| author |  Jakub Konka <kubkon@jakubkonka.com> 2023-11-09 12:24:49+01:00 |
| committer | Jakub Konka <kubkon@jakubkonka.com> 2023-11-09 12:24:49+01:00 |
| log | b1fcf0ed8f435b834f21a3d57c03f5c0333c6fd9 |
| tree | 86327d5af555728ef5975d48330f889dda963a5c |
| parent | 0efc4711220d98d8c0178dfe9d64dc897c6dee70 |
elf: emit .rela.eh_frame section contents
2 files changed, 68 insertions(+), 5 deletions(-)
src- link
src/link/Elf.zig+12-5
| ... | @@ -4245,11 +4245,10 @@ fn updateSectionSizesObject(self: *Elf) !void { | ... | @@ -4245,11 +4245,10 @@ fn updateSectionSizesObject(self: *Elf) !void { |
| 4245 | 4245 | ||
| 4246 | if (self.eh_frame_section_index) |index| { | 4246 | if (self.eh_frame_section_index) |index| { |
| 4247 | self.shdrs.items[index].sh_size = try eh_frame.calcEhFrameSize(self); | 4247 | self.shdrs.items[index].sh_size = try eh_frame.calcEhFrameSize(self); |
| 4248 | 4248 | } | |
| 4249 | if (self.eh_frame_rela_section_index) |rela_index| { | 4249 | if (self.eh_frame_rela_section_index) |index| { |
| 4250 | const shdr = &self.shdrs.items[rela_index]; | 4250 | const shdr = &self.shdrs.items[index]; |
| 4251 | shdr.sh_size = eh_frame.calcEhFrameRelocs(self) * shdr.sh_entsize; | 4251 | shdr.sh_size = eh_frame.calcEhFrameRelocs(self) * shdr.sh_entsize; |
| 4252 | } | ||
| 4253 | } | 4252 | } |
| 4254 | 4253 | ||
| 4255 | try self.updateSymtabSize(); | 4254 | try self.updateSymtabSize(); |
| ... | @@ -5013,6 +5012,14 @@ fn writeSyntheticSectionsObject(self: *Elf) !void { | ... | @@ -5013,6 +5012,14 @@ fn writeSyntheticSectionsObject(self: *Elf) !void { |
| 5013 | try eh_frame.writeEhFrame(self, buffer.writer()); | 5012 | try eh_frame.writeEhFrame(self, buffer.writer()); |
| 5014 | try self.base.file.?.pwriteAll(buffer.items, shdr.sh_offset); | 5013 | try self.base.file.?.pwriteAll(buffer.items, shdr.sh_offset); |
| 5015 | } | 5014 | } |
| 5015 | if (self.eh_frame_rela_section_index) |shndx| { | ||
| 5016 | const shdr = self.shdrs.items[shndx]; | ||
| 5017 | const sh_size = math.cast(usize, shdr.sh_size) orelse return error.Overflow; | ||
| 5018 | var buffer = try std.ArrayList(u8).initCapacity(gpa, sh_size); | ||
| 5019 | defer buffer.deinit(); | ||
| 5020 | try eh_frame.writeEhFrameRelocs(self, buffer.writer()); | ||
| 5021 | try self.base.file.?.pwriteAll(buffer.items, shdr.sh_offset); | ||
| 5022 | } | ||
| 5016 | 5023 | ||
| 5017 | try self.writeSymtab(); | 5024 | try self.writeSymtab(); |
| 5018 | try self.writeShStrtab(); | 5025 | try self.writeShStrtab(); |
src/link/Elf/eh_frame.zig+56
| ... | @@ -373,6 +373,62 @@ pub fn writeEhFrame(elf_file: *Elf, writer: anytype) !void { | ... | @@ -373,6 +373,62 @@ pub fn writeEhFrame(elf_file: *Elf, writer: anytype) !void { |
| 373 | try writer.writeInt(u32, 0, .little); | 373 | try writer.writeInt(u32, 0, .little); |
| 374 | } | 374 | } |
| 375 | 375 | ||
| 376 | fn emitReloc(elf_file: *Elf, rec: anytype, sym: *const Symbol, rel: elf.Elf64_Rela) elf.Elf64_Rela { | ||
| 377 | const r_offset = rec.address(elf_file) + rel.r_offset - rec.offset; | ||
| 378 | const r_type = rel.r_type(); | ||
| 379 | var r_addend = rel.r_addend; | ||
| 380 | var r_sym: u32 = 0; | ||
| 381 | switch (sym.type(elf_file)) { | ||
| 382 | elf.STT_SECTION => { | ||
| 383 | r_addend += @intCast(sym.value); | ||
| 384 | r_sym = elf_file.sectionSymbolOutputSymtabIndex(sym.outputShndx().?); | ||
| 385 | }, | ||
| 386 | else => { | ||
| 387 | r_sym = sym.outputSymtabIndex(elf_file) orelse 0; | ||
| 388 | }, | ||
| 389 | } | ||
| 390 | |||
| 391 | relocs_log.debug(" {s}: [{x} => {d}({s})] + {x}", .{ | ||
| 392 | Atom.fmtRelocType(r_type), | ||
| 393 | r_offset, | ||
| 394 | r_sym, | ||
| 395 | sym.name(elf_file), | ||
| 396 | r_addend, | ||
| 397 | }); | ||
| 398 | |||
| 399 | return .{ | ||
| 400 | .r_offset = r_offset, | ||
| 401 | .r_addend = r_addend, | ||
| 402 | .r_info = (@as(u64, @intCast(r_sym)) << 32) | r_type, | ||
| 403 | }; | ||
| 404 | } | ||
| 405 | |||
| 406 | pub fn writeEhFrameRelocs(elf_file: *Elf, writer: anytype) !void { | ||
| 407 | relocs_log.debug("{x}: .eh_frame", .{elf_file.shdrs.items[elf_file.eh_frame_section_index.?].sh_addr}); | ||
| 408 | |||
| 409 | for (elf_file.objects.items) |index| { | ||
| 410 | const object = elf_file.file(index).?.object; | ||
| 411 | |||
| 412 | for (object.cies.items) |cie| { | ||
| 413 | if (!cie.alive) continue; | ||
| 414 | for (cie.relocs(elf_file)) |rel| { | ||
| 415 | const sym = elf_file.symbol(object.symbols.items[rel.r_sym()]); | ||
| 416 | const out_rel = emitReloc(elf_file, cie, sym, rel); | ||
| 417 | try writer.writeStruct(out_rel); | ||
| 418 | } | ||
| 419 | } | ||
| 420 | |||
| 421 | for (object.fdes.items) |fde| { | ||
| 422 | if (!fde.alive) continue; | ||
| 423 | for (fde.relocs(elf_file)) |rel| { | ||
| 424 | const sym = elf_file.symbol(object.symbols.items[rel.r_sym()]); | ||
| 425 | const out_rel = emitReloc(elf_file, fde, sym, rel); | ||
| 426 | try writer.writeStruct(out_rel); | ||
| 427 | } | ||
| 428 | } | ||
| 429 | } | ||
| 430 | } | ||
| 431 | |||
| 376 | pub fn writeEhFrameHdr(elf_file: *Elf, writer: anytype) !void { | 432 | pub fn writeEhFrameHdr(elf_file: *Elf, writer: anytype) !void { |
| 377 | try writer.writeByte(1); // version | 433 | try writer.writeByte(1); // version |
| 378 | try writer.writeByte(EH_PE.pcrel | EH_PE.sdata4); | 434 | try writer.writeByte(EH_PE.pcrel | EH_PE.sdata4); |