diff options
Diffstat (limited to 'arch/x86/mm/init_64.c')
| -rw-r--r-- | arch/x86/mm/init_64.c | 174 |
1 files changed, 142 insertions, 32 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index d3746efb060..83e13f2d53d 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -88,6 +88,62 @@ early_param("gbpages", parse_direct_gbpages_on); int after_bootmem; +unsigned long __supported_pte_mask __read_mostly = ~0UL; +EXPORT_SYMBOL_GPL(__supported_pte_mask); + +static int do_not_nx __cpuinitdata; + +/* + * noexec=on|off + * Control non-executable mappings for 64-bit processes. + * + * on Enable (default) + * off Disable + */ +static int __init nonx_setup(char *str) +{ + if (!str) + return -EINVAL; + if (!strncmp(str, "on", 2)) { + __supported_pte_mask |= _PAGE_NX; + do_not_nx = 0; + } else if (!strncmp(str, "off", 3)) { + do_not_nx = 1; + __supported_pte_mask &= ~_PAGE_NX; + } + return 0; +} +early_param("noexec", nonx_setup); + +void __cpuinit check_efer(void) +{ + unsigned long efer; + + rdmsrl(MSR_EFER, efer); + if (!(efer & EFER_NX) || do_not_nx) + __supported_pte_mask &= ~_PAGE_NX; +} + +int force_personality32; + +/* + * noexec32=on|off + * Control non executable heap for 32bit processes. + * To control the stack too use noexec=off + * + * on PROT_READ does not imply PROT_EXEC for 32-bit processes (default) + * off PROT_READ implies PROT_EXEC + */ +static int __init nonx32_setup(char *str) +{ + if (!strcmp(str, "on")) + force_personality32 &= ~READ_IMPLIES_EXEC; + else if (!strcmp(str, "off")) + force_personality32 |= READ_IMPLIES_EXEC; + return 1; +} +__setup("noexec32=", nonx32_setup); + /* * NOTE: This function is marked __ref because it calls __init function * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. @@ -225,7 +281,7 @@ void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) void __init cleanup_highmap(void) { unsigned long vaddr = __START_KERNEL_map; - unsigned long end = round_up((unsigned long)_end, PMD_SIZE) - 1; + unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1; pmd_t *pmd = level2_kernel_pgt; pmd_t *last_pmd = pmd + PTRS_PER_PMD; @@ -271,7 +327,8 @@ static __ref void unmap_low_page(void *adr) } static unsigned long __meminit -phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end) +phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, + pgprot_t prot) { unsigned pages = 0; unsigned long last_map_addr = end; @@ -289,36 +346,43 @@ phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end) break; } + /* + * We will re-use the existing mapping. + * Xen for example has some special requirements, like mapping + * pagetable pages as RO. So assume someone who pre-setup + * these mappings are more intelligent. + */ if (pte_val(*pte)) continue; if (0) printk(" pte=%p addr=%lx pte=%016lx\n", pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); - set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL)); - last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; pages++; + set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); + last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; } + update_page_count(PG_LEVEL_4K, pages); return last_map_addr; } static unsigned long __meminit -phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end) +phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end, + pgprot_t prot) { pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd); - return phys_pte_init(pte, address, end); + return phys_pte_init(pte, address, end, prot); } static unsigned long __meminit phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, - unsigned long page_size_mask) + unsigned long page_size_mask, pgprot_t prot) { unsigned long pages = 0; unsigned long last_map_addr = end; - unsigned long start = address; int i = pmd_index(address); @@ -326,6 +390,7 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, unsigned long pte_phys; pmd_t *pmd = pmd_page + pmd_index(address); pte_t *pte; + pgprot_t new_prot = prot; if (address >= end) { if (!after_bootmem) { @@ -339,27 +404,40 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, if (!pmd_large(*pmd)) { spin_lock(&init_mm.page_table_lock); last_map_addr = phys_pte_update(pmd, address, - end); + end, prot); spin_unlock(&init_mm.page_table_lock); + continue; } - /* Count entries we're using from level2_ident_pgt */ - if (start == 0) - pages++; - continue; + /* + * If we are ok with PG_LEVEL_2M mapping, then we will + * use the existing mapping, + * + * Otherwise, we will split the large page mapping but + * use the same existing protection bits except for + * large page, so that we don't violate Intel's TLB + * Application note (317080) which says, while changing + * the page sizes, new and old translations should + * not differ with respect to page frame and + * attributes. + */ + if (page_size_mask & (1 << PG_LEVEL_2M)) + continue; + new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); } if (page_size_mask & (1<<PG_LEVEL_2M)) { pages++; spin_lock(&init_mm.page_table_lock); set_pte((pte_t *)pmd, - pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); + pfn_pte(address >> PAGE_SHIFT, + __pgprot(pgprot_val(prot) | _PAGE_PSE))); spin_unlock(&init_mm.page_table_lock); last_map_addr = (address & PMD_MASK) + PMD_SIZE; continue; } pte = alloc_low_page(&pte_phys); - last_map_addr = phys_pte_init(pte, address, end); + last_map_addr = phys_pte_init(pte, address, end, new_prot); unmap_low_page(pte); spin_lock(&init_mm.page_table_lock); @@ -372,12 +450,12 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, static unsigned long __meminit phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end, - unsigned long page_size_mask) + unsigned long page_size_mask, pgprot_t prot) { pmd_t *pmd = pmd_offset(pud, 0); unsigned long last_map_addr; - last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask); + last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot); __flush_tlb_all(); return last_map_addr; } @@ -394,6 +472,7 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, unsigned long pmd_phys; pud_t *pud = pud_page + pud_index(addr); pmd_t *pmd; + pgprot_t prot = PAGE_KERNEL; if (addr >= end) break; @@ -405,10 +484,26 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, } if (pud_val(*pud)) { - if (!pud_large(*pud)) + if (!pud_large(*pud)) { last_map_addr = phys_pmd_update(pud, addr, end, - page_size_mask); - continue; + page_size_mask, prot); + continue; + } + /* + * If we are ok with PG_LEVEL_1G mapping, then we will + * use the existing mapping. + * + * Otherwise, we will split the gbpage mapping but use + * the same existing protection bits except for large + * page, so that we don't violate Intel's TLB + * Application note (317080) which says, while changing + * the page sizes, new and old translations should + * not differ with respect to page frame and + * attributes. + */ + if (page_size_mask & (1 << PG_LEVEL_1G)) + continue; + prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); } if (page_size_mask & (1<<PG_LEVEL_1G)) { @@ -422,7 +517,8 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, } pmd = alloc_low_page(&pmd_phys); - last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask); + last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, + prot); unmap_low_page(pmd); spin_lock(&init_mm.page_table_lock); @@ -430,6 +526,7 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, spin_unlock(&init_mm.page_table_lock); } __flush_tlb_all(); + update_page_count(PG_LEVEL_1G, pages); return last_map_addr; @@ -446,27 +543,28 @@ phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end, return phys_pud_init(pud, addr, end, page_size_mask); } -static void __init find_early_table_space(unsigned long end) +static void __init find_early_table_space(unsigned long end, int use_pse, + int use_gbpages) { unsigned long puds, pmds, ptes, tables, start; puds = (end + PUD_SIZE - 1) >> PUD_SHIFT; - tables = round_up(puds * sizeof(pud_t), PAGE_SIZE); - if (direct_gbpages) { + tables = roundup(puds * sizeof(pud_t), PAGE_SIZE); + if (use_gbpages) { unsigned long extra; extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT); pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT; } else pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT; - tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE); + tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE); - if (cpu_has_pse) { + if (use_pse) { unsigned long extra; extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT); ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT; } else ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT; - tables += round_up(ptes * sizeof(pte_t), PAGE_SIZE); + tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE); /* * RED-PEN putting page tables only on node 0 could @@ -528,6 +626,7 @@ static unsigned long __init kernel_physical_mapping_init(unsigned long start, pgd_populate(&init_mm, pgd, __va(pud_phys)); spin_unlock(&init_mm.page_table_lock); } + __flush_tlb_all(); return last_map_addr; } @@ -571,6 +670,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, struct map_range mr[NR_RANGE_MR]; int nr_range, i; + int use_pse, use_gbpages; printk(KERN_INFO "init_memory_mapping\n"); @@ -584,9 +684,21 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, if (!after_bootmem) init_gbpages(); - if (direct_gbpages) +#ifdef CONFIG_DEBUG_PAGEALLOC + /* + * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. + * This will simplify cpa(), which otherwise needs to support splitting + * large pages into small in interrupt context, etc. + */ + use_pse = use_gbpages = 0; +#else + use_pse = cpu_has_pse; + use_gbpages = direct_gbpages; +#endif + + if (use_gbpages) page_size_mask |= 1 << PG_LEVEL_1G; - if (cpu_has_pse) + if (use_pse) page_size_mask |= 1 << PG_LEVEL_2M; memset(mr, 0, sizeof(mr)); @@ -647,7 +759,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k")); if (!after_bootmem) - find_early_table_space(end); + find_early_table_space(end, use_pse, use_gbpages); for (i = 0; i < nr_range; i++) last_map_addr = kernel_physical_mapping_init( @@ -806,8 +918,6 @@ void __init mem_init(void) reservedpages << (PAGE_SHIFT-10), datasize >> 10, initsize >> 10); - - cpa_init(); } void free_init_pages(char *what, unsigned long begin, unsigned long end) |