Commit 1181543dad
Changed files (1)
src
link
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.?];