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f035d41b XL |
1 | use alloc::vec::Vec; |
2 | use indexmap::IndexSet; | |
3 | use std::ops::{Deref, DerefMut}; | |
4 | ||
5 | use crate::common::{DebugFrameOffset, EhFrameOffset, Encoding, Format, Register, SectionId}; | |
6 | use crate::constants; | |
7 | use crate::write::{Address, BaseId, Error, Expression, Result, Section, Writer}; | |
8 | ||
9 | define_section!( | |
10 | DebugFrame, | |
11 | DebugFrameOffset, | |
12 | "A writable `.debug_frame` section." | |
13 | ); | |
14 | ||
15 | define_section!(EhFrame, EhFrameOffset, "A writable `.eh_frame` section."); | |
16 | ||
17 | define_id!(CieId, "An identifier for a CIE in a `FrameTable`."); | |
18 | ||
19 | /// A table of frame description entries. | |
20 | #[derive(Debug, Default)] | |
21 | pub struct FrameTable { | |
22 | /// Base id for CIEs. | |
23 | base_id: BaseId, | |
24 | /// The common information entries. | |
25 | cies: IndexSet<CommonInformationEntry>, | |
26 | /// The frame description entries. | |
27 | fdes: Vec<(CieId, FrameDescriptionEntry)>, | |
28 | } | |
29 | ||
30 | impl FrameTable { | |
31 | /// Add a CIE and return its id. | |
32 | /// | |
33 | /// If the CIE already exists, then return the id of the existing CIE. | |
34 | pub fn add_cie(&mut self, cie: CommonInformationEntry) -> CieId { | |
35 | let (index, _) = self.cies.insert_full(cie); | |
36 | CieId::new(self.base_id, index) | |
37 | } | |
38 | ||
39 | /// The number of CIEs. | |
40 | pub fn cie_count(&self) -> usize { | |
41 | self.cies.len() | |
42 | } | |
43 | ||
44 | /// Add a FDE. | |
45 | /// | |
46 | /// Does not check for duplicates. | |
47 | /// | |
48 | /// # Panics | |
49 | /// | |
50 | /// Panics if the CIE id is invalid. | |
51 | pub fn add_fde(&mut self, cie: CieId, fde: FrameDescriptionEntry) { | |
52 | debug_assert_eq!(self.base_id, cie.base_id); | |
53 | self.fdes.push((cie, fde)); | |
54 | } | |
55 | ||
56 | /// The number of FDEs. | |
57 | pub fn fde_count(&self) -> usize { | |
58 | self.fdes.len() | |
59 | } | |
60 | ||
61 | /// Write the frame table entries to the given `.debug_frame` section. | |
62 | pub fn write_debug_frame<W: Writer>(&self, w: &mut DebugFrame<W>) -> Result<()> { | |
63 | self.write(&mut w.0, false) | |
64 | } | |
65 | ||
66 | /// Write the frame table entries to the given `.eh_frame` section. | |
67 | pub fn write_eh_frame<W: Writer>(&self, w: &mut EhFrame<W>) -> Result<()> { | |
68 | self.write(&mut w.0, true) | |
69 | } | |
70 | ||
71 | fn write<W: Writer>(&self, w: &mut W, eh_frame: bool) -> Result<()> { | |
72 | let mut cie_offsets = vec![None; self.cies.len()]; | |
73 | for (cie_id, fde) in &self.fdes { | |
74 | let cie_index = cie_id.index; | |
75 | let cie = self.cies.get_index(cie_index).unwrap(); | |
76 | let cie_offset = match cie_offsets[cie_index] { | |
77 | Some(offset) => offset, | |
78 | None => { | |
79 | // Only write CIEs as they are referenced. | |
80 | let offset = cie.write(w, eh_frame)?; | |
81 | cie_offsets[cie_index] = Some(offset); | |
82 | offset | |
83 | } | |
84 | }; | |
85 | ||
86 | fde.write(w, eh_frame, cie_offset, cie)?; | |
87 | } | |
88 | // TODO: write length 0 terminator for eh_frame? | |
89 | Ok(()) | |
90 | } | |
91 | } | |
92 | ||
93 | /// A common information entry. This contains information that is shared between FDEs. | |
94 | #[derive(Debug, Clone, PartialEq, Eq, Hash)] | |
95 | pub struct CommonInformationEntry { | |
96 | encoding: Encoding, | |
97 | ||
98 | /// A constant that is factored out of code offsets. | |
99 | /// | |
100 | /// This should be set to the minimum instruction length. | |
101 | /// Writing a code offset that is not a multiple of this factor will generate an error. | |
102 | code_alignment_factor: u8, | |
103 | ||
104 | /// A constant that is factored out of data offsets. | |
105 | /// | |
106 | /// This should be set to the minimum data alignment for the frame. | |
107 | /// Writing a data offset that is not a multiple of this factor will generate an error. | |
108 | data_alignment_factor: i8, | |
109 | ||
110 | /// The return address register. This might not correspond to an actual machine register. | |
111 | return_address_register: Register, | |
112 | ||
113 | /// The address of the personality function and its encoding. | |
114 | pub personality: Option<(constants::DwEhPe, Address)>, | |
115 | ||
116 | /// The encoding to use for the LSDA address in FDEs. | |
117 | /// | |
118 | /// If set then all FDEs which use this CIE must have a LSDA address. | |
119 | pub lsda_encoding: Option<constants::DwEhPe>, | |
120 | ||
121 | /// The encoding to use for addresses in FDEs. | |
122 | pub fde_address_encoding: constants::DwEhPe, | |
123 | ||
124 | /// True for signal trampolines. | |
125 | pub signal_trampoline: bool, | |
126 | ||
127 | /// The initial instructions upon entry to this function. | |
128 | instructions: Vec<CallFrameInstruction>, | |
129 | } | |
130 | ||
131 | impl CommonInformationEntry { | |
132 | /// Create a new common information entry. | |
133 | /// | |
134 | /// The encoding version must be a CFI version, not a DWARF version. | |
135 | pub fn new( | |
136 | encoding: Encoding, | |
137 | code_alignment_factor: u8, | |
138 | data_alignment_factor: i8, | |
139 | return_address_register: Register, | |
140 | ) -> Self { | |
141 | CommonInformationEntry { | |
142 | encoding, | |
143 | code_alignment_factor, | |
144 | data_alignment_factor, | |
145 | return_address_register, | |
146 | personality: None, | |
147 | lsda_encoding: None, | |
148 | fde_address_encoding: constants::DW_EH_PE_absptr, | |
149 | signal_trampoline: false, | |
150 | instructions: Vec::new(), | |
151 | } | |
152 | } | |
153 | ||
154 | /// Add an initial instruction. | |
155 | pub fn add_instruction(&mut self, instruction: CallFrameInstruction) { | |
156 | self.instructions.push(instruction); | |
157 | } | |
158 | ||
159 | fn has_augmentation(&self) -> bool { | |
160 | self.personality.is_some() | |
161 | || self.lsda_encoding.is_some() | |
162 | || self.signal_trampoline | |
163 | || self.fde_address_encoding != constants::DW_EH_PE_absptr | |
164 | } | |
165 | ||
166 | /// Returns the section offset of the CIE. | |
167 | fn write<W: Writer>(&self, w: &mut W, eh_frame: bool) -> Result<usize> { | |
168 | let encoding = self.encoding; | |
169 | let offset = w.len(); | |
170 | ||
171 | let length_offset = w.write_initial_length(encoding.format)?; | |
172 | let length_base = w.len(); | |
173 | ||
174 | if eh_frame { | |
175 | w.write_u32(0)?; | |
176 | } else { | |
177 | match encoding.format { | |
178 | Format::Dwarf32 => w.write_u32(0xffff_ffff)?, | |
179 | Format::Dwarf64 => w.write_u64(0xffff_ffff_ffff_ffff)?, | |
180 | } | |
181 | } | |
182 | ||
183 | if eh_frame { | |
184 | if encoding.version != 1 { | |
185 | return Err(Error::UnsupportedVersion(encoding.version)); | |
186 | }; | |
187 | } else { | |
188 | match encoding.version { | |
189 | 1 | 3 | 4 => {} | |
190 | _ => return Err(Error::UnsupportedVersion(encoding.version)), | |
191 | }; | |
192 | } | |
193 | w.write_u8(encoding.version as u8)?; | |
194 | ||
195 | let augmentation = self.has_augmentation(); | |
196 | if augmentation { | |
197 | w.write_u8(b'z')?; | |
198 | if self.lsda_encoding.is_some() { | |
199 | w.write_u8(b'L')?; | |
200 | } | |
201 | if self.personality.is_some() { | |
202 | w.write_u8(b'P')?; | |
203 | } | |
204 | if self.fde_address_encoding != constants::DW_EH_PE_absptr { | |
205 | w.write_u8(b'R')?; | |
206 | } | |
207 | if self.signal_trampoline { | |
208 | w.write_u8(b'S')?; | |
209 | } | |
210 | } | |
211 | w.write_u8(0)?; | |
212 | ||
213 | if encoding.version >= 4 { | |
214 | w.write_u8(encoding.address_size)?; | |
215 | // TODO: segment_selector_size | |
216 | w.write_u8(0)?; | |
217 | } | |
218 | ||
219 | w.write_uleb128(self.code_alignment_factor.into())?; | |
220 | w.write_sleb128(self.data_alignment_factor.into())?; | |
221 | ||
222 | if !eh_frame && encoding.version == 1 { | |
223 | let register = self.return_address_register.0 as u8; | |
224 | if u16::from(register) != self.return_address_register.0 { | |
225 | return Err(Error::ValueTooLarge); | |
226 | } | |
227 | w.write_u8(register)?; | |
228 | } else { | |
229 | w.write_uleb128(self.return_address_register.0.into())?; | |
230 | } | |
231 | ||
232 | if augmentation { | |
233 | let augmentation_length_offset = w.len(); | |
234 | w.write_u8(0)?; | |
235 | let augmentation_length_base = w.len(); | |
236 | ||
237 | if let Some(eh_pe) = self.lsda_encoding { | |
238 | w.write_u8(eh_pe.0)?; | |
239 | } | |
240 | if let Some((eh_pe, address)) = self.personality { | |
241 | w.write_u8(eh_pe.0)?; | |
242 | w.write_eh_pointer(address, constants::DW_EH_PE_absptr, encoding.address_size)?; | |
243 | } | |
244 | if self.fde_address_encoding != constants::DW_EH_PE_absptr { | |
245 | w.write_u8(self.fde_address_encoding.0)?; | |
246 | } | |
247 | ||
248 | let augmentation_length = (w.len() - augmentation_length_base) as u64; | |
249 | debug_assert!(augmentation_length < 0x80); | |
250 | w.write_udata_at(augmentation_length_offset, augmentation_length, 1)?; | |
251 | } | |
252 | ||
253 | for instruction in &self.instructions { | |
254 | instruction.write(w, encoding, self)?; | |
255 | } | |
256 | ||
257 | write_nop( | |
258 | w, | |
259 | encoding.format.word_size() as usize + w.len() - length_base, | |
260 | encoding.address_size, | |
261 | )?; | |
262 | ||
263 | let length = (w.len() - length_base) as u64; | |
264 | w.write_initial_length_at(length_offset, length, encoding.format)?; | |
265 | ||
266 | Ok(offset) | |
267 | } | |
268 | } | |
269 | ||
270 | /// A frame description entry. There should be one FDE per function. | |
271 | #[derive(Debug, Clone, PartialEq, Eq)] | |
272 | pub struct FrameDescriptionEntry { | |
273 | /// The initial address of the function. | |
274 | address: Address, | |
275 | ||
276 | /// The length in bytes of the function. | |
277 | length: u32, | |
278 | ||
279 | /// The address of the LSDA. | |
280 | pub lsda: Option<Address>, | |
281 | ||
282 | /// The instructions for this function, ordered by offset. | |
283 | instructions: Vec<(u32, CallFrameInstruction)>, | |
284 | } | |
285 | ||
286 | impl FrameDescriptionEntry { | |
287 | /// Create a new frame description entry for a function. | |
288 | pub fn new(address: Address, length: u32) -> Self { | |
289 | FrameDescriptionEntry { | |
290 | address, | |
291 | length, | |
292 | lsda: None, | |
293 | instructions: Vec::new(), | |
294 | } | |
295 | } | |
296 | ||
297 | /// Add an instruction. | |
298 | /// | |
299 | /// Instructions must be added in increasing order of offset, or writing will fail. | |
300 | pub fn add_instruction(&mut self, offset: u32, instruction: CallFrameInstruction) { | |
301 | debug_assert!(self.instructions.last().map(|x| x.0).unwrap_or(0) <= offset); | |
302 | self.instructions.push((offset, instruction)); | |
303 | } | |
304 | ||
305 | fn write<W: Writer>( | |
306 | &self, | |
307 | w: &mut W, | |
308 | eh_frame: bool, | |
309 | cie_offset: usize, | |
310 | cie: &CommonInformationEntry, | |
311 | ) -> Result<()> { | |
312 | let encoding = cie.encoding; | |
313 | let length_offset = w.write_initial_length(encoding.format)?; | |
314 | let length_base = w.len(); | |
315 | ||
316 | if eh_frame { | |
317 | // .eh_frame uses a relative offset which doesn't need relocation. | |
318 | w.write_udata((w.len() - cie_offset) as u64, 4)?; | |
319 | } else { | |
320 | w.write_offset( | |
321 | cie_offset, | |
322 | SectionId::DebugFrame, | |
323 | encoding.format.word_size(), | |
324 | )?; | |
325 | } | |
326 | ||
327 | if cie.fde_address_encoding != constants::DW_EH_PE_absptr { | |
328 | w.write_eh_pointer( | |
329 | self.address, | |
330 | cie.fde_address_encoding, | |
331 | encoding.address_size, | |
332 | )?; | |
333 | w.write_eh_pointer_data( | |
334 | self.length.into(), | |
335 | cie.fde_address_encoding.format(), | |
336 | encoding.address_size, | |
337 | )?; | |
338 | } else { | |
339 | w.write_address(self.address, encoding.address_size)?; | |
340 | w.write_udata(self.length.into(), encoding.address_size)?; | |
341 | } | |
342 | ||
343 | if cie.has_augmentation() { | |
344 | let mut augmentation_length = 0u64; | |
345 | if self.lsda.is_some() { | |
346 | augmentation_length += u64::from(encoding.address_size); | |
347 | } | |
348 | w.write_uleb128(augmentation_length)?; | |
349 | ||
350 | debug_assert_eq!(self.lsda.is_some(), cie.lsda_encoding.is_some()); | |
351 | if let (Some(lsda), Some(lsda_encoding)) = (self.lsda, cie.lsda_encoding) { | |
352 | w.write_eh_pointer(lsda, lsda_encoding, encoding.address_size)?; | |
353 | } | |
354 | } | |
355 | ||
356 | let mut prev_offset = 0; | |
357 | for (offset, instruction) in &self.instructions { | |
358 | write_advance_loc(w, cie.code_alignment_factor, prev_offset, *offset)?; | |
359 | prev_offset = *offset; | |
360 | instruction.write(w, encoding, cie)?; | |
361 | } | |
362 | ||
363 | write_nop( | |
364 | w, | |
365 | encoding.format.word_size() as usize + w.len() - length_base, | |
366 | encoding.address_size, | |
367 | )?; | |
368 | ||
369 | let length = (w.len() - length_base) as u64; | |
370 | w.write_initial_length_at(length_offset, length, encoding.format)?; | |
371 | ||
372 | Ok(()) | |
373 | } | |
374 | } | |
375 | ||
376 | /// An instruction in a frame description entry. | |
377 | /// | |
378 | /// This may be a CFA definition, a register rule, or some other directive. | |
379 | #[derive(Debug, Clone, PartialEq, Eq, Hash)] | |
380 | pub enum CallFrameInstruction { | |
381 | /// Define the CFA rule to use the provided register and offset. | |
382 | Cfa(Register, i32), | |
383 | /// Update the CFA rule to use the provided register. The offset is unchanged. | |
384 | CfaRegister(Register), | |
385 | /// Update the CFA rule to use the provided offset. The register is unchanged. | |
386 | CfaOffset(i32), | |
387 | /// Define the CFA rule to use the provided expression. | |
388 | CfaExpression(Expression), | |
389 | ||
390 | /// Restore the initial rule for the register. | |
391 | Restore(Register), | |
392 | /// The previous value of the register is not recoverable. | |
393 | Undefined(Register), | |
394 | /// The register has not been modified. | |
395 | SameValue(Register), | |
396 | /// The previous value of the register is saved at address CFA + offset. | |
397 | Offset(Register, i32), | |
398 | /// The previous value of the register is CFA + offset. | |
399 | ValOffset(Register, i32), | |
400 | /// The previous value of the register is stored in another register. | |
401 | Register(Register, Register), | |
402 | /// The previous value of the register is saved at address given by the expression. | |
403 | Expression(Register, Expression), | |
404 | /// The previous value of the register is given by the expression. | |
405 | ValExpression(Register, Expression), | |
406 | ||
407 | /// Push all register rules onto a stack. | |
408 | RememberState, | |
409 | /// Pop all register rules off the stack. | |
410 | RestoreState, | |
411 | /// The size of the arguments that have been pushed onto the stack. | |
412 | ArgsSize(u32), | |
413 | } | |
414 | ||
415 | impl CallFrameInstruction { | |
416 | fn write<W: Writer>( | |
417 | &self, | |
418 | w: &mut W, | |
419 | encoding: Encoding, | |
420 | cie: &CommonInformationEntry, | |
421 | ) -> Result<()> { | |
422 | match *self { | |
423 | CallFrameInstruction::Cfa(register, offset) => { | |
424 | if offset < 0 { | |
425 | let offset = factored_data_offset(offset, cie.data_alignment_factor)?; | |
426 | w.write_u8(constants::DW_CFA_def_cfa_sf.0)?; | |
427 | w.write_uleb128(register.0.into())?; | |
428 | w.write_sleb128(offset.into())?; | |
429 | } else { | |
430 | // Unfactored offset. | |
431 | w.write_u8(constants::DW_CFA_def_cfa.0)?; | |
432 | w.write_uleb128(register.0.into())?; | |
433 | w.write_uleb128(offset as u64)?; | |
434 | } | |
435 | } | |
436 | CallFrameInstruction::CfaRegister(register) => { | |
437 | w.write_u8(constants::DW_CFA_def_cfa_register.0)?; | |
438 | w.write_uleb128(register.0.into())?; | |
439 | } | |
440 | CallFrameInstruction::CfaOffset(offset) => { | |
441 | if offset < 0 { | |
442 | let offset = factored_data_offset(offset, cie.data_alignment_factor)?; | |
443 | w.write_u8(constants::DW_CFA_def_cfa_offset_sf.0)?; | |
444 | w.write_sleb128(offset.into())?; | |
445 | } else { | |
446 | // Unfactored offset. | |
447 | w.write_u8(constants::DW_CFA_def_cfa_offset.0)?; | |
448 | w.write_uleb128(offset as u64)?; | |
449 | } | |
450 | } | |
451 | CallFrameInstruction::CfaExpression(ref expression) => { | |
452 | w.write_u8(constants::DW_CFA_def_cfa_expression.0)?; | |
453 | w.write_uleb128(expression.size(encoding, None) as u64)?; | |
454 | expression.write(w, None, encoding, None)?; | |
455 | } | |
456 | CallFrameInstruction::Restore(register) => { | |
457 | if register.0 < 0x40 { | |
458 | w.write_u8(constants::DW_CFA_restore.0 | register.0 as u8)?; | |
459 | } else { | |
460 | w.write_u8(constants::DW_CFA_restore_extended.0)?; | |
461 | w.write_uleb128(register.0.into())?; | |
462 | } | |
463 | } | |
464 | CallFrameInstruction::Undefined(register) => { | |
465 | w.write_u8(constants::DW_CFA_undefined.0)?; | |
466 | w.write_uleb128(register.0.into())?; | |
467 | } | |
468 | CallFrameInstruction::SameValue(register) => { | |
469 | w.write_u8(constants::DW_CFA_same_value.0)?; | |
470 | w.write_uleb128(register.0.into())?; | |
471 | } | |
472 | CallFrameInstruction::Offset(register, offset) => { | |
473 | let offset = factored_data_offset(offset, cie.data_alignment_factor)?; | |
474 | if offset < 0 { | |
475 | w.write_u8(constants::DW_CFA_offset_extended_sf.0)?; | |
476 | w.write_uleb128(register.0.into())?; | |
477 | w.write_sleb128(offset.into())?; | |
478 | } else if register.0 < 0x40 { | |
479 | w.write_u8(constants::DW_CFA_offset.0 | register.0 as u8)?; | |
480 | w.write_uleb128(offset as u64)?; | |
481 | } else { | |
482 | w.write_u8(constants::DW_CFA_offset_extended.0)?; | |
483 | w.write_uleb128(register.0.into())?; | |
484 | w.write_uleb128(offset as u64)?; | |
485 | } | |
486 | } | |
487 | CallFrameInstruction::ValOffset(register, offset) => { | |
488 | let offset = factored_data_offset(offset, cie.data_alignment_factor)?; | |
489 | if offset < 0 { | |
490 | w.write_u8(constants::DW_CFA_val_offset_sf.0)?; | |
491 | w.write_uleb128(register.0.into())?; | |
492 | w.write_sleb128(offset.into())?; | |
493 | } else { | |
494 | w.write_u8(constants::DW_CFA_val_offset.0)?; | |
495 | w.write_uleb128(register.0.into())?; | |
496 | w.write_uleb128(offset as u64)?; | |
497 | } | |
498 | } | |
499 | CallFrameInstruction::Register(register1, register2) => { | |
500 | w.write_u8(constants::DW_CFA_register.0)?; | |
501 | w.write_uleb128(register1.0.into())?; | |
502 | w.write_uleb128(register2.0.into())?; | |
503 | } | |
504 | CallFrameInstruction::Expression(register, ref expression) => { | |
505 | w.write_u8(constants::DW_CFA_expression.0)?; | |
506 | w.write_uleb128(register.0.into())?; | |
507 | w.write_uleb128(expression.size(encoding, None) as u64)?; | |
508 | expression.write(w, None, encoding, None)?; | |
509 | } | |
510 | CallFrameInstruction::ValExpression(register, ref expression) => { | |
511 | w.write_u8(constants::DW_CFA_val_expression.0)?; | |
512 | w.write_uleb128(register.0.into())?; | |
513 | w.write_uleb128(expression.size(encoding, None) as u64)?; | |
514 | expression.write(w, None, encoding, None)?; | |
515 | } | |
516 | CallFrameInstruction::RememberState => { | |
517 | w.write_u8(constants::DW_CFA_remember_state.0)?; | |
518 | } | |
519 | CallFrameInstruction::RestoreState => { | |
520 | w.write_u8(constants::DW_CFA_restore_state.0)?; | |
521 | } | |
522 | CallFrameInstruction::ArgsSize(size) => { | |
523 | w.write_u8(constants::DW_CFA_GNU_args_size.0)?; | |
524 | w.write_uleb128(size.into())?; | |
525 | } | |
526 | } | |
527 | Ok(()) | |
528 | } | |
529 | } | |
530 | ||
531 | fn write_advance_loc<W: Writer>( | |
532 | w: &mut W, | |
533 | code_alignment_factor: u8, | |
534 | prev_offset: u32, | |
535 | offset: u32, | |
536 | ) -> Result<()> { | |
537 | if offset == prev_offset { | |
538 | return Ok(()); | |
539 | } | |
540 | let delta = factored_code_delta(prev_offset, offset, code_alignment_factor)?; | |
541 | if delta < 0x40 { | |
542 | w.write_u8(constants::DW_CFA_advance_loc.0 | delta as u8)?; | |
543 | } else if delta < 0x100 { | |
544 | w.write_u8(constants::DW_CFA_advance_loc1.0)?; | |
545 | w.write_u8(delta as u8)?; | |
546 | } else if delta < 0x10000 { | |
547 | w.write_u8(constants::DW_CFA_advance_loc2.0)?; | |
548 | w.write_u16(delta as u16)?; | |
549 | } else { | |
550 | w.write_u8(constants::DW_CFA_advance_loc4.0)?; | |
551 | w.write_u32(delta)?; | |
552 | } | |
553 | Ok(()) | |
554 | } | |
555 | ||
556 | fn write_nop<W: Writer>(w: &mut W, len: usize, align: u8) -> Result<()> { | |
557 | debug_assert_eq!(align & (align - 1), 0); | |
558 | let tail_len = (!len + 1) & (align as usize - 1); | |
559 | for _ in 0..tail_len { | |
560 | w.write_u8(constants::DW_CFA_nop.0)?; | |
561 | } | |
562 | Ok(()) | |
563 | } | |
564 | ||
565 | fn factored_code_delta(prev_offset: u32, offset: u32, factor: u8) -> Result<u32> { | |
566 | if offset < prev_offset { | |
567 | return Err(Error::InvalidFrameCodeOffset(offset)); | |
568 | } | |
569 | let delta = offset - prev_offset; | |
570 | let factor = u32::from(factor); | |
571 | let factored_delta = delta / factor; | |
572 | if delta != factored_delta * factor { | |
573 | return Err(Error::InvalidFrameCodeOffset(offset)); | |
574 | } | |
575 | Ok(factored_delta) | |
576 | } | |
577 | ||
578 | fn factored_data_offset(offset: i32, factor: i8) -> Result<i32> { | |
579 | let factor = i32::from(factor); | |
580 | let factored_offset = offset / factor; | |
581 | if offset != factored_offset * factor { | |
582 | return Err(Error::InvalidFrameDataOffset(offset)); | |
583 | } | |
584 | Ok(factored_offset) | |
585 | } | |
586 | ||
587 | #[cfg(feature = "read")] | |
588 | pub(crate) mod convert { | |
589 | use super::*; | |
590 | use crate::read::{self, Reader}; | |
591 | use crate::write::{ConvertError, ConvertResult}; | |
592 | use std::collections::{hash_map, HashMap}; | |
593 | ||
594 | impl FrameTable { | |
595 | /// Create a frame table by reading the data in the given section. | |
596 | /// | |
597 | /// `convert_address` is a function to convert read addresses into the `Address` | |
598 | /// type. For non-relocatable addresses, this function may simply return | |
599 | /// `Address::Constant(address)`. For relocatable addresses, it is the caller's | |
600 | /// responsibility to determine the symbol and addend corresponding to the address | |
601 | /// and return `Address::Symbol { symbol, addend }`. | |
602 | pub fn from<R, Section>( | |
603 | frame: &Section, | |
604 | convert_address: &dyn Fn(u64) -> Option<Address>, | |
605 | ) -> ConvertResult<FrameTable> | |
606 | where | |
607 | R: Reader<Offset = usize>, | |
608 | Section: read::UnwindSection<R>, | |
609 | Section::Offset: read::UnwindOffset<usize>, | |
610 | { | |
611 | let bases = read::BaseAddresses::default().set_eh_frame(0); | |
612 | ||
613 | let mut frame_table = FrameTable::default(); | |
614 | ||
615 | let mut cie_ids = HashMap::new(); | |
616 | let mut entries = frame.entries(&bases); | |
617 | while let Some(entry) = entries.next()? { | |
618 | let partial = match entry { | |
619 | read::CieOrFde::Cie(_) => continue, | |
620 | read::CieOrFde::Fde(partial) => partial, | |
621 | }; | |
622 | ||
623 | // TODO: is it worth caching the parsed CIEs? It would be better if FDEs only | |
624 | // stored a reference. | |
625 | let from_fde = partial.parse(Section::cie_from_offset)?; | |
626 | let from_cie = from_fde.cie(); | |
627 | let cie_id = match cie_ids.entry(from_cie.offset()) { | |
628 | hash_map::Entry::Occupied(o) => *o.get(), | |
629 | hash_map::Entry::Vacant(e) => { | |
630 | let cie = | |
631 | CommonInformationEntry::from(from_cie, frame, &bases, convert_address)?; | |
632 | let cie_id = frame_table.add_cie(cie); | |
633 | e.insert(cie_id); | |
634 | cie_id | |
635 | } | |
636 | }; | |
637 | let fde = FrameDescriptionEntry::from(&from_fde, frame, &bases, convert_address)?; | |
638 | frame_table.add_fde(cie_id, fde); | |
639 | } | |
640 | ||
641 | Ok(frame_table) | |
642 | } | |
643 | } | |
644 | ||
645 | impl CommonInformationEntry { | |
646 | fn from<R, Section>( | |
647 | from_cie: &read::CommonInformationEntry<R>, | |
648 | frame: &Section, | |
649 | bases: &read::BaseAddresses, | |
650 | convert_address: &dyn Fn(u64) -> Option<Address>, | |
651 | ) -> ConvertResult<CommonInformationEntry> | |
652 | where | |
653 | R: Reader<Offset = usize>, | |
654 | Section: read::UnwindSection<R>, | |
655 | Section::Offset: read::UnwindOffset<usize>, | |
656 | { | |
657 | let mut cie = CommonInformationEntry::new( | |
658 | from_cie.encoding(), | |
659 | from_cie.code_alignment_factor() as u8, | |
660 | from_cie.data_alignment_factor() as i8, | |
661 | from_cie.return_address_register(), | |
662 | ); | |
663 | ||
664 | cie.personality = match from_cie.personality_with_encoding() { | |
665 | // We treat these the same because the encoding already determines | |
666 | // whether it is indirect. | |
667 | Some((eh_pe, read::Pointer::Direct(p))) | |
668 | | Some((eh_pe, read::Pointer::Indirect(p))) => { | |
669 | let address = convert_address(p).ok_or(ConvertError::InvalidAddress)?; | |
670 | Some((eh_pe, address)) | |
671 | } | |
672 | _ => None, | |
673 | }; | |
674 | cie.lsda_encoding = from_cie.lsda_encoding(); | |
675 | cie.fde_address_encoding = from_cie | |
676 | .fde_address_encoding() | |
677 | .unwrap_or(constants::DW_EH_PE_absptr); | |
678 | cie.signal_trampoline = from_cie.is_signal_trampoline(); | |
679 | ||
680 | let mut offset = 0; | |
681 | let mut from_instructions = from_cie.instructions(frame, bases); | |
682 | while let Some(from_instruction) = from_instructions.next()? { | |
683 | if let Some(instruction) = CallFrameInstruction::from( | |
684 | from_instruction, | |
685 | from_cie, | |
686 | convert_address, | |
687 | &mut offset, | |
688 | )? { | |
689 | cie.instructions.push(instruction); | |
690 | } | |
691 | } | |
692 | Ok(cie) | |
693 | } | |
694 | } | |
695 | ||
696 | impl FrameDescriptionEntry { | |
697 | fn from<R, Section>( | |
698 | from_fde: &read::FrameDescriptionEntry<R>, | |
699 | frame: &Section, | |
700 | bases: &read::BaseAddresses, | |
701 | convert_address: &dyn Fn(u64) -> Option<Address>, | |
702 | ) -> ConvertResult<FrameDescriptionEntry> | |
703 | where | |
704 | R: Reader<Offset = usize>, | |
705 | Section: read::UnwindSection<R>, | |
706 | Section::Offset: read::UnwindOffset<usize>, | |
707 | { | |
708 | let address = | |
709 | convert_address(from_fde.initial_address()).ok_or(ConvertError::InvalidAddress)?; | |
710 | let length = from_fde.len() as u32; | |
711 | let mut fde = FrameDescriptionEntry::new(address, length); | |
712 | ||
713 | match from_fde.lsda() { | |
714 | // We treat these the same because the encoding already determines | |
715 | // whether it is indirect. | |
716 | Some(read::Pointer::Direct(p)) | Some(read::Pointer::Indirect(p)) => { | |
717 | let address = convert_address(p).ok_or(ConvertError::InvalidAddress)?; | |
718 | fde.lsda = Some(address); | |
719 | } | |
720 | None => {} | |
721 | } | |
722 | ||
723 | let from_cie = from_fde.cie(); | |
724 | let mut offset = 0; | |
725 | let mut from_instructions = from_fde.instructions(frame, bases); | |
726 | while let Some(from_instruction) = from_instructions.next()? { | |
727 | if let Some(instruction) = CallFrameInstruction::from( | |
728 | from_instruction, | |
729 | from_cie, | |
730 | convert_address, | |
731 | &mut offset, | |
732 | )? { | |
733 | fde.instructions.push((offset, instruction)); | |
734 | } | |
735 | } | |
736 | ||
737 | Ok(fde) | |
738 | } | |
739 | } | |
740 | ||
741 | impl CallFrameInstruction { | |
742 | fn from<R: Reader<Offset = usize>>( | |
743 | from_instruction: read::CallFrameInstruction<R>, | |
744 | from_cie: &read::CommonInformationEntry<R>, | |
745 | convert_address: &dyn Fn(u64) -> Option<Address>, | |
746 | offset: &mut u32, | |
747 | ) -> ConvertResult<Option<CallFrameInstruction>> { | |
748 | let convert_expression = | |
749 | |x| Expression::from(x, from_cie.encoding(), None, None, None, convert_address); | |
750 | // TODO: validate integer type conversions | |
751 | Ok(Some(match from_instruction { | |
752 | read::CallFrameInstruction::SetLoc { .. } => { | |
753 | return Err(ConvertError::UnsupportedCfiInstruction); | |
754 | } | |
755 | read::CallFrameInstruction::AdvanceLoc { delta } => { | |
756 | *offset += delta * from_cie.code_alignment_factor() as u32; | |
757 | return Ok(None); | |
758 | } | |
759 | read::CallFrameInstruction::DefCfa { register, offset } => { | |
760 | CallFrameInstruction::Cfa(register, offset as i32) | |
761 | } | |
762 | read::CallFrameInstruction::DefCfaSf { | |
763 | register, | |
764 | factored_offset, | |
765 | } => { | |
766 | let offset = factored_offset * from_cie.data_alignment_factor(); | |
767 | CallFrameInstruction::Cfa(register, offset as i32) | |
768 | } | |
769 | read::CallFrameInstruction::DefCfaRegister { register } => { | |
770 | CallFrameInstruction::CfaRegister(register) | |
771 | } | |
772 | ||
773 | read::CallFrameInstruction::DefCfaOffset { offset } => { | |
774 | CallFrameInstruction::CfaOffset(offset as i32) | |
775 | } | |
776 | read::CallFrameInstruction::DefCfaOffsetSf { factored_offset } => { | |
777 | let offset = factored_offset * from_cie.data_alignment_factor(); | |
778 | CallFrameInstruction::CfaOffset(offset as i32) | |
779 | } | |
780 | read::CallFrameInstruction::DefCfaExpression { expression } => { | |
781 | CallFrameInstruction::CfaExpression(convert_expression(expression)?) | |
782 | } | |
783 | read::CallFrameInstruction::Undefined { register } => { | |
784 | CallFrameInstruction::Undefined(register) | |
785 | } | |
786 | read::CallFrameInstruction::SameValue { register } => { | |
787 | CallFrameInstruction::SameValue(register) | |
788 | } | |
789 | read::CallFrameInstruction::Offset { | |
790 | register, | |
791 | factored_offset, | |
792 | } => { | |
793 | let offset = factored_offset as i64 * from_cie.data_alignment_factor(); | |
794 | CallFrameInstruction::Offset(register, offset as i32) | |
795 | } | |
796 | read::CallFrameInstruction::OffsetExtendedSf { | |
797 | register, | |
798 | factored_offset, | |
799 | } => { | |
800 | let offset = factored_offset * from_cie.data_alignment_factor(); | |
801 | CallFrameInstruction::Offset(register, offset as i32) | |
802 | } | |
803 | read::CallFrameInstruction::ValOffset { | |
804 | register, | |
805 | factored_offset, | |
806 | } => { | |
807 | let offset = factored_offset as i64 * from_cie.data_alignment_factor(); | |
808 | CallFrameInstruction::ValOffset(register, offset as i32) | |
809 | } | |
810 | read::CallFrameInstruction::ValOffsetSf { | |
811 | register, | |
812 | factored_offset, | |
813 | } => { | |
814 | let offset = factored_offset * from_cie.data_alignment_factor(); | |
815 | CallFrameInstruction::ValOffset(register, offset as i32) | |
816 | } | |
817 | read::CallFrameInstruction::Register { | |
818 | dest_register, | |
819 | src_register, | |
820 | } => CallFrameInstruction::Register(dest_register, src_register), | |
821 | read::CallFrameInstruction::Expression { | |
822 | register, | |
823 | expression, | |
824 | } => CallFrameInstruction::Expression(register, convert_expression(expression)?), | |
825 | read::CallFrameInstruction::ValExpression { | |
826 | register, | |
827 | expression, | |
828 | } => CallFrameInstruction::ValExpression(register, convert_expression(expression)?), | |
829 | read::CallFrameInstruction::Restore { register } => { | |
830 | CallFrameInstruction::Restore(register) | |
831 | } | |
832 | read::CallFrameInstruction::RememberState => CallFrameInstruction::RememberState, | |
833 | read::CallFrameInstruction::RestoreState => CallFrameInstruction::RestoreState, | |
834 | read::CallFrameInstruction::ArgsSize { size } => { | |
835 | CallFrameInstruction::ArgsSize(size as u32) | |
836 | } | |
837 | read::CallFrameInstruction::Nop => return Ok(None), | |
838 | })) | |
839 | } | |
840 | } | |
841 | } | |
842 | ||
843 | #[cfg(test)] | |
844 | #[cfg(feature = "read")] | |
845 | mod tests { | |
846 | use super::*; | |
847 | use crate::arch::X86_64; | |
848 | use crate::read; | |
849 | use crate::write::EndianVec; | |
850 | use crate::LittleEndian; | |
851 | ||
852 | #[test] | |
853 | fn test_frame_table() { | |
854 | for &version in &[1, 3, 4] { | |
855 | for &address_size in &[4, 8] { | |
856 | for &format in &[Format::Dwarf32, Format::Dwarf64] { | |
857 | let encoding = Encoding { | |
858 | format, | |
859 | version, | |
860 | address_size, | |
861 | }; | |
862 | let mut frames = FrameTable::default(); | |
863 | ||
864 | let cie1 = CommonInformationEntry::new(encoding, 1, 8, X86_64::RA); | |
865 | let cie1_id = frames.add_cie(cie1.clone()); | |
866 | assert_eq!(cie1_id, frames.add_cie(cie1.clone())); | |
867 | ||
868 | let mut cie2 = CommonInformationEntry::new(encoding, 1, 8, X86_64::RA); | |
869 | cie2.lsda_encoding = Some(constants::DW_EH_PE_absptr); | |
870 | cie2.personality = | |
871 | Some((constants::DW_EH_PE_absptr, Address::Constant(0x1234))); | |
872 | cie2.signal_trampoline = true; | |
873 | let cie2_id = frames.add_cie(cie2.clone()); | |
874 | assert_ne!(cie1_id, cie2_id); | |
875 | assert_eq!(cie2_id, frames.add_cie(cie2.clone())); | |
876 | ||
877 | let fde1 = FrameDescriptionEntry::new(Address::Constant(0x1000), 0x10); | |
878 | frames.add_fde(cie1_id, fde1.clone()); | |
879 | ||
880 | let fde2 = FrameDescriptionEntry::new(Address::Constant(0x2000), 0x20); | |
881 | frames.add_fde(cie1_id, fde2.clone()); | |
882 | ||
883 | let mut fde3 = FrameDescriptionEntry::new(Address::Constant(0x3000), 0x30); | |
884 | fde3.lsda = Some(Address::Constant(0x3300)); | |
885 | frames.add_fde(cie2_id, fde3.clone()); | |
886 | ||
887 | let mut fde4 = FrameDescriptionEntry::new(Address::Constant(0x4000), 0x40); | |
888 | fde4.lsda = Some(Address::Constant(0x4400)); | |
889 | frames.add_fde(cie2_id, fde4.clone()); | |
890 | ||
891 | // Test writing `.debug_frame`. | |
892 | let mut debug_frame = DebugFrame::from(EndianVec::new(LittleEndian)); | |
893 | frames.write_debug_frame(&mut debug_frame).unwrap(); | |
894 | ||
895 | let mut read_debug_frame = | |
896 | read::DebugFrame::new(debug_frame.slice(), LittleEndian); | |
897 | read_debug_frame.set_address_size(address_size); | |
898 | let convert_frames = FrameTable::from(&read_debug_frame, &|address| { | |
899 | Some(Address::Constant(address)) | |
900 | }) | |
901 | .unwrap(); | |
902 | assert_eq!(frames.cies, convert_frames.cies); | |
903 | assert_eq!(frames.fdes.len(), convert_frames.fdes.len()); | |
904 | for (a, b) in frames.fdes.iter().zip(convert_frames.fdes.iter()) { | |
905 | assert_eq!(a.1, b.1); | |
906 | } | |
907 | ||
908 | if version == 1 { | |
909 | // Test writing `.eh_frame`. | |
910 | let mut eh_frame = EhFrame::from(EndianVec::new(LittleEndian)); | |
911 | frames.write_eh_frame(&mut eh_frame).unwrap(); | |
912 | ||
913 | let mut read_eh_frame = read::EhFrame::new(eh_frame.slice(), LittleEndian); | |
914 | read_eh_frame.set_address_size(address_size); | |
915 | let convert_frames = FrameTable::from(&read_eh_frame, &|address| { | |
916 | Some(Address::Constant(address)) | |
917 | }) | |
918 | .unwrap(); | |
919 | assert_eq!(frames.cies, convert_frames.cies); | |
920 | assert_eq!(frames.fdes.len(), convert_frames.fdes.len()); | |
921 | for (a, b) in frames.fdes.iter().zip(convert_frames.fdes.iter()) { | |
922 | assert_eq!(a.1, b.1); | |
923 | } | |
924 | } | |
925 | } | |
926 | } | |
927 | } | |
928 | } | |
929 | ||
930 | #[test] | |
931 | fn test_frame_instruction() { | |
932 | let mut expression = Expression::new(); | |
933 | expression.op_constu(0); | |
934 | ||
935 | let cie_instructions = [ | |
936 | CallFrameInstruction::Cfa(X86_64::RSP, 8), | |
937 | CallFrameInstruction::Offset(X86_64::RA, -8), | |
938 | ]; | |
939 | ||
940 | let fde_instructions = [ | |
941 | (0, CallFrameInstruction::Cfa(X86_64::RSP, 0)), | |
942 | (0, CallFrameInstruction::Cfa(X86_64::RSP, -8)), | |
943 | (2, CallFrameInstruction::CfaRegister(X86_64::RBP)), | |
944 | (4, CallFrameInstruction::CfaOffset(8)), | |
945 | (4, CallFrameInstruction::CfaOffset(0)), | |
946 | (4, CallFrameInstruction::CfaOffset(-8)), | |
947 | (6, CallFrameInstruction::CfaExpression(expression.clone())), | |
948 | (8, CallFrameInstruction::Restore(Register(1))), | |
949 | (8, CallFrameInstruction::Restore(Register(101))), | |
950 | (10, CallFrameInstruction::Undefined(Register(2))), | |
951 | (12, CallFrameInstruction::SameValue(Register(3))), | |
952 | (14, CallFrameInstruction::Offset(Register(4), 16)), | |
953 | (14, CallFrameInstruction::Offset(Register(104), 16)), | |
954 | (16, CallFrameInstruction::ValOffset(Register(5), -24)), | |
955 | (16, CallFrameInstruction::ValOffset(Register(5), 24)), | |
956 | (18, CallFrameInstruction::Register(Register(6), Register(7))), | |
957 | ( | |
958 | 20, | |
959 | CallFrameInstruction::Expression(Register(8), expression.clone()), | |
960 | ), | |
961 | ( | |
962 | 22, | |
963 | CallFrameInstruction::ValExpression(Register(9), expression.clone()), | |
964 | ), | |
965 | (24 + 0x80, CallFrameInstruction::RememberState), | |
966 | (26 + 0x280, CallFrameInstruction::RestoreState), | |
967 | (28 + 0x20280, CallFrameInstruction::ArgsSize(23)), | |
968 | ]; | |
969 | ||
970 | for &version in &[1, 3, 4] { | |
971 | for &address_size in &[4, 8] { | |
972 | for &format in &[Format::Dwarf32, Format::Dwarf64] { | |
973 | let encoding = Encoding { | |
974 | format, | |
975 | version, | |
976 | address_size, | |
977 | }; | |
978 | let mut frames = FrameTable::default(); | |
979 | ||
980 | let mut cie = CommonInformationEntry::new(encoding, 2, 8, X86_64::RA); | |
981 | for i in &cie_instructions { | |
982 | cie.add_instruction(i.clone()); | |
983 | } | |
984 | let cie_id = frames.add_cie(cie); | |
985 | ||
986 | let mut fde = FrameDescriptionEntry::new(Address::Constant(0x1000), 0x10); | |
987 | for (o, i) in &fde_instructions { | |
988 | fde.add_instruction(*o, i.clone()); | |
989 | } | |
990 | frames.add_fde(cie_id, fde); | |
991 | ||
992 | let mut debug_frame = DebugFrame::from(EndianVec::new(LittleEndian)); | |
993 | frames.write_debug_frame(&mut debug_frame).unwrap(); | |
994 | ||
995 | let mut read_debug_frame = | |
996 | read::DebugFrame::new(debug_frame.slice(), LittleEndian); | |
997 | read_debug_frame.set_address_size(address_size); | |
998 | let frames = FrameTable::from(&read_debug_frame, &|address| { | |
999 | Some(Address::Constant(address)) | |
1000 | }) | |
1001 | .unwrap(); | |
1002 | ||
1003 | assert_eq!( | |
1004 | &frames.cies.get_index(0).unwrap().instructions, | |
1005 | &cie_instructions | |
1006 | ); | |
1007 | assert_eq!(&frames.fdes[0].1.instructions, &fde_instructions); | |
1008 | } | |
1009 | } | |
1010 | } | |
1011 | } | |
1012 | } |