[PATCH] D123985: [ELF] Assert on invalid GOT or PLT relocations

[Shoaib Meenai via Phabricator via llvm-commits]

smeenai added a comment.

In D123985#3463657 <https://reviews.llvm.org/D123985#3463657>, @nathanchance wrote:

> This assertion triggers when building the Linux kernel for arm64:
>
>   $ make -skj"$(nproc)" ARCH=arm64 LLVM=1 mrproper defconfig all
>   ld.lld: /home/nathan/cbl/src/llvm-project/lld/ELF/SyntheticSections.cpp:1597: uint32_t lld::elf::DynamicReloc::getSymIndex(lld::elf::SymbolTableBaseSection *) const: Assertion `(index != 0 || type != target->gotRel && type != target->pltRel) && "GOT or PLT relocation must refer to symbol in dynamic symbol table"' failed.
>   ld.lld: /home/nathan/cbl/src/llvm-project/lld/ELF/SyntheticSections.cpp:1597: uint32_t lld::elf::DynamicReloc::getSymIndex(lld::elf::SymbolTableBaseSection *) const: Assertion `(index != 0 || type != target->gotRel && type != target->pltRel) && "GOT or PLT relocation must refer to symbol in dynamic symbol table"' failed.
>   ld.lld: /home/nathan/cbl/src/llvm-project/lld/ELF/SyntheticSections.cpp:1597: uint32_t lld::elf::DynamicReloc::getSymIndex(lld::elf::SymbolTableBaseSection *) const: Assertion `(index != 0 || type != target->gotRel && type != target->pltRel) && "GOT or PLT relocation must refer to symbol in dynamic symbol table"' failed.
>   ld.lld: /home/nathan/cbl/src/llvm-project/lld/ELF/SyntheticSections.cpp:1597: uint32_t lld::elf::DynamicReloc::getSymIndex(lld::elf::SymbolTableBaseSection *) const: Assertion `(index != 0 || type != target->gotRel && type != target->pltRel) && "GOT or PLT relocation must refer to symbol in dynamic symbol table"' failed.
>   ld.lld: /home/nathan/cbl/src/llvm-project/lld/ELF/SyntheticSections.cpp:1597: uint32_t lld::elf::DynamicReloc::getSymIndex(lld::elf::SymbolTableBaseSection *) const: Assertion `(index != 0 || type != target->gotRel && type != target->pltRel) && "GOT or PLT relocation must refer to symbol in dynamic symbol table"' failed.
>   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
>   ld.lld: /home/nathan/cbl/src/llvm-project/lld/ELF/SyntheticSections.cpp:1597: uint32_t lld::elf::DynamicReloc::getSymIndex(lld::elf::SymbolTableBaseSection *) const: Assertion `(index != 0 || type != target->gotRel && type != target->pltRel) && "GOT or PLT relocation must refer to symbol in dynamic symbol table"' failed.
>   ld.lld: /home/nathan/cbl/src/llvm-project/lld/ELF/SyntheticSections.cpp:1597: uint32_t lld::elf::DynamicReloc::getSymIndex(lld::elf::SymbolTableBaseSection *) const: Assertion `(index != 0 || type != target->gotRel && type != target->pltRel) && "GOT or PLT relocation must refer to symbol in dynamic symbol table"' failed.
>   ld.lld: /home/nathan/cbl/src/llvm-project/lld/ELF/SyntheticSections.cpp:1597: uint32_t lld::elf::DynamicReloc::getSymIndex(lld::elf::SymbolTableBaseSection *) const: Assertion `(index != 0 || type != target->gotRel && type != target->pltRel) && "GOT or PLT relocation must refer to symbol in dynamic symbol table"' failed.
>   scripts/link-vmlinux.sh: line 164: 2580614 Aborted                 (core dumped) ${ld} ${ldflags} -o ${output} ${wl}--whole-archive ${objs} ${wl}--no-whole-archive ${wl}--start-group ${libs} ${wl}--end-group $@ ${ldlibs}
>   make[1]: *** [Makefile:1158: vmlinux] Error 134
>
> What can I provide to help investigate this further?

Hmm, this is interesting. I think the assertion should only fire when the linker would have otherwise produced an invalid binary, but maybe there's something in the Linux kernel which would make this work.

Could you create a tarball with `--reproduce` and upload that somewhere? Feel free to revert this in the meantime if it's blocking you.


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