This is a note to let you know that I've just added the patch titled x86/build: Turn off -fcf-protection for realmode targets to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-build-turn-off-fcf-protection-for-realmode-targe.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 58530088f094119387f717632210b472cfcd38b1 Author: Arnd Bergmann <arnd@xxxxxxxx> Date: Tue Mar 23 13:48:36 2021 +0100 x86/build: Turn off -fcf-protection for realmode targets [ Upstream commit 9fcb51c14da2953de585c5c6e50697b8a6e91a7b ] The new Ubuntu GCC packages turn on -fcf-protection globally, which causes a build failure in the x86 realmode code: cc1: error: â??-fcf-protectionâ?? is not compatible with this target Turn it off explicitly on compilers that understand this option. Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210323124846.1584944-1-arnd@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 0a6d497221e4..9c86f2dc16b1 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -34,7 +34,7 @@ M16_CFLAGS := $(call cc-option, -m16, $(CODE16GCC_CFLAGS)) REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING \ -Wall -Wstrict-prototypes -march=i386 -mregparm=3 \ -fno-strict-aliasing -fomit-frame-pointer -fno-pic \ - -mno-mmx -mno-sse + -mno-mmx -mno-sse $(call cc-option,-fcf-protection=none) REALMODE_CFLAGS += -ffreestanding REALMODE_CFLAGS += -fno-stack-protector