[ELF] - Do sign extend for addends of R_386_8, R_386_16 relocations

George Rimar · George Rimar · commit bdce4ad21d67 · 2017-02-14T13:22:03.000Z
Patch makes addends for addends of R_386_8, R_386_16 relocations be sign extended. The same we did earlier for PC ones, currenly LLD fails to link linux kernel, reporting relocation out of range because of this. Differential revision: https://reviews.llvm.org/D29714 llvm-svn: 295052
diff --git a/lld/ELF/Target.cpp b/lld/ELF/Target.cpp
@@ -491,11 +491,9 @@ int64_t X86TargetInfo::getImplicitAddend(const uint8_t *Buf,
   default:
     return 0;
   case R_386_8:
-    return *Buf;
   case R_386_PC8:
     return SignExtend64<8>(*Buf);
   case R_386_16:
-    return read16le(Buf);
   case R_386_PC16:
     return SignExtend64<16>(read16le(Buf));
   case R_386_32:
diff --git a/lld/test/ELF/i386-reloc8-reloc16-addend.s b/lld/test/ELF/i386-reloc8-reloc16-addend.s
@@ -0,0 +1,17 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=i386-pc-linux-gnu %s -o %t1.o
+
+# RUN: ld.lld -Ttext=0x0 %t1.o -o %t.out
+# RUN: llvm-objdump -s -t %t.out | FileCheck %s
+# CHECK:      Contents of section .text:
+# CHECK-NEXT:  0000 020100 
+## 0x3 + addend(-1) = 0x02
+## 0x3 + addend(-2) = 0x0100
+# CHECK: SYMBOL TABLE:
+# CHECK: 00000003 .und
+
+.byte  und-1
+.short und-2
+
+.section .und, "ax"
+und:
