Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / arch / x86_64 / mm / pageattr.c

diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c
index 94862e1..531ad21 100644 (file)
--- a/arch/x86_64/mm/pageattr.c
+++ b/arch/x86_64/mm/pageattr.c
@@ -45,6 +45,13 @@ static struct page *split_large_page(unsigned long address, pgprot_t prot,
        pte_t *pbase;
        if (!base) 
                return NULL;
+       /*
+        * page_private is used to track the number of entries in
+        * the page table page have non standard attributes.
+        */
+       SetPagePrivate(base);
+       page_private(base) = 0;
+
        address = __pa(address);
        addr = address & LARGE_PAGE_MASK; 
        pbase = (pte_t *)page_address(base);
@@ -77,26 +84,12 @@ static inline void flush_map(unsigned long address)
        on_each_cpu(flush_kernel_map, (void *)address, 1, 1);
 }
 
-struct deferred_page { 
-       struct deferred_page *next; 
-       struct page *fpage;
-       unsigned long address;
-}; 
-static struct deferred_page *df_list; /* protected by init_mm.mmap_sem */
+static struct page *deferred_pages; /* protected by init_mm.mmap_sem */
 
-static inline void save_page(unsigned long address, struct page *fpage)
+static inline void save_page(struct page *fpage)
 {
-       struct deferred_page *df;
-       df = kmalloc(sizeof(struct deferred_page), GFP_KERNEL); 
-       if (!df) {
-               flush_map(address);
-               __free_page(fpage);
-       } else { 
-               df->next = df_list;
-               df->fpage = fpage;
-               df->address = address;
-               df_list = df;
-       }                       
+       fpage->lru.next = (struct list_head *)deferred_pages;
+       deferred_pages = fpage;
 }
 
 /* 
@@ -128,6 +121,7 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
        pte_t *kpte; 
        struct page *kpte_page;
        unsigned kpte_flags;
+       pgprot_t ref_prot2;
        kpte = lookup_address(address);
        if (!kpte) return 0;
        kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK);
@@ -137,32 +131,33 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
                        set_pte(kpte, pfn_pte(pfn, prot));
                } else {
                        /*
-                        * split_large_page will take the reference for this change_page_attr
-                        * on the split page.
+                        * split_large_page will take the reference for this
+                        * change_page_attr on the split page.
                         */
-                       struct page *split = split_large_page(address, prot, ref_prot); 
+
+                       struct page *split;
+                       ref_prot2 = __pgprot(pgprot_val(pte_pgprot(*lookup_address(address))) & ~(1<<_PAGE_BIT_PSE));
+
+                       split = split_large_page(address, prot, ref_prot2);
                        if (!split)
                                return -ENOMEM;
-                       set_pte(kpte,mk_pte(split, ref_prot));
+                       set_pte(kpte,mk_pte(split, ref_prot2));
                        kpte_page = split;
                }       
-               get_page(kpte_page);
+               page_private(kpte_page)++;
        } else if ((kpte_flags & _PAGE_PSE) == 0) { 
                set_pte(kpte, pfn_pte(pfn, ref_prot));
-               __put_page(kpte_page);
+               BUG_ON(page_private(kpte_page) == 0);
+               page_private(kpte_page)--;
        } else
                BUG();
 
        /* on x86-64 the direct mapping set at boot is not using 4k pages */
        BUG_ON(PageReserved(kpte_page));
 
-       switch (page_count(kpte_page)) {
-       case 1:
-               save_page(address, kpte_page);               
+       if (page_private(kpte_page) == 0) {
+               save_page(kpte_page);
                revert_page(address, ref_prot);
-               break;
-       case 0:
-               BUG(); /* memleak and failed 2M page regeneration */
        }
        return 0;
 } 
@@ -215,19 +210,18 @@ int change_page_attr(struct page *page, int numpages, pgprot_t prot)
 
 void global_flush_tlb(void)
 { 
-       struct deferred_page *df, *next_df;
+       struct page *dpage;
 
        down_read(&init_mm.mmap_sem);
-       df = xchg(&df_list, NULL);
+       dpage = xchg(&deferred_pages, NULL);
        up_read(&init_mm.mmap_sem);
-       if (!df)
-               return;
-       flush_map((df && !df->next) ? df->address : 0);
-       for (; df; df = next_df) { 
-               next_df = df->next;
-               if (df->fpage) 
-                       __free_page(df->fpage);
-               kfree(df);
+
+       flush_map((dpage && !dpage->lru.next) ? (unsigned long)page_address(dpage) : 0);
+       while (dpage) {
+               struct page *tmp = dpage;
+               dpage = (struct page *)dpage->lru.next;
+               ClearPagePrivate(tmp);
+               __free_page(tmp);
        } 
 }