On Fri, Jan 14, 2022 at 02:14:02PM +0000, Paul Barker wrote:
Hi folks,
Please backport commit f634ca650f72 "kbuild: Add $(KBUILD_HOSTLDFLAGS) to 'has_libelf' test" to stable series 5.10.y, 5.4.y & 4.19.y.
This backport is needed to fix builds with CONFIG_UNWINDER_ORC=y where HOSTLDFLAGS is given on the make command line containing library paths needed to link against libelf. The issue was found when trying to build stable kernel branches for x86-64 using Yocto Project after commit 7fd06a57a1d9 "kernel: Rework kernel make flag to variable mappings" was added to openembedded-core back in October.
The backport to 5.10.y is trivial. The backports to 5.4.y & 4.19.y need a minor tweak so I'll send patches for those following this email.
The build failure is also seen in 4.14.y but I can't see a trivial way to address this as KBUILD_HOSTLDFLAGS does not exist in 4.14.y and backporting the commit which introduces KBUILD_HOSTLDFLAGS would change several other kbuild areas. I'm happy to workaround this locally by disabling CONFIG_UNWINDER_ORC for 4.14.y builds but it may be worth considering alternative fixes for this branch.
Added to 4.19.y queue right now. Will add to 5.4.y queue once the next release is out as it is currently in -rc status.
thanks,
greg k-h