Commit-ID: eedb92abb9bb03ef21442614a6f5867eaac6e77f Gitweb: https://git.kernel.org/tip/eedb92abb9bb03ef21442614a6f5867eaac6e77f Author: Kirill A. Shutemov <kirill.shute...@linux.intel.com> AuthorDate: Wed, 14 Feb 2018 14:16:50 +0300 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 14 Feb 2018 13:11:13 +0100
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.shute...@linux.intel.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Borislav Petkov <b...@suse.de> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: linux...@kvack.org Link: http://lkml.kernel.org/r/20180214111656.88514-4-kirill.shute...@linux.intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/Kconfig | 8 ++++++++ arch/x86/include/asm/kaslr.h | 4 ---- arch/x86/include/asm/page_64.h | 4 ++++ arch/x86/include/asm/page_64_types.h | 4 ++-- arch/x86/include/asm/pgtable_64_types.h | 4 ++-- arch/x86/kernel/head64.c | 9 +++++++++ arch/x86/mm/kaslr.c | 8 -------- 7 files changed, 25 insertions(+), 16 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 63bf349..9225648 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1430,6 +1430,7 @@ config X86_PAE config X86_5LEVEL bool "Enable 5-level page tables support" + select DYNAMIC_MEMORY_LAYOUT depends on X86_64 ---help--- 5-level paging enables access to larger address space: @@ -2143,10 +2144,17 @@ config PHYSICAL_ALIGN Don't change this unless you know what you are doing. +config DYNAMIC_MEMORY_LAYOUT + bool + ---help--- + This option makes base addresses of vmalloc and vmemmap as well as + __PAGE_OFFSET movable during boot. + config RANDOMIZE_MEMORY bool "Randomize the kernel memory sections" depends on X86_64 depends on RANDOMIZE_BASE + select DYNAMIC_MEMORY_LAYOUT default RANDOMIZE_BASE ---help--- Randomizes the base virtual address of kernel memory sections diff --git a/arch/x86/include/asm/kaslr.h b/arch/x86/include/asm/kaslr.h index 460991e..db7ba2f 100644 --- a/arch/x86/include/asm/kaslr.h +++ b/arch/x86/include/asm/kaslr.h @@ -5,10 +5,6 @@ unsigned long kaslr_get_random_long(const char *purpose); #ifdef CONFIG_RANDOMIZE_MEMORY -extern unsigned long page_offset_base; -extern unsigned long vmalloc_base; -extern unsigned long vmemmap_base; - void kernel_randomize_memory(void); #else static inline void kernel_randomize_memory(void) { } diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h index 4baa6bc..09637865 100644 --- a/arch/x86/include/asm/page_64.h +++ b/arch/x86/include/asm/page_64.h @@ -11,6 +11,10 @@ extern unsigned long max_pfn; extern unsigned long phys_base; +extern unsigned long page_offset_base; +extern unsigned long vmalloc_base; +extern unsigned long vmemmap_base; + static inline unsigned long __phys_addr_nodebug(unsigned long x) { unsigned long y = x - __START_KERNEL_map; diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h index f68e652..d54a3d5 100644 --- a/arch/x86/include/asm/page_64_types.h +++ b/arch/x86/include/asm/page_64_types.h @@ -43,11 +43,11 @@ #define __PAGE_OFFSET_BASE _AC(0xffff880000000000, UL) #endif -#ifdef CONFIG_RANDOMIZE_MEMORY +#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT #define __PAGE_OFFSET page_offset_base #else #define __PAGE_OFFSET __PAGE_OFFSET_BASE -#endif /* CONFIG_RANDOMIZE_MEMORY */ +#endif /* CONFIG_DYNAMIC_MEMORY_LAYOUT */ #define __START_KERNEL_map _AC(0xffffffff80000000, UL) diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index 7168de7..a0db91a 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -100,13 +100,13 @@ typedef struct { pteval_t pte; } pte_t; # define LDT_BASE_ADDR (LDT_PGD_ENTRY << PGDIR_SHIFT) #endif -#ifdef CONFIG_RANDOMIZE_MEMORY +#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT # define VMALLOC_START vmalloc_base # define VMEMMAP_START vmemmap_base #else # define VMALLOC_START __VMALLOC_BASE # define VMEMMAP_START __VMEMMAP_BASE -#endif /* CONFIG_RANDOMIZE_MEMORY */ +#endif /* CONFIG_DYNAMIC_MEMORY_LAYOUT */ #define VMALLOC_END (VMALLOC_START + _AC((VMALLOC_SIZE_TB << 40) - 1, UL)) diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 7ba5d81..bf5c9ba 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) diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c index aedebd2..515b98a 100644 --- a/arch/x86/mm/kaslr.c +++ b/arch/x86/mm/kaslr.c @@ -43,14 +43,6 @@ static const unsigned long vaddr_start = __PAGE_OFFSET_BASE; static const unsigned long vaddr_end = CPU_ENTRY_AREA_BASE; -/* Default values */ -unsigned long page_offset_base = __PAGE_OFFSET_BASE; -EXPORT_SYMBOL(page_offset_base); -unsigned long vmalloc_base = __VMALLOC_BASE; -EXPORT_SYMBOL(vmalloc_base); -unsigned long vmemmap_base = __VMEMMAP_BASE; -EXPORT_SYMBOL(vmemmap_base); - /* * Memory regions randomized by KASLR (except modules that use a separate logic * earlier during boot). The list is ordered based on virtual addresses. This
