[PATCH] x86/purgatory: Compile purgatory with -D__DISABLE_EXPORTS

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

A previous patch fixed compile-time issues by setting __NO_FORTIFY
for all of the purgatory code, but this is insufficient and still
leaves build failures that appeared recently in linux-next:

ld.lld: error: undefined symbol: __memset
>>> referenced by string.c
>>>               arch/x86/purgatory/purgatory.ro:(__UNIQUE_ID_addressable___memset_2)

ld.lld: error: undefined symbol: __memmove
>>> referenced by string.c
>>>               arch/x86/purgatory/purgatory.ro:(__UNIQUE_ID_addressable___memmove_3)

Set __DISABLE_EXPORTS as well, to avoid pulling in a reference to the
wrong string functions.

Fixes: 65cbe410d312 ("x86/purgatory: Compile purgatory with -D__NO_FORTIFY")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/x86/purgatory/Makefile | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index cde8463b4d84..df7dbb5b3387 100644
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -11,8 +11,6 @@ $(obj)/string.o: $(srctree)/arch/x86/boot/compressed/string.c FORCE
 $(obj)/sha256.o: $(srctree)/lib/crypto/sha256.c FORCE
 	$(call if_changed_rule,cc_o_c)
 
-CFLAGS_sha256.o := -D__DISABLE_EXPORTS
-
 # When profile-guided optimization is enabled, llvm emits two different
 # overlapping text sections, which is not supported by kexec. Remove profile
 # optimization flags.
@@ -37,7 +35,7 @@ PURGATORY_CFLAGS := -mcmodel=small -ffreestanding -fno-zero-initialized-in-bss -
 PURGATORY_CFLAGS += -fpic -fvisibility=hidden
 PURGATORY_CFLAGS += $(DISABLE_KSTACK_ERASE) -DDISABLE_BRANCH_PROFILING
 PURGATORY_CFLAGS += -fno-stack-protector
-PURGATORY_CFLAGS += -D__NO_FORTIFY
+PURGATORY_CFLAGS += -D__NO_FORTIFY -D__DISABLE_EXPORTS
 
 # 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
-- 
2.53.0