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

source code of compiler-rt/lib/asan/asan_flags.cpp