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
24namespace __asan {
25
26Flags asan_flags_dont_use_directly;  // use via flags().
27
28static const char *MaybeCallAsanDefaultOptions() {
29  return (&__asan_default_options) ? __asan_default_options() : "";
30}
31
32static const char *MaybeUseAsanDefaultOptionsCompileDefinition() {
33#ifdef ASAN_DEFAULT_OPTIONS
34  return SANITIZER_STRINGIFY(ASAN_DEFAULT_OPTIONS);
35#else
36  return "";
37#endif
38}
39
40void Flags::SetDefaults() {
41#define ASAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
42#include "asan_flags.inc"
43#undef ASAN_FLAG
44}
45
46static 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
53void 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
211SANITIZER_INTERFACE_WEAK_DEF(const char*, __asan_default_options, void) {
212  return "";
213}
214