Commit 5eef7577d1
Changed files (1)
src
link
Elf
src/link/Elf/Atom.zig
@@ -460,10 +460,35 @@ pub fn resolveRelocs(self: Atom, elf_file: *Elf, code: []u8) !void {
elf.R_X86_64_64 => try cwriter.writeIntLittle(i64, S + A),
+ elf.R_X86_64_32 => try cwriter.writeIntLittle(u32, @as(u32, @truncate(@as(u64, @intCast(S + A))))),
+ elf.R_X86_64_32S => try cwriter.writeIntLittle(i32, @as(i32, @truncate(S + A))),
+
elf.R_X86_64_PLT32,
elf.R_X86_64_PC32,
=> try cwriter.writeIntLittle(i32, @as(i32, @intCast(S + A - P))),
+ elf.R_X86_64_GOTPCREL => try cwriter.writeIntLittle(i32, @as(i32, @intCast(G + GOT + A - P))),
+ elf.R_X86_64_GOTPC32 => try cwriter.writeIntLittle(i32, @as(i32, @intCast(GOT + A - P))),
+ elf.R_X86_64_GOTPC64 => try cwriter.writeIntLittle(i64, GOT + A - P),
+
+ elf.R_X86_64_GOTPCRELX => {
+ if (!target.flags.import and !target.isIFunc(elf_file) and !target.isAbs(elf_file)) blk: {
+ x86_64.relaxGotpcrelx(code[rel.r_offset - 2 ..]) catch break :blk;
+ try cwriter.writeIntLittle(i32, @as(i32, @intCast(S + A - P)));
+ continue;
+ }
+ try cwriter.writeIntLittle(i32, @as(i32, @intCast(G + GOT + A - P)));
+ },
+
+ elf.R_X86_64_REX_GOTPCRELX => {
+ if (!target.flags.import and !target.isIFunc(elf_file) and !target.isAbs(elf_file)) blk: {
+ x86_64.relaxRexGotpcrelx(code[rel.r_offset - 3 ..]) catch break :blk;
+ try cwriter.writeIntLittle(i32, @as(i32, @intCast(S + A - P)));
+ continue;
+ }
+ try cwriter.writeIntLittle(i32, @as(i32, @intCast(G + GOT + A - P)));
+ },
+
else => {
log.err("TODO: unhandled relocation type {}", .{fmtRelocType(rel.r_type())});
@panic("TODO unhandled relocation type");
@@ -591,6 +616,58 @@ fn format2(
// future.
pub const Index = u16;
+const x86_64 = struct {
+ pub fn relaxGotpcrelx(code: []u8) !void {
+ const old_inst = disassemble(code) orelse return error.RelaxFail;
+ const inst = switch (old_inst.encoding.mnemonic) {
+ .call => try Instruction.new(old_inst.prefix, .call, &.{
+ // TODO: hack to force imm32s in the assembler
+ .{ .imm = Immediate.s(-129) },
+ }),
+ .jmp => try Instruction.new(old_inst.prefix, .jmp, &.{
+ // TODO: hack to force imm32s in the assembler
+ .{ .imm = Immediate.s(-129) },
+ }),
+ else => return error.RelaxFail,
+ };
+ relocs_log.debug(" relaxing {} => {}", .{ old_inst.encoding, inst.encoding });
+ const nop = try Instruction.new(.none, .nop, &.{});
+ encode(&.{ nop, inst }, code) catch return error.RelaxFail;
+ }
+
+ pub fn relaxRexGotpcrelx(code: []u8) !void {
+ const old_inst = disassemble(code) orelse return error.RelaxFail;
+ switch (old_inst.encoding.mnemonic) {
+ .mov => {
+ const inst = try Instruction.new(old_inst.prefix, .lea, &old_inst.ops);
+ relocs_log.debug(" relaxing {} => {}", .{ old_inst.encoding, inst.encoding });
+ encode(&.{inst}, code) catch return error.RelaxFail;
+ },
+ else => return error.RelaxFail,
+ }
+ }
+
+ fn disassemble(code: []const u8) ?Instruction {
+ var disas = Disassembler.init(code);
+ const inst = disas.next() catch return null;
+ return inst;
+ }
+
+ fn encode(insts: []const Instruction, code: []u8) !void {
+ var stream = std.io.fixedBufferStream(code);
+ const writer = stream.writer();
+ for (insts) |inst| {
+ try inst.encode(writer, .{});
+ }
+ }
+
+ const bits = @import("../../arch/x86_64/bits.zig");
+ const encoder = @import("../../arch/x86_64/encoder.zig");
+ const Disassembler = @import("../../arch/x86_64/Disassembler.zig");
+ const Immediate = bits.Immediate;
+ const Instruction = encoder.Instruction;
+};
+
const std = @import("std");
const assert = std.debug.assert;
const elf = std.elf;