|
150
|
1 //===- Relocations.h -------------------------------------------*- 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 LLD_ELF_RELOCATIONS_H
|
|
|
10 #define LLD_ELF_RELOCATIONS_H
|
|
|
11
|
|
|
12 #include "lld/Common/LLVM.h"
|
|
|
13 #include "llvm/ADT/DenseMap.h"
|
|
|
14 #include <map>
|
|
|
15 #include <vector>
|
|
|
16
|
|
|
17 namespace lld {
|
|
|
18 namespace elf {
|
|
|
19 class Symbol;
|
|
|
20 class InputSection;
|
|
|
21 class InputSectionBase;
|
|
|
22 class OutputSection;
|
|
|
23 class SectionBase;
|
|
|
24
|
|
|
25 // Represents a relocation type, such as R_X86_64_PC32 or R_ARM_THM_CALL.
|
|
|
26 using RelType = uint32_t;
|
|
173
|
27 using JumpModType = uint32_t;
|
|
150
|
28
|
|
|
29 // List of target-independent relocation types. Relocations read
|
|
|
30 // from files are converted to these types so that the main code
|
|
|
31 // doesn't have to know about architecture-specific details.
|
|
|
32 enum RelExpr {
|
|
|
33 R_ABS,
|
|
|
34 R_ADDEND,
|
|
|
35 R_DTPREL,
|
|
|
36 R_GOT,
|
|
|
37 R_GOT_OFF,
|
|
|
38 R_GOT_PC,
|
|
|
39 R_GOTONLY_PC,
|
|
|
40 R_GOTPLTONLY_PC,
|
|
|
41 R_GOTPLT,
|
|
|
42 R_GOTPLTREL,
|
|
|
43 R_GOTREL,
|
|
|
44 R_NONE,
|
|
|
45 R_PC,
|
|
|
46 R_PLT,
|
|
|
47 R_PLT_PC,
|
|
|
48 R_RELAX_GOT_PC,
|
|
|
49 R_RELAX_GOT_PC_NOPIC,
|
|
|
50 R_RELAX_TLS_GD_TO_IE,
|
|
|
51 R_RELAX_TLS_GD_TO_IE_ABS,
|
|
|
52 R_RELAX_TLS_GD_TO_IE_GOT_OFF,
|
|
|
53 R_RELAX_TLS_GD_TO_IE_GOTPLT,
|
|
|
54 R_RELAX_TLS_GD_TO_LE,
|
|
|
55 R_RELAX_TLS_GD_TO_LE_NEG,
|
|
|
56 R_RELAX_TLS_IE_TO_LE,
|
|
|
57 R_RELAX_TLS_LD_TO_LE,
|
|
|
58 R_RELAX_TLS_LD_TO_LE_ABS,
|
|
|
59 R_SIZE,
|
|
207
|
60 R_TPREL,
|
|
|
61 R_TPREL_NEG,
|
|
150
|
62 R_TLSDESC,
|
|
|
63 R_TLSDESC_CALL,
|
|
|
64 R_TLSDESC_PC,
|
|
|
65 R_TLSGD_GOT,
|
|
|
66 R_TLSGD_GOTPLT,
|
|
|
67 R_TLSGD_PC,
|
|
|
68 R_TLSIE_HINT,
|
|
|
69 R_TLSLD_GOT,
|
|
|
70 R_TLSLD_GOTPLT,
|
|
|
71 R_TLSLD_GOT_OFF,
|
|
|
72 R_TLSLD_HINT,
|
|
|
73 R_TLSLD_PC,
|
|
|
74
|
|
|
75 // The following is abstract relocation types used for only one target.
|
|
|
76 //
|
|
|
77 // Even though RelExpr is intended to be a target-neutral representation
|
|
|
78 // of a relocation type, there are some relocations whose semantics are
|
|
|
79 // unique to a target. Such relocation are marked with R_<TARGET_NAME>.
|
|
|
80 R_AARCH64_GOT_PAGE_PC,
|
|
207
|
81 R_AARCH64_GOT_PAGE,
|
|
150
|
82 R_AARCH64_PAGE_PC,
|
|
|
83 R_AARCH64_RELAX_TLS_GD_TO_IE_PAGE_PC,
|
|
|
84 R_AARCH64_TLSDESC_PAGE,
|
|
173
|
85 R_ARM_PCA,
|
|
150
|
86 R_ARM_SBREL,
|
|
|
87 R_MIPS_GOTREL,
|
|
|
88 R_MIPS_GOT_GP,
|
|
|
89 R_MIPS_GOT_GP_PC,
|
|
|
90 R_MIPS_GOT_LOCAL_PAGE,
|
|
|
91 R_MIPS_GOT_OFF,
|
|
|
92 R_MIPS_GOT_OFF32,
|
|
|
93 R_MIPS_TLSGD,
|
|
|
94 R_MIPS_TLSLD,
|
|
|
95 R_PPC32_PLTREL,
|
|
|
96 R_PPC64_CALL,
|
|
|
97 R_PPC64_CALL_PLT,
|
|
|
98 R_PPC64_RELAX_TOC,
|
|
|
99 R_PPC64_TOCBASE,
|
|
207
|
100 R_PPC64_RELAX_GOT_PC,
|
|
150
|
101 R_RISCV_ADD,
|
|
|
102 R_RISCV_PC_INDIRECT,
|
|
|
103 };
|
|
|
104
|
|
|
105 // Architecture-neutral representation of relocation.
|
|
|
106 struct Relocation {
|
|
|
107 RelExpr expr;
|
|
|
108 RelType type;
|
|
|
109 uint64_t offset;
|
|
|
110 int64_t addend;
|
|
|
111 Symbol *sym;
|
|
|
112 };
|
|
|
113
|
|
173
|
114 // Manipulate jump instructions with these modifiers. These are used to relax
|
|
|
115 // jump instruction opcodes at basic block boundaries and are particularly
|
|
|
116 // useful when basic block sections are enabled.
|
|
|
117 struct JumpInstrMod {
|
|
|
118 JumpModType original;
|
|
|
119 uint64_t offset;
|
|
|
120 unsigned size;
|
|
|
121 };
|
|
|
122
|
|
150
|
123 // This function writes undefined symbol diagnostics to an internal buffer.
|
|
|
124 // Call reportUndefinedSymbols() after calling scanRelocations() to emit
|
|
|
125 // the diagnostics.
|
|
|
126 template <class ELFT> void scanRelocations(InputSectionBase &);
|
|
|
127
|
|
|
128 template <class ELFT> void reportUndefinedSymbols();
|
|
|
129
|
|
173
|
130 void hexagonTLSSymbolUpdate(ArrayRef<OutputSection *> outputSections);
|
|
|
131 bool hexagonNeedsTLSSymbol(ArrayRef<OutputSection *> outputSections);
|
|
|
132
|
|
150
|
133 class ThunkSection;
|
|
|
134 class Thunk;
|
|
207
|
135 class InputSectionDescription;
|
|
150
|
136
|
|
|
137 class ThunkCreator {
|
|
|
138 public:
|
|
|
139 // Return true if Thunks have been added to OutputSections
|
|
|
140 bool createThunks(ArrayRef<OutputSection *> outputSections);
|
|
|
141
|
|
|
142 // The number of completed passes of createThunks this permits us
|
|
|
143 // to do one time initialization on Pass 0 and put a limit on the
|
|
|
144 // number of times it can be called to prevent infinite loops.
|
|
|
145 uint32_t pass = 0;
|
|
|
146
|
|
|
147 private:
|
|
|
148 void mergeThunks(ArrayRef<OutputSection *> outputSections);
|
|
|
149
|
|
|
150 ThunkSection *getISDThunkSec(OutputSection *os, InputSection *isec,
|
|
207
|
151 InputSectionDescription *isd,
|
|
|
152 const Relocation &rel, uint64_t src);
|
|
150
|
153
|
|
|
154 ThunkSection *getISThunkSec(InputSection *isec);
|
|
|
155
|
|
|
156 void createInitialThunkSections(ArrayRef<OutputSection *> outputSections);
|
|
|
157
|
|
|
158 std::pair<Thunk *, bool> getThunk(InputSection *isec, Relocation &rel,
|
|
|
159 uint64_t src);
|
|
|
160
|
|
|
161 ThunkSection *addThunkSection(OutputSection *os, InputSectionDescription *,
|
|
|
162 uint64_t off);
|
|
|
163
|
|
|
164 bool normalizeExistingThunk(Relocation &rel, uint64_t src);
|
|
|
165
|
|
|
166 // Record all the available Thunks for a (Symbol, addend) pair, where Symbol
|
|
|
167 // is represented as a (section, offset) pair. There may be multiple
|
|
|
168 // relocations sharing the same (section, offset + addend) pair. We may revert
|
|
|
169 // a relocation back to its original non-Thunk target, and restore the
|
|
|
170 // original addend, so we cannot fold offset + addend. A nested pair is used
|
|
|
171 // because DenseMapInfo is not specialized for std::tuple.
|
|
|
172 llvm::DenseMap<std::pair<std::pair<SectionBase *, uint64_t>, int64_t>,
|
|
|
173 std::vector<Thunk *>>
|
|
|
174 thunkedSymbolsBySectionAndAddend;
|
|
|
175 llvm::DenseMap<std::pair<Symbol *, int64_t>, std::vector<Thunk *>>
|
|
|
176 thunkedSymbols;
|
|
|
177
|
|
|
178 // Find a Thunk from the Thunks symbol definition, we can use this to find
|
|
|
179 // the Thunk from a relocation to the Thunks symbol definition.
|
|
|
180 llvm::DenseMap<Symbol *, Thunk *> thunks;
|
|
|
181
|
|
|
182 // Track InputSections that have an inline ThunkSection placed in front
|
|
|
183 // an inline ThunkSection may have control fall through to the section below
|
|
|
184 // so we need to make sure that there is only one of them.
|
|
|
185 // The Mips LA25 Thunk is an example of an inline ThunkSection.
|
|
|
186 llvm::DenseMap<InputSection *, ThunkSection *> thunkedSections;
|
|
|
187 };
|
|
|
188
|
|
|
189 // Return a int64_t to make sure we get the sign extension out of the way as
|
|
|
190 // early as possible.
|
|
|
191 template <class ELFT>
|
|
|
192 static inline int64_t getAddend(const typename ELFT::Rel &rel) {
|
|
|
193 return 0;
|
|
|
194 }
|
|
|
195 template <class ELFT>
|
|
|
196 static inline int64_t getAddend(const typename ELFT::Rela &rel) {
|
|
|
197 return rel.r_addend;
|
|
|
198 }
|
|
207
|
199
|
|
|
200 template <typename RelTy>
|
|
|
201 ArrayRef<RelTy> sortRels(ArrayRef<RelTy> rels, SmallVector<RelTy, 0> &storage) {
|
|
|
202 auto cmp = [](const RelTy &a, const RelTy &b) {
|
|
|
203 return a.r_offset < b.r_offset;
|
|
|
204 };
|
|
|
205 if (!llvm::is_sorted(rels, cmp)) {
|
|
|
206 storage.assign(rels.begin(), rels.end());
|
|
|
207 llvm::stable_sort(storage, cmp);
|
|
|
208 rels = storage;
|
|
|
209 }
|
|
|
210 return rels;
|
|
|
211 }
|
|
150
|
212 } // namespace elf
|
|
|
213 } // namespace lld
|
|
|
214
|
|
|
215 #endif
|
