X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fmm%2Fpageattr.c;h=862326f5dc38e65e358f2230d1d36737d0f5602d;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=4cfc303495120cdb81801b9836250dfad0119f7e;hpb=87fc8d1bb10cd459024a742c6a10961fefcef18f;p=linux-2.6.git

diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c
index 4cfc30349..862326f5d 100644
--- 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);