x86: return the page table level in lookup_address()

based on this patch from Andi Kleen:

|  Subject: CPA: Return the page table level in lookup_address()
|  From: Andi Kleen <ak@suse.de>
|
|  Needed for the next change.
|
|  And change all the callers.

and ported it to x86.git.

Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

5 files changed, 20 insertions, 9 deletions

diff --git a/arch/x86/mm/fault_32.c b/arch/x86/mm/fault_32.c
index f7972ae7da07..f4f8c324715f 100644
--- a/arch/x86/mm/fault_32.c
+++ b/arch/x86/mm/fault_32.c
@@ -613,7 +613,8 @@ no_context:
 
 #ifdef CONFIG_X86_PAE
                 if (error_code & PF_INSTR) {
-                        pte_t *pte = lookup_address(address);
+                        int level;
+                        pte_t *pte = lookup_address(address, &level);
 
                         if (pte && pte_present(*pte) && !pte_exec(*pte))
                                 printk(KERN_CRIT "kernel tried to execute "
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 5080646da771..206e3f6800b9 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -535,11 +535,12 @@ int __init set_kernel_exec(unsigned long vaddr, int enable)
 {
         pte_t *pte;
         int ret = 1;
+        int level;
 
         if (!nx_enabled)
                 goto out;
 
-        pte = lookup_address(vaddr);
+        pte = lookup_address(vaddr, &level);
         BUG_ON(!pte);
 
         if (!pte_exec(*pte))
diff --git a/arch/x86/mm/pageattr_32.c b/arch/x86/mm/pageattr_32.c
index be4656403d77..523fd5b37df9 100644
--- a/arch/x86/mm/pageattr_32.c
+++ b/arch/x86/mm/pageattr_32.c
@@ -18,7 +18,7 @@
 static DEFINE_SPINLOCK(cpa_lock);
 static struct list_head df_list = LIST_HEAD_INIT(df_list);
 
-pte_t *lookup_address(unsigned long address)
+pte_t *lookup_address(unsigned long address, int *level)
 {
         pgd_t *pgd = pgd_offset_k(address);
         pud_t *pud;
@@ -32,8 +32,10 @@ pte_t *lookup_address(unsigned long address)
         pmd = pmd_offset(pud, address);
         if (pmd_none(*pmd))
                 return NULL;
+        *level = 2;
         if (pmd_large(*pmd))
                 return (pte_t *)pmd;
+        *level = 3;
 
         return pte_offset_kernel(pmd, address);
 }
@@ -156,11 +158,12 @@ static int __change_page_attr(struct page *page, pgprot_t prot)
         struct page *kpte_page;
         unsigned long address;
         pte_t *kpte;
+        int level;
 
         BUG_ON(PageHighMem(page));
         address = (unsigned long)page_address(page);
 
-        kpte = lookup_address(address);
+        kpte = lookup_address(address, &level);
         if (!kpte)
                 return -EINVAL;
 
diff --git a/arch/x86/mm/pageattr_64.c b/arch/x86/mm/pageattr_64.c
index 14ab327cde0c..59cd066f6741 100644
--- a/arch/x86/mm/pageattr_64.c
+++ b/arch/x86/mm/pageattr_64.c
@@ -14,7 +14,7 @@
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
-pte_t *lookup_address(unsigned long address)
+pte_t *lookup_address(unsigned long address, int *level)
 {
         pgd_t *pgd = pgd_offset_k(address);
         pud_t *pud;
@@ -29,8 +29,10 @@ pte_t *lookup_address(unsigned long address)
         pmd = pmd_offset(pud, address);
         if (!pmd_present(*pmd))
                 return NULL;
+        *level = 3;
         if (pmd_large(*pmd))
                 return (pte_t *)pmd;
+        *level = 4;
 
         pte = pte_offset_kernel(pmd, address);
         if (pte && !pte_present(*pte))
@@ -140,8 +142,9 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
         struct page *kpte_page;
         pgprot_t ref_prot2;
         pte_t *kpte;
+        int level;
 
-        kpte = lookup_address(address);
+        kpte = lookup_address(address, &level);
         if (!kpte)
                 return 0;
 
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index e6184735545f..45aa771e73a9 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -58,7 +58,8 @@
 
 xmaddr_t arbitrary_virt_to_machine(unsigned long address)
 {
-        pte_t *pte = lookup_address(address);
+        int level;
+        pte_t *pte = lookup_address(address, &level);
         unsigned offset = address & PAGE_MASK;
 
         BUG_ON(pte == NULL);
@@ -70,8 +71,9 @@ void make_lowmem_page_readonly(void *vaddr)
 {
         pte_t *pte, ptev;
         unsigned long address = (unsigned long)vaddr;
+        int level;
 
-        pte = lookup_address(address);
+        pte = lookup_address(address, &level);
         BUG_ON(pte == NULL);
 
         ptev = pte_wrprotect(*pte);
@@ -84,8 +86,9 @@ void make_lowmem_page_readwrite(void *vaddr)
 {
         pte_t *pte, ptev;
         unsigned long address = (unsigned long)vaddr;
+        int level;
 
-        pte = lookup_address(address);
+        pte = lookup_address(address, &level);
         BUG_ON(pte == NULL);
 
         ptev = pte_mkwrite(*pte);