riscv64 TLS support.

Signed-off-by: Mao Han <han_mao@linux.alibaba.com>
Signed-off-by: Xia Lifang <lifang_xia@linux.alibaba.com>
Signed-off-by: Chen Guoyin <chenguoyin.cgy@linux.alibaba.com>
Signed-off-by: Wang Chen <wangchen20@iscas.ac.cn>
Signed-off-by: Lu Xufan <luxufan@iscas.ac.cn>
Test: treehugger
Change-Id: I14efb4a03a3dc2ec736d7e47a3f8859c886eb9d6
diff --git a/linker/linker_relocate.cpp b/linker/linker_relocate.cpp
index c7c7bfb..952dade 100644
--- a/linker/linker_relocate.cpp
+++ b/linker/linker_relocate.cpp
@@ -49,7 +49,9 @@
     case R_GENERIC_TLS_DTPMOD:
     case R_GENERIC_TLS_DTPREL:
     case R_GENERIC_TLS_TPREL:
+#if defined(R_GENERIC_TLSDESC)
     case R_GENERIC_TLSDESC:
+#endif
       return true;
     default:
       return false;
@@ -426,7 +428,7 @@
     case R_GENERIC_TLS_DTPREL:
       count_relocation_if<IsGeneral>(kRelocRelative);
       {
-        const ElfW(Addr) result = sym_addr + get_addend_rel();
+        const ElfW(Addr) result = sym_addr + get_addend_rel() - TLS_DTV_OFFSET;
         trace_reloc("RELO TLS_DTPREL %16p <- %16p %s",
                     rel_target, reinterpret_cast<void*>(result), sym_name);
         *static_cast<ElfW(Addr)*>(rel_target) = result;