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Subject[PATCH] KVM: arm64: nvhe: Disable profile optimization
Date
Kernel build with -fprofile-sample-use raises the following failure:

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

SHT_REL is generated by the latest lld, see
https://reviews.llvm.org/rGca3bdb57fa1ac98b711a735de048c12b5fdd8086.
Disable profile optimization in kvm/nvhe to fix the build with
AutoFDO.

Signed-off-by: Denis Nikitin <denik@chromium.org>
---
arch/arm64/kvm/hyp/nvhe/Makefile | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index b5c5119c7396..6a6188374a52 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -89,6 +89,9 @@ 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))
+# Profile optimization creates SHT_REL section '.llvm.call-graph-profile' for
+# the hot code. SHT_REL is currently not supported by the KVM tools.
+KBUILD_CFLAGS += $(call cc-option,-fno-profile-sample-use,-fno-profile-use)

# 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
--
2.37.3.968.ga6b4b080e4-goog
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