Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 377 insertions, 0 deletions

diff --git a/drivers/usb/serial/metro-usb.c b/drivers/usb/serial/metro-usb.c
new file mode 100644
index 000000000..22c5f071f
--- /dev/null
+++ b/drivers/usb/serial/metro-usb.c
@@ -0,0 +1,377 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+  Some of this code is credited to Linux USB open source files that are
+  distributed with Linux.
+
+  Copyright:	2007 Metrologic Instruments. All rights reserved.
+  Copyright:	2011 Azimut Ltd. <http://azimutrzn.ru/>
+*/
+
+#include <linux/kernel.h>
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/tty_flip.h>
+#include <linux/spinlock.h>
+#include <linux/usb/serial.h>
+
+#define DRIVER_DESC "Metrologic Instruments Inc. - USB-POS driver"
+
+/* Product information. */
+#define FOCUS_VENDOR_ID			0x0C2E
+#define FOCUS_PRODUCT_ID_BI		0x0720
+#define FOCUS_PRODUCT_ID_UNI		0x0700
+
+#define METROUSB_SET_REQUEST_TYPE	0x40
+#define METROUSB_SET_MODEM_CTRL_REQUEST	10
+#define METROUSB_SET_BREAK_REQUEST	0x40
+#define METROUSB_MCR_NONE		0x08	/* Deactivate DTR and RTS. */
+#define METROUSB_MCR_RTS		0x0a	/* Activate RTS. */
+#define METROUSB_MCR_DTR		0x09	/* Activate DTR. */
+#define WDR_TIMEOUT			5000	/* default urb timeout. */
+
+/* Private data structure. */
+struct metrousb_private {
+	spinlock_t lock;
+	int throttled;
+	int throttle_req;
+	unsigned long control_state;
+};
+
+/* Device table list. */
+static const struct usb_device_id id_table[] = {
+	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_BI) },
+	{ USB_DEVICE(FOCUS_VENDOR_ID, FOCUS_PRODUCT_ID_UNI) },
+	{ USB_DEVICE_INTERFACE_CLASS(0x0c2e, 0x0730, 0xff) },	/* MS7820 */
+	{ }, /* Terminating entry. */
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+/* UNI-Directional mode commands for device configure */
+#define UNI_CMD_OPEN	0x80
+#define UNI_CMD_CLOSE	0xFF
+
+static int metrousb_is_unidirectional_mode(struct usb_serial *serial)
+{
+	u16 product_id = le16_to_cpu(serial->dev->descriptor.idProduct);
+
+	return product_id == FOCUS_PRODUCT_ID_UNI;
+}
+
+static int metrousb_calc_num_ports(struct usb_serial *serial,
+				   struct usb_serial_endpoints *epds)
+{
+	if (metrousb_is_unidirectional_mode(serial)) {
+		if (epds->num_interrupt_out == 0) {
+			dev_err(&serial->interface->dev, "interrupt-out endpoint missing\n");
+			return -ENODEV;
+		}
+	}
+
+	return 1;
+}
+
+static int metrousb_send_unidirectional_cmd(u8 cmd, struct usb_serial_port *port)
+{
+	int ret;
+	int actual_len;
+	u8 *buffer_cmd = NULL;
+
+	if (!metrousb_is_unidirectional_mode(port->serial))
+		return 0;
+
+	buffer_cmd = kzalloc(sizeof(cmd), GFP_KERNEL);
+	if (!buffer_cmd)
+		return -ENOMEM;
+
+	*buffer_cmd = cmd;
+
+	ret = usb_interrupt_msg(port->serial->dev,
+		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
+		buffer_cmd, sizeof(cmd),
+		&actual_len, USB_CTRL_SET_TIMEOUT);
+
+	kfree(buffer_cmd);
+
+	if (ret < 0)
+		return ret;
+	else if (actual_len != sizeof(cmd))
+		return -EIO;
+	return 0;
+}
+
+static void metrousb_read_int_callback(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
+	unsigned char *data = urb->transfer_buffer;
+	unsigned long flags;
+	int throttled = 0;
+	int result;
+
+	dev_dbg(&port->dev, "%s\n", __func__);
+
+	switch (urb->status) {
+	case 0:
+		/* Success status, read from the port. */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		/* urb has been terminated. */
+		dev_dbg(&port->dev,
+			"%s - urb shutting down, error code=%d\n",
+			__func__, urb->status);
+		return;
+	default:
+		dev_dbg(&port->dev,
+			"%s - non-zero urb received, error code=%d\n",
+			__func__, urb->status);
+		goto exit;
+	}
+
+
+	/* Set the data read from the usb port into the serial port buffer. */
+	if (urb->actual_length) {
+		/* Loop through the data copying each byte to the tty layer. */
+		tty_insert_flip_string(&port->port, data, urb->actual_length);
+
+		/* Force the data to the tty layer. */
+		tty_flip_buffer_push(&port->port);
+	}
+
+	/* Set any port variables. */
+	spin_lock_irqsave(&metro_priv->lock, flags);
+	if (metro_priv->throttle_req) {
+		metro_priv->throttled = 1;
+		throttled = 1;
+	}
+	spin_unlock_irqrestore(&metro_priv->lock, flags);
+
+	if (throttled)
+		return;
+exit:
+	/* Try to resubmit the urb. */
+	result = usb_submit_urb(urb, GFP_ATOMIC);
+	if (result)
+		dev_err(&port->dev,
+			"%s - failed submitting interrupt in urb, error code=%d\n",
+			__func__, result);
+}
+
+static void metrousb_cleanup(struct usb_serial_port *port)
+{
+	usb_kill_urb(port->interrupt_in_urb);
+
+	metrousb_send_unidirectional_cmd(UNI_CMD_CLOSE, port);
+}
+
+static int metrousb_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+	struct usb_serial *serial = port->serial;
+	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	int result;
+
+	/* Set the private data information for the port. */
+	spin_lock_irqsave(&metro_priv->lock, flags);
+	metro_priv->control_state = 0;
+	metro_priv->throttled = 0;
+	metro_priv->throttle_req = 0;
+	spin_unlock_irqrestore(&metro_priv->lock, flags);
+
+	/* Clear the urb pipe. */
+	usb_clear_halt(serial->dev, port->interrupt_in_urb->pipe);
+
+	/* Start reading from the device */
+	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
+			  usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
+			   port->interrupt_in_urb->transfer_buffer,
+			   port->interrupt_in_urb->transfer_buffer_length,
+			   metrousb_read_int_callback, port, 1);
+	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
+
+	if (result) {
+		dev_err(&port->dev,
+			"%s - failed submitting interrupt in urb, error code=%d\n",
+			__func__, result);
+		return result;
+	}
+
+	/* Send activate cmd to device */
+	result = metrousb_send_unidirectional_cmd(UNI_CMD_OPEN, port);
+	if (result) {
+		dev_err(&port->dev,
+			"%s - failed to configure device, error code=%d\n",
+			__func__, result);
+		goto err_kill_urb;
+	}
+
+	return 0;
+
+err_kill_urb:
+	usb_kill_urb(port->interrupt_in_urb);
+
+	return result;
+}
+
+static int metrousb_set_modem_ctrl(struct usb_serial *serial, unsigned int control_state)
+{
+	int retval = 0;
+	unsigned char mcr = METROUSB_MCR_NONE;
+
+	dev_dbg(&serial->dev->dev, "%s - control state = %d\n",
+		__func__, control_state);
+
+	/* Set the modem control value. */
+	if (control_state & TIOCM_DTR)
+		mcr |= METROUSB_MCR_DTR;
+	if (control_state & TIOCM_RTS)
+		mcr |= METROUSB_MCR_RTS;
+
+	/* Send the command to the usb port. */
+	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+				METROUSB_SET_REQUEST_TYPE, METROUSB_SET_MODEM_CTRL_REQUEST,
+				control_state, 0, NULL, 0, WDR_TIMEOUT);
+	if (retval < 0)
+		dev_err(&serial->dev->dev,
+			"%s - set modem ctrl=0x%x failed, error code=%d\n",
+			__func__, mcr, retval);
+
+	return retval;
+}
+
+static int metrousb_port_probe(struct usb_serial_port *port)
+{
+	struct metrousb_private *metro_priv;
+
+	metro_priv = kzalloc_obj(*metro_priv);
+	if (!metro_priv)
+		return -ENOMEM;
+
+	spin_lock_init(&metro_priv->lock);
+
+	usb_set_serial_port_data(port, metro_priv);
+
+	return 0;
+}
+
+static void metrousb_port_remove(struct usb_serial_port *port)
+{
+	struct metrousb_private *metro_priv;
+
+	metro_priv = usb_get_serial_port_data(port);
+	kfree(metro_priv);
+}
+
+static void metrousb_throttle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	/* Set the private information for the port to stop reading data. */
+	spin_lock_irqsave(&metro_priv->lock, flags);
+	metro_priv->throttle_req = 1;
+	spin_unlock_irqrestore(&metro_priv->lock, flags);
+}
+
+static int metrousb_tiocmget(struct tty_struct *tty)
+{
+	unsigned long control_state = 0;
+	struct usb_serial_port *port = tty->driver_data;
+	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&metro_priv->lock, flags);
+	control_state = metro_priv->control_state;
+	spin_unlock_irqrestore(&metro_priv->lock, flags);
+
+	return control_state;
+}
+
+static int metrousb_tiocmset(struct tty_struct *tty,
+			     unsigned int set, unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct usb_serial *serial = port->serial;
+	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned long control_state = 0;
+
+	dev_dbg(&port->dev, "%s - set=%d, clear=%d\n", __func__, set, clear);
+
+	spin_lock_irqsave(&metro_priv->lock, flags);
+	control_state = metro_priv->control_state;
+
+	/* Set the RTS and DTR values. */
+	if (set & TIOCM_RTS)
+		control_state |= TIOCM_RTS;
+	if (set & TIOCM_DTR)
+		control_state |= TIOCM_DTR;
+	if (clear & TIOCM_RTS)
+		control_state &= ~TIOCM_RTS;
+	if (clear & TIOCM_DTR)
+		control_state &= ~TIOCM_DTR;
+
+	metro_priv->control_state = control_state;
+	spin_unlock_irqrestore(&metro_priv->lock, flags);
+	return metrousb_set_modem_ctrl(serial, control_state);
+}
+
+static void metrousb_unthrottle(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct metrousb_private *metro_priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	int throttled;
+	int result;
+
+	/* Set the private information for the port to resume reading data. */
+	spin_lock_irqsave(&metro_priv->lock, flags);
+	throttled = metro_priv->throttled;
+	metro_priv->throttled = 0;
+	metro_priv->throttle_req = 0;
+	spin_unlock_irqrestore(&metro_priv->lock, flags);
+
+	if (throttled) {
+		result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
+		if (result) {
+			dev_err(&port->dev, "failed to submit interrupt in urb: %d\n",
+				result);
+		}
+	}
+}
+
+static struct usb_serial_driver metrousb_device = {
+	.driver = {
+		.name =		"metro-usb",
+	},
+	.description		= "Metrologic USB to Serial",
+	.id_table		= id_table,
+	.num_interrupt_in	= 1,
+	.calc_num_ports		= metrousb_calc_num_ports,
+	.open			= metrousb_open,
+	.close			= metrousb_cleanup,
+	.read_int_callback	= metrousb_read_int_callback,
+	.port_probe		= metrousb_port_probe,
+	.port_remove		= metrousb_port_remove,
+	.throttle		= metrousb_throttle,
+	.unthrottle		= metrousb_unthrottle,
+	.tiocmget		= metrousb_tiocmget,
+	.tiocmset		= metrousb_tiocmset,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&metrousb_device,
+	NULL,
+};
+
+module_usb_serial_driver(serial_drivers, id_table);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Philip Nicastro");
+MODULE_AUTHOR("Aleksey Babahin <tamerlan311@gmail.com>");
+MODULE_DESCRIPTION(DRIVER_DESC);