diff options
Diffstat (limited to 'arch/x86/mm')
-rw-r--r-- | arch/x86/mm/dump_pagetables.c | 11 | ||||
-rw-r--r-- | arch/x86/mm/extable.c | 100 | ||||
-rw-r--r-- | arch/x86/mm/fault.c | 17 | ||||
-rw-r--r-- | arch/x86/mm/gup.c | 72 | ||||
-rw-r--r-- | arch/x86/mm/hugetlbpage.c | 4 | ||||
-rw-r--r-- | arch/x86/mm/init.c | 36 | ||||
-rw-r--r-- | arch/x86/mm/init_32.c | 6 | ||||
-rw-r--r-- | arch/x86/mm/init_64.c | 63 | ||||
-rw-r--r-- | arch/x86/mm/kasan_init_64.c | 17 | ||||
-rw-r--r-- | arch/x86/mm/kmmio.c | 88 | ||||
-rw-r--r-- | arch/x86/mm/mmap.c | 26 | ||||
-rw-r--r-- | arch/x86/mm/mpx.c | 2 | ||||
-rw-r--r-- | arch/x86/mm/numa.c | 67 | ||||
-rw-r--r-- | arch/x86/mm/pageattr.c | 41 | ||||
-rw-r--r-- | arch/x86/mm/pat.c | 9 | ||||
-rw-r--r-- | arch/x86/mm/pgtable.c | 13 | ||||
-rw-r--r-- | arch/x86/mm/setup_nx.c | 6 | ||||
-rw-r--r-- | arch/x86/mm/tlb.c | 29 |
18 files changed, 379 insertions, 228 deletions
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index 4a6f1d9b5106..99bfb192803f 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -358,20 +358,19 @@ static void walk_pud_level(struct seq_file *m, struct pg_state *st, pgd_t addr, #define pgd_none(a) pud_none(__pud(pgd_val(a))) #endif -#ifdef CONFIG_X86_64 static inline bool is_hypervisor_range(int idx) { +#ifdef CONFIG_X86_64 /* * ffff800000000000 - ffff87ffffffffff is reserved for * the hypervisor. */ - return paravirt_enabled() && - (idx >= pgd_index(__PAGE_OFFSET) - 16) && - (idx < pgd_index(__PAGE_OFFSET)); -} + return (idx >= pgd_index(__PAGE_OFFSET) - 16) && + (idx < pgd_index(__PAGE_OFFSET)); #else -static inline bool is_hypervisor_range(int idx) { return false; } + return false; #endif +} static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd, bool checkwx) diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 903ec1e9c326..9dd7e4b7fcde 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -3,6 +3,9 @@ #include <linux/sort.h> #include <asm/uaccess.h> +typedef bool (*ex_handler_t)(const struct exception_table_entry *, + struct pt_regs *, int); + static inline unsigned long ex_insn_addr(const struct exception_table_entry *x) { @@ -13,11 +16,56 @@ ex_fixup_addr(const struct exception_table_entry *x) { return (unsigned long)&x->fixup + x->fixup; } +static inline ex_handler_t +ex_fixup_handler(const struct exception_table_entry *x) +{ + return (ex_handler_t)((unsigned long)&x->handler + x->handler); +} -int fixup_exception(struct pt_regs *regs) +bool ex_handler_default(const struct exception_table_entry *fixup, + struct pt_regs *regs, int trapnr) { - const struct exception_table_entry *fixup; - unsigned long new_ip; + regs->ip = ex_fixup_addr(fixup); + return true; +} +EXPORT_SYMBOL(ex_handler_default); + +bool ex_handler_fault(const struct exception_table_entry *fixup, + struct pt_regs *regs, int trapnr) +{ + regs->ip = ex_fixup_addr(fixup); + regs->ax = trapnr; + return true; +} +EXPORT_SYMBOL_GPL(ex_handler_fault); + +bool ex_handler_ext(const struct exception_table_entry *fixup, + struct pt_regs *regs, int trapnr) +{ + /* Special hack for uaccess_err */ + current_thread_info()->uaccess_err = 1; + regs->ip = ex_fixup_addr(fixup); + return true; +} +EXPORT_SYMBOL(ex_handler_ext); + +bool ex_has_fault_handler(unsigned long ip) +{ + const struct exception_table_entry *e; + ex_handler_t handler; + + e = search_exception_tables(ip); + if (!e) + return false; + handler = ex_fixup_handler(e); + + return handler == ex_handler_fault; +} + +int fixup_exception(struct pt_regs *regs, int trapnr) +{ + const struct exception_table_entry *e; + ex_handler_t handler; #ifdef CONFIG_PNPBIOS if (unlikely(SEGMENT_IS_PNP_CODE(regs->cs))) { @@ -33,42 +81,34 @@ int fixup_exception(struct pt_regs *regs) } #endif - fixup = search_exception_tables(regs->ip); - if (fixup) { - new_ip = ex_fixup_addr(fixup); - - if (fixup->fixup - fixup->insn >= 0x7ffffff0 - 4) { - /* Special hack for uaccess_err */ - current_thread_info()->uaccess_err = 1; - new_ip -= 0x7ffffff0; - } - regs->ip = new_ip; - return 1; - } + e = search_exception_tables(regs->ip); + if (!e) + return 0; - return 0; + handler = ex_fixup_handler(e); + return handler(e, regs, trapnr); } /* Restricted version used during very early boot */ int __init early_fixup_exception(unsigned long *ip) { - const struct exception_table_entry *fixup; + const struct exception_table_entry *e; unsigned long new_ip; + ex_handler_t handler; - fixup = search_exception_tables(*ip); - if (fixup) { - new_ip = ex_fixup_addr(fixup); + e = search_exception_tables(*ip); + if (!e) + return 0; - if (fixup->fixup - fixup->insn >= 0x7ffffff0 - 4) { - /* uaccess handling not supported during early boot */ - return 0; - } + new_ip = ex_fixup_addr(e); + handler = ex_fixup_handler(e); - *ip = new_ip; - return 1; - } + /* special handling not supported during early boot */ + if (handler != ex_handler_default) + return 0; - return 0; + *ip = new_ip; + return 1; } /* @@ -133,6 +173,8 @@ void sort_extable(struct exception_table_entry *start, i += 4; p->fixup += i; i += 4; + p->handler += i; + i += 4; } sort(start, finish - start, sizeof(struct exception_table_entry), @@ -145,6 +187,8 @@ void sort_extable(struct exception_table_entry *start, i += 4; p->fixup -= i; i += 4; + p->handler -= i; + i += 4; } } diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index eef44d9a3f77..03898aea6e0f 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -287,6 +287,9 @@ static noinline int vmalloc_fault(unsigned long address) if (!pmd_k) return -1; + if (pmd_huge(*pmd_k)) + return 0; + pte_k = pte_offset_kernel(pmd_k, address); if (!pte_present(*pte_k)) return -1; @@ -360,8 +363,6 @@ void vmalloc_sync_all(void) * 64-bit: * * Handle a fault on the vmalloc area - * - * This assumes no large pages in there. */ static noinline int vmalloc_fault(unsigned long address) { @@ -403,17 +404,23 @@ static noinline int vmalloc_fault(unsigned long address) if (pud_none(*pud_ref)) return -1; - if (pud_none(*pud) || pud_page_vaddr(*pud) != pud_page_vaddr(*pud_ref)) + if (pud_none(*pud) || pud_pfn(*pud) != pud_pfn(*pud_ref)) BUG(); + if (pud_huge(*pud)) + return 0; + pmd = pmd_offset(pud, address); pmd_ref = pmd_offset(pud_ref, address); if (pmd_none(*pmd_ref)) return -1; - if (pmd_none(*pmd) || pmd_page(*pmd) != pmd_page(*pmd_ref)) + if (pmd_none(*pmd) || pmd_pfn(*pmd) != pmd_pfn(*pmd_ref)) BUG(); + if (pmd_huge(*pmd)) + return 0; + pte_ref = pte_offset_kernel(pmd_ref, address); if (!pte_present(*pte_ref)) return -1; @@ -656,7 +663,7 @@ no_context(struct pt_regs *regs, unsigned long error_code, int sig; /* Are we prepared to handle this kernel fault? */ - if (fixup_exception(regs)) { + if (fixup_exception(regs, X86_TRAP_PF)) { /* * Any interrupt that takes a fault gets the fixup. This makes * the below recursive fault logic only apply to a faults from diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c index ae9a37bf1371..d8a798d8bf50 100644 --- a/arch/x86/mm/gup.c +++ b/arch/x86/mm/gup.c @@ -9,6 +9,7 @@ #include <linux/vmstat.h> #include <linux/highmem.h> #include <linux/swap.h> +#include <linux/memremap.h> #include <asm/pgtable.h> @@ -63,6 +64,16 @@ retry: #endif } +static void undo_dev_pagemap(int *nr, int nr_start, struct page **pages) +{ + while ((*nr) - nr_start) { + struct page *page = pages[--(*nr)]; + + ClearPageReferenced(page); + put_page(page); + } +} + /* * The performance critical leaf functions are made noinline otherwise gcc * inlines everything into a single function which results in too much @@ -71,7 +82,9 @@ retry: static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { + struct dev_pagemap *pgmap = NULL; unsigned long mask; + int nr_start = *nr; pte_t *ptep; mask = _PAGE_PRESENT|_PAGE_USER; @@ -89,13 +102,21 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, return 0; } - if ((pte_flags(pte) & (mask | _PAGE_SPECIAL)) != mask) { + if (pte_devmap(pte)) { + pgmap = get_dev_pagemap(pte_pfn(pte), pgmap); + if (unlikely(!pgmap)) { + undo_dev_pagemap(nr, nr_start, pages); + pte_unmap(ptep); + return 0; + } + } else if ((pte_flags(pte) & (mask | _PAGE_SPECIAL)) != mask) { pte_unmap(ptep); return 0; } VM_BUG_ON(!pfn_valid(pte_pfn(pte))); page = pte_page(pte); get_page(page); + put_dev_pagemap(pgmap); SetPageReferenced(page); pages[*nr] = page; (*nr)++; @@ -114,6 +135,32 @@ static inline void get_head_page_multiple(struct page *page, int nr) SetPageReferenced(page); } +static int __gup_device_huge_pmd(pmd_t pmd, unsigned long addr, + unsigned long end, struct page **pages, int *nr) +{ + int nr_start = *nr; + unsigned long pfn = pmd_pfn(pmd); + struct dev_pagemap *pgmap = NULL; + + pfn += (addr & ~PMD_MASK) >> PAGE_SHIFT; + do { + struct page *page = pfn_to_page(pfn); + + pgmap = get_dev_pagemap(pfn, pgmap); + if (unlikely(!pgmap)) { + undo_dev_pagemap(nr, nr_start, pages); + return 0; + } + SetPageReferenced(page); + pages[*nr] = page; + get_page(page); + put_dev_pagemap(pgmap); + (*nr)++; + pfn++; + } while (addr += PAGE_SIZE, addr != end); + return 1; +} + static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { @@ -126,9 +173,13 @@ static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr, mask |= _PAGE_RW; if ((pmd_flags(pmd) & mask) != mask) return 0; + + VM_BUG_ON(!pfn_valid(pmd_pfn(pmd))); + if (pmd_devmap(pmd)) + return __gup_device_huge_pmd(pmd, addr, end, pages, nr); + /* hugepages are never "special" */ VM_BUG_ON(pmd_flags(pmd) & _PAGE_SPECIAL); - VM_BUG_ON(!pfn_valid(pmd_pfn(pmd))); refs = 0; head = pmd_page(pmd); @@ -136,8 +187,6 @@ static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr, do { VM_BUG_ON_PAGE(compound_head(page) != head, page); pages[*nr] = page; - if (PageTail(page)) - get_huge_page_tail(page); (*nr)++; page++; refs++; @@ -158,18 +207,7 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end, pmd_t pmd = *pmdp; next = pmd_addr_end(addr, end); - /* - * The pmd_trans_splitting() check below explains why - * pmdp_splitting_flush has to flush the tlb, to stop - * this gup-fast code from running while we set the - * splitting bit in the pmd. Returning zero will take - * the slow path that will call wait_split_huge_page() - * if the pmd is still in splitting state. gup-fast - * can't because it has irq disabled and - * wait_split_huge_page() would never return as the - * tlb flush IPI wouldn't run. - */ - if (pmd_none(pmd) || pmd_trans_splitting(pmd)) + if (pmd_none(pmd)) return 0; if (unlikely(pmd_large(pmd) || !pmd_present(pmd))) { /* @@ -212,8 +250,6 @@ static noinline int gup_huge_pud(pud_t pud, unsigned long addr, do { VM_BUG_ON_PAGE(compound_head(page) != head, page); pages[*nr] = page; - if (PageTail(page)) - get_huge_page_tail(page); (*nr)++; page++; refs++; diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c index 42982b26e32b..740d7ac03a55 100644 --- a/arch/x86/mm/hugetlbpage.c +++ b/arch/x86/mm/hugetlbpage.c @@ -173,10 +173,10 @@ static __init int setup_hugepagesz(char *opt) } __setup("hugepagesz=", setup_hugepagesz); -#ifdef CONFIG_CMA +#if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA) static __init int gigantic_pages_init(void) { - /* With CMA we can allocate gigantic pages at runtime */ + /* With compaction or CMA we can allocate gigantic pages at runtime */ if (cpu_has_gbpages && !size_to_hstate(1UL << PUD_SHIFT)) hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); return 0; diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 493f54172b4a..9d56f271d519 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -150,13 +150,14 @@ static int page_size_mask; static void __init probe_page_size_mask(void) { -#if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK) +#if !defined(CONFIG_KMEMCHECK) /* - * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. + * For CONFIG_KMEMCHECK or pagealloc debugging, identity mapping will + * use small pages. * This will simplify cpa(), which otherwise needs to support splitting * large pages into small in interrupt context, etc. */ - if (cpu_has_pse) + if (cpu_has_pse && !debug_pagealloc_enabled()) page_size_mask |= 1 << PG_LEVEL_2M; #endif @@ -666,21 +667,22 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end) * mark them not present - any buggy init-section access will * create a kernel page fault: */ -#ifdef CONFIG_DEBUG_PAGEALLOC - printk(KERN_INFO "debug: unmapping init [mem %#010lx-%#010lx]\n", - begin, end - 1); - set_memory_np(begin, (end - begin) >> PAGE_SHIFT); -#else - /* - * We just marked the kernel text read only above, now that - * we are going to free part of that, we need to make that - * writeable and non-executable first. - */ - set_memory_nx(begin, (end - begin) >> PAGE_SHIFT); - set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); + if (debug_pagealloc_enabled()) { + pr_info("debug: unmapping init [mem %#010lx-%#010lx]\n", + begin, end - 1); + set_memory_np(begin, (end - begin) >> PAGE_SHIFT); + } else { + /* + * We just marked the kernel text read only above, now that + * we are going to free part of that, we need to make that + * writeable and non-executable first. + */ + set_memory_nx(begin, (end - begin) >> PAGE_SHIFT); + set_memory_rw(begin, (end - begin) >> PAGE_SHIFT); - free_reserved_area((void *)begin, (void *)end, POISON_FREE_INITMEM, what); -#endif + free_reserved_area((void *)begin, (void *)end, + POISON_FREE_INITMEM, what); + } } void free_initmem(void) diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index cb4ef3de61f9..bd7a9b9e2e14 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -388,7 +388,6 @@ repeat: } pte_t *kmap_pte; -pgprot_t kmap_prot; static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr) { @@ -405,8 +404,6 @@ static void __init kmap_init(void) */ kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); kmap_pte = kmap_get_fixmap_pte(kmap_vstart); - - kmap_prot = PAGE_KERNEL; } #ifdef CONFIG_HIGHMEM @@ -871,7 +868,6 @@ static noinline int do_test_wp_bit(void) return flag; } -#ifdef CONFIG_DEBUG_RODATA const int rodata_test_data = 0xC3; EXPORT_SYMBOL_GPL(rodata_test_data); @@ -960,5 +956,3 @@ void mark_rodata_ro(void) if (__supported_pte_mask & _PAGE_NX) debug_checkwx(); } -#endif - diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index ec081fe0ce2c..214afda97911 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -30,6 +30,7 @@ #include <linux/module.h> #include <linux/memory.h> #include <linux/memory_hotplug.h> +#include <linux/memremap.h> #include <linux/nmi.h> #include <linux/gfp.h> #include <linux/kcore.h> @@ -52,6 +53,7 @@ #include <asm/numa.h> #include <asm/cacheflush.h> #include <asm/init.h> +#include <asm/uv/uv.h> #include <asm/setup.h> #include "mm_internal.h" @@ -714,6 +716,12 @@ static void __meminit free_pagetable(struct page *page, int order) { unsigned long magic; unsigned int nr_pages = 1 << order; + struct vmem_altmap *altmap = to_vmem_altmap((unsigned long) page); + + if (altmap) { + vmem_altmap_free(altmap, nr_pages); + return; + } /* bootmem page has reserved flag */ if (PageReserved(page)) { @@ -814,8 +822,7 @@ remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end, if (phys_addr < (phys_addr_t)0x40000000) return; - if (IS_ALIGNED(addr, PAGE_SIZE) && - IS_ALIGNED(next, PAGE_SIZE)) { + if (PAGE_ALIGNED(addr) && PAGE_ALIGNED(next)) { /* * Do not free direct mapping pages since they were * freed when offlining, or simplely not in use. @@ -1018,13 +1025,19 @@ int __ref arch_remove_memory(u64 start, u64 size) { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; + struct page *page = pfn_to_page(start_pfn); + struct vmem_altmap *altmap; struct zone *zone; int ret; - zone = page_zone(pfn_to_page(start_pfn)); - kernel_physical_mapping_remove(start, start + size); + /* With altmap the first mapped page is offset from @start */ + altmap = to_vmem_altmap((unsigned long) page); + if (altmap) + page += vmem_altmap_offset(altmap); + zone = page_zone(page); ret = __remove_pages(zone, start_pfn, nr_pages); WARN_ON_ONCE(ret); + kernel_physical_mapping_remove(start, start + size); return ret; } @@ -1062,7 +1075,6 @@ void __init mem_init(void) mem_init_print_info(NULL); } -#ifdef CONFIG_DEBUG_RODATA const int rodata_test_data = 0xC3; EXPORT_SYMBOL_GPL(rodata_test_data); @@ -1154,8 +1166,6 @@ void mark_rodata_ro(void) debug_checkwx(); } -#endif - int kern_addr_valid(unsigned long addr) { unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT; @@ -1194,26 +1204,13 @@ int kern_addr_valid(unsigned long addr) static unsigned long probe_memory_block_size(void) { - /* start from 2g */ - unsigned long bz = 1UL<<31; + unsigned long bz = MIN_MEMORY_BLOCK_SIZE; - if (totalram_pages >= (64ULL << (30 - PAGE_SHIFT))) { - pr_info("Using 2GB memory block size for large-memory system\n"); - return 2UL * 1024 * 1024 * 1024; - } - - /* less than 64g installed */ - if ((max_pfn << PAGE_SHIFT) < (16UL << 32)) - return MIN_MEMORY_BLOCK_SIZE; - - /* get the tail size */ - while (bz > MIN_MEMORY_BLOCK_SIZE) { - if (!((max_pfn << PAGE_SHIFT) & (bz - 1))) - break; - bz >>= 1; - } + /* if system is UV or has 64GB of RAM or more, use large blocks */ + if (is_uv_system() || ((max_pfn << PAGE_SHIFT) >= (64UL << 30))) + bz = 2UL << 30; /* 2GB */ - printk(KERN_DEBUG "memory block size : %ldMB\n", bz >> 20); + pr_info("x86/mm: Memory block size: %ldMB\n", bz >> 20); return bz; } @@ -1236,7 +1233,7 @@ static void __meminitdata *p_start, *p_end; static int __meminitdata node_start; static int __meminit vmemmap_populate_hugepages(unsigned long start, - unsigned long end, int node) + unsigned long end, int node, struct vmem_altmap *altmap) { unsigned long addr; unsigned long next; @@ -1259,7 +1256,7 @@ static int __meminit vmemmap_populate_hugepages(unsigned long start, if (pmd_none(*pmd)) { void *p; - p = vmemmap_alloc_block_buf(PMD_SIZE, node); + p = __vmemmap_alloc_block_buf(PMD_SIZE, node, altmap); if (p) { pte_t entry; @@ -1280,7 +1277,8 @@ static int __meminit vmemmap_populate_hugepages(unsigned long start, addr_end = addr + PMD_SIZE; p_end = p + PMD_SIZE; continue; - } + } else if (altmap) + return -ENOMEM; /* no fallback */ } else if (pmd_large(*pmd)) { vmemmap_verify((pte_t *)pmd, node, addr, next); continue; @@ -1294,11 +1292,16 @@ static int __meminit vmemmap_populate_hugepages(unsigned long start, int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) { + struct vmem_altmap *altmap = to_vmem_altmap(start); int err; if (cpu_has_pse) - err = vmemmap_populate_hugepages(start, end, node); - else + err = vmemmap_populate_hugepages(start, end, node, altmap); + else if (altmap) { + pr_err_once("%s: no cpu support for altmap allocations\n", + __func__); + err = -ENOMEM; + } else err = vmemmap_populate_basepages(start, end, node); if (!err) sync_global_pgds(start, end - 1, 0); diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index d470cf219a2d..1b1110fa0057 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -120,11 +120,22 @@ void __init kasan_init(void) kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END), (void *)KASAN_SHADOW_END); - memset(kasan_zero_page, 0, PAGE_SIZE); - load_cr3(init_level4_pgt); __flush_tlb_all(); - init_task.kasan_depth = 0; + /* + * kasan_zero_page has been used as early shadow memory, thus it may + * contain some garbage. Now we can clear and write protect it, since + * after the TLB flush no one should write to it. + */ + memset(kasan_zero_page, 0, PAGE_SIZE); + for (i = 0; i < PTRS_PER_PTE; i++) { + pte_t pte = __pte(__pa(kasan_zero_page) | __PAGE_KERNEL_RO); + set_pte(&kasan_zero_pte[i], pte); + } + /* Flush TLBs again to be sure that write protection applied. */ + __flush_tlb_all(); + + init_task.kasan_depth = 0; pr_info("KernelAddressSanitizer initialized\n"); } diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c index 637ab34ed632..ddb2244b06a1 100644 --- a/arch/x86/mm/kmmio.c +++ b/arch/x86/mm/kmmio.c @@ -33,7 +33,7 @@ struct kmmio_fault_page { struct list_head list; struct kmmio_fault_page *release_next; - unsigned long page; /* location of the fault page */ + unsigned long addr; /* the requested address */ pteval_t old_presence; /* page presence prior to arming */ bool armed; @@ -70,9 +70,16 @@ unsigned int kmmio_count; static struct list_head kmmio_page_table[KMMIO_PAGE_TABLE_SIZE]; static LIST_HEAD(kmmio_probes); -static struct list_head *kmmio_page_list(unsigned long page) +static struct list_head *kmmio_page_list(unsigned long addr) { - return &kmmio_page_table[hash_long(page, KMMIO_PAGE_HASH_BITS)]; + unsigned int l; + pte_t *pte = lookup_address(addr, &l); + + if (!pte) + return NULL; + addr &= page_level_mask(l); + + return &kmmio_page_table[hash_long(addr, KMMIO_PAGE_HASH_BITS)]; } /* Accessed per-cpu */ @@ -98,15 +105,19 @@ static struct kmmio_probe *get_kmmio_probe(unsigned long addr) } /* You must be holding RCU read lock. */ -static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page) +static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long addr) { struct list_head *head; struct kmmio_fault_page *f; + unsigned int l; + pte_t *pte = lookup_address(addr, &l); - page &= PAGE_MASK; - head = kmmio_page_list(page); + if (!pte) + return NULL; + addr &= page_level_mask(l); + head = kmmio_page_list(addr); list_for_each_entry_rcu(f, head, list) { - if (f->page == page) + if (f->addr == addr) return f; } return NULL; @@ -137,10 +148,10 @@ static void clear_pte_presence(pte_t *pte, bool clear, pteval_t *old) static int clear_page_presence(struct kmmio_fault_page *f, bool clear) { unsigned int level; - pte_t *pte = lookup_address(f->page, &level); + pte_t *pte = lookup_address(f->addr, &level); if (!pte) { - pr_err("no pte for page 0x%08lx\n", f->page); + pr_err("no pte for addr 0x%08lx\n", f->addr); return -1; } @@ -156,7 +167,7 @@ static int clear_page_presence(struct kmmio_fault_page *f, bool clear) return -1; } - __flush_tlb_one(f->page); + __flush_tlb_one(f->addr); return 0; } @@ -176,12 +187,12 @@ static int arm_kmmio_fault_page(struct kmmio_fault_page *f) int ret; WARN_ONCE(f->armed, KERN_ERR pr_fmt("kmmio page already armed.\n")); if (f->armed) { - pr_warning("double-arm: page 0x%08lx, ref %d, old %d\n", - f->page, f->count, !!f->old_presence); + pr_warning("double-arm: addr 0x%08lx, ref %d, old %d\n", + f->addr, f->count, !!f->old_presence); } ret = clear_page_presence(f, true); - WARN_ONCE(ret < 0, KERN_ERR pr_fmt("arming 0x%08lx failed.\n"), - f->page); + WARN_ONCE(ret < 0, KERN_ERR pr_fmt("arming at 0x%08lx failed.\n"), + f->addr); f->armed = true; return ret; } @@ -191,7 +202,7 @@ static void disarm_kmmio_fault_page(struct kmmio_fault_page *f) { int ret = clear_page_presence(f, false); WARN_ONCE(ret < 0, - KERN_ERR "kmmio disarming 0x%08lx failed.\n", f->page); + KERN_ERR "kmmio disarming at 0x%08lx failed.\n", f->addr); f->armed = false; } @@ -215,6 +226,12 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) struct kmmio_context *ctx; struct kmmio_fault_page *faultpage; int ret = 0; /* default to fault not handled */ + unsigned long page_base = addr; + unsigned int l; + pte_t *pte = lookup_address(addr, &l); + if (!pte) + return -EINVAL; + page_base &= page_level_mask(l); /* * Preemption is now disabled to prevent process switch during @@ -227,7 +244,7 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) preempt_disable(); rcu_read_lock(); - faultpage = get_kmmio_fault_page(addr); + faultpage = get_kmmio_fault_page(page_base); if (!faultpage) { /* * Either this page fault is not caused by kmmio, or @@ -239,7 +256,7 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) ctx = &get_cpu_var(kmmio_ctx); if (ctx->active) { - if (addr == ctx->addr) { + if (page_base == ctx->addr) { /* * A second fault on the same page means some other * condition needs handling by do_page_fault(), the @@ -267,9 +284,9 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) ctx->active++; ctx->fpage = faultpage; - ctx->probe = get_kmmio_probe(addr); + ctx->probe = get_kmmio_probe(page_base); ctx->saved_flags = (regs->flags & (X86_EFLAGS_TF | X86_EFLAGS_IF)); - ctx->addr = addr; + ctx->addr = page_base; if (ctx->probe && ctx->probe->pre_handler) ctx->probe->pre_handler(ctx->probe, regs, addr); @@ -354,12 +371,11 @@ out: } /* You must be holding kmmio_lock. */ -static int add_kmmio_fault_page(unsigned long page) +static int add_kmmio_fault_page(unsigned long addr) { struct kmmio_fault_page *f; - page &= PAGE_MASK; - f = get_kmmio_fault_page(page); + f = get_kmmio_fault_page(addr); if (f) { if (!f->count) arm_kmmio_fault_page(f); @@ -372,26 +388,25 @@ static int add_kmmio_fault_page(unsigned long page) return -1; f->count = 1; - f->page = page; + f->addr = addr; if (arm_kmmio_fault_page(f)) { kfree(f); return -1; } - list_add_rcu(&f->list, kmmio_page_list(f->page)); + list_add_rcu(&f->list, kmmio_page_list(f->addr)); return 0; } /* You must be holding kmmio_lock. */ -static void release_kmmio_fault_page(unsigned long page, +static void release_kmmio_fault_page(unsigned long addr, struct kmmio_fault_page **release_list) { struct kmmio_fault_page *f; - page &= PAGE_MASK; - f = get_kmmio_fault_page(page); + f = get_kmmio_fault_page(addr); if (!f) return; @@ -420,18 +435,27 @@ int register_kmmio_probe(struct kmmio_probe *p) int ret = 0; unsigned long size = 0; const unsigned long size_lim = p->len + (p->addr & ~PAGE_MASK); + unsigned int l; + pte_t *pte; spin_lock_irqsave(&kmmio_lock, flags); if (get_kmmio_probe(p->addr)) { ret = -EEXIST; goto out; } + + pte = lookup_address(p->addr, &l); + if (!pte) { + ret = -EINVAL; + goto out; + } + kmmio_count++; list_add_rcu(&p->list, &kmmio_probes); while (size < size_lim) { if (add_kmmio_fault_page(p->addr + size)) pr_err("Unable to set page fault.\n"); - size += PAGE_SIZE; + size += page_level_size(l); } out: spin_unlock_irqrestore(&kmmio_lock, flags); @@ -506,11 +530,17 @@ void unregister_kmmio_probe(struct kmmio_probe *p) const unsigned long size_lim = p->len + (p->addr & ~PAGE_MASK); struct kmmio_fault_page *release_list = NULL; struct kmmio_delayed_release *drelease; + unsigned int l; + pte_t *pte; + + pte = lookup_address(p->addr, &l); + if (!pte) + return; spin_lock_irqsave(&kmmio_lock, flags); while (size < size_lim) { release_kmmio_fault_page(p->addr + size, &release_list); - size += PAGE_SIZE; + size += page_level_size(l); } list_del_rcu(&p->list); kmmio_count--; diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index 844b06d67df4..d2dc0438d654 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -69,14 +69,14 @@ unsigned long arch_mmap_rnd(void) { unsigned long rnd; - /* - * 8 bits of randomness in 32bit mmaps, 20 address space bits - * 28 bits of randomness in 64bit mmaps, 40 address space bits - */ if (mmap_is_ia32()) - rnd = (unsigned long)get_random_int() % (1<<8); +#ifdef CONFIG_COMPAT + rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); +#else + rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); +#endif else - rnd = (unsigned long)get_random_int() % (1<<28); + rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); return rnd << PAGE_SHIFT; } @@ -94,18 +94,6 @@ static unsigned long mmap_base(unsigned long rnd) } /* - * Bottom-up (legacy) layout on X86_32 did not support randomization, X86_64 - * does, but not when emulating X86_32 - */ -static unsigned long mmap_legacy_base(unsigned long rnd) -{ - if (mmap_is_ia32()) - return TASK_UNMAPPED_BASE; - else - return TASK_UNMAPPED_BASE + rnd; -} - -/* * This function, called very early during the creation of a new * process VM image, sets up which VM layout function to use: */ @@ -116,7 +104,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm) if (current->flags & PF_RANDOMIZE) random_factor = arch_mmap_rnd(); - mm->mmap_legacy_base = mmap_legacy_base(random_factor); + mm->mmap_legacy_base = TASK_UNMAPPED_BASE + random_factor; if (mmap_is_legacy()) { mm->mmap_base = mm->mmap_legacy_base; diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c index b2fd67da1701..ef05755a1900 100644 --- a/arch/x86/mm/mpx.c +++ b/arch/x86/mm/mpx.c @@ -123,7 +123,7 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs, break; } - if (regno > nr_registers) { + if (regno >= nr_registers) { WARN_ONCE(1, "decoded an instruction with an invalid register"); return -EINVAL; } diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c index c3b3f653ed0c..f70c1ff46125 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -465,46 +465,67 @@ static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi) return true; } +/* + * Mark all currently memblock-reserved physical memory (which covers the + * kernel's own memory ranges) as hot-unswappable. + */ static void __init numa_clear_kernel_node_hotplug(void) { - int i, nid; - nodemask_t numa_kernel_nodes = NODE_MASK_NONE; - unsigned long start, end; - struct memblock_region *r; + nodemask_t reserved_nodemask = NODE_MASK_NONE; + struct memblock_region *mb_region; + int i; /* + * We have to do some preprocessing of memblock regions, to + * make them suitable for reservation. + * * At this time, all memory regions reserved by memblock are - * used by the kernel. Set the nid in memblock.reserved will - * mark out all the nodes the kernel resides in. + * used by the kernel, but those regions are not split up + * along node boundaries yet, and don't necessarily have their + * node ID set yet either. + * + * So iterate over all memory known to the x86 architecture, + * and use those ranges to set the nid in memblock.reserved. + * This will split up the memblock regions along node + * boundaries and will set the node IDs as well. */ for (i = 0; i < numa_meminfo.nr_blks; i++) { - struct numa_memblk *mb = &numa_meminfo.blk[i]; + struct numa_memblk *mb = numa_meminfo.blk + i; + int ret; - memblock_set_node(mb->start, mb->end - mb->start, - &memblock.reserved, mb->nid); + ret = memblock_set_node(mb->start, mb->end - mb->start, &memblock.reserved, mb->nid); + WARN_ON_ONCE(ret); } /* - * Mark all kernel nodes. + * Now go over all reserved memblock regions, to construct a + * node mask of all kernel reserved memory areas. * - * When booting with mem=nn[kMG] or in a kdump kernel, numa_meminfo - * may not include all the memblock.reserved memory ranges because - * trim_snb_memory() reserves specific pages for Sandy Bridge graphics. + * [ Note, when booting with mem=nn[kMG] or in a kdump kernel, + * numa_meminfo might not include all memblock.reserved + * memory ranges, because quirks such as trim_snb_memory() + * reserve specific pages for Sandy Bridge graphics. ] */ - for_each_memblock(reserved, r) - if (r->nid != MAX_NUMNODES) - node_set(r->nid, numa_kernel_nodes); + for_each_memblock(reserved, mb_region) { + if (mb_region->nid != MAX_NUMNODES) + node_set(mb_region->nid, reserved_nodemask); + } - /* Clear MEMBLOCK_HOTPLUG flag for memory in kernel nodes. */ + /* + * Finally, clear the MEMBLOCK_HOTPLUG flag for all memory + * belonging to the reserved node mask. + * + * Note that this will include memory regions that reside + * on nodes that contain kernel memory - entire nodes + * become hot-unpluggable: + */ for (i = 0; i < numa_meminfo.nr_blks; i++) { - nid = numa_meminfo.blk[i].nid; - if (!node_isset(nid, numa_kernel_nodes)) - continue; + struct numa_memblk *mb = numa_meminfo.blk + i; - start = numa_meminfo.blk[i].start; - end = numa_meminfo.blk[i].end; + if (!node_isset(mb->nid, reserved_nodemask)) + continue; - memblock_clear_hotplug(start, end - start); + memblock_clear_hotplug(mb->start, mb->end - mb->start); } } diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 6000ad7f560c..4d0b26253042 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -33,7 +33,7 @@ struct cpa_data { pgd_t *pgd; pgprot_t mask_set; pgprot_t mask_clr; - int numpages; + unsigned long numpages; int flags; unsigned long pfn; unsigned force_split : 1; @@ -66,6 +66,9 @@ void update_page_count(int level, unsigned long pages) static void split_page_count(int level) { + if (direct_pages_count[level] == 0) + return; + direct_pages_count[level]--; direct_pages_count[level - 1] += PTRS_PER_PTE; } @@ -103,12 +106,6 @@ static inline unsigned long highmap_end_pfn(void) #endif -#ifdef CONFIG_DEBUG_PAGEALLOC -# define debug_pagealloc 1 -#else -# define debug_pagealloc 0 -#endif - static inline int within(unsigned long addr, unsigned long start, unsigned long end) { @@ -280,7 +277,7 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address, __pa_symbol(__end_rodata) >> PAGE_SHIFT)) pgprot_val(forbidden) |= _PAGE_RW; -#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA) +#if defined(CONFIG_X86_64) /* * Once the kernel maps the text as RO (kernel_set_to_readonly is set), * kernel text mappings for the large page aligned text, rodata sections @@ -416,24 +413,30 @@ pmd_t *lookup_pmd_address(unsigned long address) phys_addr_t slow_virt_to_phys(void *__virt_addr) { unsigned long virt_addr = (unsigned long)__virt_addr; - unsigned long phys_addr, offset; + phys_addr_t phys_addr; + unsigned long offset; enum pg_level level; pte_t *pte; pte = lookup_address(virt_addr, &level); BUG_ON(!pte); + /* + * pXX_pfn() returns unsigned long, which must be cast to phys_addr_t + * before being left-shifted PAGE_SHIFT bits -- this trick is to + * make 32-PAE kernel work correctly. + */ switch (level) { case PG_LEVEL_1G: - phys_addr = pud_pfn(*(pud_t *)pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pud_pfn(*(pud_t *)pte) << PAGE_SHIFT; offset = virt_addr & ~PUD_PAGE_MASK; break; case PG_LEVEL_2M: - phys_addr = pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT; offset = virt_addr & ~PMD_PAGE_MASK; break; default: - phys_addr = pte_pfn(*pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; offset = virt_addr & ~PAGE_MASK; } @@ -705,10 +708,10 @@ static int split_large_page(struct cpa_data *cpa, pte_t *kpte, { struct page *base; - if (!debug_pagealloc) + if (!debug_pagealloc_enabled()) spin_unlock(&cpa_lock); base = alloc_pages(GFP_KERNEL | __GFP_NOTRACK, 0); - if (!debug_pagealloc) + if (!debug_pagealloc_enabled()) spin_lock(&cpa_lock); if (!base) return -ENOMEM; @@ -1119,8 +1122,10 @@ static int __cpa_process_fault(struct cpa_data *cpa, unsigned long vaddr, /* * Ignore all non primary paths. */ - if (!primary) + if (!primary) { + cpa->numpages = 1; return 0; + } /* * Ignore the NULL PTE for kernel identity mapping, as it is expected @@ -1328,10 +1333,10 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias) if (cpa->flags & (CPA_ARRAY | CPA_PAGES_ARRAY)) cpa->numpages = 1; - if (!debug_pagealloc) + if (!debug_pagealloc_enabled()) spin_lock(&cpa_lock); ret = __change_page_attr(cpa, checkalias); - if (!debug_pagealloc) + if (!debug_pagealloc_enabled()) spin_unlock(&cpa_lock); if (ret) return ret; @@ -1347,7 +1352,7 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias) * CPA operation. Either a large page has been * preserved or a single page update happened. */ - BUG_ON(cpa->numpages > numpages); + BUG_ON(cpa->numpages > numpages || !cpa->numpages); numpages -= cpa->numpages; if (cpa->flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) cpa->curpage++; diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 031782e74231..04e2e7144bee 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -12,6 +12,7 @@ #include <linux/debugfs.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/pfn_t.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/fs.h> @@ -942,14 +943,14 @@ int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot, return -EINVAL; } - *prot = __pgprot((pgprot_val(vma->vm_page_prot) & (~_PAGE_CACHE_MASK)) | + *prot = __pgprot((pgprot_val(*prot) & (~_PAGE_CACHE_MASK)) | cachemode2protval(pcm)); return 0; } int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot, - unsigned long pfn) + pfn_t pfn) { enum page_cache_mode pcm; @@ -957,8 +958,8 @@ int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot, return 0; /* Set prot based on lookup */ - pcm = lookup_memtype((resource_size_t)pfn << PAGE_SHIFT); - *prot = __pgprot((pgprot_val(vma->vm_page_prot) & (~_PAGE_CACHE_MASK)) | + pcm = lookup_memtype(pfn_t_to_phys(pfn)); + *prot = __pgprot((pgprot_val(*prot) & (~_PAGE_CACHE_MASK)) | cachemode2protval(pcm)); return 0; diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index ee9c2e3a7199..4eb287e25043 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -505,19 +505,6 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma, return young; } - -void pmdp_splitting_flush(struct vm_area_struct *vma, - unsigned long address, pmd_t *pmdp) -{ - int set; - VM_BUG_ON(address & ~HPAGE_PMD_MASK); - set = !test_and_set_bit(_PAGE_BIT_SPLITTING, - (unsigned long *)pmdp); - if (set) { - /* need tlb flush only to serialize against gup-fast */ - flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); - } -} #endif /** diff --git a/arch/x86/mm/setup_nx.c b/arch/x86/mm/setup_nx.c index 92e2eacb3321..8bea84724a7d 100644 --- a/arch/x86/mm/setup_nx.c +++ b/arch/x86/mm/setup_nx.c @@ -4,6 +4,7 @@ #include <asm/pgtable.h> #include <asm/proto.h> +#include <asm/cpufeature.h> static int disable_nx; @@ -31,9 +32,8 @@ early_param("noexec", noexec_setup); void x86_configure_nx(void) { - if (boot_cpu_has(X86_FEATURE_NX) && !disable_nx) - __supported_pte_mask |= _PAGE_NX; - else + /* If disable_nx is set, clear NX on all new mappings going forward. */ + if (disable_nx) __supported_pte_mask &= ~_PAGE_NX; } diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 8ddb5d0d66fb..8f4cc3dfac32 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -161,7 +161,10 @@ void flush_tlb_current_task(void) preempt_disable(); count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); + + /* This is an implicit full barrier that synchronizes with switch_mm. */ local_flush_tlb(); + trace_tlb_flush(TLB_LOCAL_SHOOTDOWN, TLB_FLUSH_ALL); if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids) flush_tlb_others(mm_cpumask(mm), mm, 0UL, TLB_FLUSH_ALL); @@ -188,17 +191,29 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, unsigned long base_pages_to_flush = TLB_FLUSH_ALL; preempt_disable(); - if (current->active_mm != mm) + if (current->active_mm != mm) { + /* Synchronize with switch_mm. */ + smp_mb(); + goto out; + } if (!current->mm) { leave_mm(smp_processor_id()); + + /* Synchronize with switch_mm. */ + smp_mb(); + goto out; } if ((end != TLB_FLUSH_ALL) && !(vmflag & VM_HUGETLB)) base_pages_to_flush = (end - start) >> PAGE_SHIFT; + /* + * Both branches below are implicit full barriers (MOV to CR or + * INVLPG) that synchronize with switch_mm. + */ if (base_pages_to_flush > tlb_single_page_flush_ceiling) { base_pages_to_flush = TLB_FLUSH_ALL; count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); @@ -228,10 +243,18 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long start) preempt_disable(); if (current->active_mm == mm) { - if (current->mm) + if (current->mm) { + /* + * Implicit full barrier (INVLPG) that synchronizes + * with switch_mm. + */ __flush_tlb_one(start); - else + } else { leave_mm(smp_processor_id()); + + /* Synchronize with switch_mm. */ + smp_mb(); + } } if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids) |