Revert "binder_alloc: Add missing mmap_lock calls when using the VMA"

This reverts commit d6f35446.

It is coming in through Andrew's tree instead, and for some reason we
have different versions.  I trust the version from Andrew more as the
original offending commit came through his tree.

Fixes: d6f35446 ("binder_alloc: Add missing mmap_lock calls when using the VMA")
Cc: stable <stable@kernel.org>
Cc: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/r/20220819184027.7b3fda3e@canb.auug.org.auSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/android/binder_alloc.c

@@ -402,15 +402,12 @@ static struct binder_buffer *binder_alloc_new_buf_locked(
 	size_t size, data_offsets_size;
 	int ret;
 
-	mmap_read_lock(alloc->vma_vm_mm);
 	if (!binder_alloc_get_vma(alloc)) {
-		mmap_read_unlock(alloc->vma_vm_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);
 
 	data_offsets_size = ALIGN(data_size, sizeof(void *)) +
 		ALIGN(offsets_size, sizeof(void *));
@@ -932,25 +929,17 @@ void binder_alloc_print_pages(struct seq_file *m,
 	 * Make sure the binder_alloc is fully initialized, otherwise we might
 	 * read inconsistent state.
 	 */
-
-	mmap_read_lock(alloc->vma_vm_mm);
-	if (binder_alloc_get_vma(alloc) == NULL) {
-		mmap_read_unlock(alloc->vma_vm_mm);
-		goto uninitialized;
-	}
-
-	mmap_read_unlock(alloc->vma_vm_mm);
-	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++;
+	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++;
+		}
 	}
-
-uninitialized:
 	mutex_unlock(&alloc->mutex);
 	seq_printf(m, "  pages: %d:%d:%d\n", active, lru, free);
 	seq_printf(m, "  pages high watermark: %zu\n", alloc->pages_high);