x86: use the right protections for split-up pagetables

[safe/jmp/linux-2.6] / arch / x86 / mm / init_32.c

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 3ffed25..2cef050 100644 (file)
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -21,6 +21,7 @@
 #include <linux/init.h>
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
+#include <linux/pci.h>
 #include <linux/pfn.h>
 #include <linux/poison.h>
 #include <linux/bootmem.h>
@@ -67,7 +68,7 @@ static unsigned long __meminitdata table_top;
 
 static int __initdata after_init_bootmem;
 
-static __init void *alloc_low_page(unsigned long *phys)
+static __init void *alloc_low_page(void)
 {
        unsigned long pfn = table_end++;
        void *adr;
@@ -77,7 +78,6 @@ static __init void *alloc_low_page(unsigned long *phys)
 
        adr = __va(pfn * PAGE_SIZE);
        memset(adr, 0, PAGE_SIZE);
-       *phys  = pfn * PAGE_SIZE;
        return adr;
 }
 
@@ -92,12 +92,11 @@ static pmd_t * __init one_md_table_init(pgd_t *pgd)
        pmd_t *pmd_table;
 
 #ifdef CONFIG_X86_PAE
-       unsigned long phys;
        if (!(pgd_val(*pgd) & _PAGE_PRESENT)) {
                if (after_init_bootmem)
                        pmd_table = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
                else
-                       pmd_table = (pmd_t *)alloc_low_page(&phys);
+                       pmd_table = (pmd_t *)alloc_low_page();
                paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT);
                set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
                pud = pud_offset(pgd, 0);
@@ -128,10 +127,8 @@ static pte_t * __init one_page_table_init(pmd_t *pmd)
                        if (!page_table)
                                page_table =
                                (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
-               } else {
-                       unsigned long phys;
-                       page_table = (pte_t *)alloc_low_page(&phys);
-               }
+               } else
+                       page_table = (pte_t *)alloc_low_page();
 
                paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT);
                set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
@@ -141,6 +138,47 @@ static pte_t * __init one_page_table_init(pmd_t *pmd)
        return pte_offset_kernel(pmd, 0);
 }
 
+static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
+                                          unsigned long vaddr, pte_t *lastpte)
+{
+#ifdef CONFIG_HIGHMEM
+       /*
+        * Something (early fixmap) may already have put a pte
+        * page here, which causes the page table allocation
+        * to become nonlinear. Attempt to fix it, and if it
+        * is still nonlinear then we have to bug.
+        */
+       int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT;
+       int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT;
+
+       if (pmd_idx_kmap_begin != pmd_idx_kmap_end
+           && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin
+           && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end
+           && ((__pa(pte) >> PAGE_SHIFT) < table_start
+               || (__pa(pte) >> PAGE_SHIFT) >= table_end)) {
+               pte_t *newpte;
+               int i;
+
+               BUG_ON(after_init_bootmem);
+               newpte = alloc_low_page();
+               for (i = 0; i < PTRS_PER_PTE; i++)
+                       set_pte(newpte + i, pte[i]);
+
+               paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT);
+               set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE));
+               BUG_ON(newpte != pte_offset_kernel(pmd, 0));
+               __flush_tlb_all();
+
+               paravirt_release_pte(__pa(pte) >> PAGE_SHIFT);
+               pte = newpte;
+       }
+       BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1)
+              && vaddr > fix_to_virt(FIX_KMAP_END)
+              && lastpte && lastpte + PTRS_PER_PTE != pte);
+#endif
+       return pte;
+}
+
 /*
  * This function initializes a certain range of kernel virtual memory
  * with new bootmem page tables, everywhere page tables are missing in
@@ -157,6 +195,7 @@ page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
        unsigned long vaddr;
        pgd_t *pgd;
        pmd_t *pmd;
+       pte_t *pte = NULL;
 
        vaddr = start;
        pgd_idx = pgd_index(vaddr);
@@ -168,7 +207,8 @@ page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base)
                pmd = pmd + pmd_index(vaddr);
                for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end);
                                                        pmd++, pmd_idx++) {
-                       one_page_table_init(pmd);
+                       pte = page_table_kmap_check(one_page_table_init(pmd),
+                                                   pmd, vaddr, pte);
 
                        vaddr += PMD_SIZE;
                }
@@ -331,6 +371,8 @@ int devmem_is_allowed(unsigned long pagenr)
 {
        if (pagenr <= 256)
                return 1;
+       if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
+               return 0;
        if (!page_is_ram(pagenr))
                return 1;
        return 0;
@@ -438,8 +480,12 @@ static void __init set_highmem_pages_init(void)
 #endif /* !CONFIG_NUMA */
 
 #else
-# define permanent_kmaps_init(pgd_base)                do { } while (0)
-# define set_highmem_pages_init()      do { } while (0)
+static inline void permanent_kmaps_init(pgd_t *pgd_base)
+{
+}
+static inline void set_highmem_pages_init(void)
+{
+}
 #endif /* CONFIG_HIGHMEM */
 
 void __init native_pagetable_setup_start(pgd_t *base)
@@ -505,7 +551,6 @@ static void __init early_ioremap_page_table_range_init(pgd_t *pgd_base)
         * Fixed mappings, only the page table structure has to be
         * created - mappings will be set by set_fixmap():
         */
-       early_ioremap_clear();
        vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
        end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
        page_table_range_init(vaddr, end, pgd_base);
@@ -798,7 +843,7 @@ static void __init find_early_table_space(unsigned long end, int use_pse)
        tables += PAGE_ALIGN(ptes * sizeof(pte_t));
 
        /* for fixmap */
-       tables += PAGE_SIZE * 2;
+       tables += PAGE_ALIGN(__end_of_fixed_addresses * sizeof(pte_t));
 
        /*
         * RED-PEN putting page tables only on node 0 could
@@ -971,7 +1016,7 @@ void __init mem_init(void)
        int codesize, reservedpages, datasize, initsize;
        int tmp;
 
-       start_periodic_check_for_corruption();
+       pci_iommu_alloc();
 
 #ifdef CONFIG_FLATMEM
        BUG_ON(!mem_map);
@@ -1042,11 +1087,25 @@ void __init mem_init(void)
                (unsigned long)&_text, (unsigned long)&_etext,
                ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
 
+       /*
+        * Check boundaries twice: Some fundamental inconsistencies can
+        * be detected at build time already.
+        */
+#define __FIXADDR_TOP (-PAGE_SIZE)
+#ifdef CONFIG_HIGHMEM
+       BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE  > FIXADDR_START);
+       BUILD_BUG_ON(VMALLOC_END                        > PKMAP_BASE);
+#endif
+#define high_memory (-128UL << 20)
+       BUILD_BUG_ON(VMALLOC_START                      >= VMALLOC_END);
+#undef high_memory
+#undef __FIXADDR_TOP
+
 #ifdef CONFIG_HIGHMEM
        BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE        > FIXADDR_START);
        BUG_ON(VMALLOC_END                              > PKMAP_BASE);
 #endif
-       BUG_ON(VMALLOC_START                            > VMALLOC_END);
+       BUG_ON(VMALLOC_START                            >= VMALLOC_END);
        BUG_ON((unsigned long)high_memory               > VMALLOC_START);
 
        if (boot_cpu_data.wp_works_ok < 0)
@@ -1064,7 +1123,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
        unsigned long start_pfn = start >> PAGE_SHIFT;
        unsigned long nr_pages = size >> PAGE_SHIFT;
 
-       return __add_pages(zone, start_pfn, nr_pages);
+       return __add_pages(nid, zone, start_pfn, nr_pages);
 }
 #endif