authorgravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2020-11-28 12:52:41+01:00
committergravatar for kubkon@jakubkonka.comJakub Konka <kubkon@jakubkonka.com> 2020-12-01 10:49:31+01:00
log545721ccd1e7297719fc53dfde99fa046fb3edef
treefe19372798428fb18c635e6941c19caef9caf852
parente8ffae60a27e4b82c23c1c9943899850bd18db9a

lld: add code signature padding

1 files changed, 45 insertions(+), 25 deletions(-)

src/link/MachO.zig+45-25
...@@ -807,33 +807,53 @@ fn linkWithLLD(self: *MachO, comp: *Compilation) !void {...@@ -807,33 +807,53 @@ fn linkWithLLD(self: *MachO, comp: *Compilation) !void {
807 // binaries up!807 // binaries up!
808 var parser = Parser.init(self.base.allocator);808 var parser = Parser.init(self.base.allocator);
809 defer parser.deinit();809 defer parser.deinit();
810 const out_file = try directory.handle.openFile(full_out_path, .{});810 const out_file = try directory.handle.openFile(full_out_path, .{ .write = true });
811 defer out_file.close();
811 try parser.parseFile(out_file);812 try parser.parseFile(out_file);
812 out_file.close();
813 var end_pos: ?usize = null;
814 var text_fileoff: ?usize = null;
815 var text_filesize: ?usize = null;
816 for (parser.load_commands.items) |cmd| {
817 switch (cmd.cmd()) {
818 macho.LC_SYMTAB => switch (cmd) {
819 .Symtab => |x| {
820 end_pos = x.stroff + x.strsize;
821 },
822 else => unreachable,
823 },
824 macho.LC_SEGMENT_64 => switch (cmd) {
825 .Segment => |x| {
826 if (!mem.eql(u8, x.inner.segname[0..6], "__TEXT")) continue;
827 text_fileoff = x.inner.fileoff;
828 text_filesize = x.inner.filesize;
829 },
830 else => unreachable,
831 },
832 else => {},
833 }
834 }
835 // Pad out space for code signature813 // Pad out space for code signature
836 std.debug.print("end_pos={},text_fileoff={},text_filesize={}\n", .{ end_pos, text_fileoff, text_filesize });814 const text_cmd = parser.load_commands.items[parser.text_cmd_index.?].Segment.inner;
815 std.debug.print("end_pos={},text_fileoff={},text_filesize={}\n", .{
816 parser.end_pos,
817 text_cmd.fileoff,
818 text_cmd.filesize,
819 });
820 const dataoff = @intCast(u32, mem.alignForward(parser.end_pos.?, @sizeOf(u64)));
821 const code_sig = macho.linkedit_data_command{
822 .cmd = macho.LC_CODE_SIGNATURE,
823 .cmdsize = @sizeOf(macho.linkedit_data_command),
824 .dataoff = dataoff,
825 .datasize = 0x1000,
826 };
827
828 const linkedit_seg = parser.load_commands.items[parser.linkedit_cmd_index.?].Segment.inner;
829 const linkedit = macho.segment_command_64{
830 .cmd = linkedit_seg.cmd,
831 .cmdsize = linkedit_seg.cmdsize,
832 .segname = linkedit_seg.segname,
833 .vmaddr = linkedit_seg.vmaddr,
834 .vmsize = mem.alignForwardGeneric(u64, linkedit_seg.vmsize + 0x1000, self.page_size),
835 .fileoff = linkedit_seg.fileoff,
836 .filesize = linkedit_seg.filesize + (dataoff - parser.end_pos.?) + 0x1000,
837 .maxprot = linkedit_seg.maxprot,
838 .initprot = linkedit_seg.initprot,
839 .nsects = linkedit_seg.nsects,
840 .flags = linkedit_seg.flags,
841 };
842 const header_cmd = parser.header.?;
843 const header = macho.mach_header_64{
844 .magic = header_cmd.magic,
845 .cputype = header_cmd.cputype,
846 .cpusubtype = header_cmd.cpusubtype,
847 .filetype = header_cmd.filetype,
848 .ncmds = header_cmd.ncmds + 1,
849 .sizeofcmds = header_cmd.sizeofcmds + @sizeOf(macho.linkedit_data_command),
850 .flags = header_cmd.flags,
851 .reserved = header_cmd.reserved,
852 };
853 try out_file.pwriteAll(&[_]u8{0}, code_sig.dataoff + code_sig.datasize);
854 try out_file.pwriteAll(mem.sliceAsBytes(&[_]macho.linkedit_data_command{code_sig}), parser.code_sig_cmd_offset.?);
855 try out_file.pwriteAll(mem.sliceAsBytes(&[_]macho.segment_command_64{linkedit}), parser.linkedit_cmd_offset.?);
856 try out_file.pwriteAll(mem.sliceAsBytes(&[_]macho.mach_header_64{header}), 0);
837 }857 }
838 }858 }
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