On 02/02/18 15:30, James Pearson wrote: > OK, I know CentOS has nothing to do with RHEL beta releases, but I > wanted to test if el7.5 has added support for a particular peripheral > (Wacom Pro 2 tablet) ... but was unable to install the propriety Nvidia > display driver (v390.25) on a test workstation - and was wondering if > anyone could explain on what is going on. > > All I've done is upgrade an existing CentOS 7.4 install with the RHEL > 7.5 beta kernel RPMS > > However, when installing the Nvidia driver, it fails with: > > FATAL: modpost: GPL-incompatible module nvidia.ko uses GPL-only symbol > '__cachemode2pte_tbl' > > A bit of Googling seems to suggest that this issue has been 'fixed' in > later upstream kernels by changing the export of this symbol from > 'EXPORT_SYMBOL_GPL' to 'EXPORT_SYMBOL' > > However, 7.4 and earlier el7 kernels also export this symbol as > EXPORT_SYMBOL_GPL - but the Nvidia driver builds/installs fine on 7.4 > kernels ... > > So, I'm not really sure what the issue is - i.e. is it an Nvidia or > Redhat issue ? > It looks like a regression. This was originally fixed upstream (kernel.org) 3 years ago, so if the RHEL7.5 beta kernel has reverted to 'EXPORT_SYMBOL_GPL' then it is a regression that will break building any out-of-tree non-gpl modules which need to set caching mode in pte's You should file a bug report with Red Hat. > For now, I've managed to hack around this by patching the stub Nvidia > driver src to change MODULE_LICENSE from "NVIDIA" to "GPL" - and the > Nvidia driver now installs and loads OK > The correct fix in the kernel is in arch/x86/mm/init.c -EXPORT_SYMBOL_GPL(__cachemode2pte_tbl); +EXPORT_SYMBOL(__cachemode2pte_tbl); > If anyone knows any more about this, then please let me know > > Thanks > > James Pearson