Hi Kefeng, It's probably a bug fix that unveils the link errors. tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.4.y head: cac6eb2794c85e7777fb0caac6fa75b6364d81a0 commit: 1865d6440fb63ad979d7034b2d7c94937bfd2200 [2066/5257] PCI: mobiveil: Fix csr_read()/write() build issue config: riscv-allyesconfig (attached as .config) compiler: riscv64-linux-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout 1865d6440fb63ad979d7034b2d7c94937bfd2200 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=riscv If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>, old ones prefixed by <<): riscv64-linux-ld: lib/ubsan.o: in function `.L2': >> ubsan.c:(.text.unlikely+0x38): undefined reference to `__ashlti3' >> riscv64-linux-ld: ubsan.c:(.text.unlikely+0x42): undefined reference to `__ashrti3'

--- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

On 2020/5/20 14:54, kbuild test robot wrote: > Hi Kefeng, > > It's probably a bug fix that unveils the link errors. > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.4.y > head: cac6eb2794c85e7777fb0caac6fa75b6364d81a0 > commit: 1865d6440fb63ad979d7034b2d7c94937bfd2200 [2066/5257] PCI: mobiveil: Fix csr_read()/write() build issue > config: riscv-allyesconfig (attached as .config) > compiler: riscv64-linux-gcc (GCC) 9.3.0 > reproduce: > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > git checkout 1865d6440fb63ad979d7034b2d7c94937bfd2200 > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=riscv > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kbuild test robot <lkp(a)intel.com&gt; > > All errors (new ones prefixed by >>, old ones prefixed by <<): > > riscv64-linux-ld: lib/ubsan.o: in function `.L2': > > > ubsan.c:(.text.unlikely+0x38): undefined reference to `__ashlti3' > > > riscv64-linux-ld: ubsan.c:(.text.unlikely+0x42): undefined reference to `__ashrti3' My patch is irrelevant，it seems that the following patch fix build error. commit fc585d4a5cf614727f64d86550b794bcad29d5c3 Author: Olof Johansson <olof(a)lixom.net&gt; Date:   Mon Dec 16 20:06:31 2019 -0800     riscv: Less inefficient gcc tishift helpers (and export their symbols)