From: Nathan Chancellor nathan@kernel.org
commit 33806e7cb8d50379f55c3e8f335e91e1b359dc7b upstream.
A recent change in LLVM made CONFIG_EFI_STUB unselectable because it no longer pretends to support -mabi=ms, breaking the dependency in Kconfig. Lack of CONFIG_EFI_STUB can prevent kernels from booting via EFI in certain circumstances.
This check was added by
8f24f8c2fc82 ("efi/libstub: Annotate firmware routines as __efiapi")
to ensure that __attribute__((ms_abi)) was available, as -mabi=ms is not actually used in any cflags.
According to the GCC documentation, this attribute has been supported since GCC 4.4.7. The kernel currently requires GCC 5.1 so this check is not necessary; even when that change landed in 5.6, the kernel required GCC 4.9 so it was unnecessary then as well.
Clang supports __attribute__((ms_abi)) for all versions that are supported for building the kernel so no additional check is needed. Remove the 'depends on' line altogether to allow CONFIG_EFI_STUB to be selected when CONFIG_EFI is enabled, regardless of compiler.
Fixes: 8f24f8c2fc82 ("efi/libstub: Annotate firmware routines as __efiapi") Signed-off-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Borislav Petkov bp@suse.de Reviewed-by: Nick Desaulniers ndesaulniers@google.com Acked-by: Ard Biesheuvel ardb@kernel.org Cc: stable@vger.kernel.org Link: https://github.com/llvm/llvm-project/commit/d1ad006a8f64bdc17f618deffa9e7c91... [nathan: Fix conflict due to lack of c6dbd3e5e69c in older trees] Signed-off-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/Kconfig | 1 - 1 file changed, 1 deletion(-)
--- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1945,7 +1945,6 @@ config EFI config EFI_STUB bool "EFI stub support" depends on EFI && !X86_USE_3DNOW - depends on $(cc-option,-mabi=ms) || X86_32 select RELOCATABLE help This kernel feature allows a bzImage to be loaded directly