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, 403 insertions, 0 deletions

diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
new file mode 100644
index 000000000..152dfc901
--- /dev/null
+++ b/drivers/usb/serial/opticon.c
@@ -0,0 +1,403 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Opticon USB barcode to serial driver
+ *
+ * Copyright (C) 2011 - 2012 Johan Hovold <jhovold@gmail.com>
+ * Copyright (C) 2011 Martin Jansen <martin.jansen@opticon.com>
+ * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (C) 2008 - 2009 Novell Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/tty.h>
+#include <linux/slab.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+
+#define CONTROL_RTS			0x02
+#define RESEND_CTS_STATE	0x03
+
+/* max number of write urbs in flight */
+#define URB_UPPER_LIMIT	8
+
+/* This driver works for the Opticon 1D barcode reader
+ * an examples of 1D barcode types are EAN, UPC, Code39, IATA etc.. */
+#define DRIVER_DESC	"Opticon USB barcode to serial driver (1D)"
+
+static const struct usb_device_id id_table[] = {
+	{ USB_DEVICE(0x065a, 0x0009) },
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+/* This structure holds all of the individual device information */
+struct opticon_private {
+	spinlock_t lock;	/* protects the following flags */
+	bool rts;
+	bool cts;
+	int outstanding_urbs;
+	int outstanding_bytes;
+
+	struct usb_anchor anchor;
+};
+
+
+static void opticon_process_data_packet(struct usb_serial_port *port,
+					const unsigned char *buf, size_t len)
+{
+	tty_insert_flip_string(&port->port, buf, len);
+	tty_flip_buffer_push(&port->port);
+}
+
+static void opticon_process_status_packet(struct usb_serial_port *port,
+					const unsigned char *buf, size_t len)
+{
+	struct opticon_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (buf[0] == 0x00)
+		priv->cts = false;
+	else
+		priv->cts = true;
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static void opticon_process_read_urb(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	const unsigned char *hdr = urb->transfer_buffer;
+	const unsigned char *data = hdr + 2;
+	size_t data_len = urb->actual_length - 2;
+
+	if (urb->actual_length <= 2) {
+		dev_dbg(&port->dev, "malformed packet received: %d bytes\n",
+							urb->actual_length);
+		return;
+	}
+	/*
+	 * Data from the device comes with a 2 byte header:
+	 *
+	 * <0x00><0x00>data...
+	 *      This is real data to be sent to the tty layer
+	 * <0x00><0x01>level
+	 *      This is a CTS level change, the third byte is the CTS
+	 *      value (0 for low, 1 for high).
+	 */
+	if ((hdr[0] == 0x00) && (hdr[1] == 0x00)) {
+		opticon_process_data_packet(port, data, data_len);
+	} else if ((hdr[0] == 0x00) && (hdr[1] == 0x01)) {
+		opticon_process_status_packet(port, data, data_len);
+	} else {
+		dev_dbg(&port->dev, "unknown packet received: %02x %02x\n",
+							hdr[0], hdr[1]);
+	}
+}
+
+static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
+				u8 val)
+{
+	struct usb_serial *serial = port->serial;
+	int retval;
+	u8 *buffer;
+
+	buffer = kzalloc(1, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	buffer[0] = val;
+	/* Send the message to the vendor control endpoint
+	 * of the connected device */
+	retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+				requesttype,
+				USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+				0, 0, buffer, 1, USB_CTRL_SET_TIMEOUT);
+	kfree(buffer);
+
+	if (retval < 0)
+		return retval;
+
+	return 0;
+}
+
+static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
+{
+	struct opticon_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	int res;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	priv->rts = false;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* Clear RTS line */
+	send_control_msg(port, CONTROL_RTS, 0);
+
+	/* clear the halt status of the endpoint */
+	usb_clear_halt(port->serial->dev, port->read_urb->pipe);
+
+	res = usb_serial_generic_open(tty, port);
+	if (res)
+		return res;
+
+	/* Request CTS line state, sometimes during opening the current
+	 * CTS state can be missed. */
+	send_control_msg(port, RESEND_CTS_STATE, 1);
+
+	return res;
+}
+
+static void opticon_close(struct usb_serial_port *port)
+{
+	struct opticon_private *priv = usb_get_serial_port_data(port);
+
+	usb_kill_anchored_urbs(&priv->anchor);
+
+	usb_serial_generic_close(port);
+}
+
+static void opticon_write_control_callback(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+	struct opticon_private *priv = usb_get_serial_port_data(port);
+	int status = urb->status;
+	unsigned long flags;
+
+	/* free up the transfer buffer, as usb_free_urb() does not do this */
+	kfree(urb->transfer_buffer);
+
+	/* setup packet may be set if we're using it for writing */
+	kfree(urb->setup_packet);
+
+	if (status)
+		dev_dbg(&port->dev,
+			"%s - non-zero urb status received: %d\n",
+			__func__, status);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	--priv->outstanding_urbs;
+	priv->outstanding_bytes -= urb->transfer_buffer_length;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	usb_serial_port_softint(port);
+}
+
+static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
+			 const unsigned char *buf, int count)
+{
+	struct opticon_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	struct urb *urb;
+	unsigned char *buffer;
+	unsigned long flags;
+	struct usb_ctrlrequest *dr;
+	int ret = -ENOMEM;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
+		return 0;
+	}
+	priv->outstanding_urbs++;
+	priv->outstanding_bytes += count;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	buffer = kmemdup(buf, count, GFP_ATOMIC);
+	if (!buffer)
+		goto error_no_buffer;
+
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+	if (!urb)
+		goto error_no_urb;
+
+	usb_serial_debug_data(&port->dev, __func__, count, buffer);
+
+	/* The connected devices do not have a bulk write endpoint,
+	 * to transmit data to de barcode device the control endpoint is used */
+	dr = kmalloc_obj(struct usb_ctrlrequest, GFP_ATOMIC);
+	if (!dr)
+		goto error_no_dr;
+
+	dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
+	dr->bRequest = 0x01;
+	dr->wValue = 0;
+	dr->wIndex = 0;
+	dr->wLength = cpu_to_le16(count);
+
+	usb_fill_control_urb(urb, serial->dev,
+		usb_sndctrlpipe(serial->dev, 0),
+		(unsigned char *)dr, buffer, count,
+		opticon_write_control_callback, port);
+
+	usb_anchor_urb(urb, &priv->anchor);
+
+	/* send it down the pipe */
+	ret = usb_submit_urb(urb, GFP_ATOMIC);
+	if (ret) {
+		dev_err(&port->dev, "failed to submit write urb: %d\n", ret);
+		usb_unanchor_urb(urb);
+		goto error;
+	}
+
+	/* we are done with this urb, so let the host driver
+	 * really free it when it is finished with it */
+	usb_free_urb(urb);
+
+	return count;
+error:
+	kfree(dr);
+error_no_dr:
+	usb_free_urb(urb);
+error_no_urb:
+	kfree(buffer);
+error_no_buffer:
+	spin_lock_irqsave(&priv->lock, flags);
+	--priv->outstanding_urbs;
+	priv->outstanding_bytes -= count;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return ret;
+}
+
+static unsigned int opticon_write_room(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct opticon_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	/*
+	 * We really can take almost anything the user throws at us
+	 * but let's pick a nice big number to tell the tty
+	 * layer that we have lots of free space, unless we don't.
+	 */
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
+		return 0;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 2048;
+}
+
+static unsigned int opticon_chars_in_buffer(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct opticon_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	unsigned int count;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	count = priv->outstanding_bytes;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return count;
+}
+
+static int opticon_tiocmget(struct tty_struct *tty)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct opticon_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	int result = 0;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->rts)
+		result |= TIOCM_RTS;
+	if (priv->cts)
+		result |= TIOCM_CTS;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	dev_dbg(&port->dev, "%s - %x\n", __func__, result);
+	return result;
+}
+
+static int opticon_tiocmset(struct tty_struct *tty,
+			   unsigned int set, unsigned int clear)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	struct opticon_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+	bool rts;
+	bool changed = false;
+	int ret;
+
+	/* We only support RTS so we only handle that */
+	spin_lock_irqsave(&priv->lock, flags);
+
+	rts = priv->rts;
+	if (set & TIOCM_RTS)
+		priv->rts = true;
+	if (clear & TIOCM_RTS)
+		priv->rts = false;
+	changed = rts ^ priv->rts;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (!changed)
+		return 0;
+
+	ret = send_control_msg(port, CONTROL_RTS, !rts);
+	if (ret)
+		return usb_translate_errors(ret);
+
+	return 0;
+}
+
+static int opticon_port_probe(struct usb_serial_port *port)
+{
+	struct opticon_private *priv;
+
+	priv = kzalloc_obj(*priv);
+	if (!priv)
+		return -ENOMEM;
+
+	spin_lock_init(&priv->lock);
+	init_usb_anchor(&priv->anchor);
+
+	usb_set_serial_port_data(port, priv);
+
+	return 0;
+}
+
+static void opticon_port_remove(struct usb_serial_port *port)
+{
+	struct opticon_private *priv = usb_get_serial_port_data(port);
+
+	kfree(priv);
+}
+
+static struct usb_serial_driver opticon_device = {
+	.driver = {
+		.name =		"opticon",
+	},
+	.id_table =		id_table,
+	.num_ports =		1,
+	.num_bulk_in =		1,
+	.bulk_in_size =		256,
+	.port_probe =		opticon_port_probe,
+	.port_remove =		opticon_port_remove,
+	.open =			opticon_open,
+	.close =		opticon_close,
+	.write =		opticon_write,
+	.write_room = 		opticon_write_room,
+	.chars_in_buffer =	opticon_chars_in_buffer,
+	.throttle =		usb_serial_generic_throttle,
+	.unthrottle =		usb_serial_generic_unthrottle,
+	.tiocmget =		opticon_tiocmget,
+	.tiocmset =		opticon_tiocmset,
+	.process_read_urb =	opticon_process_read_urb,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&opticon_device, NULL
+};
+
+module_usb_serial_driver(serial_drivers, id_table);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL v2");