1 //===-- scudo_flags.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 /// Hardened Allocator flag parsing logic.
10 ///
11 //===----------------------------------------------------------------------===//
12
13 #include "scudo_flags.h"
14 #include "scudo_interface_internal.h"
15 #include "scudo_utils.h"
16
17 #include "sanitizer_common/sanitizer_flags.h"
18 #include "sanitizer_common/sanitizer_flag_parser.h"
19
20 namespace __scudo {
21
22 static Flags ScudoFlags; // Use via getFlags().
23
setDefaults()24 void Flags::setDefaults() {
25 #define SCUDO_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
26 #include "scudo_flags.inc"
27 #undef SCUDO_FLAG
28 }
29
RegisterScudoFlags(FlagParser * parser,Flags * f)30 static void RegisterScudoFlags(FlagParser *parser, Flags *f) {
31 #define SCUDO_FLAG(Type, Name, DefaultValue, Description) \
32 RegisterFlag(parser, #Name, Description, &f->Name);
33 #include "scudo_flags.inc"
34 #undef SCUDO_FLAG
35 }
36
getCompileDefinitionScudoDefaultOptions()37 static const char *getCompileDefinitionScudoDefaultOptions() {
38 #ifdef SCUDO_DEFAULT_OPTIONS
39 return SANITIZER_STRINGIFY(SCUDO_DEFAULT_OPTIONS);
40 #else
41 return "";
42 #endif
43 }
44
getScudoDefaultOptions()45 static const char *getScudoDefaultOptions() {
46 return (&__scudo_default_options) ? __scudo_default_options() : "";
47 }
48
initFlags()49 void initFlags() {
50 SetCommonFlagsDefaults();
51 {
52 CommonFlags cf;
53 cf.CopyFrom(*common_flags());
54 cf.exitcode = 1;
55 OverrideCommonFlags(cf);
56 }
57 Flags *f = getFlags();
58 f->setDefaults();
59
60 FlagParser ScudoParser;
61 RegisterScudoFlags(&ScudoParser, f);
62 RegisterCommonFlags(&ScudoParser);
63
64 // Override from compile definition.
65 ScudoParser.ParseString(getCompileDefinitionScudoDefaultOptions());
66
67 // Override from user-specified string.
68 ScudoParser.ParseString(getScudoDefaultOptions());
69
70 // Override from environment.
71 ScudoParser.ParseStringFromEnv("SCUDO_OPTIONS");
72
73 InitializeCommonFlags();
74
75 // Sanity checks and default settings for the Quarantine parameters.
76
77 if (f->QuarantineSizeMb >= 0) {
78 // Backward compatible logic if QuarantineSizeMb is set.
79 if (f->QuarantineSizeKb >= 0) {
80 dieWithMessage("ERROR: please use either QuarantineSizeMb (deprecated) "
81 "or QuarantineSizeKb, but not both\n");
82 }
83 if (f->QuarantineChunksUpToSize >= 0) {
84 dieWithMessage("ERROR: QuarantineChunksUpToSize cannot be used in "
85 " conjunction with the deprecated QuarantineSizeMb option\n");
86 }
87 // If everything is in order, update QuarantineSizeKb accordingly.
88 f->QuarantineSizeKb = f->QuarantineSizeMb * 1024;
89 } else {
90 // Otherwise proceed with the new options.
91 if (f->QuarantineSizeKb < 0) {
92 const int DefaultQuarantineSizeKb = FIRST_32_SECOND_64(64, 256);
93 f->QuarantineSizeKb = DefaultQuarantineSizeKb;
94 }
95 if (f->QuarantineChunksUpToSize < 0) {
96 const int DefaultQuarantineChunksUpToSize = FIRST_32_SECOND_64(512, 2048);
97 f->QuarantineChunksUpToSize = DefaultQuarantineChunksUpToSize;
98 }
99 }
100
101 // We enforce an upper limit for the chunk quarantine threshold of 4Mb.
102 if (f->QuarantineChunksUpToSize > (4 * 1024 * 1024)) {
103 dieWithMessage("ERROR: the chunk quarantine threshold is too large\n");
104 }
105
106 // We enforce an upper limit for the quarantine size of 32Mb.
107 if (f->QuarantineSizeKb > (32 * 1024)) {
108 dieWithMessage("ERROR: the quarantine size is too large\n");
109 }
110
111 if (f->ThreadLocalQuarantineSizeKb < 0) {
112 const int DefaultThreadLocalQuarantineSizeKb = FIRST_32_SECOND_64(16, 64);
113 f->ThreadLocalQuarantineSizeKb = DefaultThreadLocalQuarantineSizeKb;
114 }
115 // And an upper limit of 8Mb for the thread quarantine cache.
116 if (f->ThreadLocalQuarantineSizeKb > (8 * 1024)) {
117 dieWithMessage("ERROR: the per thread quarantine cache size is too "
118 "large\n");
119 }
120 if (f->ThreadLocalQuarantineSizeKb == 0 && f->QuarantineSizeKb > 0) {
121 dieWithMessage("ERROR: ThreadLocalQuarantineSizeKb can be set to 0 only "
122 "when QuarantineSizeKb is set to 0\n");
123 }
124 }
125
getFlags()126 Flags *getFlags() {
127 return &ScudoFlags;
128 }
129
130 } // namespace __scudo
131
132 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
SANITIZER_INTERFACE_WEAK_DEF(const char *,__scudo_default_options,void)133 SANITIZER_INTERFACE_WEAK_DEF(const char*, __scudo_default_options, void) {
134 return "";
135 }
136 #endif
137