ieee1394: raw1394: Fix write() for 32bit userland on 64bit kernel

* write(fd, buf, 52) from 32bit app was returning 56.  Most of callers did not
  care, but some (arm registration) did, and anyway it looks bad if request for
  writing 52 bytes returns 56.  And returning sizeof anything in 'int' is not
  good as well.  So all functions now return '0' instead of
  sizeof(struct raw1394_request) on success, and write() itself provides correct
  return value (it just returns value it was asked to write on success as raw1394
  does not do any partial writes at all).

* Related to this was problem that write() could have returned 0 when kernel
  state would become corrupted and moved to different state than
  opened/initialized/connected.  Now it returns -EBADFD which seemed appropriate.
Signed-off-by: NPetr Vandrovec <petr@vandrovec.name>
Acked-by: NDan Dennedy <dan@dennedy.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (split into 3 patches)

drivers/ieee1394/raw1394.c

@@ -587,7 +587,7 @@ static int state_opened(struct file_info *fi, struct pending_request *req)
 
 	req->req.length = 0;
 	queue_complete_req(req);
-	return sizeof(struct raw1394_request);
+	return 0;
 }
 
 static int state_initialized(struct file_info *fi, struct pending_request *req)
@@ -601,7 +601,7 @@ static int state_initialized(struct file_info *fi, struct pending_request *req)
 		req->req.generation = atomic_read(&internal_generation);
 		req->req.length = 0;
 		queue_complete_req(req);
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 
 	switch (req->req.type) {
@@ -673,7 +673,7 @@ static int state_initialized(struct file_info *fi, struct pending_request *req)
 	}
 
 	queue_complete_req(req);
-	return sizeof(struct raw1394_request);
+	return 0;
 }
 
 static void handle_iso_listen(struct file_info *fi, struct pending_request *req)
@@ -865,7 +865,7 @@ static int handle_async_request(struct file_info *fi,
 	if (req->req.error) {
 		req->req.length = 0;
 		queue_complete_req(req);
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 
 	hpsb_set_packet_complete_task(packet,
@@ -883,7 +883,7 @@ static int handle_async_request(struct file_info *fi,
 		hpsb_free_tlabel(packet);
 		queue_complete_req(req);
 	}
-	return sizeof(struct raw1394_request);
+	return 0;
 }
 
 static int handle_iso_send(struct file_info *fi, struct pending_request *req,
@@ -907,7 +907,7 @@ static int handle_iso_send(struct file_info *fi, struct pending_request *req,
 		req->req.error = RAW1394_ERROR_MEMFAULT;
 		req->req.length = 0;
 		queue_complete_req(req);
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 
 	req->req.length = 0;
@@ -927,7 +927,7 @@ static int handle_iso_send(struct file_info *fi, struct pending_request *req,
 		queue_complete_req(req);
 	}
 
-	return sizeof(struct raw1394_request);
+	return 0;
 }
 
 static int handle_async_send(struct file_info *fi, struct pending_request *req)
@@ -943,7 +943,7 @@ static int handle_async_send(struct file_info *fi, struct pending_request *req)
 		req->req.error = RAW1394_ERROR_INVALID_ARG;
 		req->req.length = 0;
 		queue_complete_req(req);
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 
 	data_size = req->req.length - header_length;
@@ -957,7 +957,7 @@ static int handle_async_send(struct file_info *fi, struct pending_request *req)
 		req->req.error = RAW1394_ERROR_MEMFAULT;
 		req->req.length = 0;
 		queue_complete_req(req);
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 
 	if (copy_from_user
@@ -966,7 +966,7 @@ static int handle_async_send(struct file_info *fi, struct pending_request *req)
 		req->req.error = RAW1394_ERROR_MEMFAULT;
 		req->req.length = 0;
 		queue_complete_req(req);
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 
 	packet->type = hpsb_async;
@@ -994,7 +994,7 @@ static int handle_async_send(struct file_info *fi, struct pending_request *req)
 		queue_complete_req(req);
 	}
 
-	return sizeof(struct raw1394_request);
+	return 0;
 }
 
 static int arm_read(struct hpsb_host *host, int nodeid, quadlet_t * buffer,
@@ -1869,7 +1869,7 @@ static int arm_register(struct file_info *fi, struct pending_request *req)
 		spin_lock_irqsave(&host_info_lock, flags);
 		list_add_tail(&addr->addr_list, &fi->addr_list);
 		spin_unlock_irqrestore(&host_info_lock, flags);
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 	retval =
 	    hpsb_register_addrspace(&raw1394_highlevel, fi->host, &arm_ops,
@@ -1887,7 +1887,7 @@ static int arm_register(struct file_info *fi, struct pending_request *req)
 		return (-EALREADY);
 	}
 	free_pending_request(req);	/* immediate success or fail */
-	return sizeof(struct raw1394_request);
+	return 0;
 }
 
 static int arm_unregister(struct file_info *fi, struct pending_request *req)
@@ -1955,7 +1955,7 @@ static int arm_unregister(struct file_info *fi, struct pending_request *req)
 		vfree(addr->addr_space_buffer);
 		kfree(addr);
 		free_pending_request(req);	/* immediate success or fail */
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 	retval =
 	    hpsb_unregister_addrspace(&raw1394_highlevel, fi->host,
@@ -1971,7 +1971,7 @@ static int arm_unregister(struct file_info *fi, struct pending_request *req)
 	vfree(addr->addr_space_buffer);
 	kfree(addr);
 	free_pending_request(req);	/* immediate success or fail */
-	return sizeof(struct raw1394_request);
+	return 0;
 }
 
 /* Copy data from ARM buffer(s) to user buffer. */
@@ -2013,7 +2013,7 @@ static int arm_get_buf(struct file_info *fi, struct pending_request *req)
 				 * queue no response, and therefore nobody
 				 * will free it. */
 				free_pending_request(req);
-				return sizeof(struct raw1394_request);
+				return 0;
 			} else {
 				DBGMSG("arm_get_buf request exceeded mapping");
 				spin_unlock_irqrestore(&host_info_lock, flags);
@@ -2065,7 +2065,7 @@ static int arm_set_buf(struct file_info *fi, struct pending_request *req)
 				 * queue no response, and therefore nobody
 				 * will free it. */
 				free_pending_request(req);
-				return sizeof(struct raw1394_request);
+				return 0;
 			} else {
 				DBGMSG("arm_set_buf request exceeded mapping");
 				spin_unlock_irqrestore(&host_info_lock, flags);
@@ -2086,7 +2086,7 @@ static int reset_notification(struct file_info *fi, struct pending_request *req)
 	    (req->req.misc == RAW1394_NOTIFY_ON)) {
 		fi->notification = (u8) req->req.misc;
 		free_pending_request(req);	/* we have to free the request, because we queue no response, and therefore nobody will free it */
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 	/* error EINVAL (22) invalid argument */
 	return (-EINVAL);
@@ -2119,12 +2119,12 @@ static int write_phypacket(struct file_info *fi, struct pending_request *req)
 		req->req.length = 0;
 		queue_complete_req(req);
 	}
-	return sizeof(struct raw1394_request);
+	return 0;
 }
 
 static int get_config_rom(struct file_info *fi, struct pending_request *req)
 {
-	int ret = sizeof(struct raw1394_request);
+	int ret = 0;
 	quadlet_t *data = kmalloc(req->req.length, GFP_KERNEL);
 	int status;
 
@@ -2154,7 +2154,7 @@ static int get_config_rom(struct file_info *fi, struct pending_request *req)
 
 static int update_config_rom(struct file_info *fi, struct pending_request *req)
 {
-	int ret = sizeof(struct raw1394_request);
+	int ret = 0;
 	quadlet_t *data = kmalloc(req->req.length, GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
@@ -2221,7 +2221,7 @@ static int modify_config_rom(struct file_info *fi, struct pending_request *req)
 
 			hpsb_update_config_rom_image(fi->host);
 			free_pending_request(req);
-			return sizeof(struct raw1394_request);
+			return 0;
 		}
 	}
 
@@ -2286,7 +2286,7 @@ static int modify_config_rom(struct file_info *fi, struct pending_request *req)
 		/* we have to free the request, because we queue no response,
 		 * and therefore nobody will free it */
 		free_pending_request(req);
-		return sizeof(struct raw1394_request);
+		return 0;
 	} else {
 		for (dentry =
 		     fi->csr1212_dirs[dr]->value.directory.dentries_head;
@@ -2311,7 +2311,7 @@ static int state_connected(struct file_info *fi, struct pending_request *req)
 
 	case RAW1394_REQ_ECHO:
 		queue_complete_req(req);
-		return sizeof(struct raw1394_request);
+		return 0;
 
 	case RAW1394_REQ_ISO_SEND:
 		print_old_iso_deprecation();
@@ -2335,24 +2335,24 @@ static int state_connected(struct file_info *fi, struct pending_request *req)
 	case RAW1394_REQ_ISO_LISTEN:
 		print_old_iso_deprecation();
 		handle_iso_listen(fi, req);
-		return sizeof(struct raw1394_request);
+		return 0;
 
 	case RAW1394_REQ_FCP_LISTEN:
 		handle_fcp_listen(fi, req);
-		return sizeof(struct raw1394_request);
+		return 0;
 
 	case RAW1394_REQ_RESET_BUS:
 		if (req->req.misc == RAW1394_LONG_RESET) {
 			DBGMSG("busreset called (type: LONG)");
 			hpsb_reset_bus(fi->host, LONG_RESET);
 			free_pending_request(req);	/* we have to free the request, because we queue no response, and therefore nobody will free it */
-			return sizeof(struct raw1394_request);
+			return 0;
 		}
 		if (req->req.misc == RAW1394_SHORT_RESET) {
 			DBGMSG("busreset called (type: SHORT)");
 			hpsb_reset_bus(fi->host, SHORT_RESET);
 			free_pending_request(req);	/* we have to free the request, because we queue no response, and therefore nobody will free it */
-			return sizeof(struct raw1394_request);
+			return 0;
 		}
 		/* error EINVAL (22) invalid argument */
 		return (-EINVAL);
@@ -2371,7 +2371,7 @@ static int state_connected(struct file_info *fi, struct pending_request *req)
 		req->req.generation = get_hpsb_generation(fi->host);
 		req->req.length = 0;
 		queue_complete_req(req);
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 
 	switch (req->req.type) {
@@ -2384,7 +2384,7 @@ static int state_connected(struct file_info *fi, struct pending_request *req)
 	if (req->req.length == 0) {
 		req->req.error = RAW1394_ERROR_INVALID_ARG;
 		queue_complete_req(req);
-		return sizeof(struct raw1394_request);
+		return 0;
 	}
 
 	return handle_async_request(fi, req, node);
@@ -2395,7 +2395,7 @@ static ssize_t raw1394_write(struct file *file, const char __user * buffer,
 {
 	struct file_info *fi = (struct file_info *)file->private_data;
 	struct pending_request *req;
-	ssize_t retval = 0;
+	ssize_t retval = -EBADFD;
 
 #ifdef CONFIG_COMPAT
 	if (count == sizeof(struct compat_raw1394_req) &&
@@ -2437,6 +2437,9 @@ static ssize_t raw1394_write(struct file *file, const char __user * buffer,
 
 	if (retval < 0) {
 		free_pending_request(req);
+	} else {
+		BUG_ON(retval);
+		retval = count;
 	}
 
 	return retval;