I ran `uname -r` after the iopl and ioperm example tests failed and saw it booted my custom Debian kernel.. I reboot, select the Debian 5.18 bpo (backported) kernel and the tests return:
status: 255 So I thought OK... Either something changed between 5.18 and 5.19 or I'm missing something in my kernel.. I google, "kernel iopl" and the 3rd result down is this: https://cateee.net/lkddb/web-lkddb/X86_IOPL_IOPERM.html By default, I disable anything with "emulation" in it's name for security reasons and glanced right past it over a thousand times.. The reason I never ran into this problem before is because I've always used RTAI with the 4.19 kernel series, which was before the CONFIG_X86_IOPL_IOPERM Kconfig option existed.. IF YOU'RE BUIDLING A CUSTOM KERNEL FOR LINUXCNC, MAKE SURE "CONFIG_X86_IOPL_IOPERM: IOPERM and IOPL Emulation" IS ENABLED OR YOU WON'T HAVE A GOOD TIME!!! Related article: https://lwn.net/Articles/804143/ PROBLEM SOLVED! A long-term solution would be migrating away from ioperm() and iopl() though as these options may be removed in the future. As for an alternative, maybe this has some answers which could be useful? https://lore.kernel.org/lkml/20191028201313.ga27...@1wt.eu/T/ Anyway, cheers! Oh it feels good to have this sorted out! Alec _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
