On Sat, Mar 27, 2021 at 12:05:34AM +0800, kernel test robot wrote: > Hi Nathan, > > I love your patch! Yet something to improve: > > [auto build test ERROR on linus/master] > [also build test ERROR on v5.12-rc4 next-20210326] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch] > > url: > https://github.com/0day-ci/linux/commits/Nathan-Chancellor/riscv-Use-LD-instead-of-CC-to-link-vDSO/20210326-055421 > base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > 002322402dafd846c424ffa9240a937f49b48c42 > config: riscv-randconfig-r032-20210326 (attached as .config) > compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project > f490a5969bd52c8a48586f134ff8f02ccbb295b3) > reproduce (this is a W=1 build): > 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://github.com/0day-ci/linux/commit/dfdcaf93f40f0d15ffc3f25128442c1688e612d6 > git remote add linux-review https://github.com/0day-ci/linux > git fetch --no-tags linux-review > Nathan-Chancellor/riscv-Use-LD-instead-of-CC-to-link-vDSO/20210326-055421 > git checkout dfdcaf93f40f0d15ffc3f25128442c1688e612d6 > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv
For the record, I tried to use this script to reproduce but it has a couple of bugs: 1. It does not download the right version of clang. This report says that it is clang-13 but the one that the script downloaded is clang-12. 2. It does not download it to the right location. The script expects ~/0day/clang-latest but it is downloaded to ~/0day/clang it seems. I symlinked it to get around it. > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <l...@intel.com> > > All errors (new ones prefixed by >>): > > >> riscv64-linux-gnu-objcopy: 'arch/riscv/kernel/vdso/vdso.so.dbg': No such > >> file This error only occurs because of errors before it that are not shown due to a denylist: ld.lld: error: arch/riscv/kernel/vdso/rt_sigreturn.o:(.text+0x0): relocation R_RISCV_ALIGN requires unimplemented linker relaxation; recompile with -mno-relax ld.lld: error: arch/riscv/kernel/vdso/getcpu.o:(.text+0x0): relocation R_RISCV_ALIGN requires unimplemented linker relaxation; recompile with -mno-relax ld.lld: error: arch/riscv/kernel/vdso/flush_icache.o:(.text+0x0): relocation R_RISCV_ALIGN requires unimplemented linker relaxation; recompile with -mno-relax My patch only adds another occurrence of this error because we move from $(CC)'s default linker (in clang's case, ld.bfd) to $(LD), which in the case of 0day appears to be ld.lld. ld.lld should not be used with RISC-V in its current form due to errors of this nature, which happen without my patch as well: https://github.com/ClangBuiltLinux/linux/issues/1020 Linker relaxation in ld.lld for RISC-V is an ongoing debate/process. Please give RISC-V the current treatment as s390 with ld.lld for the time being to get meaningful reports. We will reach out once that issue has been resolved. TL;DR: Patch exposes existing issue with LD=ld.lld that would have happened without it in different areas, the report can be ignored. Cheers! Nathan