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: &parser, f: &f, cf: &cf);
50
51 cf.SetDefaults();
52 // Copy the current activation flags.
53 allocator_options.CopyTo(f: &f, cf: &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 overridden.
62 if (const char *env = GetEnv(name: "ASAN_ACTIVATION_OPTIONS")) {
63 parser.ParseString(s: env);
64 }
65
66 InitializeCommonFlags(cf: &cf);
67
68 if (Verbosity()) ReportUnrecognizedFlags();
69
70 if (cf.help) parser.PrintFlagDescriptions();
71
72 allocator_options.SetFrom(f: &f, cf: &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 format: "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(options: &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(a: 16, b: (int)ASAN_SHADOW_GRANULARITY);
116 disabled.max_redzone = disabled.min_redzone;
117 disabled.alloc_dealloc_mismatch = false;
118 disabled.may_return_null = true;
119 ReInitializeAllocator(options: 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(options: asan_deactivated_flags.allocator_options);
135
136 asan_is_deactivated = false;
137 if (Verbosity()) {
138 Report(format: "Activated with flags:\n");
139 asan_deactivated_flags.Print();
140 }
141}
142
143} // namespace __asan
144