From 91f606a8fa68264224cbc76888fa8649cdbe9990 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 14 Feb 2018 21:25:41 +0300 Subject: [PATCH] x86/mm: Replace compile-time checks for 5-level paging with runtime-time checks This patch converts the of CONFIG_X86_5LEVEL check to runtime checks for p4d folding. Signed-off-by: Kirill A. Shutemov Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: Dave Hansen Cc: David Woodhouse Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180214182542.69302-9-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/pgtable_64.h | 23 ++++++++++------------- arch/x86/mm/dump_pagetables.c | 4 +--- arch/x86/mm/fault.c | 4 ++-- arch/x86/mm/ident_map.c | 2 +- arch/x86/mm/init_64.c | 30 ++++++++++++++++++------------ arch/x86/mm/kasan_init_64.c | 12 ++++++------ arch/x86/mm/kaslr.c | 6 +++--- arch/x86/mm/tlb.c | 2 +- arch/x86/platform/efi/efi_64.c | 2 +- arch/x86/power/hibernate_64.c | 6 +++--- 10 files changed, 46 insertions(+), 45 deletions(-) diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h index 81462e9a34f6..81dda8d1d0bd 100644 --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -217,29 +217,26 @@ static inline pgd_t pti_set_user_pgd(pgd_t *pgdp, pgd_t pgd) static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d) { -#if defined(CONFIG_PAGE_TABLE_ISOLATION) && !defined(CONFIG_X86_5LEVEL) - p4dp->pgd = pti_set_user_pgd(&p4dp->pgd, p4d.pgd); -#else - *p4dp = p4d; -#endif + pgd_t pgd; + + if (pgtable_l5_enabled || !IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION)) { + *p4dp = p4d; + return; + } + + pgd = native_make_pgd(p4d_val(p4d)); + pgd = pti_set_user_pgd((pgd_t *)p4dp, pgd); + *p4dp = native_make_p4d(pgd_val(pgd)); } static inline void native_p4d_clear(p4d_t *p4d) { -#ifdef CONFIG_X86_5LEVEL native_set_p4d(p4d, native_make_p4d(0)); -#else - native_set_p4d(p4d, (p4d_t) { .pgd = native_make_pgd(0)}); -#endif } static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd) { -#ifdef CONFIG_PAGE_TABLE_ISOLATION *pgdp = pti_set_user_pgd(pgdp, pgd); -#else - *pgdp = pgd; -#endif } static inline void native_pgd_clear(pgd_t *pgd) diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index 9efee6f464ab..0d6d67d18ad6 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -348,9 +348,7 @@ static inline bool kasan_page_table(struct seq_file *m, struct pg_state *st, void *pt) { if (__pa(pt) == __pa(kasan_zero_pmd) || -#ifdef CONFIG_X86_5LEVEL - __pa(pt) == __pa(kasan_zero_p4d) || -#endif + (pgtable_l5_enabled && __pa(pt) == __pa(kasan_zero_p4d)) || __pa(pt) == __pa(kasan_zero_pud)) { pgprotval_t prot = pte_flags(kasan_zero_pte[0]); note_page(m, st, __pgprot(prot), 5); diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 800de815519c..321b78060e93 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -439,7 +439,7 @@ static noinline int vmalloc_fault(unsigned long address) if (pgd_none(*pgd_ref)) return -1; - if (CONFIG_PGTABLE_LEVELS > 4) { + if (pgtable_l5_enabled) { if (pgd_none(*pgd)) { set_pgd(pgd, *pgd_ref); arch_flush_lazy_mmu_mode(); @@ -454,7 +454,7 @@ static noinline int vmalloc_fault(unsigned long address) if (p4d_none(*p4d_ref)) return -1; - if (p4d_none(*p4d) && CONFIG_PGTABLE_LEVELS == 4) { + if (p4d_none(*p4d) && !pgtable_l5_enabled) { set_p4d(p4d, *p4d_ref); arch_flush_lazy_mmu_mode(); } else { diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c index ab33a32df2a8..9aa22be8331e 100644 --- a/arch/x86/mm/ident_map.c +++ b/arch/x86/mm/ident_map.c @@ -120,7 +120,7 @@ int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page, result = ident_p4d_init(info, p4d, addr, next); if (result) return result; - if (IS_ENABLED(CONFIG_X86_5LEVEL)) { + if (pgtable_l5_enabled) { set_pgd(pgd, __pgd(__pa(p4d) | info->kernpg_flag)); } else { /* diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 6a4b20bc7527..3186e6836036 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -88,12 +88,7 @@ static int __init nonx32_setup(char *str) } __setup("noexec32=", nonx32_setup); -/* - * When memory was added make sure all the processes MM have - * suitable PGD entries in the local PGD level page. - */ -#ifdef CONFIG_X86_5LEVEL -void sync_global_pgds(unsigned long start, unsigned long end) +static void sync_global_pgds_l5(unsigned long start, unsigned long end) { unsigned long addr; @@ -129,8 +124,8 @@ void sync_global_pgds(unsigned long start, unsigned long end) spin_unlock(&pgd_lock); } } -#else -void sync_global_pgds(unsigned long start, unsigned long end) + +static void sync_global_pgds_l4(unsigned long start, unsigned long end) { unsigned long addr; @@ -173,7 +168,18 @@ void sync_global_pgds(unsigned long start, unsigned long end) spin_unlock(&pgd_lock); } } -#endif + +/* + * When memory was added make sure all the processes MM have + * suitable PGD entries in the local PGD level page. + */ +void sync_global_pgds(unsigned long start, unsigned long end) +{ + if (pgtable_l5_enabled) + sync_global_pgds_l5(start, end); + else + sync_global_pgds_l4(start, end); +} /* * NOTE: This function is marked __ref because it calls __init function @@ -632,7 +638,7 @@ phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end, unsigned long vaddr = (unsigned long)__va(paddr); int i = p4d_index(vaddr); - if (!IS_ENABLED(CONFIG_X86_5LEVEL)) + if (!pgtable_l5_enabled) return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end, page_size_mask); for (; i < PTRS_PER_P4D; i++, paddr = paddr_next) { @@ -712,7 +718,7 @@ kernel_physical_mapping_init(unsigned long paddr_start, page_size_mask); spin_lock(&init_mm.page_table_lock); - if (IS_ENABLED(CONFIG_X86_5LEVEL)) + if (pgtable_l5_enabled) pgd_populate(&init_mm, pgd, p4d); else p4d_populate(&init_mm, p4d_offset(pgd, vaddr), (pud_t *) p4d); @@ -1093,7 +1099,7 @@ remove_p4d_table(p4d_t *p4d_start, unsigned long addr, unsigned long end, * 5-level case we should free them. This code will have to change * to adapt for boot-time switching between 4 and 5 level page tables. */ - if (CONFIG_PGTABLE_LEVELS == 5) + if (pgtable_l5_enabled) free_pud_table(pud_base, p4d, altmap); } diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 12ec90f62457..0df0dd13a71d 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -176,10 +176,10 @@ static void __init clear_pgds(unsigned long start, * With folded p4d, pgd_clear() is nop, use p4d_clear() * instead. */ - if (CONFIG_PGTABLE_LEVELS < 5) - p4d_clear(p4d_offset(pgd, start)); - else + if (pgtable_l5_enabled) pgd_clear(pgd); + else + p4d_clear(p4d_offset(pgd, start)); } pgd = pgd_offset_k(start); @@ -191,7 +191,7 @@ static inline p4d_t *early_p4d_offset(pgd_t *pgd, unsigned long addr) { unsigned long p4d; - if (!IS_ENABLED(CONFIG_X86_5LEVEL)) + if (!pgtable_l5_enabled) return (p4d_t *)pgd; p4d = __pa_nodebug(pgd_val(*pgd)) & PTE_PFN_MASK; @@ -272,7 +272,7 @@ void __init kasan_early_init(void) for (i = 0; i < PTRS_PER_PUD; i++) kasan_zero_pud[i] = __pud(pud_val); - for (i = 0; IS_ENABLED(CONFIG_X86_5LEVEL) && i < PTRS_PER_P4D; i++) + for (i = 0; pgtable_l5_enabled && i < PTRS_PER_P4D; i++) kasan_zero_p4d[i] = __p4d(p4d_val); kasan_map_early_shadow(early_top_pgt); @@ -303,7 +303,7 @@ void __init kasan_init(void) * bunch of things like kernel code, modules, EFI mapping, etc. * We need to take extra steps to not overwrite them. */ - if (IS_ENABLED(CONFIG_X86_5LEVEL)) { + if (pgtable_l5_enabled) { void *ptr; ptr = (void *)pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_END)); diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c index 641169d38184..615cc03ced84 100644 --- a/arch/x86/mm/kaslr.c +++ b/arch/x86/mm/kaslr.c @@ -124,7 +124,7 @@ void __init kernel_randomize_memory(void) */ entropy = remain_entropy / (ARRAY_SIZE(kaslr_regions) - i); prandom_bytes_state(&rand_state, &rand, sizeof(rand)); - if (IS_ENABLED(CONFIG_X86_5LEVEL)) + if (pgtable_l5_enabled) entropy = (rand % (entropy + 1)) & P4D_MASK; else entropy = (rand % (entropy + 1)) & PUD_MASK; @@ -136,7 +136,7 @@ void __init kernel_randomize_memory(void) * randomization alignment. */ vaddr += get_padding(&kaslr_regions[i]); - if (IS_ENABLED(CONFIG_X86_5LEVEL)) + if (pgtable_l5_enabled) vaddr = round_up(vaddr + 1, P4D_SIZE); else vaddr = round_up(vaddr + 1, PUD_SIZE); @@ -212,7 +212,7 @@ void __meminit init_trampoline(void) return; } - if (IS_ENABLED(CONFIG_X86_5LEVEL)) + if (pgtable_l5_enabled) init_trampoline_p4d(); else init_trampoline_pud(); diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 6550d37d0f06..92cb8a901c36 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -157,7 +157,7 @@ static void sync_current_stack_to_mm(struct mm_struct *mm) unsigned long sp = current_stack_pointer; pgd_t *pgd = pgd_offset(mm, sp); - if (CONFIG_PGTABLE_LEVELS > 4) { + if (pgtable_l5_enabled) { if (unlikely(pgd_none(*pgd))) { pgd_t *pgd_ref = pgd_offset_k(sp); diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index d52aaa7dc088..4845871a2006 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -227,7 +227,7 @@ int __init efi_alloc_page_tables(void) pud = pud_alloc(&init_mm, p4d, EFI_VA_END); if (!pud) { - if (CONFIG_PGTABLE_LEVELS > 4) + if (pgtable_l5_enabled) free_page((unsigned long) pgd_page_vaddr(*pgd)); free_page((unsigned long)efi_pgd); return -ENOMEM; diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c index 0ef5e5204968..74a532989308 100644 --- a/arch/x86/power/hibernate_64.c +++ b/arch/x86/power/hibernate_64.c @@ -50,7 +50,7 @@ static int set_up_temporary_text_mapping(pgd_t *pgd) { pmd_t *pmd; pud_t *pud; - p4d_t *p4d; + p4d_t *p4d = NULL; /* * The new mapping only has to cover the page containing the image @@ -66,7 +66,7 @@ static int set_up_temporary_text_mapping(pgd_t *pgd) * tables used by the image kernel. */ - if (IS_ENABLED(CONFIG_X86_5LEVEL)) { + if (pgtable_l5_enabled) { p4d = (p4d_t *)get_safe_page(GFP_ATOMIC); if (!p4d) return -ENOMEM; @@ -84,7 +84,7 @@ static int set_up_temporary_text_mapping(pgd_t *pgd) __pmd((jump_address_phys & PMD_MASK) | __PAGE_KERNEL_LARGE_EXEC)); set_pud(pud + pud_index(restore_jump_address), __pud(__pa(pmd) | _KERNPG_TABLE)); - if (IS_ENABLED(CONFIG_X86_5LEVEL)) { + if (p4d) { set_p4d(p4d + p4d_index(restore_jump_address), __p4d(__pa(pud) | _KERNPG_TABLE)); set_pgd(pgd + pgd_index(restore_jump_address), __pgd(__pa(p4d) | _KERNPG_TABLE)); } else {