parsing ASan and common flags.
58   SetCommonFlagsDefaults();
59   {
60     CommonFlags cf;
61     cf.CopyFrom(*common_flags());
62     cf.detect_leaks = CAN_SANITIZE_LEAKS;
63     cf.external_symbolizer_path = GetEnv("ASAN_SYMBOLIZER_PATH");
64     cf.malloc_context_size = kDefaultMallocContextSize;
65     cf.intercept_tls_get_addr = true;
66     cf.exitcode = 1;
67     OverrideCommonFlags(cf);
68   }
69   Flags *f = flags();
70   f->SetDefaults();
71 
72   FlagParser asan_parser;
73   RegisterAsanFlags(&asan_parser, f);
74   RegisterCommonFlags(&asan_parser);
75 
76   // Set the default values and prepare for parsing LSan and UBSan flags
77   // (which can also overwrite common flags).
78 #if CAN_SANITIZE_LEAKS
79   __lsan::Flags *lf = __lsan::flags();
80   lf->SetDefaults();
81 
82   FlagParser lsan_parser;
83   __lsan::RegisterLsanFlags(&lsan_parser, lf);
84   RegisterCommonFlags(&lsan_parser);
85 #endif
86 
87 #if CAN_SANITIZE_UB
88   __ubsan::Flags *uf = __ubsan::flags();
89   uf->SetDefaults();
90 
91   FlagParser ubsan_parser;
92   __ubsan::RegisterUbsanFlags(&ubsan_parser, uf);
93   RegisterCommonFlags(&ubsan_parser);
94 #endif
95 
96   // Override from ASan compile definition.
97   const char *asan_compile_def = MaybeUseAsanDefaultOptionsCompileDefinition();
98   asan_parser.ParseString(asan_compile_def);
99 
100   // Override from user-specified string.
101   const char *asan_default_options = MaybeCallAsanDefaultOptions();
102   asan_parser.ParseString(asan_default_options);
103 #if CAN_SANITIZE_UB
104   const char *ubsan_default_options = __ubsan::MaybeCallUbsanDefaultOptions();
105   ubsan_parser.ParseString(ubsan_default_options);
106 #endif
107 
108   // Override from command line.
109   asan_parser.ParseString(GetEnv("ASAN_OPTIONS"));
110 #if CAN_SANITIZE_LEAKS
111   lsan_parser.ParseString(GetEnv("LSAN_OPTIONS"));
112 #endif
113 #if CAN_SANITIZE_UB
114   ubsan_parser.ParseString(GetEnv("UBSAN_OPTIONS"));
115 #endif
116 
117   // Let activation flags override current settings. On Android they come
118   // from a system property. On other platforms this is no-op.
119   if (!flags()->start_deactivated) {
120     char buf[100];
121     GetExtraActivationFlags(buf, sizeof(buf));
122     asan_parser.ParseString(buf);
123   }
124 
125   SetVerbosity(common_flags()->verbosity);
126 
127   // TODO(eugenis): dump all flags at verbosity>=2?
128   if (Verbosity()) ReportUnrecognizedFlags();
129 
130   if (common_flags()->help) {
131     // TODO(samsonov): print all of the flags (ASan, LSan, common).
132     asan_parser.PrintFlagDescriptions();
133   }
134 
135   // Flag validation:
136   if (!CAN_SANITIZE_LEAKS && common_flags()->detect_leaks) {
137     Report("%s: detect_leaks is not supported on this platform.\n",
138            SanitizerToolName);
139     Die();
140   }
141   // Make "strict_init_order" imply "check_initialization_order".
142   // TODO(samsonov): Use a single runtime flag for an init-order checker.
143   if (f->strict_init_order) {
144     f->check_initialization_order = true;
145   }
146   CHECK_LE((uptr)common_flags()->malloc_context_size, kStackTraceMax);
147   CHECK_LE(f->min_uar_stack_size_log, f->max_uar_stack_size_log);
148   CHECK_GE(f->redzone, 16);
149   CHECK_GE(f->max_redzone, f->redzone);
150   CHECK_LE(f->max_redzone, 2048);
151   CHECK(IsPowerOfTwo(f->redzone));
152   CHECK(IsPowerOfTwo(f->max_redzone));
153 
154   // quarantine_size is deprecated but we still honor it.
155   // quarantine_size can not be used together with quarantine_size_mb.
156   if (f->quarantine_size >= 0 && f->quarantine_size_mb >= 0) {
157     Report("%s: please use either 'quarantine_size' (deprecated) or "
158            "quarantine_size_mb, but not both\n", SanitizerToolName);
159     Die();
160   }
161   if (f->quarantine_size >= 0)
162     f->quarantine_size_mb = f->quarantine_size >> 20;
163   if (f->quarantine_size_mb < 0) {
164     const int kDefaultQuarantineSizeMb =
165         (ASAN_LOW_MEMORY) ? 1UL << 6 : 1UL << 8;
166     f->quarantine_size_mb = kDefaultQuarantineSizeMb;
167   }
168 }
169 
170 }  // namespace __asan
171 
172 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
173 extern "C" {
174 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
__asan_default_options()175 const char* __asan_default_options() { return ""; }
176 }  // extern "C"
177 #endif
178