lguest: expost switcher_pages array (as lg_switcher_pages).

We will need this in page_table.c soon.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/lguest/core.c

@@ -21,8 +21,8 @@
 #include "lg.h"
 
 unsigned long switcher_addr;
+struct page **lg_switcher_pages;
 static struct vm_struct *switcher_vma;
-static struct page **switcher_pages;
 
 /* This One Big lock protects all inter-guest data structures. */
 DEFINE_MUTEX(lguest_lock);
@@ -63,9 +63,10 @@ static __init int map_switcher(void)
 	 * We allocate an array of struct page pointers.  map_vm_area() wants
 	 * this, rather than just an array of pages.
 	 */
-	switcher_pages = kmalloc(sizeof(switcher_pages[0])*TOTAL_SWITCHER_PAGES,
+	lg_switcher_pages = kmalloc(sizeof(lg_switcher_pages[0])
+				    * TOTAL_SWITCHER_PAGES,
 				    GFP_KERNEL);
-	if (!switcher_pages) {
+	if (!lg_switcher_pages) {
 		err = -ENOMEM;
 		goto out;
 	}
@@ -75,8 +76,8 @@ static __init int map_switcher(void)
 	 * so we make sure they're zeroed.
 	 */
 	for (i = 0; i < TOTAL_SWITCHER_PAGES; i++) {
-		switcher_pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
-		if (!switcher_pages[i]) {
+		lg_switcher_pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
+		if (!lg_switcher_pages[i]) {
 			err = -ENOMEM;
 			goto free_some_pages;
 		}
@@ -117,7 +118,7 @@ static __init int map_switcher(void)
 	 * array of struct pages.  It increments that pointer, but we don't
 	 * care.
 	 */
-	pagep = switcher_pages;
+	pagep = lg_switcher_pages;
 	err = map_vm_area(switcher_vma, PAGE_KERNEL_EXEC, &pagep);
 	if (err) {
 		printk("lguest: map_vm_area failed: %i\n", err);
@@ -142,8 +143,8 @@ static __init int map_switcher(void)
 	i = TOTAL_SWITCHER_PAGES;
 free_some_pages:
 	for (--i; i >= 0; i--)
-		__free_pages(switcher_pages[i], 0);
-	kfree(switcher_pages);
+		__free_pages(lg_switcher_pages[i], 0);
+	kfree(lg_switcher_pages);
 out:
 	return err;
 }
@@ -158,8 +159,8 @@ static void unmap_switcher(void)
 	vunmap(switcher_vma->addr);
 	/* Now we just need to free the pages we copied the switcher into */
 	for (i = 0; i < TOTAL_SWITCHER_PAGES; i++)
-		__free_pages(switcher_pages[i], 0);
-	kfree(switcher_pages);
+		__free_pages(lg_switcher_pages[i], 0);
+	kfree(lg_switcher_pages);
 }
 
 /*H:032
@@ -333,7 +334,7 @@ static int __init init(void)
 		goto out;
 
 	/* Now we set up the pagetable implementation for the Guests. */
-	err = init_pagetables(switcher_pages);
+	err = init_pagetables(lg_switcher_pages);
 	if (err)
 		goto unmap;
 

drivers/lguest/lg.h

@@ -124,6 +124,7 @@ bool lguest_address_ok(const struct lguest *lg,
 		       unsigned long addr, unsigned long len);
 void __lgread(struct lg_cpu *, void *, unsigned long, unsigned);
 void __lgwrite(struct lg_cpu *, unsigned long, const void *, unsigned);
+extern struct page **lg_switcher_pages;
 
 /*H:035
  * Using memory-copy operations like that is usually inconvient, so we