Hi Lorenz, I love your patch! Yet something to improve: [auto build test ERROR on bpf/master] url: https://github.com/0day-ci/linux/commits/Lorenz-Bauer/Expose-network-name... base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git master config: s390-randconfig-r002-20210209 (attached as .config) compiler: s390-linux-gcc (GCC) 9.3.0 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 # https://github.com/0day-ci/linux/commit/ec096a87ec268b0634a140515fb54b21a... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Lorenz-Bauer/Expose-network-namespace-cookies-to-user-space/20210210-201857 git checkout ec096a87ec268b0634a140515fb54b21a2c67036 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=s390 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): s390-linux-ld: kernel/dma/coherent.o: in function `dma_init_coherent_memory': coherent.c:(.text+0x208): undefined reference to `memremap' s390-linux-ld: coherent.c:(.text+0x2d2): undefined reference to `memunmap' s390-linux-ld: kernel/dma/coherent.o: in function `dma_declare_coherent_memory': coherent.c:(.text+0x6c2): undefined reference to `memunmap' s390-linux-ld: fs/nsfs.o: in function `ns_ioctl': s390-linux-ld: drivers/irqchip/irq-al-fic.o: in function `al_fic_init_dt': irq-al-fic.c:(.init.text+0x46): undefined reference to `of_iomap' s390-linux-ld: irq-al-fic.c:(.init.text+0x2a4): undefined reference to `iounmap' s390-linux-ld: drivers/char/xillybus/xillybus_of.o: in function `xilly_drv_probe': xillybus_of.c:(.text+0x146): undefined reference to `devm_platform_ioremap_resource' s390-linux-ld: drivers/pcmcia/cistpl.o: in function `set_cis_map': cistpl.c:(.text+0x386): undefined reference to `ioremap' s390-linux-ld: cistpl.c:(.text+0x3c0): undefined reference to `iounmap' s390-linux-ld: cistpl.c:(.text+0x3f2): undefined reference to `iounmap' s390-linux-ld: cistpl.c:(.text+0x404): undefined reference to `ioremap' s390-linux-ld: drivers/pcmcia/cistpl.o: in function `release_cis_mem': cistpl.c:(.text+0xe56): undefined reference to `iounmap' s390-linux-ld: drivers/input/serio/apbps2.o: in function `apbps2_of_probe': apbps2.c:(.text+0x286): undefined reference to `devm_ioremap_resource' s390-linux-ld: drivers/input/touchscreen/imx6ul_tsc.o: in function `imx6ul_tsc_probe': imx6ul_tsc.c:(.text+0x256): undefined reference to `devm_platform_ioremap_resource' s390-linux-ld: imx6ul_tsc.c:(.text+0x2bc): undefined reference to `devm_platform_ioremap_resource' --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org