1 files changed, 28 insertions, 18 deletions

diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 6d79a1b0d446..2d8b9b91dee0 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -22,6 +22,7 @@
 #include <asm/cacheflush.h>
 #include <linux/uaccess.h>
 #include <linux/highmem.h>
+#include <linux/sizes.h>
 #include "binder_alloc.h"
 #include "binder_trace.h"
 
@@ -156,7 +157,7 @@ static struct binder_buffer *binder_alloc_prepare_to_free_locked(
 }
 
 /**
- * binder_alloc_buffer_lookup() - get buffer given user ptr
+ * binder_alloc_prepare_to_free() - get buffer given user ptr
  * @alloc:	binder_alloc for this proc
  * @user_ptr:	User pointer to buffer data
  *
@@ -267,7 +268,6 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 			alloc->pages_high = index + 1;
 
 		trace_binder_alloc_page_end(alloc, index);
-		/* vm_insert_page does not seem to increment the refcount */
 	}
 	if (mm) {
 		up_read(&mm->mmap_sem);
@@ -276,8 +276,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 	return 0;
 
 free_range:
-	for (page_addr = end - PAGE_SIZE; page_addr >= start;
-	     page_addr -= PAGE_SIZE) {
+	for (page_addr = end - PAGE_SIZE; 1; page_addr -= PAGE_SIZE) {
 		bool ret;
 		size_t index;
 
@@ -290,6 +289,8 @@ free_range:
 		WARN_ON(!ret);
 
 		trace_binder_free_lru_end(alloc, index);
+		if (page_addr == start)
+			break;
 		continue;
 
 err_vm_insert_page_failed:
@@ -297,7 +298,8 @@ err_vm_insert_page_failed:
 		page->page_ptr = NULL;
 err_alloc_page_failed:
 err_page_ptr_cleared:
-		;
+		if (page_addr == start)
+			break;
 	}
 err_no_vma:
 	if (mm) {
@@ -680,16 +682,18 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 	struct binder_buffer *buffer;
 
 	mutex_lock(&binder_alloc_mmap_lock);
-	if (alloc->buffer) {
+	if (alloc->buffer_size) {
 		ret = -EBUSY;
 		failure_string = "already mapped";
 		goto err_already_mapped;
 	}
+	alloc->buffer_size = min_t(unsigned long, vma->vm_end - vma->vm_start,
+				   SZ_4M);
+	mutex_unlock(&binder_alloc_mmap_lock);
 
 	alloc->buffer = (void __user *)vma->vm_start;
-	mutex_unlock(&binder_alloc_mmap_lock);
 
-	alloc->pages = kcalloc((vma->vm_end - vma->vm_start) / PAGE_SIZE,
+	alloc->pages = kcalloc(alloc->buffer_size / PAGE_SIZE,
 			       sizeof(alloc->pages[0]),
 			       GFP_KERNEL);
 	if (alloc->pages == NULL) {
@@ -697,7 +701,6 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
 		failure_string = "alloc page array";
 		goto err_alloc_pages_failed;
 	}
-	alloc->buffer_size = vma->vm_end - vma->vm_start;
 
 	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 	if (!buffer) {
@@ -720,8 +723,9 @@ err_alloc_buf_struct_failed:
 	kfree(alloc->pages);
 	alloc->pages = NULL;
 err_alloc_pages_failed:
-	mutex_lock(&binder_alloc_mmap_lock);
 	alloc->buffer = NULL;
+	mutex_lock(&binder_alloc_mmap_lock);
+	alloc->buffer_size = 0;
 err_already_mapped:
 	mutex_unlock(&binder_alloc_mmap_lock);
 	binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
@@ -839,14 +843,20 @@ void binder_alloc_print_pages(struct seq_file *m,
 	int free = 0;
 
 	mutex_lock(&alloc->mutex);
-	for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
-		page = &alloc->pages[i];
-		if (!page->page_ptr)
-			free++;
-		else if (list_empty(&page->lru))
-			active++;
-		else
-			lru++;
+	/*
+	 * Make sure the binder_alloc is fully initialized, otherwise we might
+	 * read inconsistent state.
+	 */
+	if (binder_alloc_get_vma(alloc) != NULL) {
+		for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
+			page = &alloc->pages[i];
+			if (!page->page_ptr)
+				free++;
+			else if (list_empty(&page->lru))
+				active++;
+			else
+				lru++;
+		}
 	}
 	mutex_unlock(&alloc->mutex);
 	seq_printf(m, "  pages: %d:%d:%d\n", active, lru, free);