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 = 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 if (SANITIZER_MAC) {
97 // Support macOS MallocScribble and MallocPreScribble:
98 // <https://developer.apple.com/library/content/documentation/Performance/
99 // Conceptual/ManagingMemory/Articles/MallocDebug.html>
100 if (GetEnv("MallocScribble")) {
101 f->max_free_fill_size = 0x1000;
102 }
103 if (GetEnv("MallocPreScribble")) {
104 f->malloc_fill_byte = 0xaa;
105 }
106 }
107
108 // Override from ASan compile definition.
109 const char *asan_compile_def = MaybeUseAsanDefaultOptionsCompileDefinition();
110 asan_parser.ParseString(asan_compile_def);
111
112 // Override from user-specified string.
113 const char *asan_default_options = MaybeCallAsanDefaultOptions();
114 asan_parser.ParseString(asan_default_options);
115 #if CAN_SANITIZE_UB
116 const char *ubsan_default_options = __ubsan::MaybeCallUbsanDefaultOptions();
117 ubsan_parser.ParseString(ubsan_default_options);
118 #endif
119 #if CAN_SANITIZE_LEAKS
120 const char *lsan_default_options = __lsan::MaybeCallLsanDefaultOptions();
121 lsan_parser.ParseString(lsan_default_options);
122 #endif
123
124 // Override from command line.
125 asan_parser.ParseString(GetEnv("ASAN_OPTIONS"));
126 #if CAN_SANITIZE_LEAKS
127 lsan_parser.ParseString(GetEnv("LSAN_OPTIONS"));
128 #endif
129 #if CAN_SANITIZE_UB
130 ubsan_parser.ParseString(GetEnv("UBSAN_OPTIONS"));
131 #endif
132
133 InitializeCommonFlags();
134
135 // TODO(eugenis): dump all flags at verbosity>=2?
136 if (Verbosity()) ReportUnrecognizedFlags();
137
138 if (common_flags()->help) {
139 // TODO(samsonov): print all of the flags (ASan, LSan, common).
140 asan_parser.PrintFlagDescriptions();
141 }
142
143 // Flag validation:
144 if (!CAN_SANITIZE_LEAKS && common_flags()->detect_leaks) {
145 Report("%s: detect_leaks is not supported on this platform.\n",
146 SanitizerToolName);
147 Die();
148 }
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
162 // quarantine_size is deprecated but we still honor it.
163 // quarantine_size can not be used together with quarantine_size_mb.
164 if (f->quarantine_size >= 0 && f->quarantine_size_mb >= 0) {
165 Report("%s: please use either 'quarantine_size' (deprecated) or "
166 "quarantine_size_mb, but not both\n", SanitizerToolName);
167 Die();
168 }
169 if (f->quarantine_size >= 0)
170 f->quarantine_size_mb = f->quarantine_size >> 20;
171 if (f->quarantine_size_mb < 0) {
172 const int kDefaultQuarantineSizeMb =
173 (ASAN_LOW_MEMORY) ? 1UL << 4 : 1UL << 8;
174 f->quarantine_size_mb = kDefaultQuarantineSizeMb;
175 }
176 if (f->thread_local_quarantine_size_kb < 0) {
177 const u32 kDefaultThreadLocalQuarantineSizeKb =
178 // It is not advised to go lower than 64Kb, otherwise quarantine batches
179 // pushed from thread local quarantine to global one will create too
180 // much overhead. One quarantine batch size is 8Kb and it holds up to
181 // 1021 chunk, which amounts to 1/8 memory overhead per batch when
182 // thread local quarantine is set to 64Kb.
183 (ASAN_LOW_MEMORY) ? 1 << 6 : FIRST_32_SECOND_64(1 << 8, 1 << 10);
184 f->thread_local_quarantine_size_kb = kDefaultThreadLocalQuarantineSizeKb;
185 }
186 if (f->thread_local_quarantine_size_kb == 0 && f->quarantine_size_mb > 0) {
187 Report("%s: thread_local_quarantine_size_kb can be set to 0 only when "
188 "quarantine_size_mb is set to 0\n", SanitizerToolName);
189 Die();
190 }
191 if (!f->replace_str && common_flags()->intercept_strlen) {
192 Report("WARNING: strlen interceptor is enabled even though replace_str=0. "
193 "Use intercept_strlen=0 to disable it.");
194 }
195 if (!f->replace_str && common_flags()->intercept_strchr) {
196 Report("WARNING: strchr* interceptors are enabled even though "
197 "replace_str=0. Use intercept_strchr=0 to disable them.");
198 }
199 if (!f->replace_str && common_flags()->intercept_strndup) {
200 Report("WARNING: strndup* interceptors are enabled even though "
201 "replace_str=0. Use intercept_strndup=0 to disable them.");
202 }
203 }
204
205 } // namespace __asan
206
SANITIZER_INTERFACE_WEAK_DEF(const char *,__asan_default_options,void)207 SANITIZER_INTERFACE_WEAK_DEF(const char*, __asan_default_options, void) {
208 return "";
209 }
210