Hello, since kernel 5.12, I compile kernel and xtables-addons-kmod with CLANG using: 1) extract the kernel source, and get the config included in https://elrepo.org/linux/kernel/el8/SRPMS/kernel-ml-5.12.12-1.el8.elrepo.nosrc.rpm 2) inside the kernel source, execute env LC_ALL=C TMPDIR=/var/tmp MAKEFLAGS="LLVM=1 " make oldconfig explanation: this uses CLANG as compiler, but LTO is not enabled. 3) substitute the new .config to the one from elrepo 4) compile the kernel with env LC_ALL=C TMPDIR=/var/tmp MAKEFLAGS="LLVM=1" nice -n 20 rpmbuild --noclean --nocheck --nodebuginfo --without bpftool --without perf --without tools -ba SPECS/kernel-ml-5.12.spec 5) install and boot the new kernel 6) generate the xtables-addons-kmod with env LC_ALL=C TMPDIR=/var/tmp MAKEFLAGS="LLVM=1" akmods --kernels 5.12.12-1.el8.clang.nolto.x86_64 I also tried using MAKEFLAGS="LLVM=1 LLVM_IAS=1" and selecting "thinlto" at step 2). It either failed either produced unbootable kernels. At kernel 5.12.12, this step succeeds and produces a working kernel. But step 6, now becoming env LC_ALL=C TMPDIR=/var/tmp MAKEFLAGS="LLVM=1 LLVM_IAS=1" akmods --kernels 5.12.12-1.el8.clang.thinlto.x86_64 fails during the compilation. I tried to narrow down the problem by calling the script generated by akmods a few times. It fails after invoking ld.ldd with "error: permission denied". Restarting manually the last failed line succeeds, but relaunching the script fails at another ld.ldd invocation. The platform is x86_64 with CentOS 8 Stream, clang is 11.0 Could you please try to compile this module under a kernel with CLANG+ThinLTO enabled ? Thanks in advance Pascal Dupuis
