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-rw-r--r--arch/x86/Makefile32
1 files changed, 14 insertions, 18 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index e84cdd409b64..63d50f65b828 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -36,7 +36,7 @@ endif
# How to compile the 16-bit code. Note we always compile for -march=i386;
# that way we can complain to the user if the CPU is insufficient.
-REALMODE_CFLAGS := -m16 -g -Os -DDISABLE_BRANCH_PROFILING \
+REALMODE_CFLAGS := -m16 -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \
-Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
-fno-strict-aliasing -fomit-frame-pointer -fno-pic \
-mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)
@@ -62,8 +62,20 @@ export BITS
#
KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx
-# Intel CET isn't enabled in the kernel
+ifeq ($(CONFIG_X86_KERNEL_IBT),y)
+#
+# Kernel IBT has S_CET.NOTRACK_EN=0, as such the compilers must not generate
+# NOTRACK prefixes. Current generation compilers unconditionally employ NOTRACK
+# for jump-tables, as such, disable jump-tables for now.
+#
+# (jump-tables are implicitly disabled by RETPOLINE)
+#
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104816
+#
+KBUILD_CFLAGS += $(call cc-option,-fcf-protection=branch -fno-jump-tables)
+else
KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
+endif
ifeq ($(CONFIG_X86_32),y)
BITS := 32
@@ -140,22 +152,6 @@ else
KBUILD_CFLAGS += -mcmodel=kernel
endif
-ifdef CONFIG_X86_X32
- x32_ld_ok := $(call try-run,\
- /bin/echo -e '1: .quad 1b' | \
- $(CC) $(KBUILD_AFLAGS) -c -x assembler -o "$$TMP" - && \
- $(OBJCOPY) -O elf32-x86-64 "$$TMP" "$$TMP.o" && \
- $(LD) -m elf32_x86_64 "$$TMP.o" -o "$$TMP",y,n)
- ifeq ($(x32_ld_ok),y)
- CONFIG_X86_X32_ABI := y
- KBUILD_AFLAGS += -DCONFIG_X86_X32_ABI
- KBUILD_CFLAGS += -DCONFIG_X86_X32_ABI
- else
- $(warning CONFIG_X86_X32 enabled but no binutils support)
- endif
-endif
-export CONFIG_X86_X32_ABI
-
#
# If the function graph tracer is used with mcount instead of fentry,
# '-maccumulate-outgoing-args' is needed to prevent a GCC bug