From: Denis Nikitin denik@chromium.org

commit bde971a83bbff78561458ded236605a365411b87 upstream.

Kernel build with clang and KCFLAGS=-fprofile-sample-use=<profile> fails with:

error: arch/arm64/kvm/hyp/nvhe/kvm_nvhe.tmp.o: Unexpected SHT_REL section ".rel.llvm.call-graph-profile"

Starting from 13.0.0 llvm can generate SHT_REL section, see https://reviews.llvm.org/rGca3bdb57fa1ac98b711a735de048c12b5fdd8086. gen-hyprel does not support SHT_REL relocation section.

Filter out profile use flags to fix the build with profile optimization.

Signed-off-by: Denis Nikitin denik@chromium.org Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20221014184532.3153551-1-denik@chromium.org Signed-off-by: Stephen Boyd swboyd@chromium.org ---

I need this to properly compile 5.15.y stable kernels in the chromeos build system.

arch/arm64/kvm/hyp/nvhe/Makefile | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index 8d741f71377f..964c2134ea1e 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -83,6 +83,10 @@ quiet_cmd_hypcopy = HYPCOPY $@ # Remove ftrace, Shadow Call Stack, and CFI CFLAGS. # This is equivalent to the 'notrace', '__noscs', and '__nocfi' annotations. KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) $(CC_FLAGS_CFI), $(KBUILD_CFLAGS)) +# Starting from 13.0.0 llvm emits SHT_REL section '.llvm.call-graph-profile' +# when profile optimization is applied. gen-hyprel does not support SHT_REL and +# causes a build failure. Remove profile optimization flags. +KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%, $(KBUILD_CFLAGS))

# KVM nVHE code is run at a different exception code with a different map, so # compiler instrumentation that inserts callbacks or checks into the code may