x86/build: Remove cc-option from stack alignment flags

'-mpreferred-stack-boundary' (the GCC option) and '-mstack-alignment'
(the clang option) have been supported in their respective compilers for
some time, so it is unnecessary to check for support for them via
cc-option. '-mpreferred-stack-boundary=3' had a restriction on
'-mno-sse' until GCC 7.1 but that is irrelevant for most of the kernel,
which includes '-mno-sse'.

Move to simple Kconfig checks to avoid querying the compiler for the
flags that it supports.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/20250814-x86-min-ver-cleanups-v1-2-ff7f19457523@kernel.org

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index ed5657395d6aca74ab551f5db4f3d6f3d58e8a69..f0aa58d2ec17e853a64f410a801ac46ac7f32409 100644 (file)
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -37,10 +37,11 @@ export RETPOLINE_VDSO_CFLAGS
 
 # For gcc stack alignment is specified with -mpreferred-stack-boundary,
 # clang has the option -mstack-alignment for that purpose.
-ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
+ifdef CONFIG_CC_IS_GCC
       cc_stack_align4 := -mpreferred-stack-boundary=2
       cc_stack_align8 := -mpreferred-stack-boundary=3
-else ifneq ($(call cc-option, -mstack-alignment=16),)
+endif
+ifdef CONFIG_CC_IS_CLANG
       cc_stack_align4 := -mstack-alignment=4
       cc_stack_align8 := -mstack-alignment=8
 endif