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, 450 insertions, 0 deletions

diff --git a/drivers/usb/misc/usblcd.c b/drivers/usb/misc/usblcd.c
new file mode 100644
index 000000000..f794695de
--- /dev/null
+++ b/drivers/usb/misc/usblcd.c
@@ -0,0 +1,450 @@
+// SPDX-License-Identifier: GPL-2.0
+/*****************************************************************************
+ *                          USBLCD Kernel Driver                             *
+ *                            Version 1.05                                   *
+ *             (C) 2005 Georges Toth <g.toth@e-biz.lu>                       *
+ *                                                                           *
+ *     This file is licensed under the GPL. See COPYING in the package.      *
+ * Based on usb-skeleton.c 2.0 by Greg Kroah-Hartman (greg@kroah.com)        *
+ *                                                                           *
+ *                                                                           *
+ * 28.02.05 Complete rewrite of the original usblcd.c driver,                *
+ *          based on usb_skeleton.c.                                         *
+ *          This new driver allows more than one USB-LCD to be connected     *
+ *          and controlled, at once                                          *
+ *****************************************************************************/
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/uaccess.h>
+#include <linux/usb.h>
+
+#define DRIVER_VERSION "USBLCD Driver Version 1.05"
+
+#define USBLCD_MINOR		144
+
+#define IOCTL_GET_HARD_VERSION	1
+#define IOCTL_GET_DRV_VERSION	2
+
+
+static const struct usb_device_id id_table[] = {
+	{ .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+struct usb_lcd {
+	struct usb_device	*udev;			/* init: probe_lcd */
+	struct usb_interface	*interface;		/* the interface for
+							   this device */
+	unsigned char		*bulk_in_buffer;	/* the buffer to receive
+							   data */
+	size_t			bulk_in_size;		/* the size of the
+							   receive buffer */
+	__u8			bulk_in_endpointAddr;	/* the address of the
+							   bulk in endpoint */
+	__u8			bulk_out_endpointAddr;	/* the address of the
+							   bulk out endpoint */
+	struct kref		kref;
+	struct semaphore	limit_sem;		/* to stop writes at
+							   full throttle from
+							   using up all RAM */
+	struct usb_anchor	submitted;		/* URBs to wait for
+							   before suspend */
+	struct rw_semaphore	io_rwsem;
+	unsigned long		disconnected:1;
+};
+#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
+
+#define USB_LCD_CONCURRENT_WRITES	5
+
+static struct usb_driver lcd_driver;
+
+
+static void lcd_delete(struct kref *kref)
+{
+	struct usb_lcd *dev = to_lcd_dev(kref);
+
+	usb_put_dev(dev->udev);
+	kfree(dev->bulk_in_buffer);
+	kfree(dev);
+}
+
+
+static int lcd_open(struct inode *inode, struct file *file)
+{
+	struct usb_lcd *dev;
+	struct usb_interface *interface;
+	int subminor, r;
+
+	subminor = iminor(inode);
+
+	interface = usb_find_interface(&lcd_driver, subminor);
+	if (!interface) {
+		pr_err("USBLCD: %s - error, can't find device for minor %d\n",
+		       __func__, subminor);
+		return -ENODEV;
+	}
+
+	dev = usb_get_intfdata(interface);
+
+	/* increment our usage count for the device */
+	kref_get(&dev->kref);
+
+	/* grab a power reference */
+	r = usb_autopm_get_interface(interface);
+	if (r < 0) {
+		kref_put(&dev->kref, lcd_delete);
+		return r;
+	}
+
+	/* save our object in the file's private structure */
+	file->private_data = dev;
+
+	return 0;
+}
+
+static int lcd_release(struct inode *inode, struct file *file)
+{
+	struct usb_lcd *dev;
+
+	dev = file->private_data;
+	if (dev == NULL)
+		return -ENODEV;
+
+	/* decrement the count on our device */
+	usb_autopm_put_interface(dev->interface);
+	kref_put(&dev->kref, lcd_delete);
+	return 0;
+}
+
+static ssize_t lcd_read(struct file *file, char __user * buffer,
+			size_t count, loff_t *ppos)
+{
+	struct usb_lcd *dev;
+	int retval = 0;
+	int bytes_read;
+
+	dev = file->private_data;
+
+	down_read(&dev->io_rwsem);
+
+	if (dev->disconnected) {
+		retval = -ENODEV;
+		goto out_up_io;
+	}
+
+	/* do a blocking bulk read to get data from the device */
+	retval = usb_bulk_msg(dev->udev,
+			      usb_rcvbulkpipe(dev->udev,
+					      dev->bulk_in_endpointAddr),
+			      dev->bulk_in_buffer,
+			      min(dev->bulk_in_size, count),
+			      &bytes_read, 10000);
+
+	/* if the read was successful, copy the data to userspace */
+	if (!retval) {
+		if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
+			retval = -EFAULT;
+		else
+			retval = bytes_read;
+	}
+
+out_up_io:
+	up_read(&dev->io_rwsem);
+
+	return retval;
+}
+
+static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct usb_lcd *dev;
+	u16 bcdDevice;
+	char buf[30];
+
+	dev = file->private_data;
+	if (dev == NULL)
+		return -ENODEV;
+
+	switch (cmd) {
+	case IOCTL_GET_HARD_VERSION:
+		bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
+		sprintf(buf, "%1d%1d.%1d%1d",
+			(bcdDevice & 0xF000)>>12,
+			(bcdDevice & 0xF00)>>8,
+			(bcdDevice & 0xF0)>>4,
+			(bcdDevice & 0xF));
+		if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
+			return -EFAULT;
+		break;
+	case IOCTL_GET_DRV_VERSION:
+		sprintf(buf, DRIVER_VERSION);
+		if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
+			return -EFAULT;
+		break;
+	default:
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
+static void lcd_write_bulk_callback(struct urb *urb)
+{
+	struct usb_lcd *dev;
+	int status = urb->status;
+
+	dev = urb->context;
+
+	/* sync/async unlink faults aren't errors */
+	if (status &&
+	    !(status == -ENOENT ||
+	      status == -ECONNRESET ||
+	      status == -ESHUTDOWN)) {
+		dev_dbg(&dev->interface->dev,
+			"nonzero write bulk status received: %d\n", status);
+	}
+
+	/* free up our allocated buffer */
+	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
+			  urb->transfer_buffer, urb->transfer_dma);
+	up(&dev->limit_sem);
+}
+
+static ssize_t lcd_write(struct file *file, const char __user * user_buffer,
+			 size_t count, loff_t *ppos)
+{
+	struct usb_lcd *dev;
+	int retval = 0, r;
+	struct urb *urb = NULL;
+	char *buf = NULL;
+
+	dev = file->private_data;
+
+	/* verify that we actually have some data to write */
+	if (count == 0)
+		goto exit;
+
+	r = down_interruptible(&dev->limit_sem);
+	if (r < 0)
+		return -EINTR;
+
+	down_read(&dev->io_rwsem);
+
+	if (dev->disconnected) {
+		retval = -ENODEV;
+		goto err_up_io;
+	}
+
+	/* create a urb, and a buffer for it, and copy the data to the urb */
+	urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!urb) {
+		retval = -ENOMEM;
+		goto err_up_io;
+	}
+
+	buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL,
+				 &urb->transfer_dma);
+	if (!buf) {
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	if (copy_from_user(buf, user_buffer, count)) {
+		retval = -EFAULT;
+		goto error;
+	}
+
+	/* initialize the urb properly */
+	usb_fill_bulk_urb(urb, dev->udev,
+			  usb_sndbulkpipe(dev->udev,
+			  dev->bulk_out_endpointAddr),
+			  buf, count, lcd_write_bulk_callback, dev);
+	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+	usb_anchor_urb(urb, &dev->submitted);
+
+	/* send the data out the bulk port */
+	retval = usb_submit_urb(urb, GFP_KERNEL);
+	if (retval) {
+		dev_err(&dev->udev->dev,
+			"%s - failed submitting write urb, error %d\n",
+			__func__, retval);
+		goto error_unanchor;
+	}
+
+	/* release our reference to this urb,
+	   the USB core will eventually free it entirely */
+	usb_free_urb(urb);
+
+	up_read(&dev->io_rwsem);
+exit:
+	return count;
+error_unanchor:
+	usb_unanchor_urb(urb);
+error:
+	usb_free_coherent(dev->udev, count, buf, urb->transfer_dma);
+	usb_free_urb(urb);
+err_up_io:
+	up_read(&dev->io_rwsem);
+	up(&dev->limit_sem);
+	return retval;
+}
+
+static const struct file_operations lcd_fops = {
+	.owner =        THIS_MODULE,
+	.read =         lcd_read,
+	.write =        lcd_write,
+	.open =         lcd_open,
+	.unlocked_ioctl = lcd_ioctl,
+	.release =      lcd_release,
+	.llseek =	 noop_llseek,
+};
+
+/*
+ * usb class driver info in order to get a minor number from the usb core,
+ * and to have the device registered with the driver core
+ */
+static struct usb_class_driver lcd_class = {
+	.name =         "lcd%d",
+	.fops =         &lcd_fops,
+	.minor_base =   USBLCD_MINOR,
+};
+
+static int lcd_probe(struct usb_interface *interface,
+		     const struct usb_device_id *id)
+{
+	struct usb_lcd *dev = NULL;
+	struct usb_endpoint_descriptor *bulk_in, *bulk_out;
+	int i;
+	int retval;
+
+	/* allocate memory for our device state and initialize it */
+	dev = kzalloc_obj(*dev);
+	if (!dev)
+		return -ENOMEM;
+
+	kref_init(&dev->kref);
+	sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
+	init_rwsem(&dev->io_rwsem);
+	init_usb_anchor(&dev->submitted);
+
+	dev->udev = usb_get_dev(interface_to_usbdev(interface));
+	dev->interface = interface;
+
+	if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
+		dev_warn(&interface->dev, "USBLCD model not supported.\n");
+		retval = -ENODEV;
+		goto error;
+	}
+
+	/* set up the endpoint information */
+	/* use only the first bulk-in and bulk-out endpoints */
+	retval = usb_find_common_endpoints(interface->cur_altsetting,
+			&bulk_in, &bulk_out, NULL, NULL);
+	if (retval) {
+		dev_err(&interface->dev,
+			"Could not find both bulk-in and bulk-out endpoints\n");
+		goto error;
+	}
+
+	dev->bulk_in_size = usb_endpoint_maxp(bulk_in);
+	dev->bulk_in_endpointAddr = bulk_in->bEndpointAddress;
+	dev->bulk_in_buffer = kmalloc(dev->bulk_in_size, GFP_KERNEL);
+	if (!dev->bulk_in_buffer) {
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	dev->bulk_out_endpointAddr = bulk_out->bEndpointAddress;
+
+	/* save our data pointer in this interface device */
+	usb_set_intfdata(interface, dev);
+
+	/* we can register the device now, as it is ready */
+	retval = usb_register_dev(interface, &lcd_class);
+	if (retval) {
+		/* something prevented us from registering this driver */
+		dev_err(&interface->dev,
+			"Not able to get a minor for this device.\n");
+		goto error;
+	}
+
+	i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
+
+	dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found "
+		 "at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8,
+		 (i & 0xF0)>>4, (i & 0xF), dev->udev->devnum);
+
+	/* let the user know what node this device is now attached to */
+	dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n",
+		 interface->minor);
+	return 0;
+
+error:
+	kref_put(&dev->kref, lcd_delete);
+	return retval;
+}
+
+static void lcd_draw_down(struct usb_lcd *dev)
+{
+	int time;
+
+	time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
+	if (!time)
+		usb_kill_anchored_urbs(&dev->submitted);
+}
+
+static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct usb_lcd *dev = usb_get_intfdata(intf);
+
+	if (!dev)
+		return 0;
+	lcd_draw_down(dev);
+	return 0;
+}
+
+static int lcd_resume(struct usb_interface *intf)
+{
+	return 0;
+}
+
+static void lcd_disconnect(struct usb_interface *interface)
+{
+	struct usb_lcd *dev = usb_get_intfdata(interface);
+	int minor = interface->minor;
+
+	/* give back our minor */
+	usb_deregister_dev(interface, &lcd_class);
+
+	down_write(&dev->io_rwsem);
+	dev->disconnected = 1;
+	up_write(&dev->io_rwsem);
+
+	usb_kill_anchored_urbs(&dev->submitted);
+
+	/* decrement our usage count */
+	kref_put(&dev->kref, lcd_delete);
+
+	dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor);
+}
+
+static struct usb_driver lcd_driver = {
+	.name =		"usblcd",
+	.probe =	lcd_probe,
+	.disconnect =	lcd_disconnect,
+	.suspend =	lcd_suspend,
+	.resume =	lcd_resume,
+	.id_table =	id_table,
+	.supports_autosuspend = 1,
+};
+
+module_usb_driver(lcd_driver);
+
+MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
+MODULE_DESCRIPTION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");