[PATCH v5 23/29] KVM: arm64: disable LTO for the nVHE directory

Sami Tolvanen samitolvanen at google.com
Fri Oct 9 12:13:32 EDT 2020


We use objcopy to manipulate ELF binaries for the nVHE code,
which fails with LTO as the compiler produces LLVM bitcode
instead. Disable LTO for this code to allow objcopy to be used.

Signed-off-by: Sami Tolvanen <samitolvanen at google.com>
Reviewed-by: Kees Cook <keescook at chromium.org>
---
 arch/arm64/kvm/hyp/nvhe/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index aef76487edc2..c903c8f31280 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -45,9 +45,9 @@ quiet_cmd_hypcopy = HYPCOPY $@
 		   --rename-section=.text=.hyp.text			\
 		   $< $@
 
-# Remove ftrace and Shadow Call Stack CFLAGS.
+# Remove ftrace, LTO, and Shadow Call Stack CFLAGS.
 # This is equivalent to the 'notrace' and '__noscs' annotations.
-KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))
+KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE) $(CC_FLAGS_LTO) $(CC_FLAGS_SCS), $(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
-- 
2.28.0.1011.ga647a8990f-goog




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