| ... | ... | @@ -15,37 +15,72 @@ node: struct { |
| 15 | 15 | header: MappedFile.Node.Index, |
| 16 | 16 | symtab: MappedFile.Node.Index, |
| 17 | 17 | strtab: MappedFile.Node.Index, |
| 18 | got_indirect_syms: MappedFile.Node.Index, |
| 19 | stubs_indirect_syms: MappedFile.Node.Index, |
| 20 | fixup_chains_header: MappedFile.Node.Index, |
| 21 | fixup_chains_imports: MappedFile.Node.Index, |
| 22 | fixup_chains_starts_in_image: MappedFile.Node.Index, |
| 23 | fixup_chains_symbol_names: MappedFile.Node.Index, |
| 18 | 24 | }, |
| 19 | 25 | |
| 20 | 26 | lc: struct { |
| 21 | 27 | offsets: std.ArrayList(u32), |
| 22 | 28 | pagezero: LoadCommand, |
| 23 | 29 | symtab: LoadCommand, |
| 30 | dysymtab: LoadCommand, |
| 24 | 31 | entry_point: ?LoadCommand, |
| 25 | 32 | }, |
| 33 | known_sections: struct { |
| 34 | got: Section, |
| 35 | stubs: Section, |
| 36 | }, |
| 26 | 37 | /// Does not contain an entry for the `__PAGEZERO` segment. |
| 27 | 38 | segments: std.MultiArrayList(struct { |
| 28 | 39 | lc: LoadCommand, |
| 29 | 40 | node: MappedFile.Node.Index, |
| 41 | fixup_chain_starts: MappedFile.Node.Index.Optional, |
| 30 | 42 | }), |
| 31 | 43 | sections: std.MultiArrayList(struct { |
| 32 | 44 | lc: LoadCommand, |
| 33 | 45 | node: MappedFile.Node.Index, |
| 34 | | first_symbol: Symbol.Index.Optional, |
| 46 | segment: Segment, |
| 35 | 47 | index: u8, |
| 36 | 48 | }), |
| 37 | | /// Accessed with `Segment.NameAdapter` using `[]const u8` keys. |
| 38 | | segments_by_name: std.array_hash_map.Custom(void, void, void, true), |
| 39 | 49 | /// Accessed with `Section.NameAdapter` using `Section.NameAdapter.SegmentAndSection`. |
| 40 | 50 | sections_by_name: std.array_hash_map.Custom(void, void, void, true), |
| 41 | 51 | |
| 52 | dirty_fixup_chain_pages: std.array_hash_map.Auto(struct { seg: Segment, page: u16 }, void), |
| 53 | |
| 54 | input_atoms: std.ArrayList(InputAtom), |
| 55 | |
| 42 | 56 | /// Accessed with `String.Adapter` using `[]const u8` keys. |
| 43 | 57 | strtab: std.array_hash_map.Custom(String, void, void, true), |
| 44 | 58 | |
| 45 | 59 | symtab: std.ArrayList(Symbol), |
| 46 | 60 | |
| 61 | /// Contains all symbols which can be referenced by name. Mach-O generally calls these "external" |
| 62 | /// symbols, but I'm avoiding that name in favour of ELF's term "global symbol", because the Mach-O |
| 63 | /// term is needlessly confusing (they may be defined locally!). |
| 64 | /// |
| 65 | /// Accessed with `Symbol.GlobalAdapter` using `[]const u8` keys. |
| 66 | global_symbols: std.array_hash_map.Custom(Symbol.Index, void, void, true), |
| 67 | |
| 68 | relocs: std.ArrayList(Reloc), |
| 69 | overflowed_reloc_count: u32, |
| 70 | misaligned_reloc_count: u32, |
| 71 | |
| 72 | imports: std.array_hash_map.Auto(Symbol.Index, void), |
| 73 | fixup_chain_symbol_names_len: u32, |
| 74 | got: std.array_hash_map.Auto(Symbol.Index, void), |
| 75 | stubs: std.array_hash_map.Auto(Symbol.Index, void), |
| 76 | |
| 47 | 77 | sections_changed_index: std.array_hash_map.Auto(Section, void), |
| 48 | 78 | |
| 79 | /// The file offset of the `__got` section relative to its parent segment at the time that fixups |
| 80 | /// for the GOT were last marked dirty. We track this so that when the GOT moves, we know its |
| 81 | /// previous location and can invalidate those fixup pages too (to clear the old fixup entries). |
| 82 | prev_got_offset: u32, |
| 83 | |
| 49 | 84 | const Error = link.Error || error{MappedFileIo}; |
| 50 | 85 | |
| 51 | 86 | /// Stable reference to a particular load command (or `std.macho.section_64`, despite those not |
| ... | ... | @@ -72,6 +107,10 @@ const LoadCommand = enum(u32) { |
| 72 | 107 | /// This type is backed by `u8` instead of a larger type because Mach-O itself uses 8-bit indices to |
| 73 | 108 | /// refer to sections, so the limitation exists regardless. |
| 74 | 109 | const Segment = enum(u8) { |
| 110 | /// Aside from `__PAGEZERO` (which we don't assign a `Segment`), the `__TEXT` segment must come |
| 111 | /// first in memory. This segment is special: it must contain the Mach header, and some offsets |
| 112 | /// are relative to its vmaddr. So, as it's special and always exists, we give it a named tag! |
| 113 | text, |
| 75 | 114 | _, |
| 76 | 115 | |
| 77 | 116 | fn lc(seg: Segment, macho: *const MachO) LoadCommand { |
| ... | ... | @@ -96,17 +135,9 @@ const Segment = enum(u8) { |
| 96 | 135 | return macho.segments.items(.node)[@backingInt(seg)]; |
| 97 | 136 | } |
| 98 | 137 | |
| 99 | | const NameAdapter = struct { |
| 100 | | macho: *const MachO, |
| 101 | | pub fn eql(ctx: NameAdapter, a_seg_name: []const u8, _: void, b_seg_raw: usize) bool { |
| 102 | | const b_seg: Segment = @fromBackingInt(@intCast(b_seg_raw)); |
| 103 | | return std.mem.eql(u8, a_seg_name, b_seg.name(ctx.macho)); |
| 104 | | } |
| 105 | | pub fn hash(ctx: NameAdapter, a_seg_name: []const u8) u32 { |
| 106 | | _ = ctx; |
| 107 | | return std.array_hash_map.hashString(a_seg_name); |
| 108 | | } |
| 109 | | }; |
| 138 | fn fixupChainStartsNode(seg: Segment, macho: *const MachO) MappedFile.Node.Index.Optional { |
| 139 | return macho.segments.items(.fixup_chain_starts)[@backingInt(seg)]; |
| 140 | } |
| 110 | 141 | }; |
| 111 | 142 | |
| 112 | 143 | /// Stable reference to a section defined by a `std.macho.section_64` in the load commands. |
| ... | ... | @@ -133,14 +164,26 @@ const Section = enum(u8) { |
| 133 | 164 | return std.mem.sliceTo(§.lcPtrConst(macho).sectname, 0); |
| 134 | 165 | } |
| 135 | 166 | |
| 167 | fn vaddr(sect: Section, macho: *const MachO) u64 { |
| 168 | return macho.targetLoad(§.lcPtrConst(macho).addr); |
| 169 | } |
| 170 | |
| 136 | 171 | fn segmentName(sect: Section, macho: *const MachO) []const u8 { |
| 137 | 172 | return std.mem.sliceTo(§.lcPtrConst(macho).segname, 0); |
| 138 | 173 | } |
| 139 | 174 | |
| 175 | fn segment(sect: Section, macho: *const MachO) Segment { |
| 176 | return macho.sections.items(.segment)[@backingInt(sect)]; |
| 177 | } |
| 178 | |
| 140 | 179 | fn node(sect: Section, macho: *const MachO) MappedFile.Node.Index { |
| 141 | 180 | return macho.sections.items(.node)[@backingInt(sect)]; |
| 142 | 181 | } |
| 143 | 182 | |
| 183 | fn alignment(sect: Section, macho: *const MachO) MappedFile.Alignment { |
| 184 | return .fromLog2Units(@intCast(macho.targetLoad(§.lcPtrConst(macho).@"align"))); |
| 185 | } |
| 186 | |
| 144 | 187 | /// Returns this section's index in the Mach-O file. Section indices are implicitly assigned |
| 145 | 188 | /// based on the order of load commands, so this value may change in response to segments or |
| 146 | 189 | /// sections being added. When this value changes for a given `Section`, it is added to |
| ... | ... | @@ -149,11 +192,6 @@ const Section = enum(u8) { |
| 149 | 192 | return macho.sections.items(.index)[@backingInt(sect)]; |
| 150 | 193 | } |
| 151 | 194 | |
| 152 | | /// Returns the head of a linked list of symbols defined relative to this section. |
| 153 | | fn firstSymbol(sect: Section, macho: *MachO) *Symbol.Index.Optional { |
| 154 | | return &macho.sections.items(.first_symbol)[@backingInt(sect)]; |
| 155 | | } |
| 156 | | |
| 157 | 195 | const NameAdapter = struct { |
| 158 | 196 | macho: *const MachO, |
| 159 | 197 | const SegmentAndSection = struct { |
| ... | ... | @@ -173,22 +211,450 @@ const Section = enum(u8) { |
| 173 | 211 | return @truncate(h.final()); |
| 174 | 212 | } |
| 175 | 213 | }; |
| 214 | |
| 215 | /// Matches the layout of `std.macho.section_64.flags`. |
| 216 | /// |
| 217 | /// TODO: move to `std.macho` and use as the type of `std.macho.section_64.flags`. |
| 218 | const Flags = packed struct(u32) { |
| 219 | type: enum(u8) { |
| 220 | regular = 0x00, |
| 221 | zerofill = 0x01, |
| 222 | cstring_literals = 0x02, |
| 223 | @"4byte_literals" = 0x03, |
| 224 | @"8byte_literals" = 0x04, |
| 225 | literal_pointers = 0x05, |
| 226 | non_lazy_symbol_pointers = 0x06, |
| 227 | lazy_symbol_pointers = 0x07, |
| 228 | symbol_stubs = 0x08, |
| 229 | mod_init_func_pointers = 0x09, |
| 230 | mod_term_func_pointers = 0x0a, |
| 231 | coalesced = 0x0b, |
| 232 | gb_zerofill = 0x0c, |
| 233 | interposing = 0x0d, |
| 234 | @"16byte_literals" = 0x0e, |
| 235 | dtrace_dof = 0x0f, |
| 236 | lazy_dylib_symbol_pointers = 0x10, |
| 237 | thread_local_regular = 0x11, |
| 238 | thread_local_zerofill = 0x12, |
| 239 | thread_local_variables = 0x13, |
| 240 | thread_local_variable_pointers = 0x14, |
| 241 | thread_local_init_function_pointers = 0x15, |
| 242 | init_func_offsets = 0x16, |
| 243 | _, |
| 244 | }, |
| 245 | loc_reloc: bool = false, |
| 246 | ext_reloc: bool = false, |
| 247 | some_instructions: bool = false, |
| 248 | _unused: u15 = 0, |
| 249 | self_modifying_code: bool = false, |
| 250 | live_support: bool = false, |
| 251 | no_dead_strip: bool = false, |
| 252 | strip_static_syms: bool = false, |
| 253 | no_toc: bool = false, |
| 254 | pure_instructions: bool = false, |
| 255 | }; |
| 256 | }; |
| 257 | |
| 258 | const InputAtom = struct { |
| 259 | node: MappedFile.Node.Index, |
| 260 | first_symbol: Symbol.Index.Optional, |
| 261 | first_reloc: Reloc.Index, |
| 262 | vaddr: u64, |
| 263 | /// `true` if there are any relocations *in* this atom which are runtime fixups. |
| 264 | /// |
| 265 | /// TODO: storing a bool here is bad for memory utilization, but there's no point in me finding |
| 266 | /// somewhere else to put this state before we finish figuring out this linker's design. It |
| 267 | /// should definitely be moved at some point though! |
| 268 | any_fixups: bool, |
| 269 | |
| 270 | const Index = enum(u32) { |
| 271 | _, |
| 272 | fn ptr(iai: InputAtom.Index, macho: *MachO) *InputAtom { |
| 273 | return &macho.input_atoms.items[@backingInt(iai)]; |
| 274 | } |
| 275 | fn ptrConst(iai: InputAtom.Index, macho: *const MachO) *const InputAtom { |
| 276 | return &macho.input_atoms.items[@backingInt(iai)]; |
| 277 | } |
| 278 | fn node(iai: InputAtom.Index, macho: *const MachO) MappedFile.Node.Index { |
| 279 | return iai.ptrConst(macho).node; |
| 280 | } |
| 281 | }; |
| 176 | 282 | }; |
| 177 | 283 | |
| 178 | 284 | const Symbol = struct { |
| 179 | | next_in_section: Symbol.Index.Optional, |
| 285 | node: MappedFile.Node.Index.Optional, |
| 286 | first_target_reloc: Reloc.Index.Optional, |
| 287 | prev_in_node: Symbol.Index.Optional, |
| 288 | next_in_node: Symbol.Index.Optional, |
| 180 | 289 | |
| 181 | 290 | const Index = enum(u32) { |
| 182 | 291 | _, |
| 183 | 292 | fn ptr(i: Index, macho: *MachO) *Symbol { |
| 184 | 293 | return &macho.symtab.items[@backingInt(i)]; |
| 185 | 294 | } |
| 295 | fn ptrConst(i: Index, macho: *const MachO) *const Symbol { |
| 296 | return &macho.symtab.items[@backingInt(i)]; |
| 297 | } |
| 186 | 298 | fn nlist(i: Index, macho: *MachO) *std.macho.nlist_64 { |
| 187 | | return &macho.nlistSlice()[@backingInt(i)]; |
| 299 | const nsyms = macho.targetLoad( |
| 300 | &macho.lc.symtab.ptrConst(macho, std.macho.symtab_command).nsyms, |
| 301 | ); |
| 302 | const slice: []std.macho.nlist_64 = @ptrCast(@alignCast( |
| 303 | macho.node.symtab.slice(&macho.mf)[0 .. nsyms * @sizeOf(std.macho.nlist_64)], |
| 304 | )); |
| 305 | return &slice[@backingInt(i)]; |
| 306 | } |
| 307 | fn nlistConst(i: Index, macho: *const MachO) *const std.macho.nlist_64 { |
| 308 | const nsyms = macho.targetLoad( |
| 309 | &macho.lc.symtab.ptrConst(macho, std.macho.symtab_command).nsyms, |
| 310 | ); |
| 311 | const slice: []const std.macho.nlist_64 = @ptrCast(@alignCast( |
| 312 | macho.node.symtab.slice(&macho.mf)[0 .. nsyms * @sizeOf(std.macho.nlist_64)], |
| 313 | )); |
| 314 | return &slice[@backingInt(i)]; |
| 315 | } |
| 316 | fn name(i: Index, macho: *const MachO) []const u8 { |
| 317 | const n_strx = macho.targetLoad(&i.nlistConst(macho).n_strx); |
| 318 | return std.mem.sliceTo(macho.node.strtab.sliceConst(&macho.mf)[n_strx..], 0); |
| 319 | } |
| 320 | fn value(i: Index, macho: *const MachO) u64 { |
| 321 | return macho.targetLoad(&i.nlistConst(macho).n_value); |
| 322 | } |
| 323 | fn flushMoved(symbol: Index, macho: *MachO, new_value: u64) Allocator.Error!void { |
| 324 | macho.targetStore(&symbol.nlist(macho).n_value, new_value); |
| 325 | try symbol.applyTargetRelocs(macho, .init(.{ |
| 326 | .symbol = true, |
| 327 | .branch = true, |
| 328 | .got = false, |
| 329 | .tlv = false, |
| 330 | })); |
| 331 | } |
| 332 | fn applyTargetRelocs( |
| 333 | i: Index, |
| 334 | macho: *MachO, |
| 335 | targets: std.enums.EnumSet(Reloc.Target), |
| 336 | ) Allocator.Error!void { |
| 337 | var reloc_it = i.ptr(macho).first_target_reloc; |
| 338 | while (reloc_it.unwrap()) |ri| : (reloc_it = ri.ptr(macho).next_with_same_target_sym) { |
| 339 | if (targets.contains(ri.ptr(macho).bits.target)) { |
| 340 | try ri.ptr(macho).apply(macho); |
| 341 | } |
| 342 | } |
| 343 | } |
| 344 | const Optional = enum(u32) { |
| 345 | none = std.math.maxInt(u32), |
| 346 | _, |
| 347 | fn unwrap(o: Optional) ?Index { |
| 348 | return switch (o) { |
| 349 | .none => null, |
| 350 | _ => @fromBackingInt(@backingInt(o)), |
| 351 | }; |
| 352 | } |
| 353 | fn wrap(i: Index) Optional { |
| 354 | return @bitCast(i); |
| 355 | } |
| 356 | }; |
| 357 | }; |
| 358 | |
| 359 | const InitValue = union(enum) { |
| 360 | abs: u64, |
| 361 | addr_in_node: struct { |
| 362 | /// Must support `getNodeVAddr`, `getNodeSection`, and `nodeFirstSymbolPtr`. |
| 363 | node: MappedFile.Node.Index, |
| 364 | offset: u64, |
| 365 | }, |
| 366 | }; |
| 367 | |
| 368 | const GlobalAdapter = struct { |
| 369 | macho: *MachO, |
| 370 | pub fn eql(ctx: GlobalAdapter, lhs_slice: []const u8, rhs_symbol: Symbol.Index, _: usize) bool { |
| 371 | const macho = ctx.macho; |
| 372 | return std.mem.eql(u8, lhs_slice, rhs_symbol.name(macho)); |
| 373 | } |
| 374 | pub fn hash(ctx: GlobalAdapter, s: []const u8) u32 { |
| 375 | _ = ctx; |
| 376 | return std.array_hash_map.hashString(s); |
| 377 | } |
| 378 | }; |
| 379 | }; |
| 380 | |
| 381 | const Reloc = struct { |
| 382 | node: MappedFile.Node.Index, |
| 383 | offset: u32, |
| 384 | target_symbol: Symbol.Index, |
| 385 | addend: u64, |
| 386 | bits: Bits, |
| 387 | next_with_same_target_sym: Reloc.Index.Optional, |
| 388 | |
| 389 | const Bits = packed struct(u8) { |
| 390 | target: Target, |
| 391 | type: Type, |
| 392 | result: enum(u2) { |
| 393 | ok, |
| 394 | overflowed, |
| 395 | misaligned, |
| 396 | /// This is a special value indicating that this relocation is lowered to a runtime |
| 397 | /// fixup rather than being resolved statically. TODO: I'm not entirely sure if this is |
| 398 | /// a good idea, particularly since the question of "is this a runtime fixup" can, I |
| 399 | /// believe, be fully recovered based on the `Bits.target` and `Bits.type`...? |
| 400 | fixup, |
| 401 | }, |
| 402 | }; |
| 403 | const Target = enum(u2) { |
| 404 | symbol, |
| 405 | branch, |
| 406 | got, |
| 407 | tlv, |
| 408 | }; |
| 409 | const Type = enum(u4) { |
| 410 | abs8, |
| 411 | abs16, |
| 412 | abs32, |
| 413 | abs64, |
| 414 | rel32, |
| 415 | arm64_branchrel26, |
| 416 | arm64_pagerel21, |
| 417 | arm64_pageoff12, |
| 418 | |
| 419 | /// If the given relocation requires a particular machine instruction to already exist in |
| 420 | /// the destination bytes, this function checks if that requirement is upheld and returns |
| 421 | /// `false` if not. |
| 422 | /// |
| 423 | /// This function does not perform length checks on `dest_overlong`; the caller guarantees |
| 424 | /// that it will be at least long enough to support this relocation type. |
| 425 | fn validateInst(t: Type, dest_overlong: []const u8) bool { |
| 426 | switch (t) { |
| 427 | .abs8, |
| 428 | .abs16, |
| 429 | .abs32, |
| 430 | .abs64, |
| 431 | .rel32, |
| 432 | => return true, |
| 433 | |
| 434 | .arm64_branchrel26 => { |
| 435 | const inst: aarch64.encoding.Instruction = .read(dest_overlong[0..4]); |
| 436 | return switch (inst.decode()) { |
| 437 | .branch_exception_generating_system => |begs| switch (begs.decode()) { |
| 438 | .unconditional_branch_immediate => true, |
| 439 | else => false, |
| 440 | }, |
| 441 | else => false, |
| 442 | }; |
| 443 | }, |
| 444 | .arm64_pagerel21 => { |
| 445 | const inst: aarch64.encoding.Instruction = .read(dest_overlong[0..4]); |
| 446 | return switch (inst.decode()) { |
| 447 | .data_processing_immediate => |dpi| switch (dpi.decode()) { |
| 448 | .pc_relative_addressing => |pra| switch (pra.decode()) { |
| 449 | .adrp => true, |
| 450 | else => false, |
| 451 | }, |
| 452 | else => false, |
| 453 | }, |
| 454 | else => false, |
| 455 | }; |
| 456 | }, |
| 457 | .arm64_pageoff12 => { |
| 458 | const inst: aarch64.encoding.Instruction = .read(dest_overlong[0..4]); |
| 459 | return switch (inst.decode()) { |
| 460 | .data_processing_immediate => |dpi| switch (dpi.decode()) { |
| 461 | .add_subtract_immediate => true, |
| 462 | else => false, |
| 463 | }, |
| 464 | .load_store => |ls| switch (ls.decode()) { |
| 465 | .register_unsigned_immediate => true, |
| 466 | else => false, |
| 467 | }, |
| 468 | else => false, |
| 469 | }; |
| 470 | }, |
| 471 | } |
| 472 | } |
| 473 | }; |
| 474 | |
| 475 | fn apply(reloc: *Reloc, macho: *MachO) Allocator.Error!void { |
| 476 | // Don't bother applying the reloc if the bytes we're writing to have a pending move event: |
| 477 | if (reloc.node.hasMoved(&macho.mf)) { |
| 478 | return; |
| 479 | } |
| 480 | |
| 481 | // Also don't bother if a pending move will change the target value: |
| 482 | { |
| 483 | const target_node: MappedFile.Node.Index.Optional = switch (reloc.bits.target) { |
| 484 | .symbol => reloc.target_symbol.ptr(macho).node, |
| 485 | .branch => switch (macho.stubs.contains(reloc.target_symbol)) { |
| 486 | false => reloc.target_symbol.ptr(macho).node, |
| 487 | true => .wrap(macho.known_sections.stubs.node(macho)), |
| 488 | }, |
| 489 | .got => .wrap(macho.known_sections.got.node(macho)), |
| 490 | .tlv => @panic("TODO(MachO2): apply TLV relocation"), |
| 491 | }; |
| 492 | if (target_node.unwrap()) |node| { |
| 493 | if (node.hasMoved(&macho.mf)) { |
| 494 | return; |
| 495 | } |
| 496 | } |
| 497 | } |
| 498 | |
| 499 | switch (reloc.bits.result) { |
| 500 | .fixup => { |
| 501 | const segment = macho.getNodeSection(reloc.node).segment(macho); |
| 502 | const offset_in_segment: u64 = reloc.node.fileLocation(&macho.mf, false).offset - |
| 503 | segment.node(macho).fileLocation(&macho.mf, false).offset + |
| 504 | reloc.offset; |
| 505 | const page_align = macho.targetPageAlign(); |
| 506 | const page_start: u32 = @intCast(@divFloor(offset_in_segment, page_align.toByteUnits())); |
| 507 | const page_end: u32 = @intCast(@divCeil(offset_in_segment + 8, page_align.toByteUnits())); |
| 508 | for (page_start..page_end) |page_index| { |
| 509 | try macho.dirty_fixup_chain_pages.put(macho.base.comp.gpa, .{ |
| 510 | .seg = segment, |
| 511 | .page = @intCast(page_index), |
| 512 | }, {}); |
| 513 | } |
| 514 | return; |
| 515 | }, |
| 516 | .ok => {}, |
| 517 | .overflowed => macho.overflowed_reloc_count -= 1, |
| 518 | .misaligned => macho.misaligned_reloc_count -= 1, |
| 519 | } |
| 520 | |
| 521 | if (reloc.applyInner(macho)) { |
| 522 | @branchHint(.likely); |
| 523 | reloc.bits.result = .ok; |
| 524 | } else |err| switch (err) { |
| 525 | error.RelocationOverflow => { |
| 526 | log.debug("relocation failed (overflow)", .{}); |
| 527 | reloc.bits.result = .overflowed; |
| 528 | macho.overflowed_reloc_count += 1; |
| 529 | }, |
| 530 | error.RelocationMisaligned => { |
| 531 | log.debug("relocation failed (misaligned)", .{}); |
| 532 | reloc.bits.result = .misaligned; |
| 533 | macho.misaligned_reloc_count += 1; |
| 534 | }, |
| 535 | } |
| 536 | } |
| 537 | fn applyInner(r: Reloc, macho: *MachO) error{ RelocationMisaligned, RelocationOverflow }!void { |
| 538 | log.debug("applying relocation: nodes[{d}][{d}..] = {t}({t}({q}) + {d})", .{ |
| 539 | r.node, r.offset, r.bits.type, r.bits.target, r.target_symbol.name(macho), r.addend, |
| 540 | }); |
| 541 | |
| 542 | const target_endian = macho.targetEndian(); |
| 543 | |
| 544 | const dest_slice = r.node.slice(&macho.mf)[r.offset..]; |
| 545 | const dest_vaddr: u64 = macho.getNodeVAddr(r.node) + r.offset; |
| 546 | |
| 547 | const target_val: u64 = switch (r.bits.target) { |
| 548 | .symbol => r.target_symbol.value(macho) +% r.addend, |
| 549 | .branch => if (macho.stubs.getIndex(r.target_symbol)) |stub_index| val: { |
| 550 | const stub_offset = @as(u64, stub_index) * macho.targetStubSize(); |
| 551 | const stub_vaddr = macho.known_sections.stubs.vaddr(macho) + stub_offset; |
| 552 | break :val stub_vaddr +% r.addend; |
| 553 | } else r.target_symbol.value(macho) +% r.addend, |
| 554 | .got => val: { |
| 555 | const got_entry_index = macho.got.getIndex(r.target_symbol).?; |
| 556 | const got_entry_offset = got_entry_index * macho.targetPtrSize(); |
| 557 | const got_entry_vaddr = macho.known_sections.got.vaddr(macho) + got_entry_offset; |
| 558 | break :val got_entry_vaddr +% r.addend; |
| 559 | }, |
| 560 | .tlv => @panic("TODO(MachO2): apply TLV relocation"), |
| 561 | }; |
| 562 | |
| 563 | switch (r.bits.type) { |
| 564 | .abs8 => std.mem.writeInt( |
| 565 | u8, |
| 566 | dest_slice[0..1], |
| 567 | std.math.cast(u8, target_val) orelse return error.RelocationOverflow, |
| 568 | target_endian, |
| 569 | ), |
| 570 | .abs16 => std.mem.writeInt( |
| 571 | u16, |
| 572 | dest_slice[0..2], |
| 573 | std.math.cast(u16, target_val) orelse return error.RelocationOverflow, |
| 574 | target_endian, |
| 575 | ), |
| 576 | .abs32 => std.mem.writeInt( |
| 577 | u32, |
| 578 | dest_slice[0..4], |
| 579 | std.math.cast(u32, target_val) orelse return error.RelocationOverflow, |
| 580 | target_endian, |
| 581 | ), |
| 582 | .abs64 => std.mem.writeInt( |
| 583 | u64, |
| 584 | dest_slice[0..8], |
| 585 | std.math.cast(u64, target_val) orelse return error.RelocationOverflow, |
| 586 | target_endian, |
| 587 | ), |
| 588 | .rel32 => std.mem.writeInt( |
| 589 | i32, |
| 590 | dest_slice[0..4], |
| 591 | std.math.cast( |
| 592 | i32, |
| 593 | @as(i64, @bitCast(target_val -% dest_vaddr)), |
| 594 | ) orelse return error.RelocationOverflow, |
| 595 | target_endian, |
| 596 | ), |
| 597 | .arm64_branchrel26 => { |
| 598 | const off: i64 = @bitCast(target_val -% dest_vaddr); |
| 599 | const shifted: i64 = off >> 2; |
| 600 | if (shifted << 2 != off) { |
| 601 | return error.RelocationMisaligned; |
| 602 | } |
| 603 | const casted = std.math.cast(i26, shifted) orelse return error.RelocationOverflow; |
| 604 | |
| 605 | var inst: aarch64.encoding.Instruction = .read(dest_slice[0..4]); |
| 606 | inst.branch_exception_generating_system.unconditional_branch_immediate.group.imm26 = casted; |
| 607 | inst.write(dest_slice[0..4]); |
| 608 | }, |
| 609 | .arm64_pagerel21 => { |
| 610 | const cur_page: u53 = @intCast(dest_vaddr >> 12); |
| 611 | const target_page: u53 = @intCast(target_val >> 12); |
| 612 | const page_off: i53 = @bitCast(target_page -% cur_page); |
| 613 | const split: packed struct(i21) { lo: u2, hi: i19 } = @bitCast( |
| 614 | std.math.cast(i21, page_off) orelse return error.RelocationOverflow, |
| 615 | ); |
| 616 | |
| 617 | var inst: aarch64.encoding.Instruction = .read(dest_slice[0..4]); |
| 618 | inst.data_processing_immediate.pc_relative_addressing.adrp.immhi = split.hi; |
| 619 | inst.data_processing_immediate.pc_relative_addressing.adrp.immlo = split.lo; |
| 620 | inst.write(dest_slice[0..4]); |
| 621 | }, |
| 622 | .arm64_pageoff12 => { |
| 623 | const page_off: u12 = @truncate(target_val); |
| 624 | |
| 625 | // This could be one of several instructions: an `ADD`, an `LDR`, or an `STR`. The |
| 626 | // `LDR` and `STR` instructions have scale factors which we need to compensate for, |
| 627 | // so we need to decode the instruction to figure out which case we're in. |
| 628 | var inst: aarch64.encoding.Instruction = .read(dest_slice[0..4]); |
| 629 | switch (inst.decode()) { |
| 630 | .data_processing_immediate => { |
| 631 | inst.data_processing_immediate.add_subtract_immediate.group.imm12 = page_off; |
| 632 | }, |
| 633 | .load_store => |ls| { |
| 634 | const scale: u3 = switch (ls.register_unsigned_immediate.decode()) { |
| 635 | .integer => |i| @backingInt(i.group.size), // 1/2/4/8-byte load/store |
| 636 | .vector => |v| @backingInt(v.group.opc1.decode(v.group.size)), // 1/2/4/8/16-byte vector load/store |
| 637 | }; |
| 638 | const shifted = page_off >> scale; |
| 639 | if (shifted << scale != page_off) { |
| 640 | return error.RelocationMisaligned; |
| 641 | } |
| 642 | inst.load_store.register_unsigned_immediate.group.imm12 = shifted; |
| 643 | }, |
| 644 | else => unreachable, |
| 645 | } |
| 646 | inst.write(dest_slice[0..4]); |
| 647 | }, |
| 188 | 648 | } |
| 649 | } |
| 650 | |
| 651 | const Index = enum(u32) { |
| 652 | _, |
| 653 | |
| 189 | 654 | const Optional = enum(u32) { |
| 190 | 655 | none = std.math.maxInt(u32), |
| 191 | 656 | _, |
| 657 | |
| 192 | 658 | fn unwrap(o: Optional) ?Index { |
| 193 | 659 | return switch (o) { |
| 194 | 660 | .none => null, |
| ... | ... | @@ -199,6 +665,10 @@ const Symbol = struct { |
| 199 | 665 | return @bitCast(i); |
| 200 | 666 | } |
| 201 | 667 | }; |
| 668 | |
| 669 | fn ptr(ri: Reloc.Index, macho: *MachO) *Reloc { |
| 670 | return &macho.relocs.items[@backingInt(ri)]; |
| 671 | } |
| 202 | 672 | }; |
| 203 | 673 | }; |
| 204 | 674 | |
| ... | ... | @@ -210,8 +680,25 @@ const Node = union(enum) { |
| 210 | 680 | symtab, |
| 211 | 681 | strtab, |
| 212 | 682 | |
| 683 | indirect_syms, |
| 684 | section_indirect_syms: Section, |
| 685 | |
| 686 | linkedit_data: LoadCommand, |
| 687 | |
| 688 | /// Header of the `LC_DYLD_CHAINED_FIXUPS` load command's `.linkedit_data` node, containing the |
| 689 | /// `std.macho.dyld_chained_fixups_header` struct. |
| 690 | fixup_chains_header, |
| 691 | fixup_chains_imports, |
| 692 | fixup_chains_symbol_names, |
| 693 | fixup_chains_starts, |
| 694 | fixup_chains_starts_in_image, |
| 695 | fixup_chains_starts_in_segment: Segment, |
| 696 | |
| 213 | 697 | segment: Segment, |
| 214 | 698 | section: Section, |
| 699 | section_manual_size: Section, |
| 700 | |
| 701 | input_atom: InputAtom.Index, |
| 215 | 702 | }; |
| 216 | 703 | fn getNode(macho: *const MachO, ni: MappedFile.Node.Index) Node { |
| 217 | 704 | return macho.nodes.get(@backingInt(ni)); |
| ... | ... | @@ -275,17 +762,34 @@ fn create( |
| 275 | 762 | .offsets = .empty, |
| 276 | 763 | .pagezero = undefined, |
| 277 | 764 | .symtab = undefined, |
| 765 | .dysymtab = undefined, |
| 278 | 766 | .entry_point = null, |
| 279 | 767 | }, |
| 768 | .known_sections = undefined, |
| 280 | 769 | .segments = .empty, |
| 281 | 770 | .sections = .empty, |
| 282 | | .segments_by_name = .empty, |
| 283 | 771 | .sections_by_name = .empty, |
| 284 | 772 | |
| 773 | .dirty_fixup_chain_pages = .empty, |
| 774 | |
| 775 | .input_atoms = .empty, |
| 776 | |
| 285 | 777 | .strtab = .empty, |
| 286 | 778 | .symtab = .empty, |
| 779 | .global_symbols = .empty, |
| 780 | |
| 781 | .relocs = .empty, |
| 782 | .overflowed_reloc_count = 0, |
| 783 | .misaligned_reloc_count = 0, |
| 784 | |
| 785 | .fixup_chain_symbol_names_len = 0, |
| 786 | .imports = .empty, |
| 787 | .got = .empty, |
| 788 | .stubs = .empty, |
| 287 | 789 | |
| 288 | 790 | .sections_changed_index = .empty, |
| 791 | |
| 792 | .prev_got_offset = 0, |
| 289 | 793 | }; |
| 290 | 794 | errdefer macho.deinit(); |
| 291 | 795 | |
| ... | ... | @@ -315,7 +819,7 @@ fn initInner(macho: *MachO) !void { |
| 315 | 819 | .moved = true, // required by `addSegment` |
| 316 | 820 | .bubbles_moved = false, |
| 317 | 821 | }); |
| 318 | | try macho.nodes.append(gpa, .{ .segment = undefined }); // populated by `addSegment` |
| 822 | try macho.nodes.append(gpa, .{ .segment = undefined }); |
| 319 | 823 | |
| 320 | 824 | macho.node.header = try text_seg_node.addOnlyHeaderChild(gpa, &macho.mf, .{ |
| 321 | 825 | .size = @sizeOf(mach_header_64), |
| ... | ... | @@ -358,7 +862,7 @@ fn initInner(macho: *MachO) !void { |
| 358 | 862 | .moved = true, // required by `addSegment` |
| 359 | 863 | .bubbles_moved = false, |
| 360 | 864 | }); |
| 361 | | try macho.nodes.append(gpa, .{ .segment = undefined }); // populated by `addSegment` |
| 865 | try macho.nodes.append(gpa, .{ .segment = undefined }); |
| 362 | 866 | |
| 363 | 867 | // The "__PAGEZERO" segment must come before any other segment load commands. It is inaccessible |
| 364 | 868 | // and occupies 4 GiB (apparently to catch invalid 32-bit pointer accesses). |
| ... | ... | @@ -374,38 +878,83 @@ fn initInner(macho: *MachO) !void { |
| 374 | 878 | .nsects = 0, |
| 375 | 879 | .flags = 0, |
| 376 | 880 | }); |
| 377 | | const text_seg = try macho.addSegment(.{ |
| 881 | assert(try macho.addSegment(.{ |
| 378 | 882 | .name = "__TEXT", |
| 379 | 883 | .prot = .{ .READ = true, .EXEC = true }, |
| 380 | 884 | .existing_node = text_seg_node, |
| 381 | | }); |
| 885 | .flags = .{}, |
| 886 | }) == .text); |
| 382 | 887 | const data_seg = try macho.addSegment(.{ |
| 383 | 888 | .name = "__DATA", |
| 384 | 889 | .prot = .{ .READ = true, .WRITE = true }, |
| 890 | .flags = .{}, |
| 385 | 891 | }); |
| 892 | // TODO: we should also create a `__DATA_CONST` segment with `.{ .flags = .read_only = true }`, |
| 893 | // and when we do, `loadObject` should use it for `InputSection.Usage.data_const_fixups`. |
| 894 | // Unfortunately, doing that now introduces a second floating segment node, which reveals that |
| 895 | // dyld has an annoying ordering requirement: |
| 896 | // |
| 897 | // dyld[77415]: segment '__DATA' file offset out of order |
| 898 | // |
| 899 | // We need to decide the best way to resolve this. Reordering the segments in the load commands |
| 900 | // and in virtual memory is probably too expensive to risk doing often, so we need to preserve |
| 901 | // the segment order somehow, e.g. by having all but one segment be a header or footer. |
| 386 | 902 | const linkedit_seg = try macho.addSegment(.{ |
| 387 | 903 | .name = "__LINKEDIT", |
| 388 | 904 | .prot = .{ .READ = true }, |
| 389 | 905 | .existing_node = linkedit_seg_node, |
| 906 | .flags = .{}, |
| 390 | 907 | }); |
| 391 | 908 | |
| 392 | 909 | _ = try macho.addSection(.{ |
| 393 | | .segment = text_seg, |
| 910 | .segment = .text, |
| 394 | 911 | .name = "__text", |
| 395 | 912 | .@"align" = .@"4", |
| 396 | | .flags = .{ .some_instructions = true }, |
| 913 | .flags = .{ .type = .regular, .some_instructions = true }, |
| 397 | 914 | }); |
| 398 | 915 | _ = try macho.addSection(.{ |
| 399 | | .segment = text_seg, |
| 916 | .segment = .text, |
| 400 | 917 | .name = "__const", |
| 401 | | .@"align" = .@"2", |
| 402 | | .flags = .{}, |
| 918 | .@"align" = .@"1", |
| 919 | .flags = .{ |
| 920 | .type = .regular, |
| 921 | }, |
| 403 | 922 | }); |
| 404 | 923 | _ = try macho.addSection(.{ |
| 405 | 924 | .segment = data_seg, |
| 406 | 925 | .name = "__data", |
| 407 | | .@"align" = .@"2", |
| 408 | | .flags = .{}, |
| 926 | .@"align" = .@"1", |
| 927 | .flags = .{ |
| 928 | .type = .regular, |
| 929 | }, |
| 930 | }); |
| 931 | |
| 932 | macho.known_sections.got = try macho.addSection(.{ |
| 933 | .segment = data_seg, |
| 934 | .name = "__got", |
| 935 | .@"align" = .@"8", |
| 936 | .manual_size = true, |
| 937 | .flags = .{ .type = .non_lazy_symbol_pointers }, |
| 938 | // This field holds an offset into the "indirect symbol table" at which this section's |
| 939 | // indirect symbol references begin. It will be populated by `flushMoved` of a |
| 940 | // `.section_indirect_syms` node we'll create shortly. |
| 941 | .reserved1 = 0, |
| 942 | }); |
| 943 | |
| 944 | macho.known_sections.stubs = try macho.addSection(.{ |
| 945 | .segment = .text, |
| 946 | .name = "__stubs", |
| 947 | .@"align" = .@"4", |
| 948 | .manual_size = true, |
| 949 | .flags = .{ |
| 950 | .type = .symbol_stubs, |
| 951 | .some_instructions = true, |
| 952 | .pure_instructions = true, |
| 953 | }, |
| 954 | // As with `__got`, will be populated by `flushMoved` of a `.section_indirect_syms` node. |
| 955 | .reserved1 = 0, |
| 956 | // `reserved2` holds the size of each stub entry. |
| 957 | .reserved2 = macho.targetStubSize(), |
| 409 | 958 | }); |
| 410 | 959 | |
| 411 | 960 | macho.node.symtab = try linkedit_seg.node(macho).addFloatingChild(gpa, &macho.mf, .{ |
| ... | ... | @@ -423,7 +972,129 @@ fn initInner(macho: *MachO) !void { |
| 423 | 972 | try macho.node.strtab.ensureMinimumSize(gpa, &macho.mf, 1); |
| 424 | 973 | macho.node.strtab.slice(&macho.mf)[0] = 0; |
| 425 | 974 | |
| 426 | | _ = try macho.appendSimpleLoadCommand(std.macho.dyld_info_command, .{}); |
| 975 | const indirect_syms_node = try linkedit_seg.node(macho).addFloatingChild(gpa, &macho.mf, .{ |
| 976 | .alignment = .@"4", |
| 977 | .moved = true, // so that `indirectsymoff` in the dysymtab load command will be set |
| 978 | }); |
| 979 | try macho.nodes.append(gpa, .indirect_syms); |
| 980 | |
| 981 | macho.node.got_indirect_syms = try indirect_syms_node.addFloatingChild(gpa, &macho.mf, .{ |
| 982 | .alignment = .@"4", |
| 983 | .moved = true, // so that `reserved1` in the section will be set |
| 984 | }); |
| 985 | try macho.nodes.append(gpa, .{ .section_indirect_syms = macho.known_sections.got }); |
| 986 | |
| 987 | macho.node.stubs_indirect_syms = try indirect_syms_node.addFloatingChild(gpa, &macho.mf, .{ |
| 988 | .alignment = .@"4", |
| 989 | .moved = true, // so that `reserved1` in the section will be set |
| 990 | }); |
| 991 | try macho.nodes.append(gpa, .{ .section_indirect_syms = macho.known_sections.stubs }); |
| 992 | |
| 993 | const chained_fixups_lc = try macho.appendSimpleLoadCommand(std.macho.linkedit_data_command, .{ |
| 994 | .cmd = .DYLD_CHAINED_FIXUPS, |
| 995 | .dataoff = 0, |
| 996 | .datasize = 0, |
| 997 | }); |
| 998 | const chained_fixups_node = try linkedit_seg.node(macho).addFloatingChild(gpa, &macho.mf, .{ |
| 999 | .alignment = macho.mf.flags.block_size.max(.@"8"), |
| 1000 | .moved = true, // so that `dataoff` will be set |
| 1001 | .bubbles_moved = false, |
| 1002 | }); |
| 1003 | try macho.nodes.append(gpa, .{ .linkedit_data = chained_fixups_lc }); |
| 1004 | |
| 1005 | macho.node.fixup_chains_header = try chained_fixups_node.addOnlyHeaderChild(gpa, &macho.mf, .{ |
| 1006 | .size = @sizeOf(std.macho.dyld_chained_fixups_header), |
| 1007 | .alignment = .@"4", |
| 1008 | }); |
| 1009 | try macho.nodes.append(gpa, .fixup_chains_header); |
| 1010 | |
| 1011 | { |
| 1012 | const chained_fixups_hdr: *std.macho.dyld_chained_fixups_header = @ptrCast(@alignCast( |
| 1013 | macho.node.fixup_chains_header.slice(&macho.mf)[0..@sizeOf(std.macho.dyld_chained_fixups_header)], |
| 1014 | )); |
| 1015 | chained_fixups_hdr.* = .{ |
| 1016 | .fixups_version = 0, |
| 1017 | .starts_offset = 0, |
| 1018 | .imports_offset = 0, |
| 1019 | .symbols_offset = 0, |
| 1020 | .imports_count = 0, |
| 1021 | .imports_format = .addend_64, |
| 1022 | .symbols_format = .uncompressed, |
| 1023 | }; |
| 1024 | if (macho.targetEndian() != std.lang.Endian.native) { |
| 1025 | std.mem.byteSwapAllFields(std.macho.dyld_chained_fixups_header, chained_fixups_hdr); |
| 1026 | } |
| 1027 | } |
| 1028 | |
| 1029 | // We are now going to create the `std.macho.dyld_chained_starts_in_segment` nodes for every |
| 1030 | // segment, which means we are assuming that no more segments will be created. Therefore, all |
| 1031 | // `addSegment` calls must come *before* this point. |
| 1032 | |
| 1033 | const fixup_chains_starts = try chained_fixups_node.addFloatingChild(gpa, &macho.mf, .{ |
| 1034 | .size = 0, |
| 1035 | .alignment = .@"8", |
| 1036 | .moved = true, // so that `starts_offset` is populated |
| 1037 | }); |
| 1038 | try macho.nodes.append(gpa, .fixup_chains_starts); |
| 1039 | |
| 1040 | macho.node.fixup_chains_starts_in_image = try fixup_chains_starts.addOnlyHeaderChild(gpa, &macho.mf, .{ |
| 1041 | .size = 8 + 4 * macho.segments.len, |
| 1042 | .alignment = .@"4", |
| 1043 | }); |
| 1044 | try macho.nodes.append(gpa, .fixup_chains_starts_in_image); |
| 1045 | |
| 1046 | { |
| 1047 | const chained_starts_in_image: []u32 = @ptrCast(@alignCast( |
| 1048 | macho.node.fixup_chains_starts_in_image.slice(&macho.mf), |
| 1049 | )); |
| 1050 | chained_starts_in_image[0] = @intCast(macho.segments.len + 1); // +1 for `__PAGEZERO` |
| 1051 | chained_starts_in_image[1] = 0; // `__PAGEZERO` |
| 1052 | chained_starts_in_image[macho.segments.len + 1] = 0; // `__LINKEDIT` |
| 1053 | for ( |
| 1054 | macho.segments.items(.fixup_chain_starts)[0 .. macho.segments.len - 1], |
| 1055 | 0.., |
| 1056 | ) |*starts_in_segment, segment_usize| { |
| 1057 | const segment: Segment = @fromBackingInt(@intCast(segment_usize)); |
| 1058 | assert(!std.mem.eql(u8, segment.name(macho), "__LINKEDIT")); |
| 1059 | starts_in_segment.* = .wrap(try fixup_chains_starts.addFloatingChild(gpa, &macho.mf, .{ |
| 1060 | .alignment = .@"8", |
| 1061 | .size = @sizeOf(std.macho.dyld_chained_starts_in_segment), |
| 1062 | .moved = true, |
| 1063 | })); |
| 1064 | try macho.nodes.append(gpa, .{ .fixup_chains_starts_in_segment = segment }); |
| 1065 | const starts_hdr: *std.macho.dyld_chained_starts_in_segment = @ptrCast(@alignCast( |
| 1066 | starts_in_segment.unwrap().?.slice(&macho.mf)[0..@sizeOf(std.macho.dyld_chained_starts_in_segment)], |
| 1067 | )); |
| 1068 | starts_hdr.* = .{ |
| 1069 | .size = @sizeOf(std.macho.dyld_chained_starts_in_segment), |
| 1070 | .page_size = @intCast(macho.targetPageAlign().toByteUnits()), |
| 1071 | .pointer_format = .@"64", |
| 1072 | .segment_offset = 0, // populated by `flushMoved` of the corresponding segment |
| 1073 | .max_valid_pointer = 0, |
| 1074 | .page_count = 0, |
| 1075 | }; |
| 1076 | if (macho.targetEndian() != std.lang.Endian.native) { |
| 1077 | std.mem.byteSwapAllFields(std.macho.dyld_chained_starts_in_segment, starts_hdr); |
| 1078 | } |
| 1079 | } |
| 1080 | } |
| 1081 | |
| 1082 | // This is a footer because dyld has an undocumented requirement that the imports must be |
| 1083 | // ordered after the starts. |
| 1084 | macho.node.fixup_chains_imports = try chained_fixups_node.addOnlyFooterChild(gpa, &macho.mf, .{ |
| 1085 | .alignment = .@"8", |
| 1086 | .moved = true, // so that `imports_offset` is populated |
| 1087 | }); |
| 1088 | try macho.nodes.append(gpa, .fixup_chains_imports); |
| 1089 | |
| 1090 | // This is a footer because `dyld_info` complains if the imports appear after the symbol name |
| 1091 | // string table. Since there's no length associated with that string table, `dyld_info` can only |
| 1092 | // be sure they don't overlap if the string table is the last thing in the chained fixups data. |
| 1093 | macho.node.fixup_chains_symbol_names = try chained_fixups_node.addFooterChildBefore(gpa, &macho.mf, .none, .{ |
| 1094 | .alignment = .@"8", // so that the alignment of `macho.node.fixup_chains_imports` is not violated |
| 1095 | .moved = true, // so that `symbols_offset` is populated |
| 1096 | }); |
| 1097 | try macho.nodes.append(gpa, .fixup_chains_symbol_names); |
| 427 | 1098 | |
| 428 | 1099 | macho.lc.symtab = try macho.appendSimpleLoadCommand(std.macho.symtab_command, .{ |
| 429 | 1100 | .symoff = 0, |
| ... | ... | @@ -432,6 +1103,48 @@ fn initInner(macho: *MachO) !void { |
| 432 | 1103 | .strsize = 1, // empty string (null terminator) |
| 433 | 1104 | }); |
| 434 | 1105 | |
| 1106 | // Nowadays, `LC_DYSYMTAB` is redundant with chained fixups and the symbol export trie. However, |
| 1107 | // if we omit it, some macOS tooling does get annoyed at us. Therefore, we try to emit a minimum |
| 1108 | // viable `LC_DYSYMTAB` command, just to keep the tooling happy. |
| 1109 | macho.lc.dysymtab = try macho.appendSimpleLoadCommand(std.macho.dysymtab_command, .{ |
| 1110 | // Some tooling will check that the number of symbols according to the `LC_DYSYMTAB` command |
| 1111 | // matches the actual length of the symbol table in `LC_SYMTAB`. However, we don't want to |
| 1112 | // need to partition our symbol table into local/extdef/undef symbols, because that makes |
| 1113 | // incremental linking less efficient. Luckily, since this information is basically useless |
| 1114 | // nowadays, nothing seems to mind if we just say that every symbol is local. So, whenever |
| 1115 | // we add any symbol to the symtab, we will increase `ilocalsym` in lockstep with the symbol |
| 1116 | // count. We also need to increment `iextdefsym` and `iundefsym`, because some tooling may |
| 1117 | // check that local symbols come before extdef and undef symbols here. I don't even know why |
| 1118 | // they *have* the `iextdefsym` and `iundefsym` fields if they're only going to allow them |
| 1119 | // to have specific values... |
| 1120 | .ilocalsym = 0, // always 0 |
| 1121 | .nlocalsym = 0, // equal to symbol count |
| 1122 | .iextdefsym = 0, // equal to symbol count |
| 1123 | .nextdefsym = 0, // always 0 |
| 1124 | .iundefsym = 0, // equal to symbol count |
| 1125 | .nundefsym = 0, // always 0 |
| 1126 | |
| 1127 | // We *do* need to emit a valid indirect symbol table, which is an array of symbol indices |
| 1128 | // indicating which symbols are being targeted by entries in `__got` and `__stubs`. Although |
| 1129 | // not required for fixups, some debug tooling will still try to read this table without any |
| 1130 | // validation, so will just crash if it's absent or invalid. Luckily, the indirection here |
| 1131 | // actually makes this pretty straightforward for us to emit. |
| 1132 | .indirectsymoff = 0, // populated by `flushMachOFileOffset` of the `.indirect_syms` node |
| 1133 | .nindirectsyms = 0, // populated by `flushResized` of the `.indirect_syms` node |
| 1134 | |
| 1135 | // These fields are *required* to be zeroed in modern Mach-O binaries. |
| 1136 | .tocoff = 0, |
| 1137 | .ntoc = 0, |
| 1138 | .modtaboff = 0, |
| 1139 | .nmodtab = 0, |
| 1140 | .extrefsymoff = 0, |
| 1141 | .nextrefsyms = 0, |
| 1142 | .extreloff = 0, |
| 1143 | .nextrel = 0, |
| 1144 | .locreloff = 0, |
| 1145 | .nlocrel = 0, |
| 1146 | }); |
| 1147 | |
| 435 | 1148 | const want_dyld_path: bool = switch (comp.config.output_mode) { |
| 436 | 1149 | .Obj => false, |
| 437 | 1150 | .Lib => switch (comp.config.link_mode) { |
| ... | ... | @@ -454,58 +1167,84 @@ fn initInner(macho: *MachO) !void { |
| 454 | 1167 | } |
| 455 | 1168 | } |
| 456 | 1169 | |
| 457 | | switch (comp.config.output_mode) { |
| 458 | | .Obj, .Lib => {}, |
| 459 | | .Exe => macho.lc.entry_point = try macho.appendSimpleLoadCommand(std.macho.entry_point_command, .{ |
| 460 | | .entryoff = 0, |
| 461 | | .stacksize = macho.options.stack_size orelse 0, |
| 462 | | }), |
| 1170 | entry: switch (macho.options.entry) { |
| 1171 | .default => switch (comp.config.output_mode) { |
| 1172 | .Exe => continue :entry .enabled, |
| 1173 | .Lib, .Obj => continue :entry .disabled, |
| 1174 | }, |
| 1175 | .disabled => {}, |
| 1176 | .enabled, .named => { |
| 1177 | macho.lc.entry_point = try macho.appendSimpleLoadCommand( |
| 1178 | std.macho.entry_point_command, |
| 1179 | .{ .entryoff = 0, .stacksize = macho.options.stack_size orelse 0 }, |
| 1180 | ); |
| 1181 | }, |
| 463 | 1182 | } |
| 464 | 1183 | |
| 465 | 1184 | _ = try macho.appendSimpleLoadCommand(std.macho.uuid_command, .{ |
| 466 | 1185 | .uuid = @splat(0), |
| 467 | 1186 | }); |
| 468 | 1187 | |
| 469 | | try macho.addSimpleSymbol("some_function", 0x1234, "__TEXT", "__text"); |
| 470 | | try macho.addSimpleSymbol("my_cool_data", 0x5678, "__DATA", "__data"); |
| 471 | | |
| 472 | 1188 | try macho.updateSegmentLoadAddresses(); |
| 473 | 1189 | } |
| 474 | | /// TODO: this function doesn't actually do anything particularly useful, it's just a placeholder |
| 475 | | /// for actual symbol creation logic so that we can test adding stuff to the symtab. |
| 476 | | fn addSimpleSymbol( |
| 477 | | macho: *MachO, |
| 1190 | fn addInternalSymbol(macho: *MachO, opts: struct { |
| 478 | 1191 | name: []const u8, |
| 479 | | value: u64, |
| 480 | | segment_name: []const u8, |
| 481 | | section_name: []const u8, |
| 482 | | ) Error!void { |
| 1192 | value: Symbol.InitValue, |
| 1193 | }) Error!Symbol.Index { |
| 483 | 1194 | const gpa = macho.base.comp.gpa; |
| 1195 | |
| 484 | 1196 | try macho.symtab.ensureUnusedCapacity(gpa, 1); |
| 485 | 1197 | try macho.node.symtab.ensureMinimumSize(gpa, &macho.mf, (macho.symtab.items.len + 1) * @sizeOf(std.macho.nlist_64)); |
| 486 | 1198 | |
| 487 | | const strx = try macho.string(name); |
| 488 | | const section = macho.sectionByName(segment_name, section_name).?; |
| 1199 | const strx = try macho.string(opts.name); |
| 489 | 1200 | |
| 490 | 1201 | const symtab_ptr = macho.lc.symtab.ptr(macho, std.macho.symtab_command); |
| 491 | 1202 | assert(macho.targetLoad(&symtab_ptr.nsyms) == macho.symtab.items.len); |
| 492 | 1203 | macho.targetStore(&symtab_ptr.nsyms, @intCast(macho.symtab.items.len + 1)); |
| 493 | 1204 | |
| 1205 | { |
| 1206 | const dysymtab_cmd = macho.lc.dysymtab.ptr(macho, std.macho.dysymtab_command); |
| 1207 | // See comment in `initInner` (around the creation of this `dysymtab_command`) for details |
| 1208 | // on why we're doing this. |
| 1209 | macho.targetStore(&dysymtab_cmd.nlocalsym, @intCast(macho.symtab.items.len + 1)); |
| 1210 | macho.targetStore(&dysymtab_cmd.iextdefsym, @intCast(macho.symtab.items.len + 1)); |
| 1211 | macho.targetStore(&dysymtab_cmd.iundefsym, @intCast(macho.symtab.items.len + 1)); |
| 1212 | } |
| 1213 | |
| 494 | 1214 | const sym_index: Symbol.Index = @fromBackingInt(@intCast(macho.symtab.items.len)); |
| 495 | 1215 | macho.symtab.appendAssumeCapacity(.{ |
| 496 | | .next_in_section = section.firstSymbol(macho).*, |
| 1216 | .node = switch (opts.value) { |
| 1217 | .abs => .none, |
| 1218 | .addr_in_node => |addr| .wrap(addr.node), |
| 1219 | }, |
| 1220 | .prev_in_node = .none, |
| 1221 | .next_in_node = .none, |
| 1222 | .first_target_reloc = .none, |
| 497 | 1223 | }); |
| 498 | | section.firstSymbol(macho).* = .wrap(sym_index); |
| 1224 | if (sym_index.ptr(macho).node.unwrap()) |node| { |
| 1225 | const head_ptr = macho.nodeFirstSymbolPtr(node); |
| 1226 | sym_index.ptr(macho).next_in_node = head_ptr.*; |
| 1227 | if (head_ptr.*.unwrap()) |next_symbol| { |
| 1228 | next_symbol.ptr(macho).prev_in_node = .wrap(sym_index); |
| 1229 | } |
| 1230 | head_ptr.* = .wrap(sym_index); |
| 1231 | } |
| 499 | 1232 | |
| 500 | 1233 | sym_index.nlist(macho).* = .{ |
| 501 | 1234 | .n_strx = @backingInt(strx), |
| 502 | 1235 | .n_type = .{ .bits = .{ |
| 503 | | .ext = true, |
| 504 | | .type = .sect, |
| 1236 | .ext = false, |
| 1237 | .type = switch (opts.value) { |
| 1238 | .abs => .abs, |
| 1239 | .addr_in_node => .sect, |
| 1240 | }, |
| 505 | 1241 | .pext = false, |
| 506 | 1242 | .is_stab = 0, |
| 507 | 1243 | } }, |
| 508 | | .n_sect = section.index(macho), |
| 1244 | .n_sect = switch (opts.value) { |
| 1245 | .abs => 0, |
| 1246 | .addr_in_node => |addr| macho.getNodeSection(addr.node).index(macho), |
| 1247 | }, |
| 509 | 1248 | .n_desc = .{ |
| 510 | 1249 | .arm_thumb_def = false, |
| 511 | 1250 | .referenced_dynamically = false, |
| ... | ... | @@ -515,54 +1254,314 @@ fn addSimpleSymbol( |
| 515 | 1254 | .symbol_resolver = false, |
| 516 | 1255 | .alt_entry = false, |
| 517 | 1256 | }, |
| 518 | | .n_value = value, |
| 1257 | .n_value = switch (opts.value) { |
| 1258 | .abs => |x| x, |
| 1259 | .addr_in_node => |addr| macho.getNodeVAddr(addr.node) + addr.offset, |
| 1260 | }, |
| 519 | 1261 | }; |
| 520 | 1262 | if (macho.targetEndian() != std.lang.Endian.native) { |
| 521 | 1263 | std.mem.byteSwapAllFields(std.macho.nlist_64, sym_index.nlist(macho)); |
| 522 | 1264 | } |
| 523 | | } |
| 524 | 1265 | |
| 525 | | fn addSegment(macho: *MachO, opts: struct { |
| 1266 | return sym_index; |
| 1267 | } |
| 1268 | fn addGlobalSymbol(macho: *MachO, opts: struct { |
| 526 | 1269 | name: []const u8, |
| 527 | | prot: std.macho.vm_prot_t, |
| 528 | | /// The caller is allowed to create the section's node themselves, in which case it is passed in |
| 529 | | /// here. The caller must initialize the `MachO.nodes` entry to `.{ .segment = undefined }`, and |
| 530 | | /// the node must be created with the option `.moved = true`. |
| 531 | | existing_node: ?MappedFile.Node.Index = null, |
| 532 | | }) Error!Segment { |
| 1270 | linkage: std.lang.GlobalLinkage, |
| 1271 | visibility: enum { default, hidden }, |
| 1272 | /// `null` means the symbol is undefined. |
| 1273 | value: ?Symbol.InitValue, |
| 1274 | }) (Error || error{MultipleDefinitions})!Symbol.Index { |
| 533 | 1275 | const gpa = macho.base.comp.gpa; |
| 534 | 1276 | |
| 535 | | const segment_command_64 = std.macho.segment_command_64; |
| 1277 | try macho.symtab.ensureUnusedCapacity(gpa, 1); |
| 1278 | try macho.node.symtab.ensureMinimumSize(gpa, &macho.mf, (macho.symtab.items.len + 1) * @sizeOf(std.macho.nlist_64)); |
| 536 | 1279 | |
| 537 | | // We limit the number of segments to 255, because there can only be 255 *sections*, so there's |
| 538 | | // no need to allow more. See corresponding check in `addSection`. |
| 539 | | if (macho.segments.len == 255) { |
| 540 | | return macho.base.comp.link_diags.fail("maximum segment count exceeded", .{}); |
| 1280 | const adapter: Symbol.GlobalAdapter = .{ .macho = macho }; |
| 1281 | const gop = try macho.global_symbols.getOrPutAdapted(gpa, opts.name, adapter); |
| 1282 | if (gop.found_existing) { |
| 1283 | const symbol = gop.key_ptr.*; |
| 1284 | |
| 1285 | switch (opts.visibility) { |
| 1286 | .default => {}, |
| 1287 | .hidden => { |
| 1288 | var n_type = macho.targetLoad(&symbol.nlist(macho).n_type); |
| 1289 | n_type.bits.pext = true; |
| 1290 | switch (macho.machFiletype()) { |
| 1291 | .OBJECT => {}, |
| 1292 | .EXECUTE, .DYLIB => n_type.bits.ext = false, |
| 1293 | } |
| 1294 | macho.targetStore(&symbol.nlist(macho).n_type, n_type); |
| 1295 | // TODO: once the exports trie is implemented, remove `symbol` from it here |
| 1296 | }, |
| 1297 | } |
| 1298 | |
| 1299 | const existing_defined: bool, const existing_linkage: std.lang.GlobalLinkage = existing: { |
| 1300 | const n_type = macho.targetLoad(&symbol.nlist(macho).n_type); |
| 1301 | const n_desc = macho.targetLoad(&symbol.nlist(macho).n_desc); |
| 1302 | break :existing switch (n_type.bits.type) { |
| 1303 | .undf => .{ false, if (n_desc.weak_ref) .weak else .strong }, |
| 1304 | else => .{ true, if (n_desc.weak_def_or_ref_to_weak) .weak else .strong }, |
| 1305 | }; |
| 1306 | }; |
| 1307 | |
| 1308 | const override: bool = if (opts.value != null) override: { |
| 1309 | if (!existing_defined) break :override true; |
| 1310 | // Two definitions of the same name! |
| 1311 | break :override switch (opts.linkage) { |
| 1312 | .strong => switch (existing_linkage) { |
| 1313 | .strong => return error.MultipleDefinitions, |
| 1314 | .weak => true, |
| 1315 | }, |
| 1316 | .weak => false, |
| 1317 | }; |
| 1318 | } else override: { |
| 1319 | if (existing_defined) break :override false; |
| 1320 | break :override switch (opts.linkage) { |
| 1321 | .strong => switch (existing_linkage) { |
| 1322 | .strong => false, |
| 1323 | .weak => true, |
| 1324 | }, |
| 1325 | .weak => false, |
| 1326 | }; |
| 1327 | }; |
| 1328 | |
| 1329 | if (override) { |
| 1330 | try macho.setGlobalSymbolValue(symbol, .{ |
| 1331 | .linkage = opts.linkage, |
| 1332 | .value = opts.value, |
| 1333 | }); |
| 1334 | } |
| 1335 | |
| 1336 | return symbol; |
| 541 | 1337 | } |
| 1338 | errdefer _ = macho.global_symbols.pop().?; |
| 542 | 1339 | |
| 543 | | try macho.nodes.ensureUnusedCapacity(gpa, 1); |
| 544 | | try macho.segments.ensureUnusedCapacity(gpa, 1); |
| 545 | | try macho.segments_by_name.ensureUnusedCapacity(gpa, 1); |
| 1340 | const strx = try macho.string(opts.name); |
| 546 | 1341 | |
| 547 | | const root_ni: MappedFile.Node.Index = .root; |
| 1342 | const symtab_ptr = macho.lc.symtab.ptr(macho, std.macho.symtab_command); |
| 1343 | assert(macho.targetLoad(&symtab_ptr.nsyms) == macho.symtab.items.len); |
| 1344 | macho.targetStore(&symtab_ptr.nsyms, @intCast(macho.symtab.items.len + 1)); |
| 548 | 1345 | |
| 549 | | const lc = try macho.appendSimpleLoadCommand(std.macho.segment_command_64, .{ |
| 550 | | .cmdsize = @sizeOf(segment_command_64), |
| 551 | | .segname = name: { |
| 552 | | var name: [16]u8 = undefined; |
| 553 | | @memcpy(name[0..opts.name.len], opts.name); |
| 554 | | @memset(name[opts.name.len..], 0); |
| 555 | | break :name name; |
| 556 | | }, |
| 557 | | .vmaddr = 0, |
| 558 | | .vmsize = 0, |
| 559 | | .fileoff = 0, // to be set by `flushMoved` |
| 560 | | .filesize = 0, |
| 561 | | .maxprot = opts.prot, |
| 562 | | .initprot = opts.prot, |
| 563 | | .nsects = 0, |
| 564 | | .flags = 0, |
| 565 | | }); |
| 1346 | { |
| 1347 | const dysymtab_cmd = macho.lc.dysymtab.ptr(macho, std.macho.dysymtab_command); |
| 1348 | // See comment in `initInner` (around the creation of this `dysymtab_command`) for details |
| 1349 | // on why we're doing this. |
| 1350 | macho.targetStore(&dysymtab_cmd.nlocalsym, @intCast(macho.symtab.items.len + 1)); |
| 1351 | macho.targetStore(&dysymtab_cmd.iextdefsym, @intCast(macho.symtab.items.len + 1)); |
| 1352 | macho.targetStore(&dysymtab_cmd.iundefsym, @intCast(macho.symtab.items.len + 1)); |
| 1353 | } |
| 1354 | |
| 1355 | const symbol: Symbol.Index = @fromBackingInt(@intCast(macho.symtab.items.len)); |
| 1356 | gop.key_ptr.* = symbol; |
| 1357 | macho.symtab.appendAssumeCapacity(.{ |
| 1358 | .node = .none, |
| 1359 | .prev_in_node = .none, |
| 1360 | .next_in_node = .none, |
| 1361 | .first_target_reloc = .none, |
| 1362 | }); |
| 1363 | symbol.nlist(macho).* = .{ |
| 1364 | .n_strx = @backingInt(strx), |
| 1365 | .n_type = .{ .bits = .{ |
| 1366 | .ext = switch (macho.machFiletype()) { |
| 1367 | .OBJECT => true, |
| 1368 | .EXECUTE, .DYLIB => switch (opts.visibility) { |
| 1369 | .default => true, |
| 1370 | .hidden => false, |
| 1371 | }, |
| 1372 | }, |
| 1373 | .pext = switch (opts.visibility) { |
| 1374 | .default => false, |
| 1375 | .hidden => true, |
| 1376 | }, |
| 1377 | .type = .undf, |
| 1378 | .is_stab = 0, |
| 1379 | } }, |
| 1380 | .n_sect = 0, |
| 1381 | .n_desc = .{ |
| 1382 | .arm_thumb_def = false, |
| 1383 | .referenced_dynamically = false, |
| 1384 | .discarded_or_no_dead_strip = false, |
| 1385 | .weak_ref = false, |
| 1386 | .weak_def_or_ref_to_weak = false, |
| 1387 | .symbol_resolver = false, |
| 1388 | .alt_entry = false, |
| 1389 | }, |
| 1390 | .n_value = 0, |
| 1391 | }; |
| 1392 | if (macho.targetEndian() != std.lang.Endian.native) { |
| 1393 | std.mem.byteSwapAllFields(std.macho.nlist_64, symbol.nlist(macho)); |
| 1394 | } |
| 1395 | |
| 1396 | try macho.setGlobalSymbolValue(symbol, .{ |
| 1397 | .linkage = opts.linkage, |
| 1398 | .value = opts.value, |
| 1399 | }); |
| 1400 | |
| 1401 | return symbol; |
| 1402 | } |
| 1403 | fn setGlobalSymbolValue(macho: *MachO, symbol: Symbol.Index, opts: struct { |
| 1404 | linkage: std.lang.GlobalLinkage, |
| 1405 | value: ?Symbol.InitValue, |
| 1406 | }) Allocator.Error!void { |
| 1407 | const gpa = macho.base.comp.gpa; |
| 1408 | |
| 1409 | log.debug("setGlobalSymbolValue({q}, {?any})", .{ symbol.name(macho), opts.value }); |
| 1410 | |
| 1411 | const nlist = symbol.nlist(macho); |
| 1412 | |
| 1413 | { |
| 1414 | const weak: bool = switch (opts.linkage) { |
| 1415 | .strong => false, |
| 1416 | .weak => true, |
| 1417 | }; |
| 1418 | var n_desc = macho.targetLoad(&nlist.n_desc); |
| 1419 | n_desc.weak_ref = opts.value == null and weak; |
| 1420 | n_desc.weak_def_or_ref_to_weak = opts.value != null and weak; |
| 1421 | macho.targetStore(&nlist.n_desc, n_desc); |
| 1422 | } |
| 1423 | |
| 1424 | // Remove this symbol from its old node. |
| 1425 | if (symbol.ptr(macho).node.unwrap()) |old_node| { |
| 1426 | if (symbol.ptr(macho).next_in_node.unwrap()) |next_symbol| { |
| 1427 | assert(next_symbol.ptr(macho).prev_in_node == Symbol.Index.Optional.wrap(symbol)); |
| 1428 | next_symbol.ptr(macho).prev_in_node = symbol.ptr(macho).prev_in_node; |
| 1429 | } |
| 1430 | if (symbol.ptr(macho).prev_in_node.unwrap()) |prev_symbol| { |
| 1431 | assert(prev_symbol.ptr(macho).next_in_node == Symbol.Index.Optional.wrap(symbol)); |
| 1432 | prev_symbol.ptr(macho).next_in_node = symbol.ptr(macho).next_in_node; |
| 1433 | } else { |
| 1434 | // We're the head of the list. |
| 1435 | macho.nodeFirstSymbolPtr(old_node).* = symbol.ptr(macho).next_in_node; |
| 1436 | } |
| 1437 | } |
| 1438 | |
| 1439 | if (opts.value) |value| switch (value) { |
| 1440 | .abs => |val| { |
| 1441 | var n_type = macho.targetLoad(&nlist.n_type); |
| 1442 | n_type.bits.type = .abs; |
| 1443 | macho.targetStore(&nlist.n_type, n_type); |
| 1444 | |
| 1445 | macho.targetStore(&nlist.n_sect, 0); |
| 1446 | macho.targetStore(&nlist.n_value, val); |
| 1447 | |
| 1448 | symbol.ptr(macho).node = .none; |
| 1449 | symbol.ptr(macho).prev_in_node = .none; |
| 1450 | symbol.ptr(macho).next_in_node = .none; |
| 1451 | }, |
| 1452 | .addr_in_node => |addr| { |
| 1453 | var n_type = macho.targetLoad(&nlist.n_type); |
| 1454 | n_type.bits.type = .sect; |
| 1455 | macho.targetStore(&nlist.n_type, n_type); |
| 1456 | |
| 1457 | macho.targetStore(&nlist.n_sect, macho.getNodeSection(addr.node).index(macho)); |
| 1458 | macho.targetStore(&nlist.n_value, macho.getNodeVAddr(addr.node) + addr.offset); |
| 1459 | |
| 1460 | const head_ptr = macho.nodeFirstSymbolPtr(addr.node); |
| 1461 | symbol.ptr(macho).node = .wrap(addr.node); |
| 1462 | symbol.ptr(macho).prev_in_node = .none; |
| 1463 | symbol.ptr(macho).next_in_node = head_ptr.*; |
| 1464 | if (head_ptr.*.unwrap()) |next_symbol| { |
| 1465 | next_symbol.ptr(macho).prev_in_node = .wrap(symbol); |
| 1466 | } |
| 1467 | head_ptr.* = .wrap(symbol); |
| 1468 | }, |
| 1469 | } else { |
| 1470 | var n_type = macho.targetLoad(&nlist.n_type); |
| 1471 | n_type.bits.type = .undf; |
| 1472 | macho.targetStore(&nlist.n_type, n_type); |
| 1473 | |
| 1474 | macho.targetStore(&nlist.n_sect, 0); |
| 1475 | macho.targetStore(&nlist.n_value, 0); |
| 1476 | |
| 1477 | symbol.ptr(macho).node = .none; |
| 1478 | symbol.ptr(macho).prev_in_node = .none; |
| 1479 | symbol.ptr(macho).next_in_node = .none; |
| 1480 | } |
| 1481 | |
| 1482 | // If `symbol` has a GOT entry, it needs regenerating. |
| 1483 | if (macho.got.getIndex(symbol)) |got_index| { |
| 1484 | if (!macho.known_sections.got.node(macho).hasMoved(&macho.mf)) { |
| 1485 | const segment = macho.known_sections.got.segment(macho); |
| 1486 | const page_index: u16 = @intCast(@divFloor( |
| 1487 | macho.prev_got_offset + got_index * macho.targetPtrSize(), |
| 1488 | macho.targetPageAlign().toByteUnits(), |
| 1489 | )); |
| 1490 | try macho.dirty_fixup_chain_pages.put(gpa, .{ .seg = segment, .page = page_index }, {}); |
| 1491 | } |
| 1492 | } |
| 1493 | |
| 1494 | // If `symbol` has an `imports` entry, it should not exist. |
| 1495 | if (macho.imports.getIndex(symbol)) |import_index| { |
| 1496 | // TODO: delete the import. For now we just mark it as weak so that dyld doesn't complain. |
| 1497 | const imports: []std.macho.dyld_chained_import_addend64 = @ptrCast(@alignCast( |
| 1498 | macho.node.fixup_chains_imports.slice(&macho.mf)[0 .. macho.imports.count() * @sizeOf(std.macho.dyld_chained_import_addend64)], |
| 1499 | )); |
| 1500 | macho.targetStore(&imports[import_index].bits, .{ |
| 1501 | .lib_ordinal = macho.targetLoad(&imports[import_index].bits).lib_ordinal, |
| 1502 | .name_offset = macho.targetLoad(&imports[import_index].bits).name_offset, |
| 1503 | .weak_import = true, |
| 1504 | }); |
| 1505 | } |
| 1506 | } |
| 1507 | fn globalByName(macho: *MachO, name: []const u8) Symbol.Index.Optional { |
| 1508 | const adapter: Symbol.GlobalAdapter = .{ .macho = macho }; |
| 1509 | if (macho.global_symbols.getKeyAdapted(name, adapter)) |symbol| { |
| 1510 | return .wrap(symbol); |
| 1511 | } else { |
| 1512 | return .none; |
| 1513 | } |
| 1514 | } |
| 1515 | |
| 1516 | /// All calls to this function must occur in `initInner`, and must be before we initialize fixup |
| 1517 | /// chains, as fixup chains requires some per-segment tracking and the logic to initialize them |
| 1518 | /// assumes that no more segments will be created. |
| 1519 | fn addSegment(macho: *MachO, opts: struct { |
| 1520 | name: []const u8, |
| 1521 | prot: std.macho.vm_prot_t, |
| 1522 | /// The caller is allowed to create the section's node themselves, in which case it is passed in |
| 1523 | /// here. The caller must initialize the `MachO.nodes` entry to `.{ .segment = undefined }`, and |
| 1524 | /// the node must be created with the option `.moved = true`. |
| 1525 | existing_node: ?MappedFile.Node.Index = null, |
| 1526 | /// This matches the layout of `std.macho.segment_command_64.flags`. |
| 1527 | flags: packed struct(u32) { |
| 1528 | _unused0: u4 = 0, |
| 1529 | read_only: bool = false, |
| 1530 | _unused1: u27 = 0, |
| 1531 | }, |
| 1532 | }) Error!Segment { |
| 1533 | const gpa = macho.base.comp.gpa; |
| 1534 | |
| 1535 | const segment_command_64 = std.macho.segment_command_64; |
| 1536 | |
| 1537 | // We limit the number of segments to 255, because there can only be 255 *sections*, so there's |
| 1538 | // no need to allow more. See corresponding check in `addSection`. |
| 1539 | if (macho.segments.len == 255) { |
| 1540 | return macho.base.comp.link_diags.fail("maximum segment count exceeded", .{}); |
| 1541 | } |
| 1542 | |
| 1543 | try macho.nodes.ensureUnusedCapacity(gpa, 1); |
| 1544 | try macho.segments.ensureUnusedCapacity(gpa, 1); |
| 1545 | |
| 1546 | const root_ni: MappedFile.Node.Index = .root; |
| 1547 | |
| 1548 | const lc = try macho.appendSimpleLoadCommand(std.macho.segment_command_64, .{ |
| 1549 | .cmdsize = @sizeOf(segment_command_64), |
| 1550 | .segname = name: { |
| 1551 | var name: [16]u8 = undefined; |
| 1552 | @memcpy(name[0..opts.name.len], opts.name); |
| 1553 | @memset(name[opts.name.len..], 0); |
| 1554 | break :name name; |
| 1555 | }, |
| 1556 | .vmaddr = 0, |
| 1557 | .vmsize = 0, |
| 1558 | .fileoff = 0, // to be set by `flushMoved` |
| 1559 | .filesize = 0, |
| 1560 | .maxprot = opts.prot, |
| 1561 | .initprot = opts.prot, |
| 1562 | .nsects = 0, |
| 1563 | .flags = @bitCast(opts.flags), |
| 1564 | }); |
| 566 | 1565 | |
| 567 | 1566 | const segment: Segment = @fromBackingInt(@intCast(macho.segments.len)); |
| 568 | 1567 | const segment_node: MappedFile.Node.Index = node: { |
| ... | ... | @@ -583,17 +1582,9 @@ fn addSegment(macho: *MachO, opts: struct { |
| 583 | 1582 | macho.segments.appendAssumeCapacity(.{ |
| 584 | 1583 | .lc = lc, |
| 585 | 1584 | .node = segment_node, |
| 1585 | .fixup_chain_starts = .none, |
| 586 | 1586 | }); |
| 587 | 1587 | |
| 588 | | { |
| 589 | | const gop = macho.segments_by_name.getOrPutAssumeCapacityAdapted( |
| 590 | | opts.name, |
| 591 | | @as(Segment.NameAdapter, .{ .macho = macho }), |
| 592 | | ); |
| 593 | | assert(!gop.found_existing); |
| 594 | | assert(gop.index == @backingInt(segment)); |
| 595 | | } |
| 596 | | |
| 597 | 1588 | return segment; |
| 598 | 1589 | } |
| 599 | 1590 | |
| ... | ... | @@ -645,16 +1636,37 @@ fn string(macho: *MachO, slice: []const u8) Error!String { |
| 645 | 1636 | return gop.key_ptr.*; |
| 646 | 1637 | } |
| 647 | 1638 | |
| 648 | | fn nlistSlice(macho: *MachO) []std.macho.nlist_64 { |
| 649 | | const nsyms = macho.targetLoad( |
| 650 | | &macho.lc.symtab.ptr(macho, std.macho.symtab_command).nsyms, |
| 651 | | ); |
| 652 | | return @ptrCast(@alignCast( |
| 653 | | macho.node.symtab.slice(&macho.mf)[0 .. nsyms * @sizeOf(std.macho.nlist_64)], |
| 654 | | )); |
| 655 | | } |
| 1639 | fn updateSegmentLoadAddresses(macho: *MachO) Error!void { |
| 1640 | const gpa = macho.base.comp.gpa; |
| 1641 | |
| 1642 | // Grow all `.fixup_chains_starts_in_segment` node to the necessary length. We need to do this |
| 1643 | // before updating the load addresses because this could cause `__LINKEDIT` to grow. |
| 1644 | for (0..macho.segments.len) |segment_raw| { |
| 1645 | const segment: Segment = @fromBackingInt(@intCast(segment_raw)); |
| 1646 | |
| 1647 | const starts_node = segment.fixupChainStartsNode(macho).unwrap() orelse { |
| 1648 | assert(std.mem.eql(u8, segment.name(macho), "__LINKEDIT")); |
| 1649 | continue; |
| 1650 | }; |
| 1651 | |
| 1652 | const size = segment.node(macho).location(&macho.mf).resolve(&macho.mf)[1]; |
| 1653 | |
| 1654 | const page_count: u16 = @intCast(@divExact(size, macho.targetPageAlign().toByteUnits())); |
| 1655 | try starts_node.ensureMinimumSize(gpa, &macho.mf, MappedFile.Alignment.@"8".forward( |
| 1656 | @sizeOf(std.macho.dyld_chained_starts_in_segment) + page_count * 2, |
| 1657 | )); |
| 1658 | const starts_hdr: *std.macho.dyld_chained_starts_in_segment = @ptrCast(@alignCast( |
| 1659 | starts_node.slice(&macho.mf)[0..@sizeOf(std.macho.dyld_chained_starts_in_segment)], |
| 1660 | )); |
| 1661 | const old_page_count = macho.targetLoad(&starts_hdr.page_count); |
| 1662 | macho.targetStore(&starts_hdr.page_count, page_count); |
| 1663 | macho.targetStore(&starts_hdr.size, @sizeOf(std.macho.dyld_chained_starts_in_segment) + 2 * page_count); |
| 1664 | const page_starts: []u16 = @ptrCast(@alignCast( |
| 1665 | starts_node.slice(&macho.mf)[@sizeOf(std.macho.dyld_chained_starts_in_segment) - 2 ..], |
| 1666 | )); |
| 1667 | @memset(page_starts[old_page_count..page_count], 0xFFFF); |
| 1668 | } |
| 656 | 1669 | |
| 657 | | fn updateSegmentLoadAddresses(macho: *MachO) Allocator.Error!void { |
| 658 | 1670 | // TODO: this segment load address allocation logic is bad because it moves segments quite |
| 659 | 1671 | // frequently. We should avoid that by introducing padding between segments so that they have |
| 660 | 1672 | // space to grow in-place. We could also consider allowing a segment which can't fit to jump |
| ... | ... | @@ -664,6 +1676,7 @@ fn updateSegmentLoadAddresses(macho: *MachO) Allocator.Error!void { |
| 664 | 1676 | assert(macho.targetLoad(&pagezero_ptr.vmaddr) == 0); |
| 665 | 1677 | break :start_addr macho.targetLoad(&pagezero_ptr.vmsize); |
| 666 | 1678 | }; |
| 1679 | |
| 667 | 1680 | for (0..macho.segments.len) |segment_raw| { |
| 668 | 1681 | const segment: Segment = @fromBackingInt(@intCast(segment_raw)); |
| 669 | 1682 | |
| ... | ... | @@ -677,7 +1690,7 @@ fn updateSegmentLoadAddresses(macho: *MachO) Allocator.Error!void { |
| 677 | 1690 | cur_addr = old_addr; |
| 678 | 1691 | } else { |
| 679 | 1692 | macho.targetStore(&cmd_ptr.vmaddr, cur_addr); |
| 680 | | try segment.node(macho).childrenMoved(macho.base.comp.gpa, &macho.mf); |
| 1693 | try segment.node(macho).childrenMoved(gpa, &macho.mf); |
| 681 | 1694 | } |
| 682 | 1695 | |
| 683 | 1696 | cur_addr = macho.targetPageAlign().forward(cur_addr + size); |
| ... | ... | @@ -761,12 +1774,10 @@ fn addSection(macho: *MachO, opts: struct { |
| 761 | 1774 | name: []const u8, |
| 762 | 1775 | segment: Segment, |
| 763 | 1776 | @"align": MappedFile.Alignment, |
| 764 | | /// This matches the layout of `std.macho.section_64.flags`. |
| 765 | | flags: packed struct(u32) { |
| 766 | | _unused0: u10 = 0, |
| 767 | | some_instructions: bool = false, |
| 768 | | _unused1: u21 = 0, |
| 769 | | }, |
| 1777 | manual_size: bool = false, |
| 1778 | flags: Section.Flags, |
| 1779 | reserved1: u32 = 0, |
| 1780 | reserved2: u32 = 0, |
| 770 | 1781 | }) Error!Section { |
| 771 | 1782 | const gpa = macho.base.comp.gpa; |
| 772 | 1783 | |
| ... | ... | @@ -796,14 +1807,18 @@ fn addSection(macho: *MachO, opts: struct { |
| 796 | 1807 | |
| 797 | 1808 | const section: Section = @fromBackingInt(@intCast(macho.sections.len)); |
| 798 | 1809 | const section_node = try opts.segment.node(macho).addFloatingChild(gpa, &macho.mf, .{ |
| 799 | | .alignment = opts.@"align", |
| 1810 | .alignment = macho.mf.flags.block_size.max(opts.@"align"), |
| 800 | 1811 | .moved = true, // so that `offset` will be set |
| 801 | 1812 | }); |
| 802 | | macho.nodes.appendAssumeCapacity(.{ .section = section }); |
| 1813 | if (opts.manual_size) { |
| 1814 | macho.nodes.appendAssumeCapacity(.{ .section_manual_size = section }); |
| 1815 | } else { |
| 1816 | macho.nodes.appendAssumeCapacity(.{ .section = section }); |
| 1817 | } |
| 803 | 1818 | macho.sections.appendAssumeCapacity(.{ |
| 804 | 1819 | .lc = @fromBackingInt(@intCast(macho.lc.offsets.items.len)), |
| 805 | 1820 | .node = section_node, |
| 806 | | .first_symbol = .none, |
| 1821 | .segment = opts.segment, |
| 807 | 1822 | .index = undefined, // populated later |
| 808 | 1823 | }); |
| 809 | 1824 | |
| ... | ... | @@ -861,9 +1876,7 @@ fn addSection(macho: *MachO, opts: struct { |
| 861 | 1876 | if (other_section == section) continue; |
| 862 | 1877 | if (other_section.lc(macho).offset(macho) > offset) { |
| 863 | 1878 | macho.sections.items(.index)[@backingInt(other_section)] += 1; |
| 864 | | if (other_section.firstSymbol(macho).* != .none) { |
| 865 | | macho.sections_changed_index.putAssumeCapacity(other_section, {}); |
| 866 | | } |
| 1879 | macho.sections_changed_index.putAssumeCapacity(other_section, {}); |
| 867 | 1880 | } else { |
| 868 | 1881 | new_section_index += 1; |
| 869 | 1882 | } |
| ... | ... | @@ -890,6 +1903,8 @@ fn addSection(macho: *MachO, opts: struct { |
| 890 | 1903 | .reloff = 0, |
| 891 | 1904 | .nreloc = 0, |
| 892 | 1905 | .flags = @bitCast(opts.flags), |
| 1906 | .reserved1 = opts.reserved1, |
| 1907 | .reserved2 = opts.reserved2, |
| 893 | 1908 | }; |
| 894 | 1909 | if (macho.targetEndian() != std.lang.Endian.native) { |
| 895 | 1910 | std.mem.byteSwapAllFields(section_64, section_cmd); |
| ... | ... | @@ -898,15 +1913,6 @@ fn addSection(macho: *MachO, opts: struct { |
| 898 | 1913 | return section; |
| 899 | 1914 | } |
| 900 | 1915 | |
| 901 | | fn segmentByName(macho: *const MachO, name: []const u8) ?Segment { |
| 902 | | const adapter: Segment.NameAdapter = .{ .macho = macho }; |
| 903 | | if (macho.segments_by_name.getIndexAdapted(name, adapter)) |segment_raw| { |
| 904 | | return @fromBackingInt(@intCast(segment_raw)); |
| 905 | | } else { |
| 906 | | return null; |
| 907 | | } |
| 908 | | } |
| 909 | | |
| 910 | 1916 | fn sectionByName(macho: *const MachO, segment_name: []const u8, section_name: []const u8) ?Section { |
| 911 | 1917 | const adapter: Section.NameAdapter = .{ .macho = macho }; |
| 912 | 1918 | const key: Section.NameAdapter.SegmentAndSection = .{ |
| ... | ... | @@ -920,13 +1926,31 @@ fn sectionByName(macho: *const MachO, segment_name: []const u8, section_name: [] |
| 920 | 1926 | } |
| 921 | 1927 | } |
| 922 | 1928 | |
| 1929 | fn machFiletype(macho: *const MachO) enum(u32) { |
| 1930 | OBJECT = std.macho.MH_OBJECT, |
| 1931 | DYLIB = std.macho.MH_DYLIB, |
| 1932 | EXECUTE = std.macho.MH_EXECUTE, |
| 1933 | } { |
| 1934 | const hdr: *const std.macho.mach_header_64 = @ptrCast(@alignCast( |
| 1935 | macho.node.header.sliceConst(&macho.mf)[0..@sizeOf(std.macho.mach_header_64)], |
| 1936 | )); |
| 1937 | return @fromBackingInt(macho.targetLoad(&hdr.filetype)); |
| 1938 | } |
| 1939 | |
| 923 | 1940 | fn targetEndian(macho: *const MachO) std.lang.Endian { |
| 924 | 1941 | _ = macho; |
| 925 | 1942 | return .little; |
| 926 | 1943 | } |
| 927 | | fn targetPageAlign(macho: *const MachO) MappedFile.Alignment { |
| 1944 | fn targetPtrSize(macho: *const MachO) u8 { |
| 928 | 1945 | _ = macho; |
| 929 | | return .fromByteUnits(0x4000); |
| 1946 | return 8; |
| 1947 | } |
| 1948 | fn targetPageAlign(macho: *const MachO) MappedFile.Alignment { |
| 1949 | return switch (macho.base.comp.getTarget().cpu.arch) { |
| 1950 | else => unreachable, |
| 1951 | .aarch64 => .fromByteUnits(0x4000), |
| 1952 | .x86_64 => .fromByteUnits(0x1000), |
| 1953 | }; |
| 930 | 1954 | } |
| 931 | 1955 | fn targetLoad(macho: *const MachO, ptr: anytype) @typeInfo(@TypeOf(ptr)).pointer.child { |
| 932 | 1956 | const pointer_ty = @typeInfo(@TypeOf(ptr)).pointer; |
| ... | ... | @@ -936,8 +1960,8 @@ fn targetLoad(macho: *const MachO, ptr: anytype) @typeInfo(@TypeOf(ptr)).pointer |
| 936 | 1960 | else => @compileError(@typeName(Child)), |
| 937 | 1961 | .int => std.mem.toNative(Child, ptr.*, macho.targetEndian()), |
| 938 | 1962 | .@"enum" => |@"enum"| @fromBackingInt(macho.targetLoad(@as(*align(alignment) const @"enum".tag_type, @ptrCast(ptr)))), |
| 939 | | .@"struct" => |@"struct"| @bitCast( |
| 940 | | macho.targetLoad(@as(*align(alignment) @"struct".backing_integer.?, @ptrCast(ptr))), |
| 1963 | inline .@"struct", .@"union" => |bitpack| @bitCast( |
| 1964 | macho.targetLoad(@as(*align(alignment) const bitpack.backing_integer.?, @ptrCast(ptr))), |
| 941 | 1965 | ), |
| 942 | 1966 | }; |
| 943 | 1967 | } |
| ... | ... | @@ -952,8 +1976,8 @@ fn targetStore(macho: *const MachO, ptr: anytype, val: @typeInfo(@TypeOf(ptr)).p |
| 952 | 1976 | @as(*align(alignment) @"enum".tag_type, @ptrCast(ptr)), |
| 953 | 1977 | @backingInt(val), |
| 954 | 1978 | ), |
| 955 | | .@"struct" => |@"struct"| macho.targetStore( |
| 956 | | @as(*align(alignment) @"struct".backing_integer.?, @ptrCast(ptr)), |
| 1979 | inline .@"struct", .@"union" => |bitpack| macho.targetStore( |
| 1980 | @as(*align(alignment) bitpack.backing_integer.?, @ptrCast(ptr)), |
| 957 | 1981 | @bitCast(val), |
| 958 | 1982 | ), |
| 959 | 1983 | }; |
| ... | ... | @@ -965,10 +1989,16 @@ pub fn deinit(macho: *MachO) void { |
| 965 | 1989 | macho.nodes.deinit(gpa); |
| 966 | 1990 | macho.segments.deinit(gpa); |
| 967 | 1991 | macho.sections.deinit(gpa); |
| 968 | | macho.segments_by_name.deinit(gpa); |
| 969 | 1992 | macho.sections_by_name.deinit(gpa); |
| 1993 | macho.dirty_fixup_chain_pages.deinit(gpa); |
| 1994 | macho.input_atoms.deinit(gpa); |
| 970 | 1995 | macho.strtab.deinit(gpa); |
| 971 | 1996 | macho.symtab.deinit(gpa); |
| 1997 | macho.global_symbols.deinit(gpa); |
| 1998 | macho.relocs.deinit(gpa); |
| 1999 | macho.imports.deinit(gpa); |
| 2000 | macho.got.deinit(gpa); |
| 2001 | macho.stubs.deinit(gpa); |
| 972 | 2002 | macho.sections_changed_index.deinit(gpa); |
| 973 | 2003 | macho.* = undefined; |
| 974 | 2004 | } |
| ... | ... | @@ -1023,41 +2053,1153 @@ pub fn loadInput(macho: *MachO, input: link.Input) link.Error!void { |
| 1023 | 2053 | error.MappedFileIo => return diags.fail("failed to write output file: {t}", .{macho.mf.io_err.?}), |
| 1024 | 2054 | else => |e| return e, |
| 1025 | 2055 | }; |
| 2056 | macho.updateSegmentLoadAddresses() catch |err| switch (err) { |
| 2057 | error.MappedFileIo => return diags.fail("failed to write output file: {t}", .{macho.mf.io_err.?}), |
| 2058 | else => |e| return e, |
| 2059 | }; |
| 1026 | 2060 | } |
| 1027 | 2061 | fn loadInputInner(macho: *MachO, input: link.Input) Error!void { |
| 2062 | const comp = macho.base.comp; |
| 2063 | const diags = &comp.link_diags; |
| 2064 | const gpa = comp.gpa; |
| 2065 | const io = comp.io; |
| 1028 | 2066 | switch (input) { |
| 1029 | 2067 | .res => unreachable, |
| 1030 | | .object => @panic("TODO(MachO2): load object"), |
| 1031 | | .archive => @panic("TODO(MachO2): load archive"), |
| 2068 | .object => |object| { |
| 2069 | var buf: [4096]u8 = undefined; |
| 2070 | var fr = object.file.reader(io, &buf); |
| 2071 | macho.loadObject(object.path, null, &fr, .{ |
| 2072 | .offset = fr.logicalPos(), |
| 2073 | .size = fr.getSize() catch |err| switch (err) { |
| 2074 | error.Canceled => |e| return e, |
| 2075 | else => |e| return diags.fail( |
| 2076 | "failed to stat \"{f}\": {t}", |
| 2077 | .{ object.path.fmtEscapeString(), e }, |
| 2078 | ), |
| 2079 | }, |
| 2080 | }) catch |err| switch (err) { |
| 2081 | else => |e| return e, |
| 2082 | error.EndOfStream => return diags.failParse( |
| 2083 | object.path, |
| 2084 | "unexpected eof", |
| 2085 | .{}, |
| 2086 | ), |
| 2087 | error.AccessDenied, error.Unexpected, error.Unseekable => |e| return diags.fail( |
| 2088 | "failed to read \"{f}\": {t}", |
| 2089 | .{ object.path.fmtEscapeString(), e }, |
| 2090 | ), |
| 2091 | error.ReadFailed => switch (fr.err.?) { |
| 2092 | error.Canceled => |e| return e, |
| 2093 | else => |e| return diags.fail( |
| 2094 | "failed to read \"{f}\": {t}", |
| 2095 | .{ object.path.fmtEscapeString(), e }, |
| 2096 | ), |
| 2097 | }, |
| 2098 | }; |
| 2099 | }, |
| 2100 | .archive => |archive| { |
| 2101 | var buf: [4096]u8 = undefined; |
| 2102 | var fr = archive.file.reader(io, &buf); |
| 2103 | macho.loadArchive(archive.path, &fr) catch |err| switch (err) { |
| 2104 | else => |e| return e, |
| 2105 | error.EndOfStream => return diags.failParse( |
| 2106 | archive.path, |
| 2107 | "unexpected eof", |
| 2108 | .{}, |
| 2109 | ), |
| 2110 | error.AccessDenied, error.Unexpected, error.Unseekable => |e| return diags.fail( |
| 2111 | "failed to read \"{f}\": {t}", |
| 2112 | .{ archive.path.fmtEscapeString(), e }, |
| 2113 | ), |
| 2114 | error.ReadFailed => switch (fr.err.?) { |
| 2115 | error.Canceled => |e| return e, |
| 2116 | else => |e| return diags.fail( |
| 2117 | "failed to read \"{f}\": {t}", |
| 2118 | .{ archive.path.fmtEscapeString(), e }, |
| 2119 | ), |
| 2120 | }, |
| 2121 | }; |
| 2122 | }, |
| 1032 | 2123 | .dso => @panic("TODO(MachO2): load dso"), |
| 1033 | 2124 | .tbd => |tbd| { |
| 1034 | 2125 | log.debug("load tbd {qf}", .{tbd.path.fmtEscapeString()}); |
| 1035 | 2126 | |
| 1036 | | // TODO: obviously this is completely wrong, we need to parse the tbd to determine the |
| 1037 | | // dylib install name; but for now this lets us link libSystem |
| 1038 | | const prefix = "/usr/lib/"; |
| 1039 | | const name = std.fs.path.stem(tbd.path.sub_path); |
| 1040 | | const suffix = ".dylib"; |
| 2127 | var lib_stub = tapi.LibStub.loadFromFile(gpa, io, tbd.file) catch |err| switch (err) { |
| 2128 | error.Canceled => |e| return e, |
| 2129 | else => |e| return diags.failParse(tbd.path, "failed to parse tbd: {t}", .{e}), |
| 2130 | }; |
| 2131 | defer lib_stub.deinit(); |
| 2132 | |
| 2133 | const umbrella_lib = lib_stub.inner[0]; |
| 1041 | 2134 | |
| 2135 | const dylib_name = umbrella_lib.installName(); |
| 1042 | 2136 | const cmd = try macho.appendLoadCommand(std.macho.dylib_command, .{ |
| 1043 | 2137 | .cmd = .LOAD_DYLIB, |
| 1044 | 2138 | .cmdsize = std.mem.alignForward(u32, @intCast( |
| 1045 | | @sizeOf(std.macho.dylib_command) + prefix.len + name.len + suffix.len + 1, |
| 2139 | @sizeOf(std.macho.dylib_command) + dylib_name.len + 1, |
| 1046 | 2140 | ), 8), |
| 1047 | 2141 | .dylib = .{ |
| 1048 | 2142 | .name = @sizeOf(std.macho.dylib_command), |
| 1049 | 2143 | .timestamp = 0, |
| 1050 | | .current_version = 0, |
| 1051 | | .compatibility_version = 0, |
| 2144 | .current_version = 0, // TODO |
| 2145 | .compatibility_version = 0, // TODO |
| 1052 | 2146 | }, |
| 1053 | 2147 | }); |
| 1054 | | @memcpy(cmd.trailing[0..prefix.len], prefix); |
| 1055 | | @memcpy(cmd.trailing[prefix.len..][0..name.len], name); |
| 1056 | | @memcpy(cmd.trailing[prefix.len + name.len ..][0..suffix.len], suffix); |
| 1057 | | @memset(cmd.trailing[prefix.len + name.len + suffix.len ..], 0); |
| 2148 | @memcpy(cmd.trailing[0..dylib_name.len], dylib_name); |
| 2149 | @memset(cmd.trailing[dylib_name.len..], 0); |
| 1058 | 2150 | }, |
| 1059 | 2151 | } |
| 1060 | 2152 | } |
| 2153 | |
| 2154 | /// Internal error set used by input parsing functions `loadObject`, `loadArchive`, `loadDso`. |
| 2155 | const LoadParseInputError = Error || Io.File.SeekError || Io.Reader.Error; |
| 2156 | |
| 2157 | fn loadArchive(macho: *MachO, path: std.Build.Cache.Path, fr: *Io.File.Reader) LoadParseInputError!void { |
| 2158 | const comp = macho.base.comp; |
| 2159 | const gpa = comp.gpa; |
| 2160 | const diags = &comp.link_diags; |
| 2161 | const r = &fr.interface; |
| 2162 | |
| 2163 | log.debug("loadArchive({f})", .{path.fmtEscapeString()}); |
| 2164 | |
| 2165 | { |
| 2166 | const magic = r.take(std.macho.ARMAG.len) catch |err| switch (err) { |
| 2167 | error.ReadFailed => |e| return e, |
| 2168 | error.EndOfStream => return diags.failParse(path, "invalid archive file", .{}), |
| 2169 | }; |
| 2170 | if (!std.mem.eql(u8, magic, std.macho.ARMAG)) { |
| 2171 | return diags.failParse(path, "invalid archive file", .{}); |
| 2172 | } |
| 2173 | } |
| 2174 | |
| 2175 | var long_name_buf: std.ArrayList(u8) = .empty; |
| 2176 | defer long_name_buf.deinit(gpa); |
| 2177 | |
| 2178 | while (r.takeStruct(std.macho.ar_hdr, .native)) |header| { |
| 2179 | if (!std.mem.eql(u8, &header.ar_fmag, std.macho.ARFMAG)) |
| 2180 | return diags.failParse(path, "bad file magic", .{}); |
| 2181 | const offset = fr.logicalPos(); |
| 2182 | const size = header.size() catch |
| 2183 | return diags.failParse(path, "bad member size", .{}); |
| 2184 | const member_name: []const u8, const member_offset: u64, const member_size: u64 = member: { |
| 2185 | const name_len = header.nameLength() orelse { |
| 2186 | break :member .{ header.name(), offset, size }; |
| 2187 | }; |
| 2188 | try long_name_buf.resize(gpa, name_len); |
| 2189 | try fr.interface.readSliceAll(long_name_buf.items); |
| 2190 | break :member .{ |
| 2191 | std.mem.sliceTo(long_name_buf.items, 0), |
| 2192 | offset + name_len, |
| 2193 | size - name_len, |
| 2194 | }; |
| 2195 | }; |
| 2196 | if (std.mem.eql(u8, member_name, std.macho.SYMDEF) or |
| 2197 | std.mem.eql(u8, member_name, std.macho.SYMDEF64) or |
| 2198 | std.mem.eql(u8, member_name, std.macho.SYMDEF_SORTED) or |
| 2199 | std.mem.eql(u8, member_name, std.macho.SYMDEF64_SORTED)) |
| 2200 | { |
| 2201 | // Ignore these special members. |
| 2202 | } else { |
| 2203 | try macho.loadObject(path, member_name, fr, .{ |
| 2204 | .offset = member_offset, |
| 2205 | .size = member_size, |
| 2206 | }); |
| 2207 | } |
| 2208 | try fr.seekTo(std.mem.alignForward(u64, offset + size, 2)); |
| 2209 | } else |err| switch (err) { |
| 2210 | else => |e| return e, |
| 2211 | error.EndOfStream => if (!fr.atEnd()) return error.EndOfStream, |
| 2212 | } |
| 2213 | } |
| 2214 | fn loadObject( |
| 2215 | macho: *MachO, |
| 2216 | path: std.Build.Cache.Path, |
| 2217 | member: ?[]const u8, |
| 2218 | fr: *Io.File.Reader, |
| 2219 | fl: MappedFile.Node.FileLocation, |
| 2220 | ) LoadParseInputError!void { |
| 2221 | const comp = macho.base.comp; |
| 2222 | const diags = &comp.link_diags; |
| 2223 | const gpa = comp.gpa; |
| 2224 | |
| 2225 | log.debug("loadObject({f}{f})", .{ path.fmtEscapeString(), fmtMemberString(member) }); |
| 2226 | |
| 2227 | const target_endian = macho.targetEndian(); |
| 2228 | |
| 2229 | switch (try fr.interface.peekInt(u32, target_endian)) { |
| 2230 | std.macho.MH_MAGIC_64 => {}, |
| 2231 | std.macho.MH_MAGIC => { |
| 2232 | return diags.failParse(path, "incorrect pointer bit width (expected 64)", .{}); |
| 2233 | }, |
| 2234 | std.macho.MH_CIGAM_64, std.macho.MH_CIGAM => { |
| 2235 | return diags.failParse(path, "incorrect endian (expected {t})", .{target_endian}); |
| 2236 | }, |
| 2237 | else => { |
| 2238 | return diags.failParse(path, "invalid Mach-O object file", .{}); |
| 2239 | }, |
| 2240 | } |
| 2241 | |
| 2242 | const header = try fr.interface.takeStruct(std.macho.mach_header_64, target_endian); |
| 2243 | assert(header.magic == std.macho.MH_MAGIC_64); // checked above |
| 2244 | |
| 2245 | if (header.filetype != std.macho.MH_OBJECT) return diags.failParse( |
| 2246 | path, |
| 2247 | "not a relocatable", |
| 2248 | .{}, |
| 2249 | ); |
| 2250 | |
| 2251 | { |
| 2252 | const output_header: *const std.macho.mach_header_64 = @ptrCast(@alignCast( |
| 2253 | macho.node.header.sliceConst(&macho.mf)[0..@sizeOf(std.macho.mach_header_64)], |
| 2254 | )); |
| 2255 | const output_cputype = macho.targetLoad(&output_header.cputype); |
| 2256 | const output_cpusubtype = macho.targetLoad(&output_header.cpusubtype); |
| 2257 | if (header.cputype != output_cputype) return diags.failParse( |
| 2258 | path, |
| 2259 | "cputype '{d}' does not match target cputype '{d}'", |
| 2260 | .{ header.cputype, output_cputype }, |
| 2261 | ); |
| 2262 | if (header.cpusubtype != output_cpusubtype) return diags.failParse( |
| 2263 | path, |
| 2264 | "cpusubtype '{d}' does not match target cpusubtype '{d}'", |
| 2265 | .{ header.cpusubtype, output_cpusubtype }, |
| 2266 | ); |
| 2267 | } |
| 2268 | |
| 2269 | if (@sizeOf(std.macho.mach_header_64) + header.sizeofcmds > fl.size) { |
| 2270 | return diags.failParse(path, "load commands exceed file size", .{}); |
| 2271 | } |
| 2272 | |
| 2273 | var maybe_symtab_lc: ?std.macho.symtab_command = null; |
| 2274 | |
| 2275 | const InputSection = struct { |
| 2276 | segname: [16]u8, |
| 2277 | sectname: [16]u8, |
| 2278 | |
| 2279 | reloff: u32, |
| 2280 | nreloc: u32, |
| 2281 | |
| 2282 | addr: u64, |
| 2283 | size: u64, |
| 2284 | @"align": MappedFile.Alignment, |
| 2285 | |
| 2286 | usage: Usage, |
| 2287 | file_offset: u32, |
| 2288 | |
| 2289 | atoms_start: usize, |
| 2290 | atoms_end: usize, |
| 2291 | |
| 2292 | const Usage = enum { |
| 2293 | text, |
| 2294 | data_const, |
| 2295 | data_const_split_4, |
| 2296 | data_const_split_8, |
| 2297 | data_const_split_16, |
| 2298 | data_const_split_c_strings, |
| 2299 | data_const_fixups, |
| 2300 | data_mut, |
| 2301 | bss, |
| 2302 | fn parentSection(usage: Usage, m: *const MachO) Section { |
| 2303 | return switch (usage) { |
| 2304 | .text => m.sectionByName("__TEXT", "__text").?, |
| 2305 | |
| 2306 | .data_const, |
| 2307 | .data_const_split_4, |
| 2308 | .data_const_split_8, |
| 2309 | .data_const_split_16, |
| 2310 | .data_const_split_c_strings, |
| 2311 | => m.sectionByName("__TEXT", "__const").?, |
| 2312 | |
| 2313 | // TODO: this should really be "__DATA_CONST,__data". See comment in `initInner` |
| 2314 | .data_const_fixups => m.sectionByName("__DATA", "__data").?, |
| 2315 | |
| 2316 | .data_mut => m.sectionByName("__DATA", "__data").?, |
| 2317 | .bss => m.sectionByName("__DATA", "__data").?, |
| 2318 | }; |
| 2319 | } |
| 2320 | }; |
| 2321 | }; |
| 2322 | var input_sections: std.ArrayList(InputSection) = .empty; |
| 2323 | defer input_sections.deinit(gpa); |
| 2324 | |
| 2325 | var cmd_offset: u64 = 0; |
| 2326 | for (0..header.ncmds) |_| { |
| 2327 | const lc = try fr.interface.peekStruct(std.macho.load_command, target_endian); |
| 2328 | if (lc.cmdsize < @sizeOf(std.macho.load_command)) return diags.failParse( |
| 2329 | path, |
| 2330 | "load command at offset 0x{X} has invalid size", |
| 2331 | .{cmd_offset + @sizeOf(std.macho.mach_header_64)}, |
| 2332 | ); |
| 2333 | if (cmd_offset + lc.cmdsize > header.sizeofcmds) return diags.failParse( |
| 2334 | path, |
| 2335 | "load command at offset 0x{X} exceeds 'sizeofcmds'", |
| 2336 | .{cmd_offset + @sizeOf(std.macho.mach_header_64)}, |
| 2337 | ); |
| 2338 | cmd_offset += lc.cmdsize; |
| 2339 | switch (lc.cmd) { |
| 2340 | else => if (std.enums.tagName(std.macho.LC, lc.cmd)) |cmd_name| { |
| 2341 | return diags.failParse(path, "unhandled load command 'LC_{s}'", .{cmd_name}); |
| 2342 | } else { |
| 2343 | return diags.failParse(path, "unknown load command 0x{X}", .{lc.cmd}); |
| 2344 | }, |
| 2345 | |
| 2346 | .NONE, |
| 2347 | .DYSYMTAB, |
| 2348 | .NOTE, |
| 2349 | .BUILD_VERSION, |
| 2350 | .DATA_IN_CODE, |
| 2351 | .LINKER_OPTIMIZATION_HINT, |
| 2352 | => try fr.interface.discardAll(lc.cmdsize), // ignore |
| 2353 | |
| 2354 | .SEGMENT_64 => { |
| 2355 | if (lc.cmdsize < @sizeOf(std.macho.segment_command_64)) { |
| 2356 | return diags.failParse(path, "bad cmdsize in 'LC_SEGMENT_64' load command", .{}); |
| 2357 | } |
| 2358 | const segment_lc = try fr.interface.takeStruct(std.macho.segment_command_64, target_endian); |
| 2359 | if (lc.cmdsize - @sizeOf(std.macho.segment_command_64) < segment_lc.nsects * @sizeOf(std.macho.section_64)) { |
| 2360 | return diags.failParse(path, "nsects in 'LC_SEGMENT_64' load command exceeds cmdsize", .{}); |
| 2361 | } |
| 2362 | try input_sections.ensureUnusedCapacity(gpa, segment_lc.nsects); |
| 2363 | for (0..segment_lc.nsects) |_| { |
| 2364 | const section = try fr.interface.takeStruct(std.macho.section_64, target_endian); |
| 2365 | |
| 2366 | const flags: Section.Flags = @bitCast(section.flags); |
| 2367 | |
| 2368 | const segname = std.mem.sliceTo(§ion.segname, 0); |
| 2369 | const sectname = std.mem.sliceTo(§ion.sectname, 0); |
| 2370 | |
| 2371 | const usage: InputSection.Usage = switch (flags.type) { |
| 2372 | _ => return diags.failParse( |
| 2373 | path, |
| 2374 | "section '{s},{s}' has unknown type '{d}'", |
| 2375 | .{ segname, sectname, flags.type }, |
| 2376 | ), |
| 2377 | |
| 2378 | else => return diags.failParse( |
| 2379 | path, |
| 2380 | "section '{s},{s}' has unsupported type '{t}'", |
| 2381 | .{ segname, sectname, flags.type }, |
| 2382 | ), |
| 2383 | |
| 2384 | .zerofill => .bss, |
| 2385 | |
| 2386 | .@"4byte_literals" => .data_const_split_4, |
| 2387 | .@"8byte_literals" => .data_const_split_8, |
| 2388 | .@"16byte_literals" => .data_const_split_16, |
| 2389 | .cstring_literals => .data_const_split_c_strings, |
| 2390 | |
| 2391 | .regular => usage: { |
| 2392 | if (flags.some_instructions or flags.pure_instructions) { |
| 2393 | break :usage .text; |
| 2394 | } |
| 2395 | |
| 2396 | // "__DATA,__const" is constant data with fixups. |
| 2397 | if (std.mem.eql(u8, segname, "__DATA") and |
| 2398 | std.mem.eql(u8, sectname, "__const")) |
| 2399 | { |
| 2400 | break :usage .data_const_fixups; |
| 2401 | } |
| 2402 | |
| 2403 | // Otherwise, the decision is based solely on segment name. |
| 2404 | if (std.mem.eql(u8, segname, "__TEXT")) { |
| 2405 | break :usage .data_const; |
| 2406 | } |
| 2407 | if (std.mem.eql(u8, segname, "__DATA_CONST")) { |
| 2408 | break :usage .data_const_fixups; |
| 2409 | } |
| 2410 | if (std.mem.eql(u8, segname, "__DATA")) { |
| 2411 | break :usage .data_mut; |
| 2412 | } |
| 2413 | |
| 2414 | return diags.failParse(path, "unknown segment name '{s}'", .{segname}); |
| 2415 | }, |
| 2416 | }; |
| 2417 | |
| 2418 | if (usage != .bss and section.offset + section.size > fl.size) { |
| 2419 | return diags.failParse(path, "section '{s},{s}' exceeds file size", .{ |
| 2420 | segname, sectname, |
| 2421 | }); |
| 2422 | } |
| 2423 | |
| 2424 | const @"align": MappedFile.Alignment = .fromLog2Units(std.math.cast(u6, section.@"align") orelse { |
| 2425 | return diags.failParse(path, "section '{s},{s}' has unsupported alignment '1 << {d}'", .{ |
| 2426 | segname, sectname, section.@"align", |
| 2427 | }); |
| 2428 | }); |
| 2429 | |
| 2430 | // Before creating the input section nodes, make sure the parent section is |
| 2431 | // suitably aligned. Unlike ELF, Mach-O does not allow customizing segment |
| 2432 | // alignment, so section alignments greater than the page size cannot be |
| 2433 | // fulfilled and must trigger an error. |
| 2434 | if (@"align".compare(.gt, macho.targetPageAlign())) { |
| 2435 | return diags.failParse(path, "section '{s},{s}' has alignment '{d}' which exceeds page alignment '{d}'", .{ |
| 2436 | segname, sectname, @"align".toByteUnits(), macho.targetPageAlign().toByteUnits(), |
| 2437 | }); |
| 2438 | } |
| 2439 | const parent_section = usage.parentSection(macho); |
| 2440 | if (@"align".compare(.gt, parent_section.alignment(macho))) { |
| 2441 | macho.targetStore(&parent_section.lcPtr(macho).@"align", @"align".toLog2Units()); |
| 2442 | if (@"align".compare(.gt, parent_section.node(macho).alignment(&macho.mf))) { |
| 2443 | try parent_section.node(macho).realign(gpa, &macho.mf, @"align"); |
| 2444 | } |
| 2445 | } |
| 2446 | |
| 2447 | input_sections.appendAssumeCapacity(.{ |
| 2448 | .segname = section.segname, |
| 2449 | .sectname = section.sectname, |
| 2450 | .reloff = section.reloff, |
| 2451 | .nreloc = section.nreloc, |
| 2452 | .addr = section.addr, |
| 2453 | .size = section.size, |
| 2454 | .@"align" = @"align", |
| 2455 | .usage = usage, |
| 2456 | .file_offset = section.offset, |
| 2457 | .atoms_start = undefined, |
| 2458 | .atoms_end = undefined, |
| 2459 | }); |
| 2460 | } |
| 2461 | try fr.interface.discardAll(lc.cmdsize - |
| 2462 | @sizeOf(std.macho.segment_command_64) - |
| 2463 | segment_lc.nsects * @sizeOf(std.macho.section_64)); |
| 2464 | }, |
| 2465 | |
| 2466 | .SYMTAB => { |
| 2467 | if (lc.cmdsize < @sizeOf(std.macho.symtab_command)) { |
| 2468 | return diags.failParse(path, "bad cmdsize in 'LC_SYMTAB' load command", .{}); |
| 2469 | } |
| 2470 | if (maybe_symtab_lc != null) { |
| 2471 | return diags.failParse(path, "duplicate 'LC_SYMTAB' load command", .{}); |
| 2472 | } |
| 2473 | maybe_symtab_lc = try fr.interface.peekStruct(std.macho.symtab_command, target_endian); |
| 2474 | try fr.interface.discardAll(lc.cmdsize); |
| 2475 | }, |
| 2476 | } |
| 2477 | } |
| 2478 | |
| 2479 | const symtab_lc = maybe_symtab_lc orelse return diags.failParse( |
| 2480 | path, |
| 2481 | "object file does not contain any 'LC_SYMTAB' load command", |
| 2482 | .{}, |
| 2483 | ); |
| 2484 | if (symtab_lc.symoff + symtab_lc.nsyms * @sizeOf(std.macho.nlist_64) > fl.size) { |
| 2485 | return diags.failParse(path, "symbol table in 'LC_SYMTAB' load command exceeds file size", .{}); |
| 2486 | } |
| 2487 | if (symtab_lc.stroff + symtab_lc.strsize > fl.size) { |
| 2488 | return diags.failParse(path, "string table in 'LC_SYMTAB' load command exceeds file size", .{}); |
| 2489 | } |
| 2490 | |
| 2491 | const symbols = try gpa.alloc(Symbol.Index, symtab_lc.nsyms); |
| 2492 | defer gpa.free(symbols); |
| 2493 | |
| 2494 | const Atom = struct { |
| 2495 | offset_in_section: u64, |
| 2496 | index: InputAtom.Index, |
| 2497 | }; |
| 2498 | var atoms: std.ArrayList(Atom) = .empty; |
| 2499 | defer atoms.deinit(gpa); |
| 2500 | |
| 2501 | // This block processes symbols and atoms (populating `symbols` and `atoms` in the process). |
| 2502 | // After the block exits, the only work remining is relocation lowering. |
| 2503 | { |
| 2504 | try fr.seekTo(fl.offset + symtab_lc.stroff); |
| 2505 | const strtab = try fr.interface.readAllocAll(gpa, symtab_lc.strsize); |
| 2506 | defer gpa.free(strtab); |
| 2507 | |
| 2508 | try fr.seekTo(fl.offset + symtab_lc.symoff); |
| 2509 | const symtab = try fr.interface.readSliceEndianAlloc(gpa, std.macho.nlist_64, symtab_lc.nsyms, target_endian); |
| 2510 | defer gpa.free(symtab); |
| 2511 | |
| 2512 | // Sort the symbols so that we can do subsection splitting efficiently. This is okay because |
| 2513 | // there is no significance to the order of the symbol table in an object file. We'll put |
| 2514 | // any symbols not in a section (undef, absolute, etc) first, and then we'll sort the |
| 2515 | // remaining symbols by section index and address. |
| 2516 | // |
| 2517 | // Small caveat: when we lower symbols into the `symbols` array we allocated earlier, we do |
| 2518 | // need to use the *original* indices rather than our sorted indices, so that we can look up |
| 2519 | // relocation target symbols by index later. To help us do that, we'll also build a mapping |
| 2520 | // from our sorted indices to the original indices. |
| 2521 | const orig_sym_indices = try gpa.alloc(u32, symtab.len); |
| 2522 | defer gpa.free(orig_sym_indices); |
| 2523 | for (orig_sym_indices, 0..) |*orig_index, i| { |
| 2524 | orig_index.* = @intCast(i); |
| 2525 | } |
| 2526 | const SymtabSortContext = struct { |
| 2527 | symtab: []std.macho.nlist_64, |
| 2528 | map: []u32, |
| 2529 | pub fn lessThan(ctx: @This(), lhs_index: usize, rhs_index: usize) bool { |
| 2530 | const lhs = ctx.symtab[lhs_index]; |
| 2531 | const rhs = ctx.symtab[rhs_index]; |
| 2532 | // Don't need to check `n_type.bits.is_stab` here, because valid object files do not |
| 2533 | // contain stabs symbols, so if any are present we'll error out later anyway. |
| 2534 | const lhs_sect: u8, const lhs_addr: u64 = switch (lhs.n_type.bits.type) { |
| 2535 | .sect => .{ lhs.n_sect, lhs.n_value }, |
| 2536 | else => .{ 0, 0 }, |
| 2537 | }; |
| 2538 | const rhs_sect: u8, const rhs_addr: u64 = switch (rhs.n_type.bits.type) { |
| 2539 | .sect => .{ rhs.n_sect, rhs.n_value }, |
| 2540 | else => .{ 0, 0 }, |
| 2541 | }; |
| 2542 | const order = std.math.order(lhs_sect, rhs_sect).differ() orelse std.math.order(lhs_addr, rhs_addr); |
| 2543 | return order.compare(.lt); |
| 2544 | } |
| 2545 | pub fn swap(ctx: @This(), lhs_index: usize, rhs_index: usize) void { |
| 2546 | std.mem.swap(std.macho.nlist_64, &ctx.symtab[lhs_index], &ctx.symtab[rhs_index]); |
| 2547 | std.mem.swap(u32, &ctx.map[lhs_index], &ctx.map[rhs_index]); |
| 2548 | } |
| 2549 | }; |
| 2550 | std.mem.sortUnstableContext(0, symtab.len, @as(SymtabSortContext, .{ |
| 2551 | .symtab = symtab, |
| 2552 | .map = orig_sym_indices, |
| 2553 | })); |
| 2554 | |
| 2555 | var sym_index: u32 = 0; |
| 2556 | |
| 2557 | // This initial loop processes all of the non-section symbols (undef, absolute, etc). When |
| 2558 | // it exits, `sym_index` points to the first symbol with `n_type.bits.type == .sect`, which |
| 2559 | // is guaranteed to have `n_sect > 0`. |
| 2560 | while (sym_index < symtab.len) : (sym_index += 1) { |
| 2561 | const nlist = &symtab[sym_index]; |
| 2562 | |
| 2563 | if (nlist.n_type.bits.is_stab != 0) return diags.failParse( |
| 2564 | path, |
| 2565 | "invalid symtab entry at index {d}: object file cannot contain stabs", |
| 2566 | .{sym_index}, |
| 2567 | ); |
| 2568 | if (nlist.n_strx > strtab.len) return diags.failParse( |
| 2569 | path, |
| 2570 | "invalid symtab entry at index {d}: 'n_strx' value '{d}' out of range", |
| 2571 | .{ sym_index, nlist.n_strx }, |
| 2572 | ); |
| 2573 | const sym_name = std.mem.sliceTo(strtab[nlist.n_strx..], 0); |
| 2574 | |
| 2575 | symbols[orig_sym_indices[sym_index]] = switch (nlist.n_type.bits.type) { |
| 2576 | .sect => if (nlist.n_sect == 0) return diags.failParse( |
| 2577 | path, |
| 2578 | "symbol '{s}' of type 'N_SECT' has invalid section index '{d}'", |
| 2579 | .{ sym_name, nlist.n_sect }, |
| 2580 | ) else { |
| 2581 | // All done with the non-section symbols! |
| 2582 | break; |
| 2583 | }, |
| 2584 | |
| 2585 | .undf => if (!nlist.n_type.bits.ext) return diags.failParse( |
| 2586 | path, |
| 2587 | "internal symbol '{s}' cannot be undefined", |
| 2588 | .{sym_name}, |
| 2589 | ) else macho.addGlobalSymbol(.{ |
| 2590 | .name = sym_name, |
| 2591 | .linkage = switch (nlist.n_desc.weak_ref) { |
| 2592 | false => .strong, |
| 2593 | true => .weak, |
| 2594 | }, |
| 2595 | .visibility = switch (nlist.n_type.bits.pext) { |
| 2596 | false => .default, |
| 2597 | true => .hidden, |
| 2598 | }, |
| 2599 | .value = null, |
| 2600 | }) catch |err| switch (err) { |
| 2601 | error.MultipleDefinitions => unreachable, // not a definition |
| 2602 | else => |e| return e, |
| 2603 | }, |
| 2604 | |
| 2605 | .abs => if (!nlist.n_type.bits.ext) try macho.addInternalSymbol(.{ |
| 2606 | .name = sym_name, |
| 2607 | .value = .{ .abs = nlist.n_value }, |
| 2608 | }) else macho.addGlobalSymbol(.{ |
| 2609 | .name = sym_name, |
| 2610 | .linkage = switch (nlist.n_desc.weak_def_or_ref_to_weak) { |
| 2611 | false => .strong, |
| 2612 | true => .weak, |
| 2613 | }, |
| 2614 | .visibility = switch (nlist.n_type.bits.pext) { |
| 2615 | false => .default, |
| 2616 | true => .hidden, |
| 2617 | }, |
| 2618 | .value = null, |
| 2619 | }) catch |err| switch (err) { |
| 2620 | error.MultipleDefinitions => return diags.failParse( |
| 2621 | path, |
| 2622 | "multiple definitions of '{s}'", |
| 2623 | .{sym_name}, |
| 2624 | ), |
| 2625 | else => |e| return e, |
| 2626 | }, |
| 2627 | |
| 2628 | .pbud, .indr => |sym_type| return diags.failParse( |
| 2629 | path, |
| 2630 | "symbol '{s}' has unsupported symbol type '{t}", |
| 2631 | .{ sym_name, sym_type }, |
| 2632 | ), |
| 2633 | |
| 2634 | _ => |sym_type| return diags.failParse( |
| 2635 | path, |
| 2636 | "symbol '{s}' has unknown symbol type '0x{X}'", |
| 2637 | .{ sym_name, sym_type }, |
| 2638 | ), |
| 2639 | }; |
| 2640 | } |
| 2641 | |
| 2642 | // Now we need to process the symbols defined in sections. We're going to do this by looping |
| 2643 | // over *sections*, just because subsection splitting turns out to be much easier this way. |
| 2644 | for (input_sections.items, 0..) |*section, section_index| { |
| 2645 | if (section.usage != .bss) { |
| 2646 | try fr.seekTo(fl.offset + section.file_offset); |
| 2647 | } |
| 2648 | |
| 2649 | const parent_section = section.usage.parentSection(macho); |
| 2650 | |
| 2651 | section.atoms_start = atoms.items.len; |
| 2652 | var cur_atom_end: u64 = 0; |
| 2653 | while (true) { |
| 2654 | const sym_in_section: bool = sym_in_section: { |
| 2655 | if (sym_index == symtab.len) break :sym_in_section false; |
| 2656 | |
| 2657 | const nlist = &symtab[sym_index]; |
| 2658 | |
| 2659 | assert(nlist.n_sect - 1 >= section_index); // we sorted the symtab by section |
| 2660 | if (nlist.n_sect - 1 != section_index) break :sym_in_section false; |
| 2661 | |
| 2662 | if (nlist.n_type.bits.is_stab != 0) return diags.failParse( |
| 2663 | path, |
| 2664 | "invalid symtab entry at index {d}: object file cannot contain stabs", |
| 2665 | .{sym_index}, |
| 2666 | ); |
| 2667 | if (nlist.n_strx > strtab.len) return diags.failParse( |
| 2668 | path, |
| 2669 | "invalid symtab entry at index {d}: 'n_strx' value '{d}' out of range", |
| 2670 | .{ sym_index, nlist.n_strx }, |
| 2671 | ); |
| 2672 | |
| 2673 | if (nlist.n_value < section.addr or |
| 2674 | // This comparison intentionally uses '>=' to disallow defining a symbol at |
| 2675 | // the exclusive end of a section. This is because of an annoying quirk of |
| 2676 | // Mach-O: when using `MH_SUBSECTIONS_VIA_SYMBOLS`, it is impossible to |
| 2677 | // define a symbol at the exclusive end of any subsection, because such a |
| 2678 | // symbol would be considered a part of the *next* subsection. |
| 2679 | nlist.n_value >= section.addr + section.size) |
| 2680 | { |
| 2681 | const sym_name = std.mem.sliceTo(strtab[nlist.n_strx..], 0); |
| 2682 | const segname = std.mem.sliceTo(§ion.segname, 0); |
| 2683 | const sectname = std.mem.sliceTo(§ion.sectname, 0); |
| 2684 | return diags.failParse( |
| 2685 | path, |
| 2686 | "symbol '{s}' address '0x{X}' exceeds range of containing section '{s},{s}'", |
| 2687 | .{ sym_name, nlist.n_value, segname, sectname }, |
| 2688 | ); |
| 2689 | } |
| 2690 | |
| 2691 | break :sym_in_section true; |
| 2692 | }; |
| 2693 | |
| 2694 | const target_atom_offset: u64 = target_atom_offset: { |
| 2695 | if (sym_in_section) { |
| 2696 | break :target_atom_offset symtab[sym_index].n_value - section.addr; |
| 2697 | } |
| 2698 | if (cur_atom_end != section.size) { |
| 2699 | // There were no more symbols in this section, but we still need to create |
| 2700 | // the atoms for the rest of the section! So just process everything up to |
| 2701 | // and including the last byte of the section. |
| 2702 | break :target_atom_offset section.size - 1; |
| 2703 | } |
| 2704 | // There are no symbols or atoms left to process, so we're done. |
| 2705 | break; |
| 2706 | }; |
| 2707 | assert(target_atom_offset < section.size); |
| 2708 | |
| 2709 | while (cur_atom_end <= target_atom_offset) { |
| 2710 | // We need to start a new atom at `cur_atom_end`. |
| 2711 | const atom_offset: u64 = cur_atom_end; |
| 2712 | const atom_size: u64 = usage: switch (section.usage) { |
| 2713 | // TODO: we should also deduplicate these |
| 2714 | .data_const_split_4 => 4, |
| 2715 | .data_const_split_8 => 8, |
| 2716 | .data_const_split_16 => 16, |
| 2717 | |
| 2718 | // TODO: split C string sections (although `MH_SUBSECTIONS_VIA_SYMBOLS` is |
| 2719 | // usually sufficient anyway); and deduplicate those too |
| 2720 | .data_const_split_c_strings => continue :usage .data_const, |
| 2721 | |
| 2722 | .text, |
| 2723 | .data_const, |
| 2724 | .data_const_fixups, |
| 2725 | .data_mut, |
| 2726 | .bss, |
| 2727 | => atom_size: { |
| 2728 | if (header.flags & std.macho.MH_SUBSECTIONS_VIA_SYMBOLS == 0) { |
| 2729 | // We aren't splitting the section into multiple atoms, so this must |
| 2730 | // mean that we haven't created *any* atom for this section yet. |
| 2731 | assert(atom_offset == 0); |
| 2732 | break :atom_size section.size; |
| 2733 | } |
| 2734 | |
| 2735 | // Find the next symbol which splits this section. Usually this is just |
| 2736 | // the next symbol, but there could be some alt entry or alias symbols. |
| 2737 | var other_sym_index = sym_index + 1; |
| 2738 | const new_atom_end: u64 = while (other_sym_index < symtab.len and |
| 2739 | symtab[other_sym_index].n_sect - 1 == section_index) : (other_sym_index += 1) |
| 2740 | { |
| 2741 | if (symtab[other_sym_index].n_value == section.addr + atom_offset) continue; |
| 2742 | if (symtab[other_sym_index].n_desc.alt_entry) continue; |
| 2743 | // This symbol splits up the subsections. We haven't validated the |
| 2744 | // value of the symbol, so it might exceed the section bounds. We |
| 2745 | // will check for that error case later when the outer loop reaches |
| 2746 | // that symbol, so we don't need to check now, but we should limit |
| 2747 | // the size of the atom so that we don't allocate a potentially huge |
| 2748 | // node just before failing. |
| 2749 | break @min( |
| 2750 | symtab[other_sym_index].n_value - section.addr, |
| 2751 | section.size, |
| 2752 | ); |
| 2753 | } else new_atom_end: { |
| 2754 | // There is no other symbol which splits this section, so the new |
| 2755 | // atom must cover the entire remainder of the section. |
| 2756 | break :new_atom_end section.size; |
| 2757 | }; |
| 2758 | |
| 2759 | break :atom_size new_atom_end - atom_offset; |
| 2760 | }, |
| 2761 | }; |
| 2762 | assert(atom_size > 0); |
| 2763 | assert(atom_offset + atom_size <= section.size); |
| 2764 | |
| 2765 | const atom_align = section.@"align".offset(atom_offset); |
| 2766 | |
| 2767 | try macho.nodes.ensureUnusedCapacity(gpa, 1); |
| 2768 | try macho.input_atoms.ensureUnusedCapacity(gpa, 1); |
| 2769 | const atom_node = try parent_section.node(macho).addFloatingChild(gpa, &macho.mf, .{ |
| 2770 | .size = atom_align.forward(atom_size), |
| 2771 | .alignment = atom_align, |
| 2772 | .moved = true, // `flushMoved` will set up vaddrs and apply relocs |
| 2773 | }); |
| 2774 | const iai: InputAtom.Index = @fromBackingInt(@intCast(macho.input_atoms.items.len)); |
| 2775 | macho.input_atoms.appendAssumeCapacity(.{ |
| 2776 | .node = atom_node, |
| 2777 | .first_symbol = .none, |
| 2778 | .first_reloc = @fromBackingInt(0), // populated for real later |
| 2779 | .vaddr = 0, |
| 2780 | .any_fixups = false, |
| 2781 | }); |
| 2782 | macho.nodes.appendAssumeCapacity(.{ .input_atom = iai }); |
| 2783 | |
| 2784 | if (section.usage != .bss) { |
| 2785 | const slice = atom_node.slice(&macho.mf); |
| 2786 | try fr.interface.readSliceAll(slice[0..@intCast(atom_size)]); |
| 2787 | } |
| 2788 | |
| 2789 | try atoms.append(gpa, .{ |
| 2790 | .offset_in_section = atom_offset, |
| 2791 | .index = iai, |
| 2792 | }); |
| 2793 | cur_atom_end = atom_offset + atom_size; |
| 2794 | } |
| 2795 | |
| 2796 | if (sym_in_section) { |
| 2797 | // We just advanced to the atom containing this symbol, so now we can add it. |
| 2798 | const atom = atoms.lastPtr().?; |
| 2799 | const nlist = &symtab[sym_index]; |
| 2800 | const sym_name = std.mem.sliceTo(strtab[nlist.n_strx..], 0); |
| 2801 | const symbol_offset_in_section = symtab[sym_index].n_value - section.addr; |
| 2802 | symbols[orig_sym_indices[sym_index]] = if (!nlist.n_type.bits.ext) try macho.addInternalSymbol(.{ |
| 2803 | .name = sym_name, |
| 2804 | .value = .{ .addr_in_node = .{ |
| 2805 | .node = atom.index.node(macho), |
| 2806 | .offset = symbol_offset_in_section - atom.offset_in_section, |
| 2807 | } }, |
| 2808 | }) else macho.addGlobalSymbol(.{ |
| 2809 | .name = sym_name, |
| 2810 | .linkage = switch (nlist.n_desc.weak_def_or_ref_to_weak) { |
| 2811 | false => .strong, |
| 2812 | true => .weak, |
| 2813 | }, |
| 2814 | .visibility = switch (nlist.n_type.bits.pext) { |
| 2815 | false => .default, |
| 2816 | true => .hidden, |
| 2817 | }, |
| 2818 | .value = .{ .addr_in_node = .{ |
| 2819 | .node = atom.index.node(macho), |
| 2820 | .offset = symbol_offset_in_section - atom.offset_in_section, |
| 2821 | } }, |
| 2822 | }) catch |err| switch (err) { |
| 2823 | error.MultipleDefinitions => return diags.failParse( |
| 2824 | path, |
| 2825 | "multiple definitions of '{s}'", |
| 2826 | .{sym_name}, |
| 2827 | ), |
| 2828 | else => |e| return e, |
| 2829 | }; |
| 2830 | |
| 2831 | sym_index += 1; |
| 2832 | } |
| 2833 | } |
| 2834 | section.atoms_end = atoms.items.len; |
| 2835 | } |
| 2836 | |
| 2837 | // If, after handling all of the input sections, there is still a symbol remaining, then |
| 2838 | // that symbol must have an out-of-range `n_sect` value. |
| 2839 | if (sym_index != symtab.len) { |
| 2840 | const nlist = &symtab[sym_index]; |
| 2841 | if (nlist.n_type.bits.is_stab != 0) return diags.failParse( |
| 2842 | path, |
| 2843 | "invalid symtab entry at index {d}: object file cannot contain stabs", |
| 2844 | .{sym_index}, |
| 2845 | ); |
| 2846 | if (nlist.n_strx > strtab.len) return diags.failParse( |
| 2847 | path, |
| 2848 | "invalid symtab entry at index {d}: 'n_strx' value '{d}' out of range", |
| 2849 | .{ sym_index, nlist.n_strx }, |
| 2850 | ); |
| 2851 | const sym_name = std.mem.sliceTo(strtab[nlist.n_strx..], 0); |
| 2852 | assert(nlist.n_type.bits.type == .sect); |
| 2853 | assert(nlist.n_sect - 1 > input_sections.items.len); |
| 2854 | return diags.failParse( |
| 2855 | path, |
| 2856 | "symbol '{s}' of type 'N_SECT' has invalid section index '{d}'", |
| 2857 | .{ sym_name, nlist.n_sect }, |
| 2858 | ); |
| 2859 | } |
| 2860 | } |
| 2861 | |
| 2862 | // Now that the symbols are done, we can process relocations. |
| 2863 | |
| 2864 | var relocs_buf: std.ArrayList(std.macho.relocation_info) = .empty; |
| 2865 | defer relocs_buf.deinit(gpa); |
| 2866 | |
| 2867 | for (input_sections.items) |*section| { |
| 2868 | if (section.reloff + section.nreloc > fl.size) { |
| 2869 | return diags.failParse(path, "relocations for '{s},{s}' exceed file size", .{ |
| 2870 | std.mem.sliceTo(§ion.segname, 0), |
| 2871 | std.mem.sliceTo(§ion.sectname, 0), |
| 2872 | }); |
| 2873 | } |
| 2874 | |
| 2875 | try relocs_buf.resize(gpa, section.nreloc); |
| 2876 | try fr.seekTo(fl.offset + section.reloff); |
| 2877 | try fr.interface.readSliceEndian(std.macho.relocation_info, relocs_buf.items, target_endian); |
| 2878 | |
| 2879 | // We need to sort the section's relocations by address for two reasons: |
| 2880 | // |
| 2881 | // * We need the relocations in each atom to be contiguous. This allows us to use sub-arrays |
| 2882 | // of `macho.relocs` for the relocations in an atom, rather than e.g. linked lists. |
| 2883 | // |
| 2884 | // * We need the relocations *within* each atom to be sorted, so that we can efficiently |
| 2885 | // generate runtime fixup chains if necessary. |
| 2886 | // |
| 2887 | // This sort must be stable so that `*_RELOC_ADDEND` and `*_RELOC_SUBTRACTOR` relocations |
| 2888 | // remain correctly paired. |
| 2889 | const SortRelocsContext = struct { |
| 2890 | fn lessThan(_: @This(), lhs: std.macho.relocation_info, rhs: std.macho.relocation_info) bool { |
| 2891 | return lhs.r_address < rhs.r_address; |
| 2892 | } |
| 2893 | }; |
| 2894 | std.mem.sort( |
| 2895 | std.macho.relocation_info, |
| 2896 | relocs_buf.items, |
| 2897 | @as(SortRelocsContext, .{}), |
| 2898 | SortRelocsContext.lessThan, |
| 2899 | ); |
| 2900 | |
| 2901 | try macho.relocs.ensureUnusedCapacity(gpa, relocs_buf.items.len); |
| 2902 | |
| 2903 | assert(atoms.items[section.atoms_start].offset_in_section == 0); |
| 2904 | |
| 2905 | var atom_index = section.atoms_start; |
| 2906 | atoms.items[atom_index].index.ptr(macho).first_reloc = @fromBackingInt(@intCast( |
| 2907 | macho.relocs.items.len, |
| 2908 | )); |
| 2909 | |
| 2910 | var paired_addend: ?u64 = null; |
| 2911 | for (relocs_buf.items) |reloc| { |
| 2912 | if (reloc.r_address < 0) { |
| 2913 | return diags.failParse(path, "scattered relocations are not supported", .{}); |
| 2914 | } |
| 2915 | const offset_in_section: u32 = @intCast(reloc.r_address); |
| 2916 | |
| 2917 | // Find the atom containing `reloc`. (This is why we sorted the relocations!) |
| 2918 | while (atom_index + 1 < section.atoms_end and |
| 2919 | offset_in_section >= atoms.items[atom_index + 1].offset_in_section) |
| 2920 | { |
| 2921 | atom_index += 1; |
| 2922 | atoms.items[atom_index].index.ptr(macho).first_reloc = @fromBackingInt(@intCast( |
| 2923 | macho.relocs.items.len, |
| 2924 | )); |
| 2925 | } |
| 2926 | |
| 2927 | { |
| 2928 | const atom_end: u64 = atom_end: { |
| 2929 | if (atom_index == section.atoms_end - 1) { |
| 2930 | break :atom_end section.size; |
| 2931 | } |
| 2932 | const next_atom = &atoms.items[atom_index + 1]; |
| 2933 | break :atom_end next_atom.offset_in_section; |
| 2934 | }; |
| 2935 | if (offset_in_section + (@as(u8, 1) << reloc.r_length) > atom_end) { |
| 2936 | const segname = std.mem.sliceTo(§ion.segname, 0); |
| 2937 | const sectname = std.mem.sliceTo(§ion.sectname, 0); |
| 2938 | return diags.failParse( |
| 2939 | path, |
| 2940 | "relocation at offset '{d}' in '{s},{s}' spans multiple atoms", |
| 2941 | .{ offset_in_section, segname, sectname }, |
| 2942 | ); |
| 2943 | } |
| 2944 | } |
| 2945 | |
| 2946 | const offset_in_atom: u32 = @intCast(offset_in_section - atoms.items[atom_index].offset_in_section); |
| 2947 | |
| 2948 | const length_types: [4]?Reloc.Type, const target: Reloc.Target, const pcrel: bool, const implicit_negative_addend: u64 = switch (header.cputype) { |
| 2949 | else => unreachable, |
| 2950 | |
| 2951 | std.macho.CPU_TYPE_X86_64 => reloc_type: switch (std.enums.fromInt( |
| 2952 | std.macho.reloc_type_x86_64, |
| 2953 | reloc.r_type, |
| 2954 | ) orelse { |
| 2955 | return diags.failParse(path, "unknown relocation type '{d}'", .{reloc.r_type}); |
| 2956 | }) { |
| 2957 | .X86_64_RELOC_SUBTRACTOR => @panic("TODO(MachO2): SUBTRACTOR relocation"), |
| 2958 | |
| 2959 | .X86_64_RELOC_UNSIGNED => .{ .{ .abs8, .abs16, .abs32, .abs64 }, .symbol, false, 0 }, |
| 2960 | .X86_64_RELOC_SIGNED => .{ .{ null, null, .rel32, null }, .symbol, true, 4 }, |
| 2961 | .X86_64_RELOC_SIGNED_1 => .{ .{ null, null, .rel32, null }, .symbol, true, if (reloc.r_extern == 0) 5 else 4 }, |
| 2962 | .X86_64_RELOC_SIGNED_2 => .{ .{ null, null, .rel32, null }, .symbol, true, if (reloc.r_extern == 0) 6 else 4 }, |
| 2963 | .X86_64_RELOC_SIGNED_4 => .{ .{ null, null, .rel32, null }, .symbol, true, if (reloc.r_extern == 0) 8 else 4 }, |
| 2964 | |
| 2965 | .X86_64_RELOC_BRANCH => .{ .{ null, null, .rel32, null }, .branch, true, 4 }, |
| 2966 | |
| 2967 | .X86_64_RELOC_TLV => .{ .{ null, null, .rel32, null }, .tlv, true, 4 }, |
| 2968 | |
| 2969 | .X86_64_RELOC_GOT_LOAD => continue :reloc_type .X86_64_RELOC_GOT, // relaxable |
| 2970 | .X86_64_RELOC_GOT => .{ .{ null, null, .rel32, null }, .got, true, 4 }, |
| 2971 | }, |
| 2972 | |
| 2973 | std.macho.CPU_TYPE_ARM64 => switch (std.enums.fromInt( |
| 2974 | std.macho.reloc_type_arm64, |
| 2975 | reloc.r_type, |
| 2976 | ) orelse { |
| 2977 | return diags.failParse(path, "unknown relocation type '{d}'", .{reloc.r_type}); |
| 2978 | }) { |
| 2979 | .ARM64_RELOC_SUBTRACTOR => @panic("TODO(MachO2): SUBTRACTOR relocation"), |
| 2980 | |
| 2981 | .ARM64_RELOC_ADDEND => { |
| 2982 | const addend: i24 = @bitCast(reloc.r_symbolnum); |
| 2983 | const extended: i64 = addend; |
| 2984 | paired_addend = @bitCast(extended); |
| 2985 | continue; |
| 2986 | }, |
| 2987 | |
| 2988 | .ARM64_RELOC_UNSIGNED => .{ .{ .abs8, .abs16, .abs32, .abs64 }, .symbol, false, 0 }, |
| 2989 | .ARM64_RELOC_BRANCH26 => .{ .{ null, null, .arm64_branchrel26, null }, .branch, true, 0 }, |
| 2990 | .ARM64_RELOC_PAGE21 => .{ .{ null, null, .arm64_pagerel21, null }, .symbol, true, 0 }, |
| 2991 | .ARM64_RELOC_PAGEOFF12 => .{ .{ null, null, .arm64_pageoff12, null }, .symbol, false, 0 }, |
| 2992 | |
| 2993 | .ARM64_RELOC_TLVP_LOAD_PAGE21 => .{ .{ null, null, .arm64_pagerel21, null }, .tlv, true, 0 }, |
| 2994 | .ARM64_RELOC_TLVP_LOAD_PAGEOFF12 => .{ .{ null, null, .arm64_pageoff12, null }, .tlv, false, 0 }, |
| 2995 | |
| 2996 | .ARM64_RELOC_GOT_LOAD_PAGE21 => .{ .{ null, null, .arm64_pagerel21, null }, .got, true, 0 }, |
| 2997 | .ARM64_RELOC_GOT_LOAD_PAGEOFF12 => .{ .{ null, null, .arm64_pageoff12, null }, .got, false, 0 }, |
| 2998 | |
| 2999 | // Apple's ld_classic supported an 8-byte non-pcrel version of this relocation, |
| 3000 | // but it had very weird semantics which didn't actually involve the GOT at all. |
| 3001 | // My guess is that they intended it to do the obvious thing but shipped with a |
| 3002 | // bug. In any case, it is not supported in Apple's new linker, and LLD does not |
| 3003 | // support it either, so therefore we should follow suit and only support the |
| 3004 | // usual form of this relocation (4-byte pcrel). |
| 3005 | .ARM64_RELOC_POINTER_TO_GOT => .{ .{ null, null, .rel32, null }, .got, true, 0 }, |
| 3006 | }, |
| 3007 | }; |
| 3008 | const reloc_type_str: []const u8 = switch (header.cputype) { |
| 3009 | else => unreachable, |
| 3010 | std.macho.CPU_TYPE_ARM64 => @tagName(@as( |
| 3011 | std.macho.reloc_type_arm64, |
| 3012 | @fromBackingInt(reloc.r_type), |
| 3013 | )), |
| 3014 | std.macho.CPU_TYPE_X86_64 => @tagName(@as( |
| 3015 | std.macho.reloc_type_x86_64, |
| 3016 | @fromBackingInt(reloc.r_type), |
| 3017 | )), |
| 3018 | }; |
| 3019 | if (@intFromBool(pcrel) != reloc.r_pcrel) { |
| 3020 | return diags.failParse(path, "relocation '{s}' {s} be pc-relative", .{ |
| 3021 | reloc_type_str, |
| 3022 | if (pcrel) "must" else "cannot", |
| 3023 | }); |
| 3024 | } |
| 3025 | const internal_type: Reloc.Type = length_types[reloc.r_length] orelse { |
| 3026 | return diags.failParse(path, "relocation '{s}' does not support length '{d}'", .{ |
| 3027 | reloc_type_str, |
| 3028 | @as(u8, 1) << reloc.r_length, |
| 3029 | }); |
| 3030 | }; |
| 3031 | |
| 3032 | const dest_slice = atoms.items[atom_index].index.node(macho).sliceConst(&macho.mf)[offset_in_atom..]; |
| 3033 | if (!internal_type.validateInst(dest_slice)) { |
| 3034 | return diags.failParse(path, "relocation '{s}' against invalid instruction", .{ |
| 3035 | reloc_type_str, |
| 3036 | }); |
| 3037 | } |
| 3038 | const stored_addend: u64 = switch (internal_type) { |
| 3039 | .abs8 => std.mem.readInt(u8, dest_slice[0..1], target_endian), |
| 3040 | .abs16 => std.mem.readInt(u16, dest_slice[0..2], target_endian), |
| 3041 | .abs32 => std.mem.readInt(u32, dest_slice[0..4], target_endian), |
| 3042 | .abs64 => std.mem.readInt(u64, dest_slice[0..8], target_endian), |
| 3043 | .rel32 => a: { |
| 3044 | const extended: i64 = std.mem.readInt(i32, dest_slice[0..4], target_endian); |
| 3045 | break :a @bitCast(extended); |
| 3046 | }, |
| 3047 | |
| 3048 | .arm64_branchrel26, |
| 3049 | .arm64_pagerel21, |
| 3050 | .arm64_pageoff12, |
| 3051 | => a: { |
| 3052 | defer paired_addend = null; |
| 3053 | break :a paired_addend orelse 0; |
| 3054 | }, |
| 3055 | }; |
| 3056 | if (paired_addend != null) { |
| 3057 | return diags.failParse(path, "relocation '{s}' does not support paired addend", .{reloc_type_str}); |
| 3058 | } |
| 3059 | const target_symbol: Symbol.Index, const final_addend: u64 = switch (reloc.r_extern) { |
| 3060 | 1 => target: { |
| 3061 | // The relocation targets a symbol. This is the nice and reasonable case. |
| 3062 | if (reloc.r_symbolnum >= symbols.len) { |
| 3063 | return diags.failParse(path, "relocation target symbol '{d}' is invalid", .{reloc.r_symbolnum}); |
| 3064 | } |
| 3065 | const target_sym = symbols[reloc.r_symbolnum]; |
| 3066 | break :target .{ target_sym, stored_addend -% implicit_negative_addend }; |
| 3067 | }, |
| 3068 | 0 => target: { |
| 3069 | // In this case, the relocation targets an offset into a *section*. I think the |
| 3070 | // best way to interpret this is to say that the "stored addend" value contains |
| 3071 | // what the relocated value *would* be if the linked image's section addresses |
| 3072 | // matched those of the relocatable itself (unlike ELF, Mach-O uses a flat |
| 3073 | // virtual address space even in relocatables). So, the best way to handle this |
| 3074 | // in the pcrel case is to reverse the computation to figure out what the actual |
| 3075 | // target address is. |
| 3076 | // |
| 3077 | // Unfortunately, this is further complicated by the existence of subsections. |
| 3078 | // Subsections split up the target section's virtual address space, and the |
| 3079 | // subsection being targeted by a relocation is determined implicitly based on |
| 3080 | // the target address. Therefore, to ensure we target the correct subsection, it |
| 3081 | // is necessary to compute the *exact* target address (no off-by-N). This Mach-O |
| 3082 | // quirk is why we have `implicit_negative_addend` on x86_64: it indicates that |
| 3083 | // the encoded pc-relative value is relative not to the exact address of the |
| 3084 | // relocation, but rather to an address a few bytes later, allowing us to |
| 3085 | // compute the exact target address instead of being 4--8 bytes short. |
| 3086 | // |
| 3087 | // Mach-O is a tremendously well-designed object format with no flaws whatsoever. |
| 3088 | if (reloc.r_symbolnum > input_sections.items.len) { |
| 3089 | return diags.failParse(path, "relocation target section '{d}' is invalid", .{reloc.r_symbolnum}); |
| 3090 | } |
| 3091 | const target_addr_in_object: u64 = switch (pcrel) { |
| 3092 | false => stored_addend +% implicit_negative_addend, |
| 3093 | true => target_addr: { |
| 3094 | const pcrel_base: u64 = section.addr + @as(u32, @intCast(reloc.r_address)); |
| 3095 | break :target_addr pcrel_base +% stored_addend +% implicit_negative_addend; |
| 3096 | }, |
| 3097 | }; |
| 3098 | const target_section = &input_sections.items[reloc.r_symbolnum - 1]; |
| 3099 | const target_offset_in_section = target_addr_in_object -% target_section.addr; |
| 3100 | if (target_offset_in_section >= target_section.size) { |
| 3101 | const segname = std.mem.sliceTo(&target_section.segname, 0); |
| 3102 | const sectname = std.mem.sliceTo(&target_section.sectname, 0); |
| 3103 | return diags.failParse( |
| 3104 | path, |
| 3105 | "relocation target offset '{d}' exceeds range of target section '{s},{s}'", |
| 3106 | .{ target_offset_in_section, segname, sectname }, |
| 3107 | ); |
| 3108 | } |
| 3109 | // We need to know which atom we're targeting. |
| 3110 | const FindAtomContext = struct { |
| 3111 | offset_in_section: u64, |
| 3112 | fn order(lhs: @This(), rhs: Atom) std.math.Order { |
| 3113 | return std.math.order(lhs.offset_in_section, rhs.offset_in_section); |
| 3114 | } |
| 3115 | }; |
| 3116 | assert(target_section.atoms_start < target_section.atoms_end); |
| 3117 | assert(atoms.items[target_section.atoms_start].offset_in_section == 0); |
| 3118 | const target_atom_index = target_section.atoms_start + std.sort.upperBound( |
| 3119 | Atom, |
| 3120 | atoms.items[target_section.atoms_start..target_section.atoms_end], |
| 3121 | @as(FindAtomContext, .{ .offset_in_section = target_offset_in_section }), |
| 3122 | FindAtomContext.order, |
| 3123 | ) - 1; // safe because atom 0 is at offset 0 so never >rhs |
| 3124 | assert(target_offset_in_section >= atoms.items[target_atom_index].offset_in_section); |
| 3125 | if (target_atom_index != target_section.atoms_end - 1) { |
| 3126 | assert(target_offset_in_section < atoms.items[target_atom_index + 1].offset_in_section); |
| 3127 | } |
| 3128 | // To preserve my own sanity, I'm just creating symbols to represent these |
| 3129 | // relocation targets. It's fine, I'm sure nobody will notice. |
| 3130 | var sym_name_buf: [64]u8 = undefined; // sectname is capped at 16 bytes |
| 3131 | const sym_name = std.mem.print( |
| 3132 | &sym_name_buf, |
| 3133 | "l_{s}_{s}_{x}", |
| 3134 | .{ |
| 3135 | std.mem.trim(u8, std.mem.sliceTo(&target_section.segname, 0), "_"), |
| 3136 | std.mem.trim(u8, std.mem.sliceTo(&target_section.sectname, 0), "_"), |
| 3137 | target_offset_in_section, |
| 3138 | }, |
| 3139 | ) catch unreachable; |
| 3140 | const target_sym = try macho.addInternalSymbol(.{ |
| 3141 | .name = sym_name, |
| 3142 | .value = .{ .addr_in_node = .{ |
| 3143 | .node = atoms.items[target_atom_index].index.node(macho), |
| 3144 | .offset = target_offset_in_section - atoms.items[target_atom_index].offset_in_section, |
| 3145 | } }, |
| 3146 | }); |
| 3147 | // Lovely, we have an actual symbol at the correct address which we can target. |
| 3148 | // Just remember to add the implicit addend back in so that the relocated |
| 3149 | // PC-relative address is relative to the correct base address! |
| 3150 | break :target .{ target_sym, -%implicit_negative_addend }; |
| 3151 | }, |
| 3152 | }; |
| 3153 | const target_is_undef = macho.targetLoad(&target_symbol.nlist(macho).n_type).bits.type == .undf; |
| 3154 | if (target_is_undef) { |
| 3155 | const imports_gop = try macho.imports.getOrPut(gpa, target_symbol); |
| 3156 | if (!imports_gop.found_existing) { |
| 3157 | assert(imports_gop.index == macho.imports.count() - 1); |
| 3158 | try macho.appendImportEntry(macho.imports.count() - 1, target_symbol); |
| 3159 | } |
| 3160 | } |
| 3161 | if (target == .got or (target_is_undef and target == .branch)) { |
| 3162 | const got_gop = try macho.got.getOrPut(gpa, target_symbol); |
| 3163 | if (!got_gop.found_existing) { |
| 3164 | assert(got_gop.index == macho.got.count() - 1); |
| 3165 | try macho.appendGotEntry(macho.got.count() - 1, target_symbol); |
| 3166 | } |
| 3167 | } |
| 3168 | if (target_is_undef and target == .branch) { |
| 3169 | const stubs_gop = try macho.stubs.getOrPut(gpa, target_symbol); |
| 3170 | if (!stubs_gop.found_existing) { |
| 3171 | assert(stubs_gop.index == macho.stubs.count() - 1); |
| 3172 | const got_index = macho.got.getIndex(target_symbol).?; // added above |
| 3173 | try macho.appendStubEntry(macho.stubs.count() - 1, got_index, target_symbol); |
| 3174 | } |
| 3175 | } |
| 3176 | const ri: Reloc.Index = @fromBackingInt(@intCast(macho.relocs.items.len)); |
| 3177 | macho.relocs.appendAssumeCapacity(.{ |
| 3178 | .node = atoms.items[atom_index].index.node(macho), |
| 3179 | .offset = offset_in_atom, |
| 3180 | .target_symbol = target_symbol, |
| 3181 | .addend = final_addend, |
| 3182 | .bits = .{ .target = target, .type = internal_type, .result = .ok }, |
| 3183 | .next_with_same_target_sym = target_symbol.ptr(macho).first_target_reloc, |
| 3184 | }); |
| 3185 | target_symbol.ptr(macho).first_target_reloc = .wrap(ri); |
| 3186 | |
| 3187 | if (target == .symbol and internal_type == .abs64) { |
| 3188 | // In this case the relocation needs a runtime fixup. This is the case even if the |
| 3189 | // target symbol is internal, because we still need to rebase the address. |
| 3190 | ri.ptr(macho).bits.result = .fixup; |
| 3191 | atoms.items[atom_index].index.ptr(macho).any_fixups = true; |
| 3192 | } |
| 3193 | } |
| 3194 | } |
| 3195 | } |
| 3196 | fn fmtMemberString(member: ?[]const u8) std.fmt.Alt(?[]const u8, memberStringEscape) { |
| 3197 | return .{ .data = member }; |
| 3198 | } |
| 3199 | fn memberStringEscape(member: ?[]const u8, w: *Io.Writer) Io.Writer.Error!void { |
| 3200 | try w.print("({f})", .{std.zig.fmtString(member orelse return)}); |
| 3201 | } |
| 3202 | |
| 1061 | 3203 | pub fn setDarwinSdkVersion(macho: *MachO, sdk_version: link.DarwinSdkVersion) link.Error!void { |
| 1062 | 3204 | const comp = macho.base.comp; |
| 1063 | 3205 | const diags = &comp.link_diags; |
| ... | ... | @@ -1098,21 +3240,54 @@ pub fn flush( |
| 1098 | 3240 | tid: Zcu.PerThread.Id, |
| 1099 | 3241 | prog_node: std.Progress.Node, |
| 1100 | 3242 | ) link.Error!void { |
| 1101 | | const diags = &macho.base.comp.link_diags; |
| 3243 | const comp = macho.base.comp; |
| 3244 | const diags = &comp.link_diags; |
| 1102 | 3245 | _ = arena; |
| 1103 | 3246 | _ = tid; |
| 1104 | 3247 | _ = prog_node; |
| 1105 | 3248 | |
| 1106 | | try macho.updateSegmentLoadAddresses(); |
| 3249 | macho.updateSegmentLoadAddresses() catch |err| switch (err) { |
| 3250 | error.MappedFileIo => return diags.fail("failed to write output file: {t}", .{macho.mf.io_err.?}), |
| 3251 | else => |e| return e, |
| 3252 | }; |
| 3253 | |
| 1107 | 3254 | while (try macho.idle()) {} |
| 1108 | 3255 | |
| 3256 | if (macho.overflowed_reloc_count > 0) { |
| 3257 | diags.addError("failed to apply {d} relocations: overflow", .{macho.overflowed_reloc_count}); |
| 3258 | } |
| 3259 | if (macho.misaligned_reloc_count > 0) { |
| 3260 | diags.addError("failed to apply {d} relocations: misaligned value", .{macho.misaligned_reloc_count}); |
| 3261 | } |
| 3262 | |
| 1109 | 3263 | if (macho.lc.entry_point) |entry_point_lc| { |
| 1110 | | // TODO: actually find the entry point. |
| 1111 | | // For now, we just set the entry point to the start of the "__TEXT,__text" section. |
| 1112 | | const entry_node = macho.sectionByName("__TEXT", "__text").?.node(macho); |
| 1113 | | const entry_file_off: u64, _ = entry_node.location(&macho.mf).resolve(&macho.mf); |
| 3264 | const sym_name: []const u8 = name: switch (macho.options.entry) { |
| 3265 | .default => switch (comp.config.output_mode) { |
| 3266 | .Exe => continue :name .enabled, |
| 3267 | .Lib, .Obj => continue :name .disabled, |
| 3268 | }, |
| 3269 | .disabled => unreachable, // `macho.lc.entry_point` is only set if entry is enabled |
| 3270 | .enabled => "_main", |
| 3271 | .named => |named| named, |
| 3272 | }; |
| 3273 | const symbol = macho.globalByName(sym_name).unwrap() orelse { |
| 3274 | return diags.fail("no definition of entry point symbol {q}", .{sym_name}); |
| 3275 | }; |
| 3276 | if (macho.targetLoad(&symbol.nlist(macho).n_type).bits.type == .undf) { |
| 3277 | return diags.fail("no definition of entry point symbol {q}", .{sym_name}); |
| 3278 | } |
| 3279 | |
| 3280 | // Documentation says that this field should be the offset of the entry point in the file, |
| 3281 | // but that's a blatant lie; if you read the dyld source code, it's actually the vaddr minus |
| 3282 | // the text base vaddr. Because, like, obviously---what the fuck would they do with the |
| 3283 | // offset in the Mach-O file? |
| 1114 | 3284 | const entry_point_ptr = entry_point_lc.ptr(macho, std.macho.entry_point_command); |
| 1115 | | macho.targetStore(&entry_point_ptr.entryoff, @intCast(entry_file_off)); |
| 3285 | macho.targetStore(&entry_point_ptr.entryoff, std.math.cast( |
| 3286 | u32, |
| 3287 | symbol.value(macho) - Segment.text.vaddr(macho), |
| 3288 | ) orelse { |
| 3289 | return diags.fail("entry point address too big", .{}); |
| 3290 | }); |
| 1116 | 3291 | } |
| 1117 | 3292 | |
| 1118 | 3293 | macho.mf.flush() catch |err| switch (err) { |
| ... | ... | @@ -1136,9 +3311,32 @@ pub fn idle(macho: *MachO) link.Error!bool { |
| 1136 | 3311 | task: { |
| 1137 | 3312 | if (macho.sections_changed_index.pop()) |kv| { |
| 1138 | 3313 | const section = kv.key; |
| 1139 | | var sym_it = section.firstSymbol(macho).*; |
| 1140 | | while (sym_it.unwrap()) |sym| : (sym_it = sym.ptr(macho).next_in_section) { |
| 1141 | | macho.targetStore(&sym.nlist(macho).n_sect, section.index(macho)); |
| 3314 | var child_it = section.node(macho).first(&macho.mf); |
| 3315 | while (child_it.unwrap()) |child| : (child_it = child.next(&macho.mf)) { |
| 3316 | switch (macho.getNode(child)) { |
| 3317 | .macho => unreachable, |
| 3318 | .macho_header => unreachable, |
| 3319 | .symtab => unreachable, |
| 3320 | .strtab => unreachable, |
| 3321 | .indirect_syms => unreachable, |
| 3322 | .section_indirect_syms => unreachable, |
| 3323 | .linkedit_data => unreachable, |
| 3324 | .fixup_chains_header => unreachable, |
| 3325 | .fixup_chains_imports => unreachable, |
| 3326 | .fixup_chains_symbol_names => unreachable, |
| 3327 | .fixup_chains_starts => unreachable, |
| 3328 | .fixup_chains_starts_in_image => unreachable, |
| 3329 | .fixup_chains_starts_in_segment => unreachable, |
| 3330 | .segment => unreachable, |
| 3331 | .section => unreachable, |
| 3332 | .section_manual_size => unreachable, |
| 3333 | .input_atom => |iai| { |
| 3334 | var sym_it = iai.ptrConst(macho).first_symbol; |
| 3335 | while (sym_it.unwrap()) |sym| : (sym_it = sym.ptr(macho).next_in_node) { |
| 3336 | macho.targetStore(&sym.nlist(macho).n_sect, section.index(macho)); |
| 3337 | } |
| 3338 | }, |
| 3339 | } |
| 1142 | 3340 | } |
| 1143 | 3341 | break :task; |
| 1144 | 3342 | } |
| ... | ... | @@ -1157,24 +3355,209 @@ pub fn idle(macho: *MachO) link.Error!bool { |
| 1157 | 3355 | |
| 1158 | 3356 | break :task; |
| 1159 | 3357 | } |
| 3358 | |
| 3359 | if (macho.dirty_fixup_chain_pages.pop()) |kv| { |
| 3360 | const sub_prog_node = macho.mf.update_prog_node.start("Fixup Chains", 0); |
| 3361 | defer sub_prog_node.end(); |
| 3362 | macho.flushFixupChains(kv.key.seg, kv.key.page); |
| 3363 | break :task; |
| 3364 | } |
| 1160 | 3365 | } |
| 1161 | 3366 | |
| 1162 | 3367 | return macho.sections_changed_index.count() > 0 or |
| 1163 | | macho.mf.updates.items.len > 0; |
| 3368 | macho.mf.updates.items.len > 0 or |
| 3369 | macho.dirty_fixup_chain_pages.count() > 0; |
| 1164 | 3370 | } |
| 1165 | 3371 | fn flushMoved(macho: *MachO, ni: MappedFile.Node.Index) link.Error!void { |
| 1166 | 3372 | macho.flushMachOFileOffset(ni); |
| 1167 | 3373 | switch (macho.getNode(ni)) { |
| 1168 | 3374 | .macho => unreachable, |
| 1169 | 3375 | .macho_header => {}, |
| 1170 | | .segment => return, // segments don't bubble moved |
| 1171 | | .section => |section| { |
| 1172 | | const segment_vaddr: u64 = macho.getNode(ni.parent(&macho.mf).unwrap().?).segment.vaddr(macho); |
| 3376 | .indirect_syms => {}, |
| 3377 | .section_indirect_syms => |section| { |
| 3378 | const offset, _ = ni.location(&macho.mf).resolve(&macho.mf); |
| 3379 | macho.targetStore(§ion.lcPtr(macho).reserved1, @intCast( |
| 3380 | @divExact(offset, 4), // valid due to alignment |
| 3381 | )); |
| 3382 | }, |
| 3383 | .segment => |segment| { |
| 3384 | if (segment.fixupChainStartsNode(macho).unwrap()) |starts_in_segment_node| { |
| 3385 | const starts_in_segment: *std.macho.dyld_chained_starts_in_segment = @ptrCast(@alignCast( |
| 3386 | starts_in_segment_node.slice(&macho.mf)[0..@sizeOf(std.macho.dyld_chained_starts_in_segment)], |
| 3387 | )); |
| 3388 | macho.targetStore( |
| 3389 | &starts_in_segment.segment_offset, |
| 3390 | segment.vaddr(macho) - Segment.text.vaddr(macho), |
| 3391 | ); |
| 3392 | } |
| 3393 | return; // segments don't bubble moved |
| 3394 | }, |
| 3395 | .section, .section_manual_size => |section| { |
| 3396 | const segment_vaddr: u64 = section.segment(macho).vaddr(macho); |
| 1173 | 3397 | const section_offset = ni.location(&macho.mf).resolve(&macho.mf)[0]; |
| 1174 | 3398 | macho.targetStore(§ion.lcPtr(macho).addr, segment_vaddr + section_offset); |
| 3399 | |
| 3400 | if (section == macho.known_sections.stubs) { |
| 3401 | for (macho.stubs.keys(), 0..) |symbol, stub_index| { |
| 3402 | const got_index = macho.got.getIndex(symbol).?; |
| 3403 | macho.writeStubEntry(stub_index, got_index); |
| 3404 | } |
| 3405 | for (macho.got.keys()) |symbol| { |
| 3406 | try symbol.applyTargetRelocs(macho, .init(.{ |
| 3407 | .symbol = false, |
| 3408 | .branch = true, |
| 3409 | .got = false, |
| 3410 | .tlv = false, |
| 3411 | })); |
| 3412 | } |
| 3413 | } |
| 3414 | |
| 3415 | if (section == macho.known_sections.got) { |
| 3416 | for (macho.stubs.keys(), 0..) |symbol, stub_index| { |
| 3417 | const got_index = macho.got.getIndex(symbol).?; |
| 3418 | macho.writeStubEntry(stub_index, got_index); |
| 3419 | } |
| 3420 | for (macho.got.keys()) |symbol| { |
| 3421 | try symbol.applyTargetRelocs(macho, .init(.{ |
| 3422 | .symbol = false, |
| 3423 | .branch = false, |
| 3424 | .got = true, |
| 3425 | .tlv = false, |
| 3426 | })); |
| 3427 | } |
| 3428 | } |
| 3429 | |
| 3430 | // If it is the GOT which has moved, its runtime fixup need to be flushed. |
| 3431 | if (section == macho.known_sections.got and macho.got.count() > 0) { |
| 3432 | const segment = section.segment(macho); |
| 3433 | |
| 3434 | const old_start = macho.prev_got_offset; |
| 3435 | const new_start: u32 = off: { |
| 3436 | const got_file_off = ni.fileLocation(&macho.mf, false).offset; |
| 3437 | const seg_file_off = segment.node(macho).fileLocation(&macho.mf, false).offset; |
| 3438 | break :off @intCast(got_file_off - seg_file_off); |
| 3439 | }; |
| 3440 | |
| 3441 | const page_align = macho.targetPageAlign(); |
| 3442 | const got_size = @as(u64, macho.got.count()) * macho.targetPtrSize(); |
| 3443 | |
| 3444 | const old_page_start: u32 = @intCast(@divFloor(old_start, page_align.toByteUnits())); |
| 3445 | const old_page_end: u32 = @intCast(@divCeil(old_start + got_size, page_align.toByteUnits())); |
| 3446 | try macho.dirty_fixup_chain_pages.ensureUnusedCapacity( |
| 3447 | macho.base.comp.gpa, |
| 3448 | old_page_end - old_page_start, |
| 3449 | ); |
| 3450 | for (old_page_start..old_page_end) |page_index| { |
| 3451 | macho.dirty_fixup_chain_pages.putAssumeCapacity(.{ |
| 3452 | .seg = segment, |
| 3453 | .page = @intCast(page_index), |
| 3454 | }, {}); |
| 3455 | } |
| 3456 | |
| 3457 | const new_page_start: u32 = @intCast(@divFloor(new_start, page_align.toByteUnits())); |
| 3458 | const new_page_end: u32 = @intCast(@divCeil(new_start + got_size, page_align.toByteUnits())); |
| 3459 | try macho.dirty_fixup_chain_pages.ensureUnusedCapacity( |
| 3460 | macho.base.comp.gpa, |
| 3461 | new_page_end - new_page_start, |
| 3462 | ); |
| 3463 | for (new_page_start..new_page_end) |page_index| { |
| 3464 | macho.dirty_fixup_chain_pages.putAssumeCapacity(.{ |
| 3465 | .seg = segment, |
| 3466 | .page = @intCast(page_index), |
| 3467 | }, {}); |
| 3468 | } |
| 3469 | |
| 3470 | macho.prev_got_offset = new_start; |
| 3471 | } |
| 1175 | 3472 | }, |
| 1176 | 3473 | .symtab => {}, |
| 1177 | 3474 | .strtab => {}, |
| 3475 | .linkedit_data => { |
| 3476 | // No need to bubble moved. |
| 3477 | return; |
| 3478 | }, |
| 3479 | .fixup_chains_header => {}, |
| 3480 | .fixup_chains_imports => { |
| 3481 | const offset: u64, _ = ni.location(&macho.mf).resolve(&macho.mf); |
| 3482 | const hdr: *std.macho.dyld_chained_fixups_header = @ptrCast(@alignCast( |
| 3483 | macho.node.fixup_chains_header.slice(&macho.mf), |
| 3484 | )); |
| 3485 | macho.targetStore(&hdr.imports_offset, @intCast(offset)); |
| 3486 | }, |
| 3487 | .fixup_chains_symbol_names => { |
| 3488 | const offset: u64, _ = ni.location(&macho.mf).resolve(&macho.mf); |
| 3489 | const hdr: *std.macho.dyld_chained_fixups_header = @ptrCast(@alignCast( |
| 3490 | macho.node.fixup_chains_header.slice(&macho.mf), |
| 3491 | )); |
| 3492 | macho.targetStore(&hdr.symbols_offset, @intCast(offset)); |
| 3493 | }, |
| 3494 | .fixup_chains_starts => { |
| 3495 | const offset: u64, _ = ni.location(&macho.mf).resolve(&macho.mf); |
| 3496 | const hdr: *std.macho.dyld_chained_fixups_header = @ptrCast(@alignCast( |
| 3497 | macho.node.fixup_chains_header.slice(&macho.mf), |
| 3498 | )); |
| 3499 | macho.targetStore(&hdr.starts_offset, @intCast(offset)); |
| 3500 | }, |
| 3501 | .fixup_chains_starts_in_image => {}, |
| 3502 | .fixup_chains_starts_in_segment => |segment| { |
| 3503 | const starts_in_image_off = macho.node.fixup_chains_starts_in_image.location(&macho.mf).resolve(&macho.mf)[0]; |
| 3504 | const starts_in_segment_off = ni.location(&macho.mf).resolve(&macho.mf)[0]; |
| 3505 | |
| 3506 | const chained_starts_in_image: []u32 = @ptrCast(@alignCast( |
| 3507 | macho.node.fixup_chains_starts_in_image.slice(&macho.mf), |
| 3508 | )); |
| 3509 | macho.targetStore( |
| 3510 | &chained_starts_in_image[@backingInt(segment) + 2], |
| 3511 | @intCast(starts_in_segment_off - starts_in_image_off), |
| 3512 | ); |
| 3513 | }, |
| 3514 | .input_atom => |iai| { |
| 3515 | const input_atom_offset: u64, _ = ni.location(&macho.mf).resolve(&macho.mf); |
| 3516 | const section = macho.getNode(iai.node(macho).parent(&macho.mf).unwrap().?).section; |
| 3517 | |
| 3518 | const old_atom_addr = iai.ptrConst(macho).vaddr; |
| 3519 | const new_atom_addr = macho.targetLoad(§ion.lcPtrConst(macho).addr) + input_atom_offset; |
| 3520 | iai.ptr(macho).vaddr = new_atom_addr; |
| 3521 | |
| 3522 | const first_reloc = iai.ptr(macho).first_reloc; |
| 3523 | for (macho.relocs.items[@backingInt(first_reloc)..]) |*reloc| { |
| 3524 | if (reloc.node != ni) break; |
| 3525 | try reloc.apply(macho); |
| 3526 | } |
| 3527 | |
| 3528 | var sym_it = iai.ptrConst(macho).first_symbol; |
| 3529 | while (sym_it.unwrap()) |sym| : (sym_it = sym.ptr(macho).next_in_node) { |
| 3530 | const new_addr = sym.value(macho) - old_atom_addr + new_atom_addr; |
| 3531 | try sym.flushMoved(macho, new_addr); |
| 3532 | } |
| 3533 | |
| 3534 | // If the atom which has moved contains runtime fixups, they need to be flushed. |
| 3535 | if (iai.ptr(macho).any_fixups) { |
| 3536 | const segment = section.segment(macho); |
| 3537 | |
| 3538 | const page_align = macho.targetPageAlign(); |
| 3539 | |
| 3540 | const new_start: u32 = off: { |
| 3541 | const ni_file_off = ni.fileLocation(&macho.mf, false).offset; |
| 3542 | const seg_file_off = segment.node(macho).fileLocation(&macho.mf, false).offset; |
| 3543 | break :off @intCast(ni_file_off - seg_file_off); |
| 3544 | }; |
| 3545 | const new_end = new_start + ni.location(&macho.mf).resolve(&macho.mf)[1]; |
| 3546 | |
| 3547 | const page_start: u32 = @intCast(@divFloor(new_start, page_align.toByteUnits())); |
| 3548 | const page_end: u32 = @intCast(@divCeil(new_end, page_align.toByteUnits())); |
| 3549 | try macho.dirty_fixup_chain_pages.ensureUnusedCapacity( |
| 3550 | macho.base.comp.gpa, |
| 3551 | page_end - page_start, |
| 3552 | ); |
| 3553 | for (page_start..page_end) |page_index| { |
| 3554 | macho.dirty_fixup_chain_pages.putAssumeCapacity(.{ |
| 3555 | .seg = segment, |
| 3556 | .page = @intCast(page_index), |
| 3557 | }, {}); |
| 3558 | } |
| 3559 | } |
| 3560 | }, |
| 1178 | 3561 | } |
| 1179 | 3562 | try ni.childrenMoved(macho.base.comp.gpa, &macho.mf); |
| 1180 | 3563 | } |
| ... | ... | @@ -1185,6 +3568,29 @@ fn flushMachOFileOffset(macho: *MachO, ni: MappedFile.Node.Index) void { |
| 1185 | 3568 | .macho_header => { |
| 1186 | 3569 | assert(offset == 0); |
| 1187 | 3570 | }, |
| 3571 | .symtab => { |
| 3572 | const symtab_cmd = macho.lc.symtab.ptr(macho, std.macho.symtab_command); |
| 3573 | macho.targetStore(&symtab_cmd.symoff, @intCast(offset)); |
| 3574 | }, |
| 3575 | .strtab => { |
| 3576 | const symtab_cmd = macho.lc.symtab.ptr(macho, std.macho.symtab_command); |
| 3577 | macho.targetStore(&symtab_cmd.stroff, @intCast(offset)); |
| 3578 | }, |
| 3579 | .indirect_syms => { |
| 3580 | const dysymtab_cmd = macho.lc.dysymtab.ptr(macho, std.macho.dysymtab_command); |
| 3581 | macho.targetStore(&dysymtab_cmd.indirectsymoff, @intCast(offset)); |
| 3582 | }, |
| 3583 | .section_indirect_syms => {}, |
| 3584 | .linkedit_data => |lc| { |
| 3585 | const linkedit_data_cmd = lc.ptr(macho, std.macho.linkedit_data_command); |
| 3586 | macho.targetStore(&linkedit_data_cmd.dataoff, @intCast(offset)); |
| 3587 | }, |
| 3588 | .fixup_chains_header => {}, |
| 3589 | .fixup_chains_imports => {}, |
| 3590 | .fixup_chains_symbol_names => {}, |
| 3591 | .fixup_chains_starts => {}, |
| 3592 | .fixup_chains_starts_in_image => {}, |
| 3593 | .fixup_chains_starts_in_segment => {}, |
| 1188 | 3594 | .segment => |segment| { |
| 1189 | 3595 | macho.targetStore(&segment.lcPtr(macho).fileoff, @intCast(offset)); |
| 1190 | 3596 | var child_oni = ni.first(&macho.mf); |
| ... | ... | @@ -1192,17 +3598,10 @@ fn flushMachOFileOffset(macho: *MachO, ni: MappedFile.Node.Index) void { |
| 1192 | 3598 | macho.flushMachOFileOffset(child_ni); |
| 1193 | 3599 | } |
| 1194 | 3600 | }, |
| 1195 | | .section => |section| { |
| 3601 | .section, .section_manual_size => |section| { |
| 1196 | 3602 | macho.targetStore(§ion.lcPtr(macho).offset, @intCast(offset)); |
| 1197 | 3603 | }, |
| 1198 | | .symtab => { |
| 1199 | | const symtab_cmd = macho.lc.symtab.ptr(macho, std.macho.symtab_command); |
| 1200 | | macho.targetStore(&symtab_cmd.symoff, @intCast(offset)); |
| 1201 | | }, |
| 1202 | | .strtab => { |
| 1203 | | const symtab_cmd = macho.lc.symtab.ptr(macho, std.macho.symtab_command); |
| 1204 | | macho.targetStore(&symtab_cmd.stroff, @intCast(offset)); |
| 1205 | | }, |
| 3604 | .input_atom => {}, |
| 1206 | 3605 | } |
| 1207 | 3606 | } |
| 1208 | 3607 | fn flushResized(macho: *MachO, ni: MappedFile.Node.Index) link.Error!void { |
| ... | ... | @@ -1210,19 +3609,215 @@ fn flushResized(macho: *MachO, ni: MappedFile.Node.Index) link.Error!void { |
| 1210 | 3609 | switch (macho.getNode(ni)) { |
| 1211 | 3610 | .macho => {}, |
| 1212 | 3611 | .macho_header => {}, |
| 3612 | .symtab, .strtab => { |
| 3613 | // Don't modify the symtab load command's `nsyms` or `strsize` field here; we only do |
| 3614 | // that when we actually add strings or symbols. |
| 3615 | }, |
| 3616 | .indirect_syms => { |
| 3617 | const dysymtab_cmd = macho.lc.dysymtab.ptr(macho, std.macho.dysymtab_command); |
| 3618 | macho.targetStore(&dysymtab_cmd.nindirectsyms, @intCast(@divExact(size, 4))); |
| 3619 | }, |
| 3620 | .section_indirect_syms => {}, |
| 3621 | .linkedit_data => |lc| { |
| 3622 | const linkedit_data_cmd = lc.ptr(macho, std.macho.linkedit_data_command); |
| 3623 | macho.targetStore(&linkedit_data_cmd.datasize, @intCast(size)); |
| 3624 | }, |
| 3625 | .fixup_chains_header => {}, |
| 3626 | .fixup_chains_imports => {}, |
| 3627 | .fixup_chains_symbol_names => {}, |
| 3628 | .fixup_chains_starts => {}, |
| 3629 | .fixup_chains_starts_in_image => {}, |
| 3630 | .fixup_chains_starts_in_segment => {}, |
| 1213 | 3631 | .segment => |segment| { |
| 1214 | 3632 | macho.targetStore(&segment.lcPtr(macho).filesize, size); |
| 1215 | 3633 | }, |
| 1216 | 3634 | .section => |section| { |
| 1217 | 3635 | macho.targetStore(§ion.lcPtr(macho).size, size); |
| 1218 | 3636 | }, |
| 1219 | | .symtab, .strtab => { |
| 1220 | | // Don't modify the symtab load command's `nsyms` or `strsize` field here; we only do |
| 1221 | | // that when we actually add strings or symbols. |
| 3637 | .section_manual_size => {}, |
| 3638 | .input_atom => {}, |
| 3639 | } |
| 3640 | } |
| 3641 | |
| 3642 | fn getNodeVAddr(macho: *MachO, ni: MappedFile.Node.Index) u64 { |
| 3643 | return switch (macho.getNode(ni)) { |
| 3644 | .macho => unreachable, |
| 3645 | .macho_header => unreachable, |
| 3646 | .symtab => unreachable, |
| 3647 | .strtab => unreachable, |
| 3648 | .indirect_syms => unreachable, |
| 3649 | .section_indirect_syms => unreachable, |
| 3650 | .linkedit_data => unreachable, |
| 3651 | .fixup_chains_header => unreachable, |
| 3652 | .fixup_chains_imports => unreachable, |
| 3653 | .fixup_chains_symbol_names => unreachable, |
| 3654 | .fixup_chains_starts => unreachable, |
| 3655 | .fixup_chains_starts_in_image => unreachable, |
| 3656 | .fixup_chains_starts_in_segment => unreachable, |
| 3657 | .segment => |segment| segment.vaddr(macho), |
| 3658 | .section, .section_manual_size => |section| section.vaddr(macho), |
| 3659 | .input_atom => |iai| iai.ptr(macho).vaddr, |
| 3660 | }; |
| 3661 | } |
| 3662 | fn getNodeSection(macho: *MachO, ni: MappedFile.Node.Index) Section { |
| 3663 | var cur_ni = ni; |
| 3664 | while (true) { |
| 3665 | switch (macho.getNode(cur_ni)) { |
| 3666 | .section, .section_manual_size => |section| return section, |
| 3667 | else => cur_ni = cur_ni.parent(&macho.mf).unwrap().?, |
| 3668 | } |
| 3669 | } |
| 3670 | } |
| 3671 | fn nodeFirstSymbolPtr(macho: *MachO, ni: MappedFile.Node.Index) *Symbol.Index.Optional { |
| 3672 | return switch (macho.getNode(ni)) { |
| 3673 | .input_atom => |iai| &iai.ptr(macho).first_symbol, |
| 3674 | else => unreachable, |
| 3675 | }; |
| 3676 | } |
| 3677 | |
| 3678 | fn targetStubSize(macho: *const MachO) u8 { |
| 3679 | return switch (macho.base.comp.getTarget().cpu.arch) { |
| 3680 | else => unreachable, |
| 3681 | .aarch64 => 12, |
| 3682 | .x86_64 => 6, |
| 3683 | }; |
| 3684 | } |
| 3685 | fn appendStubEntry(macho: *MachO, old_len: u64, got_index: u64, target_symbol: Symbol.Index) Error!void { |
| 3686 | const gpa = macho.base.comp.gpa; |
| 3687 | |
| 3688 | const entry_size = macho.targetStubSize(); |
| 3689 | const stub_offset = entry_size * old_len; |
| 3690 | assert(macho.targetLoad(&macho.known_sections.stubs.lcPtrConst(macho).size) == stub_offset); |
| 3691 | |
| 3692 | const new_size = stub_offset + entry_size; |
| 3693 | try macho.known_sections.stubs.node(macho).ensureMinimumSize(gpa, &macho.mf, new_size); |
| 3694 | macho.targetStore(&macho.known_sections.stubs.lcPtr(macho).size, new_size); |
| 3695 | |
| 3696 | macho.writeStubEntry(old_len, got_index); |
| 3697 | |
| 3698 | try macho.node.stubs_indirect_syms.ensureMinimumSize(gpa, &macho.mf, (old_len + 1) * 4); |
| 3699 | const indirect_syms: []Symbol.Index = @ptrCast(@alignCast( |
| 3700 | macho.node.stubs_indirect_syms.slice(&macho.mf), |
| 3701 | )); |
| 3702 | indirect_syms[@intCast(old_len)] = target_symbol; |
| 3703 | } |
| 3704 | fn writeStubEntry(macho: *MachO, stub_index: u64, got_index: u64) void { |
| 3705 | if (macho.known_sections.stubs.node(macho).hasMoved(&macho.mf)) return; |
| 3706 | if (macho.known_sections.got.node(macho).hasMoved(&macho.mf)) return; |
| 3707 | |
| 3708 | const entry_size = macho.targetStubSize(); |
| 3709 | const stub_offset = entry_size * stub_index; |
| 3710 | |
| 3711 | const got_entry_vaddr = macho.known_sections.got.vaddr(macho) + got_index * macho.targetPtrSize(); |
| 3712 | const new_stub_vaddr = macho.known_sections.stubs.vaddr(macho) + stub_offset; |
| 3713 | |
| 3714 | switch (macho.base.comp.getTarget().cpu.arch) { |
| 3715 | else => unreachable, |
| 3716 | .aarch64 => { |
| 3717 | // The first instruction of the stub will be an ADRP for which we need to compute the |
| 3718 | // offset from that instruction's 4k page to the GOT entry's 4k page. |
| 3719 | const cur_page_base = (new_stub_vaddr >> 12) << 12; |
| 3720 | const target_page_base = (got_entry_vaddr >> 12) << 12; |
| 3721 | const cur_page_to_target_page: i64 = @bitCast(target_page_base - cur_page_base); |
| 3722 | |
| 3723 | // Then we will use an LDR to reference the GOT entry on that page. |
| 3724 | const target_page_off: u12 = @truncate(got_entry_vaddr); |
| 3725 | |
| 3726 | const insts: []align(4) aarch64.encoding.Instruction = @ptrCast(@alignCast( |
| 3727 | macho.known_sections.stubs.node(macho).slice(&macho.mf)[@intCast(stub_offset)..][0..entry_size], |
| 3728 | )); |
| 3729 | @memcpy(insts, @as([]const aarch64.encoding.Instruction, &.{ |
| 3730 | .adrp(.x16, @intCast(cur_page_to_target_page)), |
| 3731 | .ldr(.x16, .{ .unsigned_offset = .{ .base = .x16, .offset = target_page_off } }), |
| 3732 | .br(.x16), |
| 3733 | })); |
| 3734 | if (.little != std.lang.Endian.native) { // aarch64 instructions are little-endian |
| 3735 | std.mem.byteSwapAllElements(aarch64.encoding.Instruction, insts); |
| 3736 | } |
| 3737 | }, |
| 3738 | .x86_64 => { |
| 3739 | const new_stub_slice: []align(2) u8 = @ptrCast(@alignCast( |
| 3740 | macho.known_sections.stubs.node(macho).slice(&macho.mf)[@intCast(stub_offset)..][0..entry_size], |
| 3741 | )); |
| 3742 | // jmpq *got_entry(%rip) |
| 3743 | @memcpy(new_stub_slice[0..2], @as([]const u8, &.{ 0xff, 0x25 })); |
| 3744 | const offset_ptr: *align(2) i32 = @ptrCast(new_stub_slice[2..]); |
| 3745 | const offset: i64 = @bitCast(got_entry_vaddr -% (new_stub_vaddr + 6)); |
| 3746 | macho.targetStore(offset_ptr, @intCast(offset)); |
| 1222 | 3747 | }, |
| 1223 | 3748 | } |
| 1224 | 3749 | } |
| 1225 | 3750 | |
| 3751 | fn appendGotEntry(macho: *MachO, old_len: u64, target_symbol: Symbol.Index) Error!void { |
| 3752 | const gpa = macho.base.comp.gpa; |
| 3753 | |
| 3754 | const ptr_size = macho.targetPtrSize(); |
| 3755 | const entry_offset = ptr_size * old_len; |
| 3756 | assert(macho.targetLoad(&macho.known_sections.got.lcPtrConst(macho).size) == entry_offset); |
| 3757 | |
| 3758 | const new_size = entry_offset + ptr_size; |
| 3759 | try macho.known_sections.got.node(macho).ensureMinimumSize(gpa, &macho.mf, new_size); |
| 3760 | macho.targetStore(&macho.known_sections.got.lcPtr(macho).size, new_size); |
| 3761 | |
| 3762 | const new_entry = macho.known_sections.got.node(macho).slice(&macho.mf)[@intCast(entry_offset)..][0..ptr_size]; |
| 3763 | @memset(new_entry, 0); |
| 3764 | |
| 3765 | if (!macho.known_sections.got.node(macho).hasMoved(&macho.mf)) { |
| 3766 | const segment = macho.known_sections.got.segment(macho); |
| 3767 | const page_index: u16 = @intCast(@divFloor( |
| 3768 | macho.prev_got_offset + entry_offset, |
| 3769 | macho.targetPageAlign().toByteUnits(), |
| 3770 | )); |
| 3771 | try macho.dirty_fixup_chain_pages.put(gpa, .{ .seg = segment, .page = page_index }, {}); |
| 3772 | } |
| 3773 | |
| 3774 | try macho.node.got_indirect_syms.ensureMinimumSize(gpa, &macho.mf, (old_len + 1) * 4); |
| 3775 | const indirect_syms: []Symbol.Index = @ptrCast(@alignCast( |
| 3776 | macho.node.got_indirect_syms.slice(&macho.mf), |
| 3777 | )); |
| 3778 | indirect_syms[@intCast(old_len)] = target_symbol; |
| 3779 | } |
| 3780 | |
| 3781 | fn appendImportEntry(macho: *MachO, old_len: u64, symbol_index: Symbol.Index) Error!void { |
| 3782 | const gpa = macho.base.comp.gpa; |
| 3783 | |
| 3784 | const new_size = @sizeOf(std.macho.dyld_chained_import_addend64) * (old_len + 1); |
| 3785 | try macho.node.fixup_chains_imports.ensureMinimumSize(gpa, &macho.mf, new_size); |
| 3786 | |
| 3787 | const symbol_name_off = macho.fixup_chain_symbol_names_len; |
| 3788 | macho.fixup_chain_symbol_names_len += @intCast(symbol_index.name(macho).len + 1); |
| 3789 | try macho.node.fixup_chains_symbol_names.ensureMinimumSize(gpa, &macho.mf, macho.fixup_chain_symbol_names_len); |
| 3790 | { |
| 3791 | const sym_name = symbol_index.name(macho); |
| 3792 | const name_slice = macho.node.fixup_chains_symbol_names.slice(&macho.mf)[symbol_name_off..]; |
| 3793 | @memcpy(name_slice[0..sym_name.len], sym_name); |
| 3794 | name_slice[sym_name.len] = 0; |
| 3795 | } |
| 3796 | |
| 3797 | { |
| 3798 | const hdr: *std.macho.dyld_chained_fixups_header = @ptrCast(@alignCast( |
| 3799 | macho.node.fixup_chains_header.slice(&macho.mf)[0..@sizeOf(std.macho.dyld_chained_fixups_header)], |
| 3800 | )); |
| 3801 | assert(macho.targetLoad(&hdr.imports_count) == old_len); |
| 3802 | macho.targetStore(&hdr.imports_count, @intCast(old_len + 1)); |
| 3803 | } |
| 3804 | |
| 3805 | const imports: []std.macho.dyld_chained_import_addend64 = @ptrCast(@alignCast( |
| 3806 | macho.node.fixup_chains_imports.slice(&macho.mf)[0..@intCast(new_size)], |
| 3807 | )); |
| 3808 | imports[@intCast(old_len)] = .{ |
| 3809 | .bits = .{ |
| 3810 | .lib_ordinal = 0xFFFE, |
| 3811 | .weak_import = false, |
| 3812 | .name_offset = symbol_name_off, |
| 3813 | }, |
| 3814 | .addend = 0, |
| 3815 | }; |
| 3816 | if (macho.targetEndian() != std.lang.Endian.native) { |
| 3817 | std.mem.byteSwapAllFields(std.macho.dyld_chained_import_addend64, &imports[@intCast(old_len)]); |
| 3818 | } |
| 3819 | } |
| 3820 | |
| 1226 | 3821 | pub fn updateFunc( |
| 1227 | 3822 | macho: *MachO, |
| 1228 | 3823 | pt: Zcu.PerThread, |
| ... | ... | @@ -1277,15 +3872,68 @@ fn printNode( |
| 1277 | 3872 | ni: MappedFile.Node.Index, |
| 1278 | 3873 | indent: usize, |
| 1279 | 3874 | ) Io.Writer.Error!void { |
| 1280 | | const node = macho.getNode(ni); |
| 1281 | 3875 | try w.splatByteAll(' ', indent); |
| 1282 | | switch (node) { |
| 3876 | switch (macho.getNode(ni)) { |
| 1283 | 3877 | .macho => try w.writeAll("macho"), |
| 1284 | 3878 | .macho_header => try w.writeAll("macho_header"), |
| 1285 | | .section => |section| try w.print("section({q})", .{section.name(macho)}), |
| 1286 | | .segment => |segment| try w.print("segment({q})", .{segment.name(macho)}), |
| 1287 | 3879 | .symtab => try w.writeAll("symtab"), |
| 1288 | 3880 | .strtab => try w.writeAll("strtab"), |
| 3881 | .indirect_syms => try w.writeAll("indirect_syms"), |
| 3882 | .section_indirect_syms => |section| try w.print("section_indirect_syms({s},{s})", .{ |
| 3883 | section.segmentName(macho), |
| 3884 | section.name(macho), |
| 3885 | }), |
| 3886 | .linkedit_data => |lc| try w.print("linkedit_data(LC_{t})", .{ |
| 3887 | macho.targetLoad(&lc.ptrConst(macho, std.macho.load_command).cmd), |
| 3888 | }), |
| 3889 | .fixup_chains_header => try w.writeAll("fixup_chains_header"), |
| 3890 | .fixup_chains_imports => try w.writeAll("fixup_chains_imports"), |
| 3891 | .fixup_chains_symbol_names => try w.writeAll("fixup_chains_symbol_names"), |
| 3892 | .fixup_chains_starts => try w.writeAll("fixup_chains_starts"), |
| 3893 | .fixup_chains_starts_in_image => try w.writeAll("fixup_chains_starts_in_image"), |
| 3894 | .fixup_chains_starts_in_segment => |seg| try w.print("fixup_chains_starts_in_segment({s})", .{seg.name(macho)}), |
| 3895 | .section => |section| try w.print("section({s},{s})", .{ |
| 3896 | section.segmentName(macho), |
| 3897 | section.name(macho), |
| 3898 | }), |
| 3899 | .section_manual_size => |section| try w.print("section_manual_size({s},{s})", .{ |
| 3900 | section.segmentName(macho), |
| 3901 | section.name(macho), |
| 3902 | }), |
| 3903 | .segment => |segment| try w.print("segment({s})", .{segment.name(macho)}), |
| 3904 | .input_atom => |iai| { |
| 3905 | // It's useful to try and give a name to the input atom, but input atoms don't actually |
| 3906 | // have names. However, a decent approach if the input atom only contains one symbol is |
| 3907 | // to print that symbol's name. We also accept the input atom containing many global |
| 3908 | // symbols but only one internal symbol (since that's how Zig exports work). |
| 3909 | if (iai.ptrConst(macho).first_symbol.unwrap()) |first_symbol| { |
| 3910 | if (first_symbol.ptrConst(macho).next_in_node == .none) { |
| 3911 | // There is only one symbol in the section, so it's a good identifier. |
| 3912 | try w.print("input_atom({q})", .{first_symbol.name(macho)}); |
| 3913 | } else { |
| 3914 | // Also, if it has N global symbols but only one internal symbol, go with the |
| 3915 | // internal name---this works well for how Zig handles exports. |
| 3916 | var prev_local_sym: Symbol.Index.Optional = .none; |
| 3917 | var sym_it: Symbol.Index.Optional = .wrap(first_symbol); |
| 3918 | const only_local_sym: Symbol.Index.Optional = while (sym_it.unwrap()) |sym| : (sym_it = sym.ptrConst(macho).next_in_node) { |
| 3919 | const n_type = macho.targetLoad(&sym.nlistConst(macho).n_type); |
| 3920 | if (!n_type.bits.ext and !n_type.bits.pext) { |
| 3921 | // this is an internal symbol |
| 3922 | if (prev_local_sym != .none) break .none; |
| 3923 | prev_local_sym = .wrap(sym); |
| 3924 | } |
| 3925 | } else prev_local_sym; |
| 3926 | |
| 3927 | if (only_local_sym.unwrap()) |local_sym| { |
| 3928 | try w.print("input_atom({q})", .{local_sym.name(macho)}); |
| 3929 | } else { |
| 3930 | try w.writeAll("input_atom([multiple symbols])"); |
| 3931 | } |
| 3932 | } |
| 3933 | } else { |
| 3934 | try w.writeAll("input_atom([no symbols])"); |
| 3935 | } |
| 3936 | }, |
| 1289 | 3937 | } |
| 1290 | 3938 | { |
| 1291 | 3939 | const mf_node = &macho.mf.nodes.items[@backingInt(ni)]; |
| ... | ... | @@ -1341,13 +3989,239 @@ fn printNode( |
| 1341 | 3989 | } |
| 1342 | 3990 | } |
| 1343 | 3991 | |
| 3992 | fn flushFixupChains( |
| 3993 | macho: *MachO, |
| 3994 | segment: Segment, |
| 3995 | page: u16, |
| 3996 | ) void { |
| 3997 | assert(!std.mem.eql(u8, segment.name(macho), "__LINKEDIT")); |
| 3998 | |
| 3999 | const page_size = macho.targetPageAlign().toByteUnits(); |
| 4000 | const start_vaddr = segment.vaddr(macho) + @as(u64, page) * page_size; |
| 4001 | const end_vaddr = start_vaddr + page_size; |
| 4002 | |
| 4003 | var next_vaddr: u64 = 0; |
| 4004 | var node_it = segment.node(macho).last(&macho.mf); |
| 4005 | while (node_it.unwrap()) |node| : (node_it = node.prev(&macho.mf)) { |
| 4006 | // Other than `__LINKEDIT`, segments can only contain sections. |
| 4007 | const sect: Section = switch (macho.getNode(node)) { |
| 4008 | .section, .section_manual_size => |sect| sect, |
| 4009 | .macho => unreachable, |
| 4010 | .macho_header => continue, // the Mach header and load commands are in the __TEXT section |
| 4011 | .symtab => unreachable, |
| 4012 | .strtab => unreachable, |
| 4013 | .indirect_syms => unreachable, |
| 4014 | .section_indirect_syms => unreachable, |
| 4015 | .linkedit_data => unreachable, |
| 4016 | .fixup_chains_header => unreachable, |
| 4017 | .fixup_chains_imports => unreachable, |
| 4018 | .fixup_chains_symbol_names => unreachable, |
| 4019 | .fixup_chains_starts => unreachable, |
| 4020 | .fixup_chains_starts_in_image => unreachable, |
| 4021 | .fixup_chains_starts_in_segment => unreachable, |
| 4022 | .segment => unreachable, |
| 4023 | .input_atom => unreachable, |
| 4024 | }; |
| 4025 | if (sect.vaddr(macho) >= end_vaddr) { |
| 4026 | // This section is after the page we're interested in. We're iterating backwards, so |
| 4027 | // that means we've not yet found the page. |
| 4028 | continue; |
| 4029 | } |
| 4030 | if (sect.vaddr(macho) + macho.targetLoad(§.lcPtrConst(macho).size) < start_vaddr) { |
| 4031 | // This section is before the page we're interested in. We're iterating backwards, so |
| 4032 | // that means we've finished scanning the page. |
| 4033 | break; |
| 4034 | } |
| 4035 | if (sect == macho.known_sections.got) { |
| 4036 | macho.flushFixupChainsGot( |
| 4037 | &next_vaddr, |
| 4038 | start_vaddr, |
| 4039 | start_vaddr + page_size, |
| 4040 | ); |
| 4041 | } else { |
| 4042 | var sub_node_it = node.last(&macho.mf); |
| 4043 | while (sub_node_it.unwrap()) |sub_node| : (sub_node_it = sub_node.prev(&macho.mf)) { |
| 4044 | macho.flushFixupChainsNonSpecial( |
| 4045 | sub_node, |
| 4046 | &next_vaddr, |
| 4047 | start_vaddr, |
| 4048 | start_vaddr + page_size, |
| 4049 | ); |
| 4050 | } |
| 4051 | } |
| 4052 | } |
| 4053 | |
| 4054 | const page_starts: []u16 = @ptrCast(@alignCast( |
| 4055 | segment.fixupChainStartsNode(macho).unwrap().?.slice(&macho.mf)[@sizeOf(std.macho.dyld_chained_starts_in_segment) - 2 ..], |
| 4056 | )); |
| 4057 | if (next_vaddr == 0) { |
| 4058 | macho.targetStore(&page_starts[page], 0xFFFF); |
| 4059 | } else { |
| 4060 | macho.targetStore(&page_starts[page], @intCast(next_vaddr - start_vaddr)); |
| 4061 | } |
| 4062 | } |
| 4063 | fn flushFixupChainsGot( |
| 4064 | macho: *MachO, |
| 4065 | next_vaddr: *u64, |
| 4066 | start_vaddr: u64, |
| 4067 | end_vaddr: u64, |
| 4068 | ) void { |
| 4069 | const ptr_size = macho.targetPtrSize(); |
| 4070 | const got_start_vaddr = macho.known_sections.got.vaddr(macho); |
| 4071 | const got_end_vaddr = got_start_vaddr + @as(u64, macho.got.count()) * ptr_size; |
| 4072 | if (got_start_vaddr >= end_vaddr) return; |
| 4073 | if (got_end_vaddr <= start_vaddr) return; |
| 4074 | // There is some overlap between the GOT and the page range. |
| 4075 | const start_index = @divExact(start_vaddr -| got_start_vaddr, ptr_size); |
| 4076 | const end_index = @min(@divExact(end_vaddr -| got_start_vaddr, ptr_size), macho.got.count()); |
| 4077 | |
| 4078 | const got_node = macho.known_sections.got.node(macho); |
| 4079 | const got_syms = macho.got.keys(); |
| 4080 | |
| 4081 | var got_index = end_index; |
| 4082 | while (got_index > start_index) { |
| 4083 | got_index -= 1; |
| 4084 | macho.writeOneFixup( |
| 4085 | got_syms[got_index], |
| 4086 | 0, |
| 4087 | got_node, |
| 4088 | got_index * ptr_size, |
| 4089 | start_vaddr, |
| 4090 | end_vaddr, |
| 4091 | next_vaddr, |
| 4092 | ); |
| 4093 | } |
| 4094 | } |
| 4095 | fn flushFixupChainsNonSpecial( |
| 4096 | macho: *MachO, |
| 4097 | node: MappedFile.Node.Index, |
| 4098 | next_vaddr: *u64, |
| 4099 | start_vaddr: u64, |
| 4100 | end_vaddr: u64, |
| 4101 | ) void { |
| 4102 | switch (macho.getNode(node)) { |
| 4103 | .macho => unreachable, |
| 4104 | .macho_header => unreachable, |
| 4105 | .symtab => unreachable, |
| 4106 | .strtab => unreachable, |
| 4107 | .indirect_syms => unreachable, |
| 4108 | .section_indirect_syms => unreachable, |
| 4109 | .linkedit_data => unreachable, |
| 4110 | .fixup_chains_header => unreachable, |
| 4111 | .fixup_chains_imports => unreachable, |
| 4112 | .fixup_chains_symbol_names => unreachable, |
| 4113 | .fixup_chains_starts => unreachable, |
| 4114 | .fixup_chains_starts_in_image => unreachable, |
| 4115 | .fixup_chains_starts_in_segment => unreachable, |
| 4116 | .segment => unreachable, |
| 4117 | .section => unreachable, |
| 4118 | .section_manual_size => unreachable, |
| 4119 | .input_atom => |iai| { |
| 4120 | const first_reloc = iai.ptr(macho).first_reloc; |
| 4121 | |
| 4122 | var reloc = first_reloc; |
| 4123 | var prev_reloc_off: ?u32 = null; |
| 4124 | while (@backingInt(reloc) < macho.relocs.items.len and |
| 4125 | reloc.ptr(macho).node == node) |
| 4126 | { |
| 4127 | if (prev_reloc_off) |prev_off| { |
| 4128 | assert(reloc.ptr(macho).offset > prev_off); |
| 4129 | } |
| 4130 | prev_reloc_off = reloc.ptr(macho).offset; |
| 4131 | reloc = @fromBackingInt(@backingInt(reloc) + 1); |
| 4132 | } |
| 4133 | |
| 4134 | while (reloc != first_reloc) { |
| 4135 | reloc = @fromBackingInt(@backingInt(reloc) - 1); |
| 4136 | if (reloc.ptr(macho).bits.result == .fixup) { |
| 4137 | macho.writeOneFixup( |
| 4138 | reloc.ptr(macho).target_symbol, |
| 4139 | reloc.ptr(macho).addend, |
| 4140 | reloc.ptr(macho).node, |
| 4141 | reloc.ptr(macho).offset, |
| 4142 | start_vaddr, |
| 4143 | end_vaddr, |
| 4144 | next_vaddr, |
| 4145 | ); |
| 4146 | } |
| 4147 | } |
| 4148 | }, |
| 4149 | } |
| 4150 | } |
| 4151 | fn writeOneFixup( |
| 4152 | macho: *MachO, |
| 4153 | target: Symbol.Index, |
| 4154 | addend: u64, |
| 4155 | dest_node: MappedFile.Node.Index, |
| 4156 | dest_offset: u64, |
| 4157 | start_vaddr: u64, |
| 4158 | end_vaddr: u64, |
| 4159 | next_vaddr: *u64, |
| 4160 | ) void { |
| 4161 | assert(macho.targetPtrSize() == 8); |
| 4162 | const dest_vaddr = macho.getNodeVAddr(dest_node) + dest_offset; |
| 4163 | if (dest_vaddr < start_vaddr or dest_vaddr >= end_vaddr) return; |
| 4164 | const dest_ptr: *align(4) std.macho.dyld_chained_ptr_64 = @ptrCast(@alignCast( |
| 4165 | dest_node.slice(&macho.mf)[@intCast(dest_offset)..][0..8], |
| 4166 | )); |
| 4167 | switch (macho.targetLoad(&target.nlist(macho).n_type).bits.type) { |
| 4168 | .undf => { |
| 4169 | const import_index = macho.imports.getIndex(target).?; |
| 4170 | macho.targetStore(dest_ptr, .{ |
| 4171 | .kind = .bind, |
| 4172 | .next = if (next_vaddr.* != 0) @intCast( |
| 4173 | @divExact(next_vaddr.* - dest_vaddr, 4), |
| 4174 | ) else 0, |
| 4175 | .per_kind = .{ .bind = .{ |
| 4176 | .ordinal = @intCast(import_index), |
| 4177 | .addend = std.math.cast(u8, addend) orelse { |
| 4178 | std.debug.panic("TODO(MachO2): large fixup addend (target={q}, addend={d})", .{ |
| 4179 | target.name(macho), addend, |
| 4180 | }); |
| 4181 | }, |
| 4182 | } }, |
| 4183 | }); |
| 4184 | next_vaddr.* = dest_vaddr; |
| 4185 | }, |
| 4186 | .sect => { |
| 4187 | const target_val: packed struct(u64) { |
| 4188 | low36: u36, |
| 4189 | mid: u20, |
| 4190 | high8: u8, |
| 4191 | } = @bitCast(target.value(macho) +% addend); |
| 4192 | if (target_val.mid != 0) { |
| 4193 | @panic("TODO(MachO2): report non-zero mid bits in rebase fixup (vmaddrs too large?)"); |
| 4194 | } |
| 4195 | macho.targetStore(dest_ptr, .{ |
| 4196 | .kind = .rebase, |
| 4197 | .next = if (next_vaddr.* != 0) @intCast( |
| 4198 | @divExact(next_vaddr.* - dest_vaddr, 4), |
| 4199 | ) else 0, |
| 4200 | .per_kind = .{ .rebase = .{ |
| 4201 | .target = target_val.low36, |
| 4202 | .high8 = target_val.high8, |
| 4203 | } }, |
| 4204 | }); |
| 4205 | next_vaddr.* = dest_vaddr; |
| 4206 | }, |
| 4207 | .abs => { |
| 4208 | // We actually *don't* need a fixup---this is just a static relocation with extra steps! |
| 4209 | const target_val = target.value(macho) +% addend; |
| 4210 | macho.targetStore(dest_ptr, @bitCast(target_val)); |
| 4211 | }, |
| 4212 | else => unreachable, |
| 4213 | } |
| 4214 | } |
| 4215 | |
| 1344 | 4216 | const std = @import("std"); |
| 1345 | 4217 | const assert = std.debug.assert; |
| 1346 | 4218 | const log = std.log.scoped(.link); |
| 1347 | 4219 | const Allocator = std.mem.Allocator; |
| 1348 | 4220 | const Io = std.Io; |
| 1349 | 4221 | |
| 4222 | const aarch64 = @import("../codegen/aarch64.zig"); |
| 1350 | 4223 | const link = @import("../link.zig"); |
| 4224 | const tapi = @import("tapi.zig"); |
| 1351 | 4225 | const codegen = @import("../codegen.zig"); |
| 1352 | 4226 | const Compilation = @import("../Compilation.zig"); |
| 1353 | 4227 | const InternPool = @import("../InternPool.zig"); |
Matthew Lugg <mlugg@mlugg.co.uk> 2026-10-17 01:03:57+02:00