add tlsdesc support for x86_64

arch/x86_64/reloc.h

@@ -25,6 +25,8 @@ static int remap_rel(int type)
 		return REL_DTPOFF;
 	case R_X86_64_TPOFF64:
 		return REL_TPOFF;
+	case R_X86_64_TLSDESC:
+		return REL_TLSDESC;
 	}
 	return 0;
 }

src/ldso/x86_64/tlsdesc.s

@@ -0,0 +1,40 @@
+.text
+.global __tlsdesc_static
+.type __tlsdesc_static,@function
+__tlsdesc_static:
+	mov 8(%rax),%rax
+	ret
+
+.global __tlsdesc_dynamic
+.type __tlsdesc_dynamic,@function
+__tlsdesc_dynamic:
+	mov 8(%rax),%rax
+	push %rdx
+	mov %fs:8,%rdx
+	push %rcx
+	mov (%rax),%rcx
+	cmp %rcx,(%rdx)
+	jc 1f
+	mov 8(%rax),%rax
+	add (%rdx,%rcx,8),%rax
+2:	pop %rcx
+	sub %fs:0,%rax
+	pop %rdx
+	ret
+1:	push %rdi
+	push %rdi
+	push %rsi
+	push %r8
+	push %r9
+	push %r10
+	push %r11
+	mov %rax,%rdi
+	call __tls_get_addr
+	pop %r11
+	pop %r10
+	pop %r9
+	pop %r8
+	pop %rsi
+	pop %rdi
+	pop %rdi
+	jmp 2b