mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-01-09 17:05:16 +00:00
Code Issues Packages Projects Releases Wiki Activity

x86_64: emit TLS local dynamic model when PIC

Browse Source
This commit is contained in:
Jakub Konka 2023-11-12 10:28:45 +01:00 committed by Jacob Young
parent 51efee2cb6
commit 984c598590
2 changed files with 70 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
src/arch/x86_64/Emit.zig
View File

@ -84,6 +84,24 @@ pub fn emitMir(emit: *Emit) Error!void {
} else return emit.fail("TODO implement extern reloc for {s}", .{
@tagName(emit.lower.bin_file.tag),
}),
.linker_tlsld => |data| {
const elf_file = emit.lower.bin_file.cast(link.File.Elf).?;
const atom = elf_file.symbol(data.atom_index).atom(elf_file).?;
try atom.addReloc(elf_file, .{
.r_offset = end_offset - 4,
.r_info = (@as(u64, @intCast(data.sym_index)) << 32) | std.elf.R_X86_64_TLSLD,
.r_addend = -4,
});
},
.linker_dtpoff => |data| {
const elf_file = emit.lower.bin_file.cast(link.File.Elf).?;
const atom = elf_file.symbol(data.atom_index).atom(elf_file).?;
try atom.addReloc(elf_file, .{
.r_offset = end_offset - 4,
.r_info = (@as(u64, @intCast(data.sym_index)) << 32) | std.elf.R_X86_64_DTPOFF32,
.r_addend = 0,
});
},
.linker_reloc => |data| if (emit.lower.bin_file.cast(link.File.Elf)) |elf_file| {
const is_obj_or_static_lib = switch (emit.lower.bin_file.options.output_mode) {
.Exe => false,

68
src/arch/x86_64/Lower.zig
View File

@ -11,6 +11,7 @@ result_relocs_len: u8 = undefined,
result_insts: [
std.mem.max(usize, &.{
1, // non-pseudo instructions
3, // TLS local dynamic (LD) sequence in PIC mode
2, // cmovcc: cmovcc \ cmovcc
3, // setcc: setcc \ setcc \ logicop
2, // jcc: jcc \ jcc
@ -28,6 +29,7 @@ result_relocs: [
2, // jcc: jcc \ jcc
2, // test \ jcc \ probe \ sub \ jmp
1, // probe \ sub \ jcc
3, // TLS local dynamic (LD) sequence in PIC mode
})
]Reloc = undefined,
@ -51,6 +53,8 @@ pub const Reloc = struct {
const Target = union(enum) {
inst: Mir.Inst.Index,
linker_reloc: bits.Symbol,
linker_tlsld: bits.Symbol,
linker_dtpoff: bits.Symbol,
linker_extern_fn: bits.Symbol,
linker_got: bits.Symbol,
linker_direct: bits.Symbol,
@ -353,24 +357,56 @@ fn emit(lower: *Lower, prefix: Prefix, mnemonic: Mnemonic, ops: []const Operand)
assert(mem_op.sib.scale_index.scale == 0);
if (isTls(sym, lower.bin_file)) {
lower.result_insts[lower.result_insts_len] =
try Instruction.new(.none, .mov, &[_]Operand{
.{ .reg = ops[0].reg.to64() },
.{ .mem = Memory.sib(.qword, .{ .base = .{ .reg = .fs } }) },
});
lower.result_insts_len += 1;
_ = lower.reloc(.{ .linker_reloc = sym });
if (lower.bin_file.cast(link.File.Elf)) |elf_file| {
const sym_index = elf_file.zigObjectPtr().?.symbol(sym.sym_index);
elf_file.symbol(sym_index).flags.needs_zig_got = false;
}
emit_mnemonic = .lea;
switch (mnemonic) {
.lea, .mov => break :op .{ .mem = Memory.sib(mem_op.sib.ptr_size, .{
// TODO handle extern TLS vars, i.e., emit GD model
if (lower.bin_file.options.pic) {
// Here, we currently assume local dynamic TLS vars, and so
// we emit LD model.
_ = lower.reloc(.{ .linker_tlsld = sym });
lower.result_insts[lower.result_insts_len] =
try Instruction.new(.none, .lea, &[_]Operand{
.{ .reg = ops[0].reg.to64() },
.{ .mem = Memory.rip(mem_op.sib.ptr_size, 0) },
});
lower.result_insts_len += 1;
if (lower.bin_file.cast(link.File.Elf)) |elf_file| {
_ = lower.reloc(.{ .linker_extern_fn = .{
.atom_index = sym.atom_index,
.sym_index = try elf_file.getGlobalSymbol("__tls_get_address", null),
} });
}
lower.result_insts[lower.result_insts_len] =
try Instruction.new(.none, .call, &[_]Operand{
.{ .imm = Immediate.s(0) },
});
lower.result_insts_len += 1;
_ = lower.reloc(.{ .linker_dtpoff = sym });
if (lower.bin_file.cast(link.File.Elf)) |elf_file| {
const sym_index = elf_file.zigObjectPtr().?.symbol(sym.sym_index);
elf_file.symbol(sym_index).flags.needs_zig_got = false;
}
emit_mnemonic = .lea;
break :op .{ .mem = Memory.sib(mem_op.sib.ptr_size, .{
.base = .{ .reg = ops[0].reg.to64() },
.disp = undefined,
}) },
else => unreachable,
}) };
} else {
// Since we are linking statically, we emit LE model directly.
lower.result_insts[lower.result_insts_len] =
try Instruction.new(.none, .mov, &[_]Operand{
.{ .reg = ops[0].reg.to64() },
.{ .mem = Memory.sib(.qword, .{ .base = .{ .reg = .fs } }) },
});
lower.result_insts_len += 1;
_ = lower.reloc(.{ .linker_reloc = sym });
if (lower.bin_file.cast(link.File.Elf)) |elf_file| {
const sym_index = elf_file.zigObjectPtr().?.symbol(sym.sym_index);
elf_file.symbol(sym_index).flags.needs_zig_got = false;
}
emit_mnemonic = .lea;
break :op .{ .mem = Memory.sib(mem_op.sib.ptr_size, .{
.base = .{ .reg = ops[0].reg.to64() },
.disp = undefined,
}) };
}
}