vserver 1.9.5.x5

[linux-2.6.git] / arch / i386 / mm / pageattr.c

diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c
index 4cfc303..862326f 100644 (file)
--- a/arch/i386/mm/pageattr.c
+++ b/arch/i386/mm/pageattr.c
@@ -13,17 +13,21 @@
 #include <asm/processor.h>
 #include <asm/tlbflush.h>
 
-static spinlock_t cpa_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(cpa_lock);
 static struct list_head df_list = LIST_HEAD_INIT(df_list);
 
 
 pte_t *lookup_address(unsigned long address) 
 { 
-       pgd_t *pgd = pgd_offset_k(address); 
+       pgd_t *pgd = pgd_offset_k(address);
+       pud_t *pud;
        pmd_t *pmd;
        if (pgd_none(*pgd))
                return NULL;
-       pmd = pmd_offset(pgd, address);                
+       pud = pud_offset(pgd, address);
+       if (pud_none(*pud))
+               return NULL;
+       pmd = pmd_offset(pud, address);
        if (pmd_none(*pmd))
                return NULL;
        if (pmd_large(*pmd))
@@ -77,9 +81,11 @@ static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
        spin_lock_irqsave(&pgd_lock, flags);
        for (page = pgd_list; page; page = (struct page *)page->index) {
                pgd_t *pgd;
+               pud_t *pud;
                pmd_t *pmd;
                pgd = (pgd_t *)page_address(page) + pgd_index(address);
-               pmd = pmd_offset(pgd, address);
+               pud = pud_offset(pgd, address);
+               pmd = pmd_offset(pud, address);
                set_pte_atomic((pte_t *)pmd, pte);
        }
        spin_unlock_irqrestore(&pgd_lock, flags);
@@ -92,7 +98,7 @@ static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
 static inline void revert_page(struct page *kpte_page, unsigned long address)
 {
        pte_t *linear = (pte_t *) 
-               pmd_offset(pgd_offset(&init_mm, address), address);
+               pmd_offset(pud_offset(pgd_offset_k(address), address), address);
        set_pmd_pte(linear,  address,
                    pfn_pte((__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT,
                            PAGE_KERNEL_LARGE));
@@ -105,10 +111,7 @@ __change_page_attr(struct page *page, pgprot_t prot)
        unsigned long address;
        struct page *kpte_page;
 
-#ifdef CONFIG_HIGHMEM
-       if (page >= highmem_start_page) 
-               BUG(); 
-#endif
+       BUG_ON(PageHighMem(page));
        address = (unsigned long)page_address(page);
 
        kpte = lookup_address(address);
@@ -117,27 +120,35 @@ __change_page_attr(struct page *page, pgprot_t prot)
        kpte_page = virt_to_page(kpte);
        if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) { 
                if ((pte_val(*kpte) & _PAGE_PSE) == 0) { 
-                       pte_t old = *kpte;
-                       pte_t standard = mk_pte(page, PAGE_KERNEL); 
                        set_pte_atomic(kpte, mk_pte(page, prot)); 
-                       if (pte_same(old,standard))
-                               get_page(kpte_page);
                } else {
                        struct page *split = split_large_page(address, prot); 
                        if (!split)
                                return -ENOMEM;
-                       get_page(kpte_page);
                        set_pmd_pte(kpte,address,mk_pte(split, PAGE_KERNEL));
+                       kpte_page = split;
                }       
+               get_page(kpte_page);
        } else if ((pte_val(*kpte) & _PAGE_PSE) == 0) { 
                set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL));
                __put_page(kpte_page);
-       }
+       } else
+               BUG();
 
-       if (cpu_has_pse && (page_count(kpte_page) == 1)) {
-               list_add(&kpte_page->lru, &df_list);
-               revert_page(kpte_page, address);
-       } 
+       /*
+        * If the pte was reserved, it means it was created at boot
+        * time (not via split_large_page) and in turn we must not
+        * replace it with a largepage.
+        */
+       if (!PageReserved(kpte_page)) {
+               /* memleak and potential failed 2M page regeneration */
+               BUG_ON(!page_count(kpte_page));
+
+               if (cpu_has_pse && (page_count(kpte_page) == 1)) {
+                       list_add(&kpte_page->lru, &df_list);
+                       revert_page(kpte_page, address);
+               }
+       }
        return 0;
 } 
 
@@ -208,7 +219,6 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
         */
        __flush_tlb_all();
 }
-EXPORT_SYMBOL(kernel_map_pages);
 #endif
 
 EXPORT_SYMBOL(change_page_attr);