On Sat. 14 May 2022 à 13:20, kernel test robot <lkp@xxxxxxxxx> wrote: > Hi Vincent, > > I love your patch! Yet something to improve: > > [auto build test ERROR on mkl-can-next/testing] > [also build test ERROR on v5.18-rc6 next-20220513] > [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/intel-lab-lkp/linux/commits/Vincent-Mailhol/can-skb-move-can_dropped_invalid_skb-and-can_skb_headroom_valid-to-skb-c/20220514-003707 > base: https://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git testing > config: arm-randconfig-r021-20220512 (https://download.01.org/0day-ci/archive/20220514/202205141221.H0aZXRak-lkp@xxxxxxxxx/config) > compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 38189438b69ca27b4c6ce707c52dbd217583d046) > 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 arm cross compiling tool for clang build > # apt-get install binutils-arm-linux-gnueabi > # https://github.com/intel-lab-lkp/linux/commit/8f56e6b1b9945ea47c9f410d1254451df9d6fe22 > git remote add linux-review https://github.com/intel-lab-lkp/linux > git fetch --no-tags linux-review Vincent-Mailhol/can-skb-move-can_dropped_invalid_skb-and-can_skb_headroom_valid-to-skb-c/20220514-003707 > git checkout 8f56e6b1b9945ea47c9f410d1254451df9d6fe22 > # save the config file > mkdir build_dir && cp config build_dir/.config > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > All errors (new ones prefixed by >>): > > ld.lld: warning: lld uses blx instruction, no object with architecture supporting feature detected > ld.lld: warning: lld uses blx instruction, no object with architecture supporting feature detected > >> ld.lld: error: undefined symbol: can_dropped_invalid_skb > >>> referenced by vxcan.c:45 (drivers/net/can/vxcan.c:45) > >>> net/can/vxcan.o:(vxcan_xmit) in archive drivers/built-in.a OK, so the issue is that VCAN and VXCAN are users of can_dropped_invalid_skb() but do not depend on CAN_DEV. Above error will appear if CONFIG_CAN_DEV is not set (or if CONFIG_V{,X}CAN is set to "yes" and CAN_DEV is set to "module"). I see three choices here: 1. move can_dropped_invalid_skb() outside of drivers/net/can (i.e. move it somewhere in net/can). 2. split CAN_DEV into one additional sub module: CAN_SKB and add a dependency to it in VCAN and VXCAN. 3. Add a dependency to CAN_DEV in VCAN and VXCAN 1. is I think the worse, 2. the best, 3. is the laziest option and is kind of acceptable. @Marc (and anyone else), what are your thoughts? Yours sincerely, Vincent Mailhol
