Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: "samitolvanen via sendgmr" 
        <samitolvanen@samitolvanen1.mtv.corp.google.com>
Date:   Wed, 18 Nov 2020 14:07:26 -0800
In-Reply-To: <20201118220731.925424-1-samitolvanen@google.com>
Message-Id: <20201118220731.925424-13-samitolvanen@google.com>
Mime-Version: 1.0
References: <20201118220731.925424-1-samitolvanen@google.com>
Subject: [PATCH v7 12/17] efi/libstub: disable LTO
From:   Sami Tolvanen <samitolvanen@google.com>
To:     Masahiro Yamada <masahiroy@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Will Deacon <will@kernel.org>
Cc:     Josh Poimboeuf <jpoimboe@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        clang-built-linux@googlegroups.com,
        kernel-hardening@lists.openwall.com, linux-arch@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
        Sami Tolvanen <samitolvanen@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

With CONFIG_LTO_CLANG, we produce LLVM bitcode instead of ELF object
files. Since LTO is not really needed here and the Makefile assumes we
produce an object file, disable LTO for libstub.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
 drivers/firmware/efi/libstub/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 8a94388e38b3..c23466e05e60 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -38,6 +38,8 @@ KBUILD_CFLAGS			:= $(cflags-y) -Os -DDISABLE_BRANCH_PROFILING \
 
 # remove SCS flags from all objects in this directory
 KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))
+# disable LTO
+KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO), $(KBUILD_CFLAGS))
 
 GCOV_PROFILE			:= n
 # Sanitizer runtimes are unavailable and cannot be linked here.
-- 
2.29.2.299.gdc1121823c-goog