Merge tag 'drm-misc-fixes-2023-01-26' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes

A fix and a preliminary patch to fix a memory leak in i915, and a use
after free fix for fbdev deferred io

Signed-off-by: Dave Airlie <[e-mail]>

From: Maxime Ripard <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/20230126104018.cbrcjxl5wefdbb2f@houat

drivers/gpu/drm/drm_fbdev_generic.c

···
 	.fb_imageblit	= drm_fbdev_fb_imageblit,
 };
 
-static struct fb_deferred_io drm_fbdev_defio = {
-	.delay		= HZ / 20,
-	.deferred_io	= drm_fb_helper_deferred_io,
-};
-
 /*
  * This function uses the client API to create a framebuffer backed by a dumb buffer.
  */
···
 			return -ENOMEM;
 		fbi->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
 
-		fbi->fbdefio = &drm_fbdev_defio;
-		fb_deferred_io_init(fbi);
+		/* Set a default deferred I/O handler */
+		fb_helper->fbdefio.delay = HZ / 20;
+		fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
+
+		fbi->fbdefio = &fb_helper->fbdefio;
+		ret = fb_deferred_io_init(fbi);
+		if (ret)
+			return ret;
 	} else {
 		/* buffer is mapped for HW framebuffer */
 		ret = drm_client_buffer_vmap(fb_helper->buffer, &map);

drivers/gpu/drm/drm_vma_manager.c

···
 }
 EXPORT_SYMBOL(drm_vma_offset_remove);
 
-/**
- * drm_vma_node_allow - Add open-file to list of allowed users
- * @node: Node to modify
- * @tag: Tag of file to remove
- *
- * Add @tag to the list of allowed open-files for this node. If @tag is
- * already on this list, the ref-count is incremented.
- *
- * The list of allowed-users is preserved across drm_vma_offset_add() and
- * drm_vma_offset_remove() calls. You may even call it if the node is currently
- * not added to any offset-manager.
- *
- * You must remove all open-files the same number of times as you added them
- * before destroying the node. Otherwise, you will leak memory.
- *
- * This is locked against concurrent access internally.
- *
- * RETURNS:
- * 0 on success, negative error code on internal failure (out-of-mem)
- */
-int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag)
+static int vma_node_allow(struct drm_vma_offset_node *node,
+			  struct drm_file *tag, bool ref_counted)
 {
 	struct rb_node **iter;
 	struct rb_node *parent = NULL;
···
 		entry = rb_entry(*iter, struct drm_vma_offset_file, vm_rb);
 
 		if (tag == entry->vm_tag) {
-			entry->vm_count++;
+			if (ref_counted)
+				entry->vm_count++;
 			goto unlock;
 		} else if (tag > entry->vm_tag) {
 			iter = &(*iter)->rb_right;
···
 	kfree(new);
 	return ret;
 }
+
+/**
+ * drm_vma_node_allow - Add open-file to list of allowed users
+ * @node: Node to modify
+ * @tag: Tag of file to remove
+ *
+ * Add @tag to the list of allowed open-files for this node. If @tag is
+ * already on this list, the ref-count is incremented.
+ *
+ * The list of allowed-users is preserved across drm_vma_offset_add() and
+ * drm_vma_offset_remove() calls. You may even call it if the node is currently
+ * not added to any offset-manager.
+ *
+ * You must remove all open-files the same number of times as you added them
+ * before destroying the node. Otherwise, you will leak memory.
+ *
+ * This is locked against concurrent access internally.
+ *
+ * RETURNS:
+ * 0 on success, negative error code on internal failure (out-of-mem)
+ */
+int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag)
+{
+	return vma_node_allow(node, tag, true);
+}
 EXPORT_SYMBOL(drm_vma_node_allow);
+
+/**
+ * drm_vma_node_allow_once - Add open-file to list of allowed users
+ * @node: Node to modify
+ * @tag: Tag of file to remove
+ *
+ * Add @tag to the list of allowed open-files for this node.
+ *
+ * The list of allowed-users is preserved across drm_vma_offset_add() and
+ * drm_vma_offset_remove() calls. You may even call it if the node is currently
+ * not added to any offset-manager.
+ *
+ * This is not ref-counted unlike drm_vma_node_allow() hence drm_vma_node_revoke()
+ * should only be called once after this.
+ *
+ * This is locked against concurrent access internally.
+ *
+ * RETURNS:
+ * 0 on success, negative error code on internal failure (out-of-mem)
+ */
+int drm_vma_node_allow_once(struct drm_vma_offset_node *node, struct drm_file *tag)
+{
+	return vma_node_allow(node, tag, false);
+}
+EXPORT_SYMBOL(drm_vma_node_allow_once);
 
 /**
  * drm_vma_node_revoke - Remove open-file from list of allowed users

drivers/gpu/drm/i915/gem/i915_gem_mman.c

···
 	GEM_BUG_ON(lookup_mmo(obj, mmap_type) != mmo);
 out:
 	if (file)
-		drm_vma_node_allow(&mmo->vma_node, file);
+		drm_vma_node_allow_once(&mmo->vma_node, file);
 	return mmo;
 
 err:

include/drm/drm_fb_helper.h

···
 	 * the smem_start field should always be cleared to zero.
 	 */
 	bool hint_leak_smem_start;
+
+#ifdef CONFIG_FB_DEFERRED_IO
+	/**
+	 * @fbdefio:
+	 *
+	 * Temporary storage for the driver's FB deferred I/O handler. If the
+	 * driver uses the DRM fbdev emulation layer, this is set by the core
+	 * to a generic deferred I/O handler if a driver is preferring to use
+	 * a shadow buffer.
+	 */
+	struct fb_deferred_io fbdefio;
+#endif
 };
 
 static inline struct drm_fb_helper *

include/drm/drm_vma_manager.h

···
 			   struct drm_vma_offset_node *node);
 
 int drm_vma_node_allow(struct drm_vma_offset_node *node, struct drm_file *tag);
+int drm_vma_node_allow_once(struct drm_vma_offset_node *node, struct drm_file *tag);
 void drm_vma_node_revoke(struct drm_vma_offset_node *node,
 			 struct drm_file *tag);
 bool drm_vma_node_is_allowed(struct drm_vma_offset_node *node,