1 //===-- asan_flags.cc -------------------------------------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of AddressSanitizer, an address sanity checker.
11 //
12 // ASan flag parsing logic.
13 //===----------------------------------------------------------------------===//
14
15 #include "asan_activation.h"
16 #include "asan_flags.h"
17 #include "asan_interface_internal.h"
18 #include "asan_stack.h"
19 #include "lsan/lsan_common.h"
20 #include "sanitizer_common/sanitizer_common.h"
21 #include "sanitizer_common/sanitizer_flags.h"
22 #include "sanitizer_common/sanitizer_flag_parser.h"
23 #include "ubsan/ubsan_flags.h"
24 #include "ubsan/ubsan_platform.h"
25
26 namespace __asan {
27
28 Flags asan_flags_dont_use_directly; // use via flags().
29
MaybeCallAsanDefaultOptions()30 static const char *MaybeCallAsanDefaultOptions() {
31 return (&__asan_default_options) ? __asan_default_options() : "";
32 }
33
MaybeUseAsanDefaultOptionsCompileDefinition()34 static const char *MaybeUseAsanDefaultOptionsCompileDefinition() {
35 #ifdef ASAN_DEFAULT_OPTIONS
36 return SANITIZER_STRINGIFY(ASAN_DEFAULT_OPTIONS);
37 #else
38 return "";
39 #endif
40 }
41
SetDefaults()42 void Flags::SetDefaults() {
43 #define ASAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
44 #include "asan_flags.inc"
45 #undef ASAN_FLAG
46 }
47
RegisterAsanFlags(FlagParser * parser,Flags * f)48 static void RegisterAsanFlags(FlagParser *parser, Flags *f) {
49 #define ASAN_FLAG(Type, Name, DefaultValue, Description) \
50 RegisterFlag(parser, #Name, Description, &f->Name);
51 #include "asan_flags.inc"
52 #undef ASAN_FLAG
53 }
54
InitializeFlags()55 void InitializeFlags() {
56 // Set the default values and prepare for parsing ASan and common flags.
57 SetCommonFlagsDefaults();
58 {
59 CommonFlags cf;
60 cf.CopyFrom(*common_flags());
61 cf.detect_leaks = cf.detect_leaks && CAN_SANITIZE_LEAKS;
62 cf.external_symbolizer_path = GetEnv("ASAN_SYMBOLIZER_PATH");
63 cf.malloc_context_size = kDefaultMallocContextSize;
64 cf.intercept_tls_get_addr = true;
65 cf.exitcode = 1;
66 OverrideCommonFlags(cf);
67 }
68 Flags *f = flags();
69 f->SetDefaults();
70
71 FlagParser asan_parser;
72 RegisterAsanFlags(&asan_parser, f);
73 RegisterCommonFlags(&asan_parser);
74
75 // Set the default values and prepare for parsing LSan and UBSan flags
76 // (which can also overwrite common flags).
77 #if CAN_SANITIZE_LEAKS
78 __lsan::Flags *lf = __lsan::flags();
79 lf->SetDefaults();
80
81 FlagParser lsan_parser;
82 __lsan::RegisterLsanFlags(&lsan_parser, lf);
83 RegisterCommonFlags(&lsan_parser);
84 #endif
85
86 #if CAN_SANITIZE_UB
87 __ubsan::Flags *uf = __ubsan::flags();
88 uf->SetDefaults();
89
90 FlagParser ubsan_parser;
91 __ubsan::RegisterUbsanFlags(&ubsan_parser, uf);
92 RegisterCommonFlags(&ubsan_parser);
93 #endif
94
95 if (SANITIZER_MAC) {
96 // Support macOS MallocScribble and MallocPreScribble:
97 // <https://developer.apple.com/library/content/documentation/Performance/
98 // Conceptual/ManagingMemory/Articles/MallocDebug.html>
99 if (GetEnv("MallocScribble")) {
100 f->max_free_fill_size = 0x1000;
101 }
102 if (GetEnv("MallocPreScribble")) {
103 f->malloc_fill_byte = 0xaa;
104 }
105 }
106
107 // Override from ASan compile definition.
108 const char *asan_compile_def = MaybeUseAsanDefaultOptionsCompileDefinition();
109 asan_parser.ParseString(asan_compile_def);
110
111 // Override from user-specified string.
112 const char *asan_default_options = MaybeCallAsanDefaultOptions();
113 asan_parser.ParseString(asan_default_options);
114 #if CAN_SANITIZE_UB
115 const char *ubsan_default_options = __ubsan::MaybeCallUbsanDefaultOptions();
116 ubsan_parser.ParseString(ubsan_default_options);
117 #endif
118 #if CAN_SANITIZE_LEAKS
119 const char *lsan_default_options = __lsan::MaybeCallLsanDefaultOptions();
120 lsan_parser.ParseString(lsan_default_options);
121 #endif
122
123 // Override from command line.
124 asan_parser.ParseString(GetEnv("ASAN_OPTIONS"));
125 #if CAN_SANITIZE_LEAKS
126 lsan_parser.ParseString(GetEnv("LSAN_OPTIONS"));
127 #endif
128 #if CAN_SANITIZE_UB
129 ubsan_parser.ParseString(GetEnv("UBSAN_OPTIONS"));
130 #endif
131
132 InitializeCommonFlags();
133
134 // TODO(eugenis): dump all flags at verbosity>=2?
135 if (Verbosity()) ReportUnrecognizedFlags();
136
137 if (common_flags()->help) {
138 // TODO(samsonov): print all of the flags (ASan, LSan, common).
139 asan_parser.PrintFlagDescriptions();
140 }
141
142 // Flag validation:
143 if (!CAN_SANITIZE_LEAKS && common_flags()->detect_leaks) {
144 Report("%s: detect_leaks is not supported on this platform.\n",
145 SanitizerToolName);
146 Die();
147 }
148 // Ensure that redzone is at least SHADOW_GRANULARITY.
149 if (f->redzone < (int)SHADOW_GRANULARITY)
150 f->redzone = SHADOW_GRANULARITY;
151 // Make "strict_init_order" imply "check_initialization_order".
152 // TODO(samsonov): Use a single runtime flag for an init-order checker.
153 if (f->strict_init_order) {
154 f->check_initialization_order = true;
155 }
156 CHECK_LE((uptr)common_flags()->malloc_context_size, kStackTraceMax);
157 CHECK_LE(f->min_uar_stack_size_log, f->max_uar_stack_size_log);
158 CHECK_GE(f->redzone, 16);
159 CHECK_GE(f->max_redzone, f->redzone);
160 CHECK_LE(f->max_redzone, 2048);
161 CHECK(IsPowerOfTwo(f->redzone));
162 CHECK(IsPowerOfTwo(f->max_redzone));
163 if (SANITIZER_RTEMS) {
164 CHECK(!f->unmap_shadow_on_exit);
165 CHECK(!f->protect_shadow_gap);
166 }
167
168 // quarantine_size is deprecated but we still honor it.
169 // quarantine_size can not be used together with quarantine_size_mb.
170 if (f->quarantine_size >= 0 && f->quarantine_size_mb >= 0) {
171 Report("%s: please use either 'quarantine_size' (deprecated) or "
172 "quarantine_size_mb, but not both\n", SanitizerToolName);
173 Die();
174 }
175 if (f->quarantine_size >= 0)
176 f->quarantine_size_mb = f->quarantine_size >> 20;
177 if (f->quarantine_size_mb < 0) {
178 const int kDefaultQuarantineSizeMb =
179 (ASAN_LOW_MEMORY) ? 1UL << 4 : 1UL << 8;
180 f->quarantine_size_mb = kDefaultQuarantineSizeMb;
181 }
182 if (f->thread_local_quarantine_size_kb < 0) {
183 const u32 kDefaultThreadLocalQuarantineSizeKb =
184 // It is not advised to go lower than 64Kb, otherwise quarantine batches
185 // pushed from thread local quarantine to global one will create too
186 // much overhead. One quarantine batch size is 8Kb and it holds up to
187 // 1021 chunk, which amounts to 1/8 memory overhead per batch when
188 // thread local quarantine is set to 64Kb.
189 (ASAN_LOW_MEMORY) ? 1 << 6 : FIRST_32_SECOND_64(1 << 8, 1 << 10);
190 f->thread_local_quarantine_size_kb = kDefaultThreadLocalQuarantineSizeKb;
191 }
192 if (f->thread_local_quarantine_size_kb == 0 && f->quarantine_size_mb > 0) {
193 Report("%s: thread_local_quarantine_size_kb can be set to 0 only when "
194 "quarantine_size_mb is set to 0\n", SanitizerToolName);
195 Die();
196 }
197 if (!f->replace_str && common_flags()->intercept_strlen) {
198 Report("WARNING: strlen interceptor is enabled even though replace_str=0. "
199 "Use intercept_strlen=0 to disable it.");
200 }
201 if (!f->replace_str && common_flags()->intercept_strchr) {
202 Report("WARNING: strchr* interceptors are enabled even though "
203 "replace_str=0. Use intercept_strchr=0 to disable them.");
204 }
205 if (!f->replace_str && common_flags()->intercept_strndup) {
206 Report("WARNING: strndup* interceptors are enabled even though "
207 "replace_str=0. Use intercept_strndup=0 to disable them.");
208 }
209 }
210
211 } // namespace __asan
212
SANITIZER_INTERFACE_WEAK_DEF(const char *,__asan_default_options,void)213 SANITIZER_INTERFACE_WEAK_DEF(const char*, __asan_default_options, void) {
214 return "";
215 }
216