Messages in this thread | | | Date | Mon, 19 Jun 2023 14:26:24 -0700 (PDT) | Subject | Re: ld.lld: error: relocation R_RISCV_HI20 cannot be used against symbol 'misaligned_access_speed'; recompile with -fPIC | From | Palmer Dabbelt <> |
| |
On Wed, 14 Jun 2023 09:40:28 PDT (-0700), ndesaulniers@google.com wrote: > On Tue, Jun 13, 2023 at 4:17 AM Alexandre Ghiti <alexghiti@rivosinc.com> wrote: >> >> On Sun, Jun 11, 2023 at 2:11 AM kernel test robot <lkp@intel.com> wrote: >> > >> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master >> > head: 022ce8862dff83c859089cd14bc4dca0733e2f90 >> > commit: 8dc2a7e8027fbeca0c7df81d4c82e735a59b5741 riscv: Fix relocatable kernels with early alternatives using -fno-pie >> > date: 10 days ago >> > config: riscv-randconfig-r022-20230611 (https://download.01.org/0day-ci/archive/20230611/202306110855.7TlBCIzI-lkp@intel.com/config) >> > compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07) >> > reproduce (this is a W=1 build): >> > mkdir -p ~/bin >> > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross >> > chmod +x ~/bin/make.cross >> > # install riscv cross compiling tool for clang build >> > # apt-get install binutils-riscv64-linux-gnu >> > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8dc2a7e8027fbeca0c7df81d4c82e735a59b5741 >> > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >> > git fetch --no-tags linus master >> > git checkout 8dc2a7e8027fbeca0c7df81d4c82e735a59b5741 >> > # save the config file >> > mkdir build_dir && cp config build_dir/.config >> > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=riscv olddefconfig >> > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash >> > >> > If you fix the issue in a separate patch/commit (i.e. not just a new version of >> > the same patch/commit), kindly add following tags >> > | Reported-by: kernel test robot <lkp@intel.com> >> > | Closes: https://lore.kernel.org/oe-kbuild-all/202306110855.7TlBCIzI-lkp@intel.com/ >> > >> > All errors (new ones prefixed by >>): >> > >> > >> ld.lld: error: relocation R_RISCV_HI20 cannot be used against symbol 'misaligned_access_speed'; recompile with -fPIC >> > >>> defined in vmlinux.a(arch/riscv/kernel/cpufeature.o) >> > >>> referenced by errata.c:42 (arch/riscv/errata/thead/errata.c:42) >> > >>> arch/riscv/errata/thead/errata.o:(thead_feature_probe_func) in archive vmlinux.a >> > -- >> > >> ld.lld: error: relocation R_RISCV_LO12_I cannot be used against symbol 'misaligned_access_speed'; recompile with -fPIC >> > >>> defined in vmlinux.a(arch/riscv/kernel/cpufeature.o) >> > >>> referenced by errata.c:42 (arch/riscv/errata/thead/errata.c:42) >> > >>> arch/riscv/errata/thead/errata.o:(thead_feature_probe_func) in archive vmlinux.a >> > -- >> > >> ld.lld: error: relocation R_RISCV_HI20 cannot be used against symbol 'riscv_cbom_block_size'; recompile with -fPIC >> > >>> defined in vmlinux.a(arch/riscv/mm/cacheflush.o) >> > >>> referenced by errata.c:42 (arch/riscv/errata/thead/errata.c:42) >> > >>> arch/riscv/errata/thead/errata.o:(thead_errata_patch_func) in archive vmlinux.a >> > -- >> > >> ld.lld: error: relocation R_RISCV_LO12_S cannot be used against symbol 'riscv_cbom_block_size'; recompile with -fPIC >> > >>> defined in vmlinux.a(arch/riscv/mm/cacheflush.o) >> > >>> referenced by errata.c:42 (arch/riscv/errata/thead/errata.c:42) >> > >>> arch/riscv/errata/thead/errata.o:(thead_errata_patch_func) in archive vmlinux.a >> > -- >> > >> ld.lld: error: relocation R_RISCV_HI20 cannot be used against symbol '__per_cpu_offset'; recompile with -fPIC >> > >>> defined in vmlinux.a(mm/percpu.o) >> > >>> referenced by errata.c:42 (arch/riscv/errata/thead/errata.c:42) >> > >>> arch/riscv/errata/thead/errata.o:(thead_feature_probe_func) in archive vmlinux.a >> > -- >> > >> ld.lld: error: relocation R_RISCV_LO12_I cannot be used against symbol '__per_cpu_offset'; recompile with -fPIC >> > >>> defined in vmlinux.a(mm/percpu.o) >> > >>> referenced by errata.c:42 (arch/riscv/errata/thead/errata.c:42) >> > >>> arch/riscv/errata/thead/errata.o:(thead_feature_probe_func) in archive vmlinux.a >> > >> >> So I looked into those errors, the config is basically = RELOCATABLE + >> MEDLOW - EARLY_ALTERNATIVES. Then errata/thead is not compiled as > > Thanks for taking a look. Shouldn't CONFIG_RELOCATABLE be setting > -fPIC? If so, why is LLD complaining about -fPIC not being used? > > arch/riscv/Makefile sets -fPIE if CONFIG_RELOCATABLE == y. > > Is it possible that -fpie was dropped for these object files, or > -fno-pic or -fno-pie was added to the cflags for these object files > somehow? > > I've filed > https://github.com/ClangBuiltLinux/linux/issues/1872 > to track this.
Using R_RISCV_{HI20,LO12_I,LO12_S} to refer to non-absolute symbols in a PIE shouldn't be allowed, it's not going to produce the right answer at runtime.
We've got a lot of complicated bits in the build scripts so it's worth checking to make sure that `-fPIE` actually manifests in the link step. If it is and GNU LD isn't complaining then I think we've likely got a linker bug.
>> medany, which makes sense since we only need this code to be medany >> when EARLY_ALTERNATIVES is enabled (because the code would be executed >> with mmu off, which is not the case here). >> >> I can fix those errors by adding the medany flag, but I'm not sure >> actually we want to do that since we do not need it and gcc does not >> complain: any idea? >> >> Alex >> >> >> >> > -- >> > 0-DAY CI Kernel Test Service >> > https://github.com/intel/lkp-tests/wiki >> > > > -- > Thanks, > ~Nick Desaulniers
| |