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
26namespace __asan {
27
28Flags asan_flags_dont_use_directly;  // use via flags().
29
30static const char *MaybeCallAsanDefaultOptions() {
31  return (&__asan_default_options) ? __asan_default_options() : "";
32}
33
34static const char *MaybeUseAsanDefaultOptionsCompileDefinition() {
35#ifdef ASAN_DEFAULT_OPTIONS
36  return SANITIZER_STRINGIFY(ASAN_DEFAULT_OPTIONS);
37#else
38  return "";
39#endif
40}
41
42void Flags::SetDefaults() {
43#define ASAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
44#include "asan_flags.inc"
45#undef ASAN_FLAG
46}
47
48static 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
55void 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
213SANITIZER_INTERFACE_WEAK_DEF(const char*, __asan_default_options, void) {
214  return "";
215}
216