x86/build: Disable CET instrumentation in the kernel for 32-bit too

commit 256b92af784d5043eeb7d559b6d5963dcc2ecb10 upstream.

Commit

  20bf2b378729 ("x86/build: Disable CET instrumentation in the kernel")

disabled CET instrumentation which gets added by default by the Ubuntu
gcc9 and 10 by default, but did that only for 64-bit builds. It would
still fail when building a 32-bit target. So disable CET for all x86
builds.

Fixes: 20bf2b378729 ("x86/build: Disable CET instrumentation in the kernel")
Reported-by: AC <achirvasub@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: AC <achirvasub@gmail.com>
Link: https://lkml.kernel.org/r/YCCIgMHkzh/xT4ex@arch-chirva.localdomain
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 4c8e9f12b0c4d242a7b5e2302ecd58280856b103..9f33a69b56051b2de440a9939f9c2f912382a45a 100644 (file)
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -62,6 +62,9 @@ endif
 KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
 KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
 
+# Intel CET isn't enabled in the kernel
+KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
+
 ifeq ($(CONFIG_X86_32),y)
         BITS := 32
         UTS_MACHINE := i386
@@ -138,9 +141,6 @@ else
         KBUILD_CFLAGS += -mno-red-zone
         KBUILD_CFLAGS += -mcmodel=kernel
 
-       # Intel CET isn't enabled in the kernel
-       KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
-
         # -funit-at-a-time shrinks the kernel .text considerably
         # unfortunately it makes reading oopses harder.
         KBUILD_CFLAGS += $(call cc-option,-funit-at-a-time)