diff --git a/lld/ELF/Arch/X86_64.cpp b/lld/ELF/Arch/X86_64.cpp --- a/lld/ELF/Arch/X86_64.cpp +++ b/lld/ELF/Arch/X86_64.cpp @@ -730,7 +730,12 @@ RelExpr X86_64::adjustGotPcExpr(RelType type, int64_t addend, const uint8_t *loc) const { - if (type != R_X86_64_GOTPCRELX && type != R_X86_64_REX_GOTPCRELX) + // Only R_X86_64_[REX_]GOTPCRELX can be relaxed. addend != -4 means the + // instruction does not load the full GOT entry, we cannot relax the + // relocation. E.g. movl x@GOTPCREL+4(%rip), %rax (addend=0) loads the high 32 + // bits of the GOT entry. + if ((type != R_X86_64_GOTPCRELX && type != R_X86_64_REX_GOTPCRELX) || + addend != -4) return R_GOT_PC; const uint8_t op = loc[-2]; const uint8_t modRm = loc[-1]; diff --git a/lld/test/ELF/x86-64-gotpc-offset.s b/lld/test/ELF/x86-64-gotpc-offset.s new file mode 100644 --- /dev/null +++ b/lld/test/ELF/x86-64-gotpc-offset.s @@ -0,0 +1,18 @@ +# REQUIRES: x86 +# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o +# RUN: ld.lld %t.o -o %t +# RUN: llvm-objdump -s -d %t | FileCheck %s + +# CHECK: Contents of section .got: +# CHECK-NEXT: 2021a0 9d112000 00000000 + +## The second instruction has an offset (addend!=-4). It is incorrect to relax +## movl to leal. +# CHECK: leaq 6(%rip), %rax # {{.*}} +# CHECK-NEXT: movl {{.*}}(%rip), %eax # 2021a4 + movq foo@GOTPCREL(%rip), %rax + movl foo@GOTPCREL+4(%rip), %eax + +.globl foo +foo: + nop