diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2018-02-14 14:16:50 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-14 13:11:13 +0100 |
| commit | eedb92abb9bb03ef21442614a6f5867eaac6e77f (patch) | |
| tree | 7357842772983f86aeafb8f1b03777e5b3fd79f2 /arch/x86/kernel/head64.c | |
| parent | 02390b87a9459937cdb299e6b34ff33992512ec7 (diff) | |
x86/mm: Make virtual memory layout dynamic for CONFIG_X86_5LEVEL=y
We need to be able to adjust virtual memory layout at runtime to be able
to switch between 4- and 5-level paging at boot-time.
KASLR already has movable __VMALLOC_BASE, __VMEMMAP_BASE and __PAGE_OFFSET.
Let's re-use it.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180214111656.88514-4-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/head64.c')
| -rw-r--r-- | arch/x86/kernel/head64.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 7ba5d819ebe3..bf5c9ba63ba1 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -39,6 +39,15 @@ 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_DYNAMIC_MEMORY_LAYOUT +unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE; +EXPORT_SYMBOL(page_offset_base); +unsigned long vmalloc_base __ro_after_init = __VMALLOC_BASE; +EXPORT_SYMBOL(vmalloc_base); +unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE; +EXPORT_SYMBOL(vmemmap_base); +#endif + #define __head __section(.head.text) static void __head *fixup_pointer(void *ptr, unsigned long physaddr) |