[PATCH v2 11/16] x86/build: Drop unnecessary '-ffreestanding' addition to KBUILD_CFLAGS

[Nathan Chancellor]

Now that the minimum supported version of LLVM for building the kernel
has been raised to 17.0.1, the addition of '-ffreestanding' to
KBUILD_CFLAGS for 32-bit x86 is unnecessary, as the linked LLVM bug is
resolved in all supported LLVM versions.

  16cb16e0d285 ("x86/build: Remove -ffreestanding on i386 with GCC")

intended to make the addition of '-ffreestanding' clang only but due to
a bug in the adjusted check from

  d70da12453ac ("hardening: Enable i386 FORTIFY_SOURCE on Clang 16+")

it has been applied for all versions of GCC and clang < 16.0.0. There
are no known problems with removing this for GCC but if one surfaces, it
can be restored under a CONFIG_CC_IS_GCC block.

Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---
Cc: Thomas Gleixner <tglx@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Kees Cook <kees@xxxxxxxxxx>
---
 arch/x86/Makefile | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 46fec0b08487..5720f2470cfc 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -124,11 +124,6 @@ ifeq ($(CONFIG_X86_32),y)
         include $(srctree)/arch/x86/Makefile_32.cpu
         KBUILD_CFLAGS += $(cflags-y)
 
-    ifneq ($(call clang-min-version, 160000),y)
-        # https://github.com/llvm/llvm-project/issues/53645
-        KBUILD_CFLAGS += -ffreestanding
-    endif
-
         percpu_seg := fs
 else
         BITS := 64

-- 
2.54.0