aboutsummaryrefslogtreecommitdiffstats
path: root/lib/asan/asan_flags.cpp
blob: c5c70eaed737fe6ace886b3330db265c890ea383 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
//===-- asan_flags.cpp ------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of AddressSanitizer, an address sanity checker.
//
// ASan flag parsing logic.
//===----------------------------------------------------------------------===//

#include "asan_activation.h"
#include "asan_flags.h"
#include "asan_interface_internal.h"
#include "asan_stack.h"
#include "lsan/lsan_common.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_flags.h"
#include "sanitizer_common/sanitizer_flag_parser.h"
#include "ubsan/ubsan_flags.h"
#include "ubsan/ubsan_platform.h"

namespace __asan {

Flags asan_flags_dont_use_directly;  // use via flags().

static const char *MaybeCallAsanDefaultOptions() {
  return (&__asan_default_options) ? __asan_default_options() : "";
}

static const char *MaybeUseAsanDefaultOptionsCompileDefinition() {
#ifdef ASAN_DEFAULT_OPTIONS
  return SANITIZER_STRINGIFY(ASAN_DEFAULT_OPTIONS);
#else
  return "";
#endif
}

void Flags::SetDefaults() {
#define ASAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
#include "asan_flags.inc"
#undef ASAN_FLAG
}

static void RegisterAsanFlags(FlagParser *parser, Flags *f) {
#define ASAN_FLAG(Type, Name, DefaultValue, Description) \
  RegisterFlag(parser, #Name, Description, &f->Name);
#include "asan_flags.inc"
#undef ASAN_FLAG
}

void InitializeFlags() {
  // Set the default values and prepare for parsing ASan and common flags.
  SetCommonFlagsDefaults();
  {
    CommonFlags cf;
    cf.CopyFrom(*common_flags());
    cf.detect_leaks = cf.detect_leaks && CAN_SANITIZE_LEAKS;
    cf.external_symbolizer_path = GetEnv("ASAN_SYMBOLIZER_PATH");
    cf.malloc_context_size = kDefaultMallocContextSize;
    cf.intercept_tls_get_addr = true;
    cf.exitcode = 1;
    OverrideCommonFlags(cf);
  }
  Flags *f = flags();
  f->SetDefaults();

  FlagParser asan_parser;
  RegisterAsanFlags(&asan_parser, f);
  RegisterCommonFlags(&asan_parser);

  // Set the default values and prepare for parsing LSan and UBSan flags
  // (which can also overwrite common flags).
#if CAN_SANITIZE_LEAKS
  __lsan::Flags *lf = __lsan::flags();
  lf->SetDefaults();

  FlagParser lsan_parser;
  __lsan::RegisterLsanFlags(&lsan_parser, lf);
  RegisterCommonFlags(&lsan_parser);
#endif

#if CAN_SANITIZE_UB
  __ubsan::Flags *uf = __ubsan::flags();
  uf->SetDefaults();

  FlagParser ubsan_parser;
  __ubsan::RegisterUbsanFlags(&ubsan_parser, uf);
  RegisterCommonFlags(&ubsan_parser);
#endif

  if (SANITIZER_MAC) {
    // Support macOS MallocScribble and MallocPreScribble:
    // <https://developer.apple.com/library/content/documentation/Performance/
    // Conceptual/ManagingMemory/Articles/MallocDebug.html>
    if (GetEnv("MallocScribble")) {
      f->max_free_fill_size = 0x1000;
    }
    if (GetEnv("MallocPreScribble")) {
      f->malloc_fill_byte = 0xaa;
    }
  }

  // Override from ASan compile definition.
  const char *asan_compile_def = MaybeUseAsanDefaultOptionsCompileDefinition();
  asan_parser.ParseString(asan_compile_def);

  // Override from user-specified string.
  const char *asan_default_options = MaybeCallAsanDefaultOptions();
  asan_parser.ParseString(asan_default_options);
#if CAN_SANITIZE_UB
  const char *ubsan_default_options = __ubsan::MaybeCallUbsanDefaultOptions();
  ubsan_parser.ParseString(ubsan_default_options);
#endif
#if CAN_SANITIZE_LEAKS
  const char *lsan_default_options = __lsan::MaybeCallLsanDefaultOptions();
  lsan_parser.ParseString(lsan_default_options);
#endif

  // Override from command line.
  asan_parser.ParseStringFromEnv("ASAN_OPTIONS");
#if CAN_SANITIZE_LEAKS
  lsan_parser.ParseStringFromEnv("LSAN_OPTIONS");
#endif
#if CAN_SANITIZE_UB
  ubsan_parser.ParseStringFromEnv("UBSAN_OPTIONS");
#endif

  InitializeCommonFlags();

  // TODO(eugenis): dump all flags at verbosity>=2?
  if (Verbosity()) ReportUnrecognizedFlags();

  if (common_flags()->help) {
    // TODO(samsonov): print all of the flags (ASan, LSan, common).
    asan_parser.PrintFlagDescriptions();
  }

  // Flag validation:
  if (!CAN_SANITIZE_LEAKS && common_flags()->detect_leaks) {
    Report("%s: detect_leaks is not supported on this platform.\n",
           SanitizerToolName);
    Die();
  }
  // Ensure that redzone is at least SHADOW_GRANULARITY.
  if (f->redzone < (int)SHADOW_GRANULARITY)
    f->redzone = SHADOW_GRANULARITY;
  // Make "strict_init_order" imply "check_initialization_order".
  // TODO(samsonov): Use a single runtime flag for an init-order checker.
  if (f->strict_init_order) {
    f->check_initialization_order = true;
  }
  CHECK_LE((uptr)common_flags()->malloc_context_size, kStackTraceMax);
  CHECK_LE(f->min_uar_stack_size_log, f->max_uar_stack_size_log);
  CHECK_GE(f->redzone, 16);
  CHECK_GE(f->max_redzone, f->redzone);
  CHECK_LE(f->max_redzone, 2048);
  CHECK(IsPowerOfTwo(f->redzone));
  CHECK(IsPowerOfTwo(f->max_redzone));
  if (SANITIZER_RTEMS) {
    CHECK(!f->unmap_shadow_on_exit);
    CHECK(!f->protect_shadow_gap);
  }

  // quarantine_size is deprecated but we still honor it.
  // quarantine_size can not be used together with quarantine_size_mb.
  if (f->quarantine_size >= 0 && f->quarantine_size_mb >= 0) {
    Report("%s: please use either 'quarantine_size' (deprecated) or "
           "quarantine_size_mb, but not both\n", SanitizerToolName);
    Die();
  }
  if (f->quarantine_size >= 0)
    f->quarantine_size_mb = f->quarantine_size >> 20;
  if (f->quarantine_size_mb < 0) {
    const int kDefaultQuarantineSizeMb =
        (ASAN_LOW_MEMORY) ? 1UL << 4 : 1UL << 8;
    f->quarantine_size_mb = kDefaultQuarantineSizeMb;
  }
  if (f->thread_local_quarantine_size_kb < 0) {
    const u32 kDefaultThreadLocalQuarantineSizeKb =
        // It is not advised to go lower than 64Kb, otherwise quarantine batches
        // pushed from thread local quarantine to global one will create too
        // much overhead. One quarantine batch size is 8Kb and it  holds up to
        // 1021 chunk, which amounts to 1/8 memory overhead per batch when
        // thread local quarantine is set to 64Kb.
        (ASAN_LOW_MEMORY) ? 1 << 6 : FIRST_32_SECOND_64(1 << 8, 1 << 10);
    f->thread_local_quarantine_size_kb = kDefaultThreadLocalQuarantineSizeKb;
  }
  if (f->thread_local_quarantine_size_kb == 0 && f->quarantine_size_mb > 0) {
    Report("%s: thread_local_quarantine_size_kb can be set to 0 only when "
           "quarantine_size_mb is set to 0\n", SanitizerToolName);
    Die();
  }
  if (!f->replace_str && common_flags()->intercept_strlen) {
    Report("WARNING: strlen interceptor is enabled even though replace_str=0. "
           "Use intercept_strlen=0 to disable it.");
  }
  if (!f->replace_str && common_flags()->intercept_strchr) {
    Report("WARNING: strchr* interceptors are enabled even though "
           "replace_str=0. Use intercept_strchr=0 to disable them.");
  }
  if (!f->replace_str && common_flags()->intercept_strndup) {
    Report("WARNING: strndup* interceptors are enabled even though "
           "replace_str=0. Use intercept_strndup=0 to disable them.");
  }
}

}  // namespace __asan

SANITIZER_INTERFACE_WEAK_DEF(const char*, __asan_default_options, void) {
  return "";
}