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1 //===-- asan_activation.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 activation/deactivation logic.
13 //===----------------------------------------------------------------------===//
14 
15 #include "asan_activation.h"
16 #include "asan_allocator.h"
17 #include "asan_flags.h"
18 #include "asan_internal.h"
19 #include "asan_poisoning.h"
20 #include "asan_stack.h"
21 #include "sanitizer_common/sanitizer_flags.h"
22 
23 namespace __asan {
24 
25 static struct AsanDeactivatedFlags {
26   AllocatorOptions allocator_options;
27   int malloc_context_size;
28   bool poison_heap;
29   bool coverage;
30   const char *coverage_dir;
31 
RegisterActivationFlags__asan::AsanDeactivatedFlags32   void RegisterActivationFlags(FlagParser *parser, Flags *f, CommonFlags *cf) {
33 #define ASAN_ACTIVATION_FLAG(Type, Name) \
34   RegisterFlag(parser, #Name, "", &f->Name);
35 #define COMMON_ACTIVATION_FLAG(Type, Name) \
36   RegisterFlag(parser, #Name, "", &cf->Name);
37 #include "asan_activation_flags.inc"
38 #undef ASAN_ACTIVATION_FLAG
39 #undef COMMON_ACTIVATION_FLAG
40 
41     RegisterIncludeFlags(parser, cf);
42   }
43 
OverrideFromActivationFlags__asan::AsanDeactivatedFlags44   void OverrideFromActivationFlags() {
45     Flags f;
46     CommonFlags cf;
47     FlagParser parser;
48     RegisterActivationFlags(&parser, &f, &cf);
49 
50     cf.SetDefaults();
51     // Copy the current activation flags.
52     allocator_options.CopyTo(&f, &cf);
53     cf.malloc_context_size = malloc_context_size;
54     f.poison_heap = poison_heap;
55     cf.coverage = coverage;
56     cf.coverage_dir = coverage_dir;
57     cf.verbosity = Verbosity();
58     cf.help = false; // this is activation-specific help
59 
60     // Check if activation flags need to be overriden.
61     if (const char *env = GetEnv("ASAN_ACTIVATION_OPTIONS")) {
62       parser.ParseString(env);
63     }
64 
65     InitializeCommonFlags(&cf);
66 
67     if (Verbosity()) ReportUnrecognizedFlags();
68 
69     if (cf.help) parser.PrintFlagDescriptions();
70 
71     allocator_options.SetFrom(&f, &cf);
72     malloc_context_size = cf.malloc_context_size;
73     poison_heap = f.poison_heap;
74     coverage = cf.coverage;
75     coverage_dir = cf.coverage_dir;
76   }
77 
Print__asan::AsanDeactivatedFlags78   void Print() {
79     Report(
80         "quarantine_size_mb %d, max_redzone %d, poison_heap %d, "
81         "malloc_context_size %d, alloc_dealloc_mismatch %d, "
82         "allocator_may_return_null %d, coverage %d, coverage_dir %s\n",
83         allocator_options.quarantine_size_mb, allocator_options.max_redzone,
84         poison_heap, malloc_context_size,
85         allocator_options.alloc_dealloc_mismatch,
86         allocator_options.may_return_null, coverage, coverage_dir);
87   }
88 } asan_deactivated_flags;
89 
90 static bool asan_is_deactivated;
91 
AsanDeactivate()92 void AsanDeactivate() {
93   CHECK(!asan_is_deactivated);
94   VReport(1, "Deactivating ASan\n");
95 
96   // Stash runtime state.
97   GetAllocatorOptions(&asan_deactivated_flags.allocator_options);
98   asan_deactivated_flags.malloc_context_size = GetMallocContextSize();
99   asan_deactivated_flags.poison_heap = CanPoisonMemory();
100   asan_deactivated_flags.coverage = common_flags()->coverage;
101   asan_deactivated_flags.coverage_dir = common_flags()->coverage_dir;
102 
103   // Deactivate the runtime.
104   SetCanPoisonMemory(false);
105   SetMallocContextSize(1);
106   ReInitializeCoverage(false, nullptr);
107 
108   AllocatorOptions disabled = asan_deactivated_flags.allocator_options;
109   disabled.quarantine_size_mb = 0;
110   disabled.min_redzone = 16;  // Redzone must be at least 16 bytes long.
111   disabled.max_redzone = 16;
112   disabled.alloc_dealloc_mismatch = false;
113   disabled.may_return_null = true;
114   ReInitializeAllocator(disabled);
115 
116   asan_is_deactivated = true;
117 }
118 
AsanActivate()119 void AsanActivate() {
120   if (!asan_is_deactivated) return;
121   VReport(1, "Activating ASan\n");
122 
123   UpdateProcessName();
124 
125   asan_deactivated_flags.OverrideFromActivationFlags();
126 
127   SetCanPoisonMemory(asan_deactivated_flags.poison_heap);
128   SetMallocContextSize(asan_deactivated_flags.malloc_context_size);
129   ReInitializeCoverage(asan_deactivated_flags.coverage,
130                        asan_deactivated_flags.coverage_dir);
131   ReInitializeAllocator(asan_deactivated_flags.allocator_options);
132 
133   asan_is_deactivated = false;
134   if (Verbosity()) {
135     Report("Activated with flags:\n");
136     asan_deactivated_flags.Print();
137   }
138 }
139 
140 }  // namespace __asan
141