binder: rename alloc->vma_vm_mm to alloc->mm

Rename ->vma_vm_mm to ->mm to reflect the fact that we no longer cache
this reference from vma->vm_mm but from current->mm instead.

No functional changes in this patch.
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20220906135948.3048225-2-cmllamas@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/android/binder_alloc.c

@@ -208,8 +208,8 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
 		}
 	}
 
-	if (need_mm && mmget_not_zero(alloc->vma_vm_mm))
-		mm = alloc->vma_vm_mm;
+	if (need_mm && mmget_not_zero(alloc->mm))
+		mm = alloc->mm;
 
 	if (mm) {
 		mmap_read_lock(mm);
@@ -322,9 +322,9 @@ static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
 	 */
 	if (vma) {
 		vm_start = vma->vm_start;
-		mmap_assert_write_locked(alloc->vma_vm_mm);
+		mmap_assert_write_locked(alloc->mm);
 	} else {
-		mmap_assert_locked(alloc->vma_vm_mm);
+		mmap_assert_locked(alloc->mm);
 	}
 
 	alloc->vma_addr = vm_start;
@@ -336,7 +336,7 @@ static inline struct vm_area_struct *binder_alloc_get_vma(
 	struct vm_area_struct *vma = NULL;
 
 	if (alloc->vma_addr)
-		vma = vma_lookup(alloc->vma_vm_mm, alloc->vma_addr);
+		vma = vma_lookup(alloc->mm, alloc->vma_addr);
 
 	return vma;
 }
@@ -401,15 +401,15 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
 	size_t size, data_offsets_size;
 	int ret;
 
-	mmap_read_lock(alloc->vma_vm_mm);
+	mmap_read_lock(alloc->mm);
 	if (!binder_alloc_get_vma(alloc)) {
-		mmap_read_unlock(alloc->vma_vm_mm);
+		mmap_read_unlock(alloc->mm);
 		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
 				   "%d: binder_alloc_buf, no vma\n",
 				   alloc->pid);
 		return ERR_PTR(-ESRCH);
 	}
-	mmap_read_unlock(alloc->vma_vm_mm);
+	mmap_read_unlock(alloc->mm);
 
 	data_offsets_size = ALIGN(data_size, sizeof(void *)) +
 		ALIGN(offsets_size, sizeof(void *));
@@ -823,7 +823,7 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc)
 	buffers = 0;
 	mutex_lock(&alloc->mutex);
 	BUG_ON(alloc->vma_addr &&
-	       vma_lookup(alloc->vma_vm_mm, alloc->vma_addr));
+	       vma_lookup(alloc->mm, alloc->vma_addr));
 
 	while ((n = rb_first(&alloc->allocated_buffers))) {
 		buffer = rb_entry(n, struct binder_buffer, rb_node);
@@ -873,8 +873,8 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc)
 		kfree(alloc->pages);
 	}
 	mutex_unlock(&alloc->mutex);
-	if (alloc->vma_vm_mm)
-		mmdrop(alloc->vma_vm_mm);
+	if (alloc->mm)
+		mmdrop(alloc->mm);
 
 	binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE,
 		     "%s: %d buffers %d, pages %d\n",
@@ -931,13 +931,13 @@ void binder_alloc_print_pages(struct seq_file *m,
 	 * read inconsistent state.
 	 */
 
-	mmap_read_lock(alloc->vma_vm_mm);
+	mmap_read_lock(alloc->mm);
 	if (binder_alloc_get_vma(alloc) == NULL) {
-		mmap_read_unlock(alloc->vma_vm_mm);
+		mmap_read_unlock(alloc->mm);
 		goto uninitialized;
 	}
 
-	mmap_read_unlock(alloc->vma_vm_mm);
+	mmap_read_unlock(alloc->mm);
 	for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
 		page = &alloc->pages[i];
 		if (!page->page_ptr)
@@ -1020,7 +1020,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
 	index = page - alloc->pages;
 	page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
 
-	mm = alloc->vma_vm_mm;
+	mm = alloc->mm;
 	if (!mmget_not_zero(mm))
 		goto err_mmget;
 	if (!mmap_read_trylock(mm))
@@ -1089,8 +1089,8 @@ static struct shrinker binder_shrinker = {
 void binder_alloc_init(struct binder_alloc *alloc)
 {
 	alloc->pid = current->group_leader->pid;
-	alloc->vma_vm_mm = current->mm;
-	mmgrab(alloc->vma_vm_mm);
+	alloc->mm = current->mm;
+	mmgrab(alloc->mm);
 	mutex_init(&alloc->mutex);
 	INIT_LIST_HEAD(&alloc->buffers);
 }

drivers/android/binder_alloc.h

@@ -78,7 +78,7 @@ struct binder_lru_page {
  *                      (invariant after mmap)
  * @tsk:                tid for task that called init for this proc
  *                      (invariant after init)
- * @vma_vm_mm:          copy of vma->vm_mm (invariant after mmap)
+ * @mm:                 copy of task->mm (invariant after open)
  * @buffer:             base of per-proc address space mapped via mmap
  * @buffers:            list of all buffers for this proc
  * @free_buffers:       rb tree of buffers available for allocation
@@ -101,7 +101,7 @@ struct binder_lru_page {
 struct binder_alloc {
 	struct mutex mutex;
 	unsigned long vma_addr;
-	struct mm_struct *vma_vm_mm;
+	struct mm_struct *mm;
 	void __user *buffer;
 	struct list_head buffers;
 	struct rb_root free_buffers;