diff --git a/src/link/MachO.zig b/src/link/MachO.zig index 80afdc6408..e41454fe4e 100644 --- a/src/link/MachO.zig +++ b/src/link/MachO.zig @@ -2079,62 +2079,7 @@ pub fn populateMissingMetadata(self: *MachO) !void { self.binding_info_dirty = true; } if (self.stub_helper_stubs_start_off == null) { - const text_segment = &self.load_commands.items[self.text_segment_cmd_index.?].Segment; - const stub_helper = &text_segment.sections.items[self.stub_helper_section_index.?]; - const data_segment = &self.load_commands.items[self.data_segment_cmd_index.?].Segment; - const data = &data_segment.sections.items[self.data_section_index.?]; - const data_const_segment = &self.load_commands.items[self.data_const_segment_cmd_index.?].Segment; - const got = &data_const_segment.sections.items[self.data_got_section_index.?]; - switch (self.base.options.target.cpu.arch) { - .x86_64 => { - const code_size = 15; - var code: [code_size]u8 = undefined; - // lea %r11, [rip + disp] - code[0] = 0x4c; - code[1] = 0x8d; - code[2] = 0x1d; - { - const displacement = try math.cast(u32, data.addr - stub_helper.addr - 7); - mem.writeIntLittle(u32, code[3..7], displacement); - } - // push %r11 - code[7] = 0x41; - code[8] = 0x53; - // jmp [rip + disp] - code[9] = 0xff; - code[10] = 0x25; - { - const displacement = try math.cast(u32, got.addr - stub_helper.addr - code_size); - mem.writeIntLittle(u32, code[11..], displacement); - } - self.stub_helper_stubs_start_off = stub_helper.offset + code_size; - try self.base.file.?.pwriteAll(&code, stub_helper.offset); - }, - .aarch64 => { - var code: [4 * @sizeOf(u32)]u8 = undefined; - { - const displacement = try math.cast(i21, data.addr - stub_helper.addr); - mem.writeIntLittle(u32, code[0..4], aarch64.Instruction.adr(.x17, displacement).toU32()); - } - mem.writeIntLittle(u32, code[4..8], aarch64.Instruction.stp( - .x16, - .x17, - aarch64.Register.sp, - aarch64.Instruction.LoadStorePairOffset.pre_index(-16), - ).toU32()); - { - const displacement = try math.divExact(u64, got.addr - stub_helper.addr - 2 * @sizeOf(u32), 4); - const literal = try math.cast(u19, displacement); - mem.writeIntLittle(u32, code[8..12], aarch64.Instruction.ldr(.x16, .{ - .literal = literal, - }).toU32()); - } - mem.writeIntLittle(u32, code[12..16], aarch64.Instruction.br(.x16).toU32()); - self.stub_helper_stubs_start_off = stub_helper.offset + 4 * @sizeOf(u32); - try self.base.file.?.pwriteAll(&code, stub_helper.offset); - }, - else => unreachable, - } + try self.writeStubHelperPreamble(); } } @@ -2516,6 +2461,133 @@ fn writeLazySymbolPointer(self: *MachO, index: u32) !void { try self.base.file.?.pwriteAll(&buf, off); } +fn writeStubHelperPreamble(self: *MachO) !void { + const text_segment = &self.load_commands.items[self.text_segment_cmd_index.?].Segment; + const stub_helper = &text_segment.sections.items[self.stub_helper_section_index.?]; + const data_const_segment = &self.load_commands.items[self.data_const_segment_cmd_index.?].Segment; + const got = &data_const_segment.sections.items[self.data_got_section_index.?]; + const data_segment = &self.load_commands.items[self.data_segment_cmd_index.?].Segment; + const data = &data_segment.sections.items[self.data_section_index.?]; + + switch (self.base.options.target.cpu.arch) { + .x86_64 => { + const code_size = 15; + var code: [code_size]u8 = undefined; + // lea %r11, [rip + disp] + code[0] = 0x4c; + code[1] = 0x8d; + code[2] = 0x1d; + { + const target_addr = data.addr; + const displacement = try math.cast(u32, target_addr - stub_helper.addr - 7); + mem.writeIntLittle(u32, code[3..7], displacement); + } + // push %r11 + code[7] = 0x41; + code[8] = 0x53; + // jmp [rip + disp] + code[9] = 0xff; + code[10] = 0x25; + { + const displacement = try math.cast(u32, got.addr - stub_helper.addr - code_size); + mem.writeIntLittle(u32, code[11..], displacement); + } + try self.base.file.?.pwriteAll(&code, stub_helper.offset); + self.stub_helper_stubs_start_off = stub_helper.offset + code_size; + }, + .aarch64 => { + var code: [6 * @sizeOf(u32)]u8 = undefined; + + data_blk_outer: { + const this_addr = stub_helper.addr; + const target_addr = data.addr; + data_blk: { + const displacement = math.cast(i21, target_addr - this_addr) catch |_| break :data_blk; + // adr x17, disp + mem.writeIntLittle(u32, code[0..4], aarch64.Instruction.adr(.x17, displacement).toU32()); + // nop + mem.writeIntLittle(u32, code[4..8], aarch64.Instruction.nop().toU32()); + break :data_blk_outer; + } + data_blk: { + const new_this_addr = this_addr + @sizeOf(u32); + const displacement = math.cast(i21, target_addr - new_this_addr) catch |_| break :data_blk; + // nop + mem.writeIntLittle(u32, code[0..4], aarch64.Instruction.nop().toU32()); + // adr x17, disp + mem.writeIntLittle(u32, code[4..8], aarch64.Instruction.adr(.x17, displacement).toU32()); + break :data_blk_outer; + } + // Jump is too big, replace adr with adrp and add. + const this_page = @intCast(i32, this_addr >> 12); + const target_page = @intCast(i32, target_addr >> 12); + const pages = @intCast(i21, target_page - this_page); + // adrp x17, pages + mem.writeIntLittle(u32, code[0..4], aarch64.Instruction.adrp(.x17, pages).toU32()); + const narrowed = @truncate(u12, target_addr); + mem.writeIntLittle(u32, code[4..8], aarch64.Instruction.add(.x17, .x17, narrowed, false).toU32()); + } + + // stp x16, x17, [sp, #-16]! + mem.writeIntLittle(u32, code[8..12], aarch64.Instruction.stp( + .x16, + .x17, + aarch64.Register.sp, + aarch64.Instruction.LoadStorePairOffset.pre_index(-16), + ).toU32()); + + binder_blk_outer: { + const this_addr = stub_helper.addr + 3 * @sizeOf(u32); + const target_addr = got.addr; + binder_blk: { + const displacement = math.divExact(u64, target_addr - this_addr, 4) catch |_| break :binder_blk; + const literal = math.cast(u18, displacement) catch |_| break :binder_blk; + // ldr x16, label + mem.writeIntLittle(u32, code[12..16], aarch64.Instruction.ldr(.x16, .{ + .literal = literal, + }).toU32()); + // nop + mem.writeIntLittle(u32, code[16..20], aarch64.Instruction.nop().toU32()); + break :binder_blk_outer; + } + binder_blk: { + const new_this_addr = this_addr + @sizeOf(u32); + const displacement = math.divExact(u64, target_addr - new_this_addr, 4) catch |_| break :binder_blk; + const literal = math.cast(u18, displacement) catch |_| break :binder_blk; + // nop + mem.writeIntLittle(u32, code[12..16], aarch64.Instruction.nop().toU32()); + // ldr x16, label + mem.writeIntLittle(u32, code[16..20], aarch64.Instruction.ldr(.x16, .{ + .literal = literal, + }).toU32()); + break :binder_blk_outer; + } + // Jump is too big, replace ldr with adrp and ldr(register). + const this_page = @intCast(i32, this_addr >> 12); + const target_page = @intCast(i32, target_addr >> 12); + const pages = @intCast(i21, target_page - this_page); + // adrp x16, pages + mem.writeIntLittle(u32, code[12..16], aarch64.Instruction.adrp(.x16, pages).toU32()); + const narrowed = @truncate(u12, target_addr); + const offset = try math.divExact(u12, narrowed, 8); + // ldr x16, x16, offset + mem.writeIntLittle(u32, code[16..20], aarch64.Instruction.ldr(.x16, .{ + .register = .{ + .rn = .x16, + .offset = aarch64.Instruction.LoadStoreOffset.imm(offset), + }, + }).toU32()); + } + + // br x16 + mem.writeIntLittle(u32, code[20..24], aarch64.Instruction.br(.x16).toU32()); + try self.base.file.?.pwriteAll(&code, stub_helper.offset); + self.stub_helper_stubs_start_off = stub_helper.offset + code.len; + }, + else => unreachable, + } +} + fn writeStub(self: *MachO, index: u32) !void { const text_segment = self.load_commands.items[self.text_segment_cmd_index.?].Segment; const stubs = text_segment.sections.items[self.stubs_section_index.?];