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-rw-r--r--arch/arm64/kvm/hyp/nvhe/Makefile26
1 files changed, 23 insertions, 3 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index 0b34414557d6..aef76487edc2 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -20,10 +20,30 @@ $(obj)/%.hyp.tmp.o: $(src)/%.S FORCE
$(obj)/%.hyp.o: $(obj)/%.hyp.tmp.o FORCE
$(call if_changed,hypcopy)
+# Disable reordering functions by GCC (enabled at -O2).
+# This pass puts functions into '.text.*' sections to aid the linker
+# in optimizing ELF layout. See HYPCOPY comment below for more info.
+ccflags-y += $(call cc-option,-fno-reorder-functions)
+
+# The HYPCOPY command uses `objcopy` to prefix all ELF symbol names
+# and relevant ELF section names to avoid clashes with VHE code/data.
+#
+# Hyp code is assumed to be in the '.text' section of the input object
+# files (with the exception of specialized sections such as
+# '.hyp.idmap.text'). This assumption may be broken by a compiler that
+# divides code into sections like '.text.unlikely' so as to optimize
+# ELF layout. HYPCOPY checks that no such sections exist in the input
+# using `objdump`, otherwise they would be linked together with other
+# kernel code and not memory-mapped correctly at runtime.
quiet_cmd_hypcopy = HYPCOPY $@
- cmd_hypcopy = $(OBJCOPY) --prefix-symbols=__kvm_nvhe_ \
- --rename-section=.text=.hyp.text \
- $< $@
+ cmd_hypcopy = \
+ if $(OBJDUMP) -h $< | grep -F '.text.'; then \
+ echo "$@: function reordering not supported in nVHE hyp code" >&2; \
+ /bin/false; \
+ fi; \
+ $(OBJCOPY) --prefix-symbols=__kvm_nvhe_ \
+ --rename-section=.text=.hyp.text \
+ $< $@
# Remove ftrace and Shadow Call Stack CFLAGS.
# This is equivalent to the 'notrace' and '__noscs' annotations.