1//===---- RuntimeDyldChecker.h - RuntimeDyld tester framework -----*- 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#ifndef LLVM_EXECUTIONENGINE_RUNTIMEDYLDCHECKER_H
10#define LLVM_EXECUTIONENGINE_RUNTIMEDYLDCHECKER_H
11
12#include "llvm/ADT/DenseMap.h"
13#include "llvm/ADT/Optional.h"
14#include "llvm/ExecutionEngine/JITSymbol.h"
15#include "llvm/Support/Endian.h"
16
17#include <cstdint>
18#include <memory>
19#include <string>
20#include <utility>
21
22namespace llvm {
23
24class StringRef;
25class MCDisassembler;
26class MemoryBuffer;
27class MCInstPrinter;
28class RuntimeDyld;
29class RuntimeDyldCheckerImpl;
30class raw_ostream;
31
32/// RuntimeDyld invariant checker for verifying that RuntimeDyld has
33/// correctly applied relocations.
34///
35/// The RuntimeDyldChecker class evaluates expressions against an attached
36/// RuntimeDyld instance to verify that relocations have been applied
37/// correctly.
38///
39/// The expression language supports basic pointer arithmetic and bit-masking,
40/// and has limited disassembler integration for accessing instruction
41/// operands and the next PC (program counter) address for each instruction.
42///
43/// The language syntax is:
44///
45/// check = expr '=' expr
46///
47/// expr = binary_expr
48/// | sliceable_expr
49///
50/// sliceable_expr = '*{' number '}' load_addr_expr [slice]
51/// | '(' expr ')' [slice]
52/// | ident_expr [slice]
53/// | number [slice]
54///
55/// slice = '[' high-bit-index ':' low-bit-index ']'
56///
57/// load_addr_expr = symbol
58/// | '(' symbol '+' number ')'
59/// | '(' symbol '-' number ')'
60///
61/// ident_expr = 'decode_operand' '(' symbol ',' operand-index ')'
62/// | 'next_pc' '(' symbol ')'
63/// | 'stub_addr' '(' stub-container-name ',' symbol ')'
64/// | 'got_addr' '(' stub-container-name ',' symbol ')'
65/// | symbol
66///
67/// binary_expr = expr '+' expr
68/// | expr '-' expr
69/// | expr '&' expr
70/// | expr '|' expr
71/// | expr '<<' expr
72/// | expr '>>' expr
73///
74class RuntimeDyldChecker {
75public:
76 class MemoryRegionInfo {
77 public:
78 MemoryRegionInfo() = default;
79
80 /// Constructor for symbols/sections with content.
81 MemoryRegionInfo(ArrayRef<char> Content, JITTargetAddress TargetAddress)
82 : ContentPtr(Content.data()), Size(Content.size()),
83 TargetAddress(TargetAddress) {}
84
85 /// Constructor for zero-fill symbols/sections.
86 MemoryRegionInfo(uint64_t Size, JITTargetAddress TargetAddress)
87 : Size(Size), TargetAddress(TargetAddress) {}
88
89 /// Returns true if this is a zero-fill symbol/section.
90 bool isZeroFill() const {
91 assert(Size && "setContent/setZeroFill must be called first");
92 return !ContentPtr;
93 }
94
95 /// Set the content for this memory region.
96 void setContent(ArrayRef<char> Content) {
97 assert(!ContentPtr && !Size && "Content/zero-fill already set");
98 ContentPtr = Content.data();
99 Size = Content.size();
100 }
101
102 /// Set a zero-fill length for this memory region.
103 void setZeroFill(uint64_t Size) {
104 assert(!ContentPtr && !this->Size && "Content/zero-fill already set");
105 this->Size = Size;
106 }
107
108 /// Returns the content for this section if there is any.
109 ArrayRef<char> getContent() const {
110 assert(!isZeroFill() && "Can't get content for a zero-fill section");
111 return {ContentPtr, static_cast<size_t>(Size)};
112 }
113
114 /// Returns the zero-fill length for this section.
115 uint64_t getZeroFillLength() const {
116 assert(isZeroFill() && "Can't get zero-fill length for content section");
117 return Size;
118 }
119
120 /// Set the target address for this region.
121 void setTargetAddress(JITTargetAddress TargetAddress) {
122 assert(!this->TargetAddress && "TargetAddress already set");
123 this->TargetAddress = TargetAddress;
124 }
125
126 /// Return the target address for this region.
127 JITTargetAddress getTargetAddress() const { return TargetAddress; }
128
129 private:
130 const char *ContentPtr = 0;
131 uint64_t Size = 0;
132 JITTargetAddress TargetAddress = 0;
133 };
134
135 using IsSymbolValidFunction = std::function<bool(StringRef Symbol)>;
136 using GetSymbolInfoFunction =
137 std::function<Expected<MemoryRegionInfo>(StringRef SymbolName)>;
138 using GetSectionInfoFunction = std::function<Expected<MemoryRegionInfo>(
139 StringRef FileName, StringRef SectionName)>;
140 using GetStubInfoFunction = std::function<Expected<MemoryRegionInfo>(
141 StringRef StubContainer, StringRef TargetName)>;
142 using GetGOTInfoFunction = std::function<Expected<MemoryRegionInfo>(
143 StringRef GOTContainer, StringRef TargetName)>;
144
145 RuntimeDyldChecker(IsSymbolValidFunction IsSymbolValid,
146 GetSymbolInfoFunction GetSymbolInfo,
147 GetSectionInfoFunction GetSectionInfo,
148 GetStubInfoFunction GetStubInfo,
149 GetGOTInfoFunction GetGOTInfo,
150 support::endianness Endianness,
151 MCDisassembler *Disassembler, MCInstPrinter *InstPrinter,
152 raw_ostream &ErrStream);
153 ~RuntimeDyldChecker();
154
155 /// Check a single expression against the attached RuntimeDyld
156 /// instance.
157 bool check(StringRef CheckExpr) const;
158
159 /// Scan the given memory buffer for lines beginning with the string
160 /// in RulePrefix. The remainder of the line is passed to the check
161 /// method to be evaluated as an expression.
162 bool checkAllRulesInBuffer(StringRef RulePrefix, MemoryBuffer *MemBuf) const;
163
164 /// Returns the address of the requested section (or an error message
165 /// in the second element of the pair if the address cannot be found).
166 ///
167 /// if 'LocalAddress' is true, this returns the address of the section
168 /// within the linker's memory. If 'LocalAddress' is false it returns the
169 /// address within the target process (i.e. the load address).
170 std::pair<uint64_t, std::string> getSectionAddr(StringRef FileName,
171 StringRef SectionName,
172 bool LocalAddress);
173
174 /// If there is a section at the given local address, return its load
175 /// address, otherwise return none.
176 Optional<uint64_t> getSectionLoadAddress(void *LocalAddress) const;
177
178private:
179 std::unique_ptr<RuntimeDyldCheckerImpl> Impl;
180};
181
182} // end namespace llvm
183
184#endif
185