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a2a8927a XL |
1 | use std::vec::Vec; |
2 | ||
3 | use crate::elf; | |
4 | use crate::write::elf::writer::*; | |
5 | use crate::write::string::StringId; | |
6 | use crate::write::*; | |
7 | use crate::AddressSize; | |
8 | ||
9 | #[derive(Clone, Copy)] | |
10 | struct ComdatOffsets { | |
11 | offset: usize, | |
12 | str_id: StringId, | |
13 | } | |
14 | ||
15 | #[derive(Clone, Copy)] | |
16 | struct SectionOffsets { | |
17 | index: SectionIndex, | |
18 | offset: usize, | |
19 | str_id: StringId, | |
20 | reloc_offset: usize, | |
21 | reloc_str_id: Option<StringId>, | |
22 | } | |
23 | ||
24 | #[derive(Default, Clone, Copy)] | |
25 | struct SymbolOffsets { | |
26 | index: SymbolIndex, | |
27 | str_id: Option<StringId>, | |
28 | } | |
29 | ||
30 | impl<'a> Object<'a> { | |
31 | pub(crate) fn elf_section_info( | |
32 | &self, | |
33 | section: StandardSection, | |
34 | ) -> (&'static [u8], &'static [u8], SectionKind) { | |
35 | match section { | |
36 | StandardSection::Text => (&[], &b".text"[..], SectionKind::Text), | |
37 | StandardSection::Data => (&[], &b".data"[..], SectionKind::Data), | |
38 | StandardSection::ReadOnlyData | StandardSection::ReadOnlyString => { | |
39 | (&[], &b".rodata"[..], SectionKind::ReadOnlyData) | |
40 | } | |
41 | StandardSection::ReadOnlyDataWithRel => (&[], b".data.rel.ro", SectionKind::Data), | |
42 | StandardSection::UninitializedData => { | |
43 | (&[], &b".bss"[..], SectionKind::UninitializedData) | |
44 | } | |
45 | StandardSection::Tls => (&[], &b".tdata"[..], SectionKind::Tls), | |
46 | StandardSection::UninitializedTls => { | |
47 | (&[], &b".tbss"[..], SectionKind::UninitializedTls) | |
48 | } | |
49 | StandardSection::TlsVariables => { | |
50 | // Unsupported section. | |
51 | (&[], &[], SectionKind::TlsVariables) | |
52 | } | |
53 | StandardSection::Common => { | |
54 | // Unsupported section. | |
55 | (&[], &[], SectionKind::Common) | |
56 | } | |
57 | } | |
58 | } | |
59 | ||
60 | pub(crate) fn elf_subsection_name(&self, section: &[u8], value: &[u8]) -> Vec<u8> { | |
61 | let mut name = section.to_vec(); | |
62 | name.push(b'.'); | |
63 | name.extend_from_slice(value); | |
64 | name | |
65 | } | |
66 | ||
67 | fn elf_has_relocation_addend(&self) -> Result<bool> { | |
68 | Ok(match self.architecture { | |
69 | Architecture::Aarch64 => true, | |
70 | Architecture::Arm => false, | |
71 | Architecture::Avr => true, | |
72 | Architecture::Bpf => false, | |
73 | Architecture::I386 => false, | |
74 | Architecture::X86_64 => true, | |
75 | Architecture::X86_64_X32 => true, | |
76 | Architecture::Hexagon => true, | |
77 | Architecture::Mips => false, | |
78 | Architecture::Mips64 => true, | |
79 | Architecture::Msp430 => true, | |
80 | Architecture::PowerPc => true, | |
81 | Architecture::PowerPc64 => true, | |
82 | Architecture::Riscv64 => true, | |
83 | Architecture::Riscv32 => true, | |
84 | Architecture::S390x => true, | |
85 | Architecture::Sparc64 => true, | |
86 | _ => { | |
87 | return Err(Error(format!( | |
88 | "unimplemented architecture {:?}", | |
89 | self.architecture | |
90 | ))); | |
91 | } | |
92 | }) | |
93 | } | |
94 | ||
95 | pub(crate) fn elf_fixup_relocation(&mut self, mut relocation: &mut Relocation) -> Result<i64> { | |
96 | // Return true if we should use a section symbol to avoid preemption. | |
97 | fn want_section_symbol(relocation: &Relocation, symbol: &Symbol) -> bool { | |
98 | if symbol.scope != SymbolScope::Dynamic { | |
99 | // Only dynamic symbols can be preemptible. | |
100 | return false; | |
101 | } | |
102 | match symbol.kind { | |
103 | SymbolKind::Text | SymbolKind::Data => {} | |
104 | _ => return false, | |
105 | } | |
106 | match relocation.kind { | |
107 | // Anything using GOT or PLT is preemptible. | |
108 | // We also require that `Other` relocations must already be correct. | |
109 | RelocationKind::Got | |
110 | | RelocationKind::GotRelative | |
111 | | RelocationKind::GotBaseRelative | |
112 | | RelocationKind::PltRelative | |
113 | | RelocationKind::Elf(_) => return false, | |
114 | // Absolute relocations are preemptible for non-local data. | |
115 | // TODO: not sure if this rule is exactly correct | |
116 | // This rule was added to handle global data references in debuginfo. | |
117 | // Maybe this should be a new relocation kind so that the caller can decide. | |
118 | RelocationKind::Absolute => { | |
119 | if symbol.kind == SymbolKind::Data { | |
120 | return false; | |
121 | } | |
122 | } | |
123 | _ => {} | |
124 | } | |
125 | true | |
126 | } | |
127 | ||
128 | // Use section symbols for relocations where required to avoid preemption. | |
129 | // Otherwise, the linker will fail with: | |
130 | // relocation R_X86_64_PC32 against symbol `SomeSymbolName' can not be used when | |
131 | // making a shared object; recompile with -fPIC | |
132 | let symbol = &self.symbols[relocation.symbol.0]; | |
133 | if want_section_symbol(relocation, symbol) { | |
134 | if let Some(section) = symbol.section.id() { | |
135 | relocation.addend += symbol.value as i64; | |
136 | relocation.symbol = self.section_symbol(section); | |
137 | } | |
138 | } | |
139 | ||
140 | // Determine whether the addend is stored in the relocation or the data. | |
141 | if self.elf_has_relocation_addend()? { | |
142 | Ok(0) | |
143 | } else { | |
144 | let constant = relocation.addend; | |
145 | relocation.addend = 0; | |
146 | Ok(constant) | |
147 | } | |
148 | } | |
149 | ||
150 | pub(crate) fn elf_write(&self, buffer: &mut dyn WritableBuffer) -> Result<()> { | |
151 | // Create reloc section header names so we can reference them. | |
152 | let is_rela = self.elf_has_relocation_addend()?; | |
153 | let reloc_names: Vec<_> = self | |
154 | .sections | |
155 | .iter() | |
156 | .map(|section| { | |
157 | let mut reloc_name = Vec::with_capacity( | |
158 | if is_rela { ".rela".len() } else { ".rel".len() } + section.name.len(), | |
159 | ); | |
160 | if !section.relocations.is_empty() { | |
161 | reloc_name.extend_from_slice(if is_rela { | |
162 | &b".rela"[..] | |
163 | } else { | |
164 | &b".rel"[..] | |
165 | }); | |
166 | reloc_name.extend_from_slice(§ion.name); | |
167 | } | |
168 | reloc_name | |
169 | }) | |
170 | .collect(); | |
171 | ||
172 | // Start calculating offsets of everything. | |
173 | let is_64 = match self.architecture.address_size().unwrap() { | |
174 | AddressSize::U8 | AddressSize::U16 | AddressSize::U32 => false, | |
175 | AddressSize::U64 => true, | |
176 | }; | |
177 | let mut writer = Writer::new(self.endian, is_64, buffer); | |
178 | writer.reserve_file_header(); | |
179 | ||
180 | // Calculate size of section data. | |
181 | let mut comdat_offsets = Vec::with_capacity(self.comdats.len()); | |
182 | for comdat in &self.comdats { | |
183 | if comdat.kind != ComdatKind::Any { | |
184 | return Err(Error(format!( | |
185 | "unsupported COMDAT symbol `{}` kind {:?}", | |
186 | self.symbols[comdat.symbol.0].name().unwrap_or(""), | |
187 | comdat.kind | |
188 | ))); | |
189 | } | |
190 | ||
191 | writer.reserve_section_index(); | |
192 | let offset = writer.reserve_comdat(comdat.sections.len()); | |
193 | let str_id = writer.add_section_name(b".group"); | |
194 | comdat_offsets.push(ComdatOffsets { offset, str_id }); | |
195 | } | |
196 | let mut section_offsets = Vec::with_capacity(self.sections.len()); | |
197 | for (section, reloc_name) in self.sections.iter().zip(reloc_names.iter()) { | |
198 | let index = writer.reserve_section_index(); | |
199 | let offset = writer.reserve(section.data.len(), section.align as usize); | |
200 | let str_id = writer.add_section_name(§ion.name); | |
201 | let mut reloc_str_id = None; | |
202 | if !section.relocations.is_empty() { | |
203 | writer.reserve_section_index(); | |
204 | reloc_str_id = Some(writer.add_section_name(reloc_name)); | |
205 | } | |
206 | section_offsets.push(SectionOffsets { | |
207 | index, | |
208 | offset, | |
209 | str_id, | |
210 | // Relocation data is reserved later. | |
211 | reloc_offset: 0, | |
212 | reloc_str_id, | |
213 | }); | |
214 | } | |
215 | ||
216 | // Calculate index of symbols and add symbol strings to strtab. | |
217 | let mut symbol_offsets = vec![SymbolOffsets::default(); self.symbols.len()]; | |
218 | // Local symbols must come before global. | |
219 | for (index, symbol) in self.symbols.iter().enumerate() { | |
220 | if symbol.is_local() { | |
221 | let section_index = symbol.section.id().map(|s| section_offsets[s.0].index); | |
222 | symbol_offsets[index].index = writer.reserve_symbol_index(section_index); | |
223 | } | |
224 | } | |
225 | let symtab_num_local = writer.symbol_count(); | |
226 | for (index, symbol) in self.symbols.iter().enumerate() { | |
227 | if !symbol.is_local() { | |
228 | let section_index = symbol.section.id().map(|s| section_offsets[s.0].index); | |
229 | symbol_offsets[index].index = writer.reserve_symbol_index(section_index); | |
230 | } | |
231 | } | |
232 | for (index, symbol) in self.symbols.iter().enumerate() { | |
233 | if symbol.kind != SymbolKind::Section && !symbol.name.is_empty() { | |
234 | symbol_offsets[index].str_id = Some(writer.add_string(&symbol.name)); | |
235 | } | |
236 | } | |
237 | ||
238 | // Calculate size of symbols. | |
239 | writer.reserve_symtab_section_index(); | |
240 | writer.reserve_symtab(); | |
241 | if writer.symtab_shndx_needed() { | |
242 | writer.reserve_symtab_shndx_section_index(); | |
243 | } | |
244 | writer.reserve_symtab_shndx(); | |
245 | writer.reserve_strtab_section_index(); | |
246 | writer.reserve_strtab(); | |
247 | ||
248 | // Calculate size of relocations. | |
249 | for (index, section) in self.sections.iter().enumerate() { | |
250 | let count = section.relocations.len(); | |
251 | if count != 0 { | |
252 | section_offsets[index].reloc_offset = writer.reserve_relocations(count, is_rela); | |
253 | } | |
254 | } | |
255 | ||
256 | // Calculate size of section headers. | |
257 | writer.reserve_shstrtab_section_index(); | |
258 | writer.reserve_shstrtab(); | |
259 | writer.reserve_section_headers(); | |
260 | ||
261 | // Start writing. | |
262 | let e_type = elf::ET_REL; | |
263 | let e_machine = match self.architecture { | |
264 | Architecture::Aarch64 => elf::EM_AARCH64, | |
265 | Architecture::Arm => elf::EM_ARM, | |
266 | Architecture::Avr => elf::EM_AVR, | |
267 | Architecture::Bpf => elf::EM_BPF, | |
268 | Architecture::I386 => elf::EM_386, | |
269 | Architecture::X86_64 => elf::EM_X86_64, | |
270 | Architecture::X86_64_X32 => elf::EM_X86_64, | |
271 | Architecture::Hexagon => elf::EM_HEXAGON, | |
272 | Architecture::Mips => elf::EM_MIPS, | |
273 | Architecture::Mips64 => elf::EM_MIPS, | |
274 | Architecture::Msp430 => elf::EM_MSP430, | |
275 | Architecture::PowerPc => elf::EM_PPC, | |
276 | Architecture::PowerPc64 => elf::EM_PPC64, | |
277 | Architecture::Riscv32 => elf::EM_RISCV, | |
278 | Architecture::Riscv64 => elf::EM_RISCV, | |
279 | Architecture::S390x => elf::EM_S390, | |
280 | Architecture::Sparc64 => elf::EM_SPARCV9, | |
281 | _ => { | |
282 | return Err(Error(format!( | |
283 | "unimplemented architecture {:?}", | |
284 | self.architecture | |
285 | ))); | |
286 | } | |
287 | }; | |
288 | let e_flags = if let FileFlags::Elf { e_flags } = self.flags { | |
289 | e_flags | |
290 | } else { | |
291 | 0 | |
292 | }; | |
293 | writer.write_file_header(&FileHeader { | |
294 | os_abi: elf::ELFOSABI_NONE, | |
295 | abi_version: 0, | |
296 | e_type, | |
297 | e_machine, | |
298 | e_entry: 0, | |
299 | e_flags, | |
300 | })?; | |
301 | ||
302 | // Write section data. | |
303 | for comdat in &self.comdats { | |
304 | writer.write_comdat_header(); | |
305 | for section in &comdat.sections { | |
306 | writer.write_comdat_entry(section_offsets[section.0].index); | |
307 | } | |
308 | } | |
309 | for (index, section) in self.sections.iter().enumerate() { | |
310 | let len = section.data.len(); | |
311 | if len != 0 { | |
312 | writer.write_align(section.align as usize); | |
313 | debug_assert_eq!(section_offsets[index].offset, writer.len()); | |
314 | writer.write(§ion.data); | |
315 | } | |
316 | } | |
317 | ||
318 | // Write symbols. | |
319 | writer.write_null_symbol(); | |
320 | let mut write_symbol = |index: usize, symbol: &Symbol| -> Result<()> { | |
321 | let st_info = if let SymbolFlags::Elf { st_info, .. } = symbol.flags { | |
322 | st_info | |
323 | } else { | |
324 | let st_type = match symbol.kind { | |
325 | SymbolKind::Null => elf::STT_NOTYPE, | |
326 | SymbolKind::Text => { | |
327 | if symbol.is_undefined() { | |
328 | elf::STT_NOTYPE | |
329 | } else { | |
330 | elf::STT_FUNC | |
331 | } | |
332 | } | |
333 | SymbolKind::Data => { | |
334 | if symbol.is_undefined() { | |
335 | elf::STT_NOTYPE | |
336 | } else if symbol.is_common() { | |
337 | elf::STT_COMMON | |
338 | } else { | |
339 | elf::STT_OBJECT | |
340 | } | |
341 | } | |
342 | SymbolKind::Section => elf::STT_SECTION, | |
343 | SymbolKind::File => elf::STT_FILE, | |
344 | SymbolKind::Tls => elf::STT_TLS, | |
345 | SymbolKind::Label => elf::STT_NOTYPE, | |
346 | SymbolKind::Unknown => { | |
347 | if symbol.is_undefined() { | |
348 | elf::STT_NOTYPE | |
349 | } else { | |
350 | return Err(Error(format!( | |
351 | "unimplemented symbol `{}` kind {:?}", | |
352 | symbol.name().unwrap_or(""), | |
353 | symbol.kind | |
354 | ))); | |
355 | } | |
356 | } | |
357 | }; | |
358 | let st_bind = if symbol.weak { | |
359 | elf::STB_WEAK | |
360 | } else if symbol.is_undefined() { | |
361 | elf::STB_GLOBAL | |
362 | } else if symbol.is_local() { | |
363 | elf::STB_LOCAL | |
364 | } else { | |
365 | elf::STB_GLOBAL | |
366 | }; | |
367 | (st_bind << 4) + st_type | |
368 | }; | |
369 | let st_other = if let SymbolFlags::Elf { st_other, .. } = symbol.flags { | |
370 | st_other | |
371 | } else if symbol.scope == SymbolScope::Linkage { | |
372 | elf::STV_HIDDEN | |
373 | } else { | |
374 | elf::STV_DEFAULT | |
375 | }; | |
376 | let (st_shndx, section) = match symbol.section { | |
377 | SymbolSection::None => { | |
378 | debug_assert_eq!(symbol.kind, SymbolKind::File); | |
379 | (elf::SHN_ABS, None) | |
380 | } | |
381 | SymbolSection::Undefined => (elf::SHN_UNDEF, None), | |
382 | SymbolSection::Absolute => (elf::SHN_ABS, None), | |
383 | SymbolSection::Common => (elf::SHN_COMMON, None), | |
384 | SymbolSection::Section(id) => (0, Some(section_offsets[id.0].index)), | |
385 | }; | |
386 | writer.write_symbol(&Sym { | |
387 | name: symbol_offsets[index].str_id, | |
388 | section, | |
389 | st_info, | |
390 | st_other, | |
391 | st_shndx, | |
392 | st_value: symbol.value, | |
393 | st_size: symbol.size, | |
394 | }); | |
395 | Ok(()) | |
396 | }; | |
397 | for (index, symbol) in self.symbols.iter().enumerate() { | |
398 | if symbol.is_local() { | |
399 | write_symbol(index, symbol)?; | |
400 | } | |
401 | } | |
402 | for (index, symbol) in self.symbols.iter().enumerate() { | |
403 | if !symbol.is_local() { | |
404 | write_symbol(index, symbol)?; | |
405 | } | |
406 | } | |
407 | writer.write_symtab_shndx(); | |
408 | writer.write_strtab(); | |
409 | ||
410 | // Write relocations. | |
411 | for (index, section) in self.sections.iter().enumerate() { | |
412 | if !section.relocations.is_empty() { | |
413 | writer.write_align_relocation(); | |
414 | debug_assert_eq!(section_offsets[index].reloc_offset, writer.len()); | |
415 | for reloc in §ion.relocations { | |
416 | let r_type = match self.architecture { | |
417 | Architecture::Aarch64 => match (reloc.kind, reloc.encoding, reloc.size) { | |
418 | (RelocationKind::Absolute, RelocationEncoding::Generic, 64) => { | |
419 | elf::R_AARCH64_ABS64 | |
420 | } | |
421 | (RelocationKind::Absolute, RelocationEncoding::Generic, 32) => { | |
422 | elf::R_AARCH64_ABS32 | |
423 | } | |
424 | (RelocationKind::Absolute, RelocationEncoding::Generic, 16) => { | |
425 | elf::R_AARCH64_ABS16 | |
426 | } | |
427 | (RelocationKind::Relative, RelocationEncoding::Generic, 64) => { | |
428 | elf::R_AARCH64_PREL64 | |
429 | } | |
430 | (RelocationKind::Relative, RelocationEncoding::Generic, 32) => { | |
431 | elf::R_AARCH64_PREL32 | |
432 | } | |
433 | (RelocationKind::Relative, RelocationEncoding::Generic, 16) => { | |
434 | elf::R_AARCH64_PREL16 | |
435 | } | |
436 | (RelocationKind::Relative, RelocationEncoding::AArch64Call, 26) | |
437 | | (RelocationKind::PltRelative, RelocationEncoding::AArch64Call, 26) => { | |
438 | elf::R_AARCH64_CALL26 | |
439 | } | |
440 | (RelocationKind::Elf(x), _, _) => x, | |
441 | _ => { | |
442 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
443 | } | |
444 | }, | |
445 | Architecture::Arm => match (reloc.kind, reloc.encoding, reloc.size) { | |
446 | (RelocationKind::Absolute, _, 32) => elf::R_ARM_ABS32, | |
447 | (RelocationKind::Elf(x), _, _) => x, | |
448 | _ => { | |
449 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
450 | } | |
451 | }, | |
452 | Architecture::Avr => match (reloc.kind, reloc.encoding, reloc.size) { | |
453 | (RelocationKind::Absolute, _, 32) => elf::R_AVR_32, | |
454 | (RelocationKind::Absolute, _, 16) => elf::R_AVR_16, | |
455 | (RelocationKind::Elf(x), _, _) => x, | |
456 | _ => { | |
457 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
458 | } | |
459 | }, | |
460 | Architecture::Bpf => match (reloc.kind, reloc.encoding, reloc.size) { | |
461 | (RelocationKind::Absolute, _, 64) => elf::R_BPF_64_64, | |
462 | (RelocationKind::Absolute, _, 32) => elf::R_BPF_64_32, | |
463 | (RelocationKind::Elf(x), _, _) => x, | |
464 | _ => { | |
465 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
466 | } | |
467 | }, | |
468 | Architecture::I386 => match (reloc.kind, reloc.size) { | |
469 | (RelocationKind::Absolute, 32) => elf::R_386_32, | |
470 | (RelocationKind::Relative, 32) => elf::R_386_PC32, | |
471 | (RelocationKind::Got, 32) => elf::R_386_GOT32, | |
472 | (RelocationKind::PltRelative, 32) => elf::R_386_PLT32, | |
473 | (RelocationKind::GotBaseOffset, 32) => elf::R_386_GOTOFF, | |
474 | (RelocationKind::GotBaseRelative, 32) => elf::R_386_GOTPC, | |
475 | (RelocationKind::Absolute, 16) => elf::R_386_16, | |
476 | (RelocationKind::Relative, 16) => elf::R_386_PC16, | |
477 | (RelocationKind::Absolute, 8) => elf::R_386_8, | |
478 | (RelocationKind::Relative, 8) => elf::R_386_PC8, | |
479 | (RelocationKind::Elf(x), _) => x, | |
480 | _ => { | |
481 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
482 | } | |
483 | }, | |
484 | Architecture::X86_64 | Architecture::X86_64_X32 => { | |
485 | match (reloc.kind, reloc.encoding, reloc.size) { | |
486 | (RelocationKind::Absolute, RelocationEncoding::Generic, 64) => { | |
487 | elf::R_X86_64_64 | |
488 | } | |
489 | (RelocationKind::Relative, _, 32) => elf::R_X86_64_PC32, | |
490 | (RelocationKind::Got, _, 32) => elf::R_X86_64_GOT32, | |
491 | (RelocationKind::PltRelative, _, 32) => elf::R_X86_64_PLT32, | |
492 | (RelocationKind::GotRelative, _, 32) => elf::R_X86_64_GOTPCREL, | |
493 | (RelocationKind::Absolute, RelocationEncoding::Generic, 32) => { | |
494 | elf::R_X86_64_32 | |
495 | } | |
496 | (RelocationKind::Absolute, RelocationEncoding::X86Signed, 32) => { | |
497 | elf::R_X86_64_32S | |
498 | } | |
499 | (RelocationKind::Absolute, _, 16) => elf::R_X86_64_16, | |
500 | (RelocationKind::Relative, _, 16) => elf::R_X86_64_PC16, | |
501 | (RelocationKind::Absolute, _, 8) => elf::R_X86_64_8, | |
502 | (RelocationKind::Relative, _, 8) => elf::R_X86_64_PC8, | |
503 | (RelocationKind::Elf(x), _, _) => x, | |
504 | _ => { | |
505 | return Err(Error(format!( | |
506 | "unimplemented relocation {:?}", | |
507 | reloc | |
508 | ))); | |
509 | } | |
510 | } | |
511 | } | |
512 | Architecture::Hexagon => match (reloc.kind, reloc.encoding, reloc.size) { | |
513 | (RelocationKind::Absolute, _, 32) => elf::R_HEX_32, | |
514 | (RelocationKind::Elf(x), _, _) => x, | |
515 | _ => { | |
516 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
517 | } | |
518 | }, | |
519 | Architecture::Mips | Architecture::Mips64 => { | |
520 | match (reloc.kind, reloc.encoding, reloc.size) { | |
521 | (RelocationKind::Absolute, _, 16) => elf::R_MIPS_16, | |
522 | (RelocationKind::Absolute, _, 32) => elf::R_MIPS_32, | |
523 | (RelocationKind::Absolute, _, 64) => elf::R_MIPS_64, | |
524 | (RelocationKind::Elf(x), _, _) => x, | |
525 | _ => { | |
526 | return Err(Error(format!( | |
527 | "unimplemented relocation {:?}", | |
528 | reloc | |
529 | ))); | |
530 | } | |
531 | } | |
532 | } | |
533 | Architecture::Msp430 => match (reloc.kind, reloc.encoding, reloc.size) { | |
534 | (RelocationKind::Absolute, _, 32) => elf::R_MSP430_32, | |
535 | (RelocationKind::Absolute, _, 16) => elf::R_MSP430_16_BYTE, | |
536 | (RelocationKind::Elf(x), _, _) => x, | |
537 | _ => { | |
538 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
539 | } | |
540 | }, | |
541 | Architecture::PowerPc => match (reloc.kind, reloc.encoding, reloc.size) { | |
542 | (RelocationKind::Absolute, _, 32) => elf::R_PPC_ADDR32, | |
543 | (RelocationKind::Elf(x), _, _) => x, | |
544 | _ => { | |
545 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
546 | } | |
547 | }, | |
548 | Architecture::PowerPc64 => match (reloc.kind, reloc.encoding, reloc.size) { | |
549 | (RelocationKind::Absolute, _, 32) => elf::R_PPC64_ADDR32, | |
550 | (RelocationKind::Absolute, _, 64) => elf::R_PPC64_ADDR64, | |
551 | (RelocationKind::Elf(x), _, _) => x, | |
552 | _ => { | |
553 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
554 | } | |
555 | }, | |
556 | Architecture::Riscv32 | Architecture::Riscv64 => { | |
557 | match (reloc.kind, reloc.encoding, reloc.size) { | |
558 | (RelocationKind::Absolute, _, 32) => elf::R_RISCV_32, | |
559 | (RelocationKind::Absolute, _, 64) => elf::R_RISCV_64, | |
560 | (RelocationKind::Elf(x), _, _) => x, | |
561 | _ => { | |
562 | return Err(Error(format!( | |
563 | "unimplemented relocation {:?}", | |
564 | reloc | |
565 | ))); | |
566 | } | |
567 | } | |
568 | } | |
569 | Architecture::S390x => match (reloc.kind, reloc.encoding, reloc.size) { | |
570 | (RelocationKind::Absolute, RelocationEncoding::Generic, 8) => { | |
571 | elf::R_390_8 | |
572 | } | |
573 | (RelocationKind::Absolute, RelocationEncoding::Generic, 16) => { | |
574 | elf::R_390_16 | |
575 | } | |
576 | (RelocationKind::Absolute, RelocationEncoding::Generic, 32) => { | |
577 | elf::R_390_32 | |
578 | } | |
579 | (RelocationKind::Absolute, RelocationEncoding::Generic, 64) => { | |
580 | elf::R_390_64 | |
581 | } | |
582 | (RelocationKind::Relative, RelocationEncoding::Generic, 16) => { | |
583 | elf::R_390_PC16 | |
584 | } | |
585 | (RelocationKind::Relative, RelocationEncoding::Generic, 32) => { | |
586 | elf::R_390_PC32 | |
587 | } | |
588 | (RelocationKind::Relative, RelocationEncoding::Generic, 64) => { | |
589 | elf::R_390_PC64 | |
590 | } | |
591 | (RelocationKind::Relative, RelocationEncoding::S390xDbl, 16) => { | |
592 | elf::R_390_PC16DBL | |
593 | } | |
594 | (RelocationKind::Relative, RelocationEncoding::S390xDbl, 32) => { | |
595 | elf::R_390_PC32DBL | |
596 | } | |
597 | (RelocationKind::PltRelative, RelocationEncoding::S390xDbl, 16) => { | |
598 | elf::R_390_PLT16DBL | |
599 | } | |
600 | (RelocationKind::PltRelative, RelocationEncoding::S390xDbl, 32) => { | |
601 | elf::R_390_PLT32DBL | |
602 | } | |
603 | (RelocationKind::Got, RelocationEncoding::Generic, 16) => { | |
604 | elf::R_390_GOT16 | |
605 | } | |
606 | (RelocationKind::Got, RelocationEncoding::Generic, 32) => { | |
607 | elf::R_390_GOT32 | |
608 | } | |
609 | (RelocationKind::Got, RelocationEncoding::Generic, 64) => { | |
610 | elf::R_390_GOT64 | |
611 | } | |
612 | (RelocationKind::GotRelative, RelocationEncoding::S390xDbl, 32) => { | |
613 | elf::R_390_GOTENT | |
614 | } | |
615 | (RelocationKind::GotBaseOffset, RelocationEncoding::Generic, 16) => { | |
616 | elf::R_390_GOTOFF16 | |
617 | } | |
618 | (RelocationKind::GotBaseOffset, RelocationEncoding::Generic, 32) => { | |
619 | elf::R_390_GOTOFF32 | |
620 | } | |
621 | (RelocationKind::GotBaseOffset, RelocationEncoding::Generic, 64) => { | |
622 | elf::R_390_GOTOFF64 | |
623 | } | |
624 | (RelocationKind::GotBaseRelative, RelocationEncoding::Generic, 64) => { | |
625 | elf::R_390_GOTPC | |
626 | } | |
627 | (RelocationKind::GotBaseRelative, RelocationEncoding::S390xDbl, 32) => { | |
628 | elf::R_390_GOTPCDBL | |
629 | } | |
630 | (RelocationKind::Elf(x), _, _) => x, | |
631 | _ => { | |
632 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
633 | } | |
634 | }, | |
635 | Architecture::Sparc64 => match (reloc.kind, reloc.encoding, reloc.size) { | |
636 | // TODO: use R_SPARC_32/R_SPARC_64 if aligned. | |
637 | (RelocationKind::Absolute, _, 32) => elf::R_SPARC_UA32, | |
638 | (RelocationKind::Absolute, _, 64) => elf::R_SPARC_UA64, | |
639 | (RelocationKind::Elf(x), _, _) => x, | |
640 | _ => { | |
641 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
642 | } | |
643 | }, | |
644 | _ => { | |
645 | if let RelocationKind::Elf(x) = reloc.kind { | |
646 | x | |
647 | } else { | |
648 | return Err(Error(format!("unimplemented relocation {:?}", reloc))); | |
649 | } | |
650 | } | |
651 | }; | |
652 | let r_sym = symbol_offsets[reloc.symbol.0].index.0; | |
653 | writer.write_relocation( | |
654 | is_rela, | |
655 | &Rel { | |
656 | r_offset: reloc.offset, | |
657 | r_sym, | |
658 | r_type, | |
659 | r_addend: reloc.addend, | |
660 | }, | |
661 | ); | |
662 | } | |
663 | } | |
664 | } | |
665 | ||
666 | writer.write_shstrtab(); | |
667 | ||
668 | // Write section headers. | |
669 | writer.write_null_section_header(); | |
670 | ||
671 | let symtab_index = writer.symtab_index(); | |
672 | for (comdat, comdat_offset) in self.comdats.iter().zip(comdat_offsets.iter()) { | |
673 | writer.write_comdat_section_header( | |
674 | comdat_offset.str_id, | |
675 | symtab_index, | |
676 | symbol_offsets[comdat.symbol.0].index, | |
677 | comdat_offset.offset, | |
678 | comdat.sections.len(), | |
679 | ); | |
680 | } | |
681 | for (index, section) in self.sections.iter().enumerate() { | |
682 | let sh_type = match section.kind { | |
683 | SectionKind::UninitializedData | SectionKind::UninitializedTls => elf::SHT_NOBITS, | |
684 | SectionKind::Note => elf::SHT_NOTE, | |
685 | SectionKind::Elf(sh_type) => sh_type, | |
686 | _ => elf::SHT_PROGBITS, | |
687 | }; | |
688 | let sh_flags = if let SectionFlags::Elf { sh_flags } = section.flags { | |
689 | sh_flags | |
690 | } else { | |
691 | match section.kind { | |
692 | SectionKind::Text => elf::SHF_ALLOC | elf::SHF_EXECINSTR, | |
693 | SectionKind::Data => elf::SHF_ALLOC | elf::SHF_WRITE, | |
694 | SectionKind::Tls => elf::SHF_ALLOC | elf::SHF_WRITE | elf::SHF_TLS, | |
695 | SectionKind::UninitializedData => elf::SHF_ALLOC | elf::SHF_WRITE, | |
696 | SectionKind::UninitializedTls => elf::SHF_ALLOC | elf::SHF_WRITE | elf::SHF_TLS, | |
697 | SectionKind::ReadOnlyData => elf::SHF_ALLOC, | |
698 | SectionKind::ReadOnlyString => { | |
699 | elf::SHF_ALLOC | elf::SHF_STRINGS | elf::SHF_MERGE | |
700 | } | |
701 | SectionKind::OtherString => elf::SHF_STRINGS | elf::SHF_MERGE, | |
702 | SectionKind::Other | |
703 | | SectionKind::Debug | |
704 | | SectionKind::Metadata | |
705 | | SectionKind::Linker | |
706 | | SectionKind::Note | |
707 | | SectionKind::Elf(_) => 0, | |
708 | SectionKind::Unknown | SectionKind::Common | SectionKind::TlsVariables => { | |
709 | return Err(Error(format!( | |
710 | "unimplemented section `{}` kind {:?}", | |
711 | section.name().unwrap_or(""), | |
712 | section.kind | |
713 | ))); | |
714 | } | |
715 | } | |
716 | .into() | |
717 | }; | |
718 | // TODO: not sure if this is correct, maybe user should determine this | |
719 | let sh_entsize = match section.kind { | |
720 | SectionKind::ReadOnlyString | SectionKind::OtherString => 1, | |
721 | _ => 0, | |
722 | }; | |
723 | writer.write_section_header(&SectionHeader { | |
724 | name: Some(section_offsets[index].str_id), | |
725 | sh_type, | |
726 | sh_flags, | |
727 | sh_addr: 0, | |
728 | sh_offset: section_offsets[index].offset as u64, | |
729 | sh_size: section.size, | |
730 | sh_link: 0, | |
731 | sh_info: 0, | |
732 | sh_addralign: section.align, | |
733 | sh_entsize, | |
734 | }); | |
735 | ||
736 | if !section.relocations.is_empty() { | |
737 | writer.write_relocation_section_header( | |
738 | section_offsets[index].reloc_str_id.unwrap(), | |
739 | section_offsets[index].index, | |
740 | symtab_index, | |
741 | section_offsets[index].reloc_offset, | |
742 | section.relocations.len(), | |
743 | is_rela, | |
744 | ); | |
745 | } | |
746 | } | |
747 | ||
748 | writer.write_symtab_section_header(symtab_num_local); | |
749 | writer.write_symtab_shndx_section_header(); | |
750 | writer.write_strtab_section_header(); | |
751 | writer.write_shstrtab_section_header(); | |
752 | ||
753 | debug_assert_eq!(writer.reserved_len(), writer.len()); | |
754 | ||
755 | Ok(()) | |
756 | } | |
757 | } |