1 //===-- asan_flags.cpp ------------------------------------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file is a part of AddressSanitizer, an address sanity checker.
11 // ASan flag parsing logic.
12 //===----------------------------------------------------------------------===//
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"
27 Flags asan_flags_dont_use_directly
; // use via flags().
29 static const char *MaybeCallAsanDefaultOptions() {
30 return (&__asan_default_options
) ? __asan_default_options() : "";
33 static const char *MaybeUseAsanDefaultOptionsCompileDefinition() {
34 #ifdef ASAN_DEFAULT_OPTIONS
35 return SANITIZER_STRINGIFY(ASAN_DEFAULT_OPTIONS
);
41 void Flags::SetDefaults() {
42 #define ASAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
43 #include "asan_flags.inc"
47 static void RegisterAsanFlags(FlagParser
*parser
, Flags
*f
) {
48 #define ASAN_FLAG(Type, Name, DefaultValue, Description) \
49 RegisterFlag(parser, #Name, Description, &f->Name);
50 #include "asan_flags.inc"
54 void InitializeFlags() {
55 // Set the default values and prepare for parsing ASan and common flags.
56 SetCommonFlagsDefaults();
59 cf
.CopyFrom(*common_flags());
60 cf
.detect_leaks
= cf
.detect_leaks
&& CAN_SANITIZE_LEAKS
;
61 cf
.external_symbolizer_path
= GetEnv("ASAN_SYMBOLIZER_PATH");
62 cf
.malloc_context_size
= kDefaultMallocContextSize
;
63 cf
.intercept_tls_get_addr
= true;
65 OverrideCommonFlags(cf
);
70 FlagParser asan_parser
;
71 RegisterAsanFlags(&asan_parser
, f
);
72 RegisterCommonFlags(&asan_parser
);
74 // Set the default values and prepare for parsing LSan and UBSan flags
75 // (which can also overwrite common flags).
76 #if CAN_SANITIZE_LEAKS
77 __lsan::Flags
*lf
= __lsan::flags();
80 FlagParser lsan_parser
;
81 __lsan::RegisterLsanFlags(&lsan_parser
, lf
);
82 RegisterCommonFlags(&lsan_parser
);
86 __ubsan::Flags
*uf
= __ubsan::flags();
89 FlagParser ubsan_parser
;
90 __ubsan::RegisterUbsanFlags(&ubsan_parser
, uf
);
91 RegisterCommonFlags(&ubsan_parser
);
95 // Support macOS MallocScribble and MallocPreScribble:
96 // <https://developer.apple.com/library/content/documentation/Performance/
97 // Conceptual/ManagingMemory/Articles/MallocDebug.html>
98 if (GetEnv("MallocScribble")) {
99 f
->max_free_fill_size
= 0x1000;
101 if (GetEnv("MallocPreScribble")) {
102 f
->malloc_fill_byte
= 0xaa;
106 // Override from ASan compile definition.
107 const char *asan_compile_def
= MaybeUseAsanDefaultOptionsCompileDefinition();
108 asan_parser
.ParseString(asan_compile_def
);
110 // Override from user-specified string.
111 const char *asan_default_options
= MaybeCallAsanDefaultOptions();
112 asan_parser
.ParseString(asan_default_options
);
114 const char *ubsan_default_options
= __ubsan::MaybeCallUbsanDefaultOptions();
115 ubsan_parser
.ParseString(ubsan_default_options
);
117 #if CAN_SANITIZE_LEAKS
118 const char *lsan_default_options
= __lsan::MaybeCallLsanDefaultOptions();
119 lsan_parser
.ParseString(lsan_default_options
);
122 // Override from command line.
123 asan_parser
.ParseStringFromEnv("ASAN_OPTIONS");
124 #if CAN_SANITIZE_LEAKS
125 lsan_parser
.ParseStringFromEnv("LSAN_OPTIONS");
128 ubsan_parser
.ParseStringFromEnv("UBSAN_OPTIONS");
131 InitializeCommonFlags();
133 // TODO(eugenis): dump all flags at verbosity>=2?
134 if (Verbosity()) ReportUnrecognizedFlags();
136 if (common_flags()->help
) {
137 // TODO(samsonov): print all of the flags (ASan, LSan, common).
138 asan_parser
.PrintFlagDescriptions();
142 if (!CAN_SANITIZE_LEAKS
&& common_flags()->detect_leaks
) {
143 Report("%s: detect_leaks is not supported on this platform.\n",
147 // Ensure that redzone is at least SHADOW_GRANULARITY.
148 if (f
->redzone
< (int)SHADOW_GRANULARITY
)
149 f
->redzone
= SHADOW_GRANULARITY
;
150 // Make "strict_init_order" imply "check_initialization_order".
151 // TODO(samsonov): Use a single runtime flag for an init-order checker.
152 if (f
->strict_init_order
) {
153 f
->check_initialization_order
= true;
155 CHECK_LE((uptr
)common_flags()->malloc_context_size
, kStackTraceMax
);
156 CHECK_LE(f
->min_uar_stack_size_log
, f
->max_uar_stack_size_log
);
157 CHECK_GE(f
->redzone
, 16);
158 CHECK_GE(f
->max_redzone
, f
->redzone
);
159 CHECK_LE(f
->max_redzone
, 2048);
160 CHECK(IsPowerOfTwo(f
->redzone
));
161 CHECK(IsPowerOfTwo(f
->max_redzone
));
162 if (SANITIZER_RTEMS
) {
163 CHECK(!f
->unmap_shadow_on_exit
);
164 CHECK(!f
->protect_shadow_gap
);
167 // quarantine_size is deprecated but we still honor it.
168 // quarantine_size can not be used together with quarantine_size_mb.
169 if (f
->quarantine_size
>= 0 && f
->quarantine_size_mb
>= 0) {
170 Report("%s: please use either 'quarantine_size' (deprecated) or "
171 "quarantine_size_mb, but not both\n", SanitizerToolName
);
174 if (f
->quarantine_size
>= 0)
175 f
->quarantine_size_mb
= f
->quarantine_size
>> 20;
176 if (f
->quarantine_size_mb
< 0) {
177 const int kDefaultQuarantineSizeMb
=
178 (ASAN_LOW_MEMORY
) ? 1UL << 4 : 1UL << 8;
179 f
->quarantine_size_mb
= kDefaultQuarantineSizeMb
;
181 if (f
->thread_local_quarantine_size_kb
< 0) {
182 const u32 kDefaultThreadLocalQuarantineSizeKb
=
183 // It is not advised to go lower than 64Kb, otherwise quarantine batches
184 // pushed from thread local quarantine to global one will create too
185 // much overhead. One quarantine batch size is 8Kb and it holds up to
186 // 1021 chunk, which amounts to 1/8 memory overhead per batch when
187 // thread local quarantine is set to 64Kb.
188 (ASAN_LOW_MEMORY
) ? 1 << 6 : FIRST_32_SECOND_64(1 << 8, 1 << 10);
189 f
->thread_local_quarantine_size_kb
= kDefaultThreadLocalQuarantineSizeKb
;
191 if (f
->thread_local_quarantine_size_kb
== 0 && f
->quarantine_size_mb
> 0) {
192 Report("%s: thread_local_quarantine_size_kb can be set to 0 only when "
193 "quarantine_size_mb is set to 0\n", SanitizerToolName
);
196 if (!f
->replace_str
&& common_flags()->intercept_strlen
) {
197 Report("WARNING: strlen interceptor is enabled even though replace_str=0. "
198 "Use intercept_strlen=0 to disable it.");
200 if (!f
->replace_str
&& common_flags()->intercept_strchr
) {
201 Report("WARNING: strchr* interceptors are enabled even though "
202 "replace_str=0. Use intercept_strchr=0 to disable them.");
204 if (!f
->replace_str
&& common_flags()->intercept_strndup
) {
205 Report("WARNING: strndup* interceptors are enabled even though "
206 "replace_str=0. Use intercept_strndup=0 to disable them.");
210 } // namespace __asan
212 SANITIZER_INTERFACE_WEAK_DEF(const char*, __asan_default_options
, void) {