From f77767ed5f4d398b29119563155e4ece2dfeee13 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ardb@kernel.org>
Date: Mon, 4 May 2020 10:06:29 +0200
Subject: [PATCH] efi/libstub/x86: Work around LLVM ELF quirk build regression
Git-commit: f77767ed5f4d398b29119563155e4ece2dfeee13
Patch-mainline: v5.8-rc1
References: git-fixes
When building the x86 EFI stub with Clang, the libstub Makefile rules
that manipulate the ELF object files may throw an error like:
STUBCPY drivers/firmware/efi/libstub/efi-stub-helper.stub.o
strip: drivers/firmware/efi/libstub/efi-stub-helper.stub.o: Failed to find link section for section 10
objcopy: drivers/firmware/efi/libstub/efi-stub-helper.stub.o: Failed to find link section for section 10
This is the result of a LLVM feature [0] where symbol references are
stored in a LLVM specific .llvm_addrsig section in a non-transparent way,
causing generic ELF tools such as strip or objcopy to choke on them.
So force the compiler not to emit these sections, by passing the
appropriate command line option.
[0] https://sourceware.org/bugzilla/show_bug.cgi?id=23817
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/firmware/efi/libstub/Makefile | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 8d246b51bd49..e5a49dc8e9bc 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -30,6 +30,7 @@ KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \
-D__NO_FORTIFY \
$(call cc-option,-ffreestanding) \
$(call cc-option,-fno-stack-protector) \
+ $(call cc-option,-fno-addrsig) \
-D__DISABLE_EXPORTS
GCOV_PROFILE := n
--
2.26.2