1//===-- asan_activation.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 activation/deactivation logic.
12//===----------------------------------------------------------------------===//
13
14#include "asan_activation.h"
15#include "asan_allocator.h"
16#include "asan_flags.h"
17#include "asan_internal.h"
18#include "asan_mapping.h"
19#include "asan_poisoning.h"
20#include "asan_stack.h"
21#include "sanitizer_common/sanitizer_common.h"
22#include "sanitizer_common/sanitizer_flags.h"
23
24namespace __asan {
25
26static struct AsanDeactivatedFlags {
27  AllocatorOptions allocator_options;
28  int malloc_context_size;
29  bool poison_heap;
30  bool coverage;
31  const char *coverage_dir;
32
33  void RegisterActivationFlags(FlagParser *parser, Flags *f, CommonFlags *cf) {
34#define ASAN_ACTIVATION_FLAG(Type, Name) \
35  RegisterFlag(parser, #Name, "", &f->Name);
36#define COMMON_ACTIVATION_FLAG(Type, Name) \
37  RegisterFlag(parser, #Name, "", &cf->Name);
38#include "asan_activation_flags.inc"
39#undef ASAN_ACTIVATION_FLAG
40#undef COMMON_ACTIVATION_FLAG
41
42    RegisterIncludeFlags(parser, cf);
43  }
44
45  void OverrideFromActivationFlags() {
46    Flags f;
47    CommonFlags cf;
48    FlagParser parser;
49    RegisterActivationFlags(&parser, &f, &cf);
50
51    cf.SetDefaults();
52    // Copy the current activation flags.
53    allocator_options.CopyTo(&f, &cf);
54    cf.malloc_context_size = malloc_context_size;
55    f.poison_heap = poison_heap;
56    cf.coverage = coverage;
57    cf.coverage_dir = coverage_dir;
58    cf.verbosity = Verbosity();
59    cf.help = false; // this is activation-specific help
60
61    // Check if activation flags need to be overriden.
62    if (const char *env = GetEnv("ASAN_ACTIVATION_OPTIONS")) {
63      parser.ParseString(env);
64    }
65
66    InitializeCommonFlags(&cf);
67
68    if (Verbosity()) ReportUnrecognizedFlags();
69
70    if (cf.help) parser.PrintFlagDescriptions();
71
72    allocator_options.SetFrom(&f, &cf);
73    malloc_context_size = cf.malloc_context_size;
74    poison_heap = f.poison_heap;
75    coverage = cf.coverage;
76    coverage_dir = cf.coverage_dir;
77  }
78
79  void Print() {
80    Report(
81        "quarantine_size_mb %d, thread_local_quarantine_size_kb %d, "
82        "max_redzone %d, poison_heap %d, malloc_context_size %d, "
83        "alloc_dealloc_mismatch %d, allocator_may_return_null %d, coverage %d, "
84        "coverage_dir %s, allocator_release_to_os_interval_ms %d\n",
85        allocator_options.quarantine_size_mb,
86        allocator_options.thread_local_quarantine_size_kb,
87        allocator_options.max_redzone, poison_heap, malloc_context_size,
88        allocator_options.alloc_dealloc_mismatch,
89        allocator_options.may_return_null, coverage, coverage_dir,
90        allocator_options.release_to_os_interval_ms);
91  }
92} asan_deactivated_flags;
93
94static bool asan_is_deactivated;
95
96void AsanDeactivate() {
97  CHECK(!asan_is_deactivated);
98  VReport(1, "Deactivating ASan\n");
99
100  // Stash runtime state.
101  GetAllocatorOptions(&asan_deactivated_flags.allocator_options);
102  asan_deactivated_flags.malloc_context_size = GetMallocContextSize();
103  asan_deactivated_flags.poison_heap = CanPoisonMemory();
104  asan_deactivated_flags.coverage = common_flags()->coverage;
105  asan_deactivated_flags.coverage_dir = common_flags()->coverage_dir;
106
107  // Deactivate the runtime.
108  SetCanPoisonMemory(false);
109  SetMallocContextSize(1);
110
111  AllocatorOptions disabled = asan_deactivated_flags.allocator_options;
112  disabled.quarantine_size_mb = 0;
113  disabled.thread_local_quarantine_size_kb = 0;
114  // Redzone must be at least Max(16, granularity) bytes long.
115  disabled.min_redzone = Max(16, (int)SHADOW_GRANULARITY);
116  disabled.max_redzone = disabled.min_redzone;
117  disabled.alloc_dealloc_mismatch = false;
118  disabled.may_return_null = true;
119  ReInitializeAllocator(disabled);
120
121  asan_is_deactivated = true;
122}
123
124void AsanActivate() {
125  if (!asan_is_deactivated) return;
126  VReport(1, "Activating ASan\n");
127
128  UpdateProcessName();
129
130  asan_deactivated_flags.OverrideFromActivationFlags();
131
132  SetCanPoisonMemory(asan_deactivated_flags.poison_heap);
133  SetMallocContextSize(asan_deactivated_flags.malloc_context_size);
134  ReInitializeAllocator(asan_deactivated_flags.allocator_options);
135
136  asan_is_deactivated = false;
137  if (Verbosity()) {
138    Report("Activated with flags:\n");
139    asan_deactivated_flags.Print();
140  }
141}
142
143}  // namespace __asan
144