On Mon, Nov 16, 2020 at 10:21:26AM +0100, Arnd Bergmann wrote: > > Don't we need the dependencies on HAS_IOMEM for the CONFIG_UML=y > > case, too? > > I would have expected that as well, but I don't see the problem when building > an arch/um kernel, all I get is > > ERROR: modpost: "devm_platform_ioremap_resource" > [drivers/iio/adc/adi-axi-adc.ko] undefined! > ERROR: modpost: "devm_platform_ioremap_resource" > [drivers/ptp/ptp_ines.ko] undefined! > ERROR: modpost: "devm_ioremap_resource" > [drivers/net/ethernet/xilinx/xilinx_emac.ko] undefined! > ERROR: modpost: "devm_platform_ioremap_resource_byname" > [drivers/net/ethernet/xilinx/ll_temac.ko] undefined! > ERROR: modpost: "devm_ioremap" > [drivers/net/ethernet/xilinx/ll_temac.ko] undefined! > ERROR: modpost: "devm_of_iomap" > [drivers/net/ethernet/xilinx/ll_temac.ko] undefined! > ERROR: modpost: "__open64_2" [fs/hostfs/hostfs.ko] undefined! > > If I disable those five drivers, I can build and link a uml kernel without > warnings. I could not find the difference compared to s390 here. > > Looking a bit further, I now find that we ended up disabling > CONFIG_COMPILE_TEST > entirely for arch/um, which is clearly an option that would also work for > s390.
I'll add a patch to the s390 tree which disables CONFIG_COMPILE_TEST for s390. I wouldn't like to start again chasing/adding missing 'select' or 'depends on' statements in various config files.
