[Xen-changelog] Fix make_page_readonly/make_page_writeable on PAE guests - previous behaviour

[Xen patchbot -unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User smh22@xxxxxxxxxxxxxxxxxxxx
# Node ID e023e37b3c7aca1d5702715eed4b586e267a75ee
# Parent  980967b0b161aa2a0d77066c5c43afa1c4e3a14c
Fix make_page_readonly/make_page_writeable on PAE guests - previous behaviour 
was incorrect when machine address > 4GB. We believe this fixes bugzilla #267. 

Also tidy up and fix show_page_walk.


Signed-off-by: Steven Hand <steven@xxxxxxxxxxxxx> 
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>

diff -r 980967b0b161 -r e023e37b3c7a 
linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c
--- a/linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c   Fri Nov 11 16:56:02 2005
+++ b/linux-2.6-xen-sparse/arch/xen/i386/mm/pgtable.c   Fri Nov 11 18:02:49 2005
@@ -398,14 +398,14 @@
 {
        pte_t *pte = virt_to_ptep(va);
        set_pte(pte, pte_wrprotect(*pte));
-       if ( (unsigned long)va >= (unsigned long)high_memory )
-       {
-               unsigned long phys;
-               phys = machine_to_phys(*(unsigned long *)pte & PAGE_MASK);
+       if ((unsigned long)va >= (unsigned long)high_memory) {
+               unsigned long pfn; 
+               pfn = pte_pfn(*pte); 
 #ifdef CONFIG_HIGHMEM
-               if ( (phys >> PAGE_SHIFT) < highstart_pfn )
+               if (pfn < highstart_pfn)
 #endif
-                       make_lowmem_page_readonly(phys_to_virt(phys));
+                       make_lowmem_page_readonly(
+                               phys_to_virt(pfn << PAGE_SHIFT)); 
        }
 }
 
@@ -413,21 +413,20 @@
 {
        pte_t *pte = virt_to_ptep(va);
        set_pte(pte, pte_mkwrite(*pte));
-       if ( (unsigned long)va >= (unsigned long)high_memory )
-       {
-               unsigned long phys;
-               phys = machine_to_phys(*(unsigned long *)pte & PAGE_MASK);
+       if ((unsigned long)va >= (unsigned long)high_memory) {
+               unsigned long pfn; 
+               pfn = pte_pfn(*pte); 
 #ifdef CONFIG_HIGHMEM
-               if ( (phys >> PAGE_SHIFT) < highstart_pfn )
+               if (pfn < highstart_pfn)
 #endif
-                       make_lowmem_page_writable(phys_to_virt(phys));
+                       make_lowmem_page_writable(
+                               phys_to_virt(pfn << PAGE_SHIFT)); 
        }
 }
 
 void make_pages_readonly(void *va, unsigned int nr)
 {
-       while ( nr-- != 0 )
-       {
+       while (nr-- != 0) {
                make_page_readonly(va);
                va = (void *)((unsigned long)va + PAGE_SIZE);
        }
@@ -435,8 +434,7 @@
 
 void make_pages_writable(void *va, unsigned int nr)
 {
-       while ( nr-- != 0 )
-       {
+       while (nr-- != 0) {
                make_page_writable(va);
                va = (void *)((unsigned long)va + PAGE_SIZE);
        }
diff -r 980967b0b161 -r e023e37b3c7a xen/arch/x86/x86_32/traps.c
--- a/xen/arch/x86/x86_32/traps.c       Fri Nov 11 16:56:02 2005
+++ b/xen/arch/x86/x86_32/traps.c       Fri Nov 11 18:02:49 2005
@@ -84,32 +84,37 @@
 
 void show_page_walk(unsigned long addr)
 {
-    unsigned long pfn = read_cr3() >> PAGE_SHIFT;
+    unsigned long mfn = read_cr3() >> PAGE_SHIFT;
     intpte_t *ptab, ent;
+    unsigned long pfn; 
 
     printk("Pagetable walk from %08lx:\n", addr);
 
 #ifdef CONFIG_X86_PAE
-    ptab = map_domain_page(pfn);
-    ent = ptab[l3_table_offset(addr)];
-    printk(" L3 = %"PRIpte"\n", ent);
+    ptab = map_domain_page(mfn);
+    ent  = ptab[l3_table_offset(addr)];
+    pfn  = machine_to_phys_mapping[(u32)(ent >> PAGE_SHIFT)]; 
+    printk(" L3 = %"PRIpte" %08lx\n", ent, pfn);
     unmap_domain_page(ptab);
     if ( !(ent & _PAGE_PRESENT) )
         return;
-    pfn = ent >> PAGE_SHIFT;
+    mfn = ent >> PAGE_SHIFT;
 #endif
 
-    ptab = map_domain_page(pfn);
-    ent = ptab[l2_table_offset(addr)];
-    printk("  L2 = %"PRIpte" %s\n", ent, (ent & _PAGE_PSE) ? "(PSE)" : "");
+    ptab = map_domain_page(mfn);
+    ent  = ptab[l2_table_offset(addr)];
+    pfn  = machine_to_phys_mapping[(u32)(ent >> PAGE_SHIFT)]; 
+    printk("  L2 = %"PRIpte" %08lx %s\n", ent, pfn, 
+           (ent & _PAGE_PSE) ? "(PSE)" : "");
     unmap_domain_page(ptab);
     if ( !(ent & _PAGE_PRESENT) || (ent & _PAGE_PSE) )
         return;
-    pfn = ent >> PAGE_SHIFT;
+    mfn = ent >> PAGE_SHIFT;
 
     ptab = map_domain_page(ent >> PAGE_SHIFT);
-    ent = ptab[l2_table_offset(addr)];
-    printk("   L1 = %"PRIpte"\n", ent);
+    ent  = ptab[l1_table_offset(addr)];
+    pfn  = machine_to_phys_mapping[(u32)(ent >> PAGE_SHIFT)]; 
+    printk("   L1 = %"PRIpte" %08lx\n", ent, pfn);
     unmap_domain_page(ptab);
 }
 

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog