On Wed, Feb 21, 2024 at 12:33:08AM +0100, Ard Biesheuvel wrote: > Right, this is the same issue as in #11 - in both cases, the extern > declaration of __pgtable_l5_enabled needs to be visible regardless of > CONFIG_X86_5LEVEL. Yap, I don't mind something like below. 5LEVEL will be practically enabled everywhere. diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 158da0fd01d2..eeb1744215f2 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -52,13 +52,11 @@ extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD]; static unsigned int __initdata next_early_pgt; pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); -#ifdef CONFIG_X86_5LEVEL unsigned int __pgtable_l5_enabled __ro_after_init; unsigned int pgdir_shift __ro_after_init = 39; EXPORT_SYMBOL(pgdir_shift); unsigned int ptrs_per_p4d __ro_after_init = 1; EXPORT_SYMBOL(ptrs_per_p4d); -#endif #ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE_L4; -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette