1 files changed, 63 insertions, 17 deletions
diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index 3cf302b26332..5ce1d4263000 100644
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -1,37 +1,83 @@
 # SPDX-License-Identifier: GPL-2.0
-OBJECT_FILES_NON_STANDARD := y
 
 purgatory-y := purgatory.o stack.o setup-x86_$(BITS).o sha256.o entry64.o string.o
 
 targets += $(purgatory-y)
 PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
 
-$(obj)/sha256.o: $(srctree)/lib/sha256.c FORCE
+$(obj)/string.o: $(srctree)/arch/x86/boot/compressed/string.c FORCE
 	$(call if_changed_rule,cc_o_c)
 
-LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib
-targets += purgatory.ro
+$(obj)/sha256.o: $(srctree)/lib/crypto/sha256.c FORCE
+	$(call if_changed_rule,cc_o_c)
+
+CFLAGS_sha256.o := -D__DISABLE_EXPORTS -D__NO_FORTIFY
+
+# When profile-guided optimization is enabled, llvm emits two different
+# overlapping text sections, which is not supported by kexec. Remove profile
+# optimization flags.
+KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%,$(KBUILD_CFLAGS))
+
+# When LTO is enabled, llvm emits many text sections, which is not supported
+# by kexec. Remove -flto=* flags.
+KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS))
 
-KASAN_SANITIZE	:= n
-KCOV_INSTRUMENT := n
+# When linking purgatory.ro with -r unresolved symbols are not checked,
+# also link a purgatory.chk binary without -r to check for unresolved symbols.
+PURGATORY_LDFLAGS := -e purgatory_start -z nodefaultlib
+LDFLAGS_purgatory.ro := -r $(PURGATORY_LDFLAGS)
+LDFLAGS_purgatory.chk := $(PURGATORY_LDFLAGS)
+targets += purgatory.ro purgatory.chk
+
+# These are adjustments to the compiler flags used for objects that
+# make up the standalone purgatory.ro
+
+PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel
+PURGATORY_CFLAGS := -mcmodel=small -ffreestanding -fno-zero-initialized-in-bss -g0
+PURGATORY_CFLAGS += -fpic -fvisibility=hidden
+PURGATORY_CFLAGS += $(DISABLE_KSTACK_ERASE) -DDISABLE_BRANCH_PROFILING
+PURGATORY_CFLAGS += -fno-stack-protector
 
 # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
 # in turn leaves some undefined symbols like __fentry__ in purgatory and not
-# sure how to relocate those. Like kexec-tools, use custom flags.
+# sure how to relocate those.
+ifdef CONFIG_FUNCTION_TRACER
+PURGATORY_CFLAGS_REMOVE		+= $(CC_FLAGS_FTRACE)
+endif
+
+ifdef CONFIG_STACKPROTECTOR
+PURGATORY_CFLAGS_REMOVE		+= -fstack-protector
+endif
+
+ifdef CONFIG_STACKPROTECTOR_STRONG
+PURGATORY_CFLAGS_REMOVE		+= -fstack-protector-strong
+endif
 
-KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes -fno-zero-initialized-in-bss -fno-builtin -ffreestanding -c -Os -mcmodel=large
-KBUILD_CFLAGS += -m$(BITS)
-KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
+ifdef CONFIG_MITIGATION_RETPOLINE
+PURGATORY_CFLAGS_REMOVE		+= $(RETPOLINE_CFLAGS)
+endif
+
+ifdef CONFIG_CFI
+PURGATORY_CFLAGS_REMOVE		+= $(CC_FLAGS_CFI)
+endif
+
+CFLAGS_REMOVE_purgatory.o	+= $(PURGATORY_CFLAGS_REMOVE)
+CFLAGS_purgatory.o		+= $(PURGATORY_CFLAGS)
+
+CFLAGS_REMOVE_sha256.o		+= $(PURGATORY_CFLAGS_REMOVE)
+CFLAGS_sha256.o			+= $(PURGATORY_CFLAGS)
+
+CFLAGS_REMOVE_string.o		+= $(PURGATORY_CFLAGS_REMOVE)
+CFLAGS_string.o			+= $(PURGATORY_CFLAGS)
+
+asflags-remove-y		+= $(foreach x, -g -gdwarf-4 -gdwarf-5, $(x) -Wa,$(x))
 
 $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
 		$(call if_changed,ld)
 
-targets += kexec-purgatory.c
-
-quiet_cmd_bin2c = BIN2C   $@
-      cmd_bin2c = $(objtree)/scripts/bin2c kexec_purgatory < $< > $@
+$(obj)/purgatory.chk: $(obj)/purgatory.ro FORCE
+		$(call if_changed,ld)
 
-$(obj)/kexec-purgatory.c: $(obj)/purgatory.ro FORCE
-	$(call if_changed,bin2c)
+$(obj)/kexec-purgatory.o: $(obj)/purgatory.ro $(obj)/purgatory.chk
 
-obj-$(CONFIG_KEXEC_FILE)	+= kexec-purgatory.o
+obj-y += kexec-purgatory.o