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 return SANITIZER_STRINGIFY(ASAN_DEFAULT_OPTIONS);
35 #else
36 return "";
37 #endif
38 }
39
SetDefaults()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
RegisterAsanFlags(FlagParser * parser,Flags * f)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
InitializeFlags()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
SANITIZER_INTERFACE_WEAK_DEF(const char *,__asan_default_options,void)211 SANITIZER_INTERFACE_WEAK_DEF(const char*, __asan_default_options, void) {
212 return "";
213 }
214