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, 354 insertions, 0 deletions

diff --git a/drivers/usb/misc/appledisplay.c b/drivers/usb/misc/appledisplay.c
new file mode 100644
index 000000000..16883592f
--- /dev/null
+++ b/drivers/usb/misc/appledisplay.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Apple Cinema Display driver
+ *
+ * Copyright (C) 2006  Michael Hanselmann (linux-kernel@hansmi.ch)
+ *
+ * Thanks to Caskey L. Dickson for his work with acdctl.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/hid.h>
+#include <linux/usb.h>
+#include <linux/backlight.h>
+#include <linux/timer.h>
+#include <linux/workqueue.h>
+#include <linux/atomic.h>
+
+#define APPLE_VENDOR_ID		0x05AC
+
+#define ACD_USB_TIMEOUT		250
+
+#define ACD_USB_EDID		0x0302
+#define ACD_USB_BRIGHTNESS	0x0310
+
+#define ACD_BTN_NONE		0
+#define ACD_BTN_BRIGHT_UP	3
+#define ACD_BTN_BRIGHT_DOWN	4
+
+#define ACD_URB_BUFFER_LEN	2
+#define ACD_MSG_BUFFER_LEN	2
+
+#define APPLEDISPLAY_DEVICE(prod)				\
+	.match_flags = USB_DEVICE_ID_MATCH_DEVICE |		\
+		       USB_DEVICE_ID_MATCH_INT_CLASS |		\
+		       USB_DEVICE_ID_MATCH_INT_PROTOCOL,	\
+	.idVendor = APPLE_VENDOR_ID,				\
+	.idProduct = (prod),					\
+	.bInterfaceClass = USB_CLASS_HID,			\
+	.bInterfaceProtocol = 0x00
+
+/* table of devices that work with this driver */
+static const struct usb_device_id appledisplay_table[] = {
+	{ APPLEDISPLAY_DEVICE(0x9218) },
+	{ APPLEDISPLAY_DEVICE(0x9219) },
+	{ APPLEDISPLAY_DEVICE(0x921c) },
+	{ APPLEDISPLAY_DEVICE(0x921d) },
+	{ APPLEDISPLAY_DEVICE(0x9222) },
+	{ APPLEDISPLAY_DEVICE(0x9226) },
+	{ APPLEDISPLAY_DEVICE(0x9236) },
+
+	/* Terminating entry */
+	{ }
+};
+MODULE_DEVICE_TABLE(usb, appledisplay_table);
+
+/* Structure to hold all of our device specific stuff */
+struct appledisplay {
+	struct usb_device *udev;	/* usb device */
+	struct urb *urb;		/* usb request block */
+	struct backlight_device *bd;	/* backlight device */
+	u8 *urbdata;			/* interrupt URB data buffer */
+	u8 *msgdata;			/* control message data buffer */
+
+	struct delayed_work work;
+	int button_pressed;
+	struct mutex sysfslock;		/* concurrent read and write */
+};
+
+static atomic_t count_displays = ATOMIC_INIT(0);
+
+static void appledisplay_complete(struct urb *urb)
+{
+	struct appledisplay *pdata = urb->context;
+	struct device *dev = &pdata->udev->dev;
+	int status = urb->status;
+	int retval;
+
+	switch (status) {
+	case 0:
+		/* success */
+		break;
+	case -EOVERFLOW:
+		dev_err(dev,
+			"OVERFLOW with data length %d, actual length is %d\n",
+			ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
+		fallthrough;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		/* This urb is terminated, clean up */
+		dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
+			__func__, status);
+		return;
+	default:
+		dev_dbg(dev, "%s - nonzero urb status received: %d\n",
+			__func__, status);
+		goto exit;
+	}
+
+	switch(pdata->urbdata[1]) {
+	case ACD_BTN_BRIGHT_UP:
+	case ACD_BTN_BRIGHT_DOWN:
+		pdata->button_pressed = 1;
+		/*
+		 * there is a window during which no device
+		 * is registered
+		 */
+		if (pdata->bd )
+			schedule_delayed_work(&pdata->work, 0);
+		break;
+	case ACD_BTN_NONE:
+	default:
+		pdata->button_pressed = 0;
+		break;
+	}
+
+exit:
+	retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
+	if (retval) {
+		dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
+			__func__, retval);
+	}
+}
+
+static int appledisplay_bl_update_status(struct backlight_device *bd)
+{
+	struct appledisplay *pdata = bl_get_data(bd);
+	int retval;
+
+	mutex_lock(&pdata->sysfslock);
+	pdata->msgdata[0] = 0x10;
+	pdata->msgdata[1] = bd->props.brightness;
+
+	retval = usb_control_msg(
+		pdata->udev,
+		usb_sndctrlpipe(pdata->udev, 0),
+		HID_REQ_SET_REPORT,
+		USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+		ACD_USB_BRIGHTNESS,
+		0,
+		pdata->msgdata, 2,
+		ACD_USB_TIMEOUT);
+	mutex_unlock(&pdata->sysfslock);
+
+	if (retval < 0)
+		return retval;
+	else
+		return 0;
+}
+
+static int appledisplay_bl_get_brightness(struct backlight_device *bd)
+{
+	struct appledisplay *pdata = bl_get_data(bd);
+	int retval, brightness;
+
+	mutex_lock(&pdata->sysfslock);
+	retval = usb_control_msg(
+		pdata->udev,
+		usb_rcvctrlpipe(pdata->udev, 0),
+		HID_REQ_GET_REPORT,
+		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+		ACD_USB_BRIGHTNESS,
+		0,
+		pdata->msgdata, 2,
+		ACD_USB_TIMEOUT);
+	if (retval < 2) {
+		if (retval >= 0)
+			retval = -EMSGSIZE;
+	} else {
+		brightness = pdata->msgdata[1];
+	}
+	mutex_unlock(&pdata->sysfslock);
+
+	if (retval < 0)
+		return retval;
+	else
+		return brightness;
+}
+
+static const struct backlight_ops appledisplay_bl_data = {
+	.get_brightness	= appledisplay_bl_get_brightness,
+	.update_status	= appledisplay_bl_update_status,
+};
+
+static void appledisplay_work(struct work_struct *work)
+{
+	struct appledisplay *pdata =
+		container_of(work, struct appledisplay, work.work);
+	int retval;
+
+	retval = appledisplay_bl_get_brightness(pdata->bd);
+	if (retval >= 0)
+		pdata->bd->props.brightness = retval;
+
+	/* Poll again in about 125ms if there's still a button pressed */
+	if (pdata->button_pressed)
+		schedule_delayed_work(&pdata->work, HZ / 8);
+}
+
+static int appledisplay_probe(struct usb_interface *iface,
+	const struct usb_device_id *id)
+{
+	struct backlight_properties props;
+	struct backlight_device *backlight;
+	struct appledisplay *pdata;
+	struct usb_device *udev = interface_to_usbdev(iface);
+	struct usb_endpoint_descriptor *endpoint;
+	int int_in_endpointAddr = 0;
+	int retval, brightness;
+	char bl_name[20];
+
+	/* set up the endpoint information */
+	/* use only the first interrupt-in endpoint */
+	retval = usb_find_int_in_endpoint(iface->cur_altsetting, &endpoint);
+	if (retval) {
+		dev_err(&iface->dev, "Could not find int-in endpoint\n");
+		return retval;
+	}
+
+	int_in_endpointAddr = endpoint->bEndpointAddress;
+
+	/* allocate memory for our device state and initialize it */
+	pdata = kzalloc_obj(struct appledisplay);
+	if (!pdata) {
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	pdata->udev = udev;
+
+	INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
+	mutex_init(&pdata->sysfslock);
+
+	/* Allocate buffer for control messages */
+	pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
+	if (!pdata->msgdata) {
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	/* Allocate interrupt URB */
+	pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!pdata->urb) {
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	/* Allocate buffer for interrupt data */
+	pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
+		GFP_KERNEL, &pdata->urb->transfer_dma);
+	if (!pdata->urbdata) {
+		retval = -ENOMEM;
+		dev_err(&iface->dev, "Allocating URB buffer failed\n");
+		goto error;
+	}
+
+	/* Configure interrupt URB */
+	usb_fill_int_urb(pdata->urb, udev,
+		usb_rcvintpipe(udev, int_in_endpointAddr),
+		pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
+		pdata, 1);
+	pdata->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+	if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
+		retval = -EIO;
+		dev_err(&iface->dev, "Submitting URB failed\n");
+		goto error;
+	}
+
+	/* Register backlight device */
+	snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
+		atomic_inc_return(&count_displays) - 1);
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_RAW;
+	props.max_brightness = 0xff;
+	backlight = backlight_device_register(bl_name, NULL, pdata,
+					      &appledisplay_bl_data, &props);
+	if (IS_ERR(backlight)) {
+		dev_err(&iface->dev, "Backlight registration failed\n");
+		retval = PTR_ERR(backlight);
+		goto error;
+	}
+	pdata->bd = backlight;
+
+	/* Try to get brightness */
+	brightness = appledisplay_bl_get_brightness(pdata->bd);
+
+	if (brightness < 0) {
+		retval = brightness;
+		dev_err(&iface->dev,
+			"Error while getting initial brightness: %d\n", retval);
+		goto error;
+	}
+
+	/* Set brightness in backlight device */
+	pdata->bd->props.brightness = brightness;
+
+	/* save our data pointer in the interface device */
+	usb_set_intfdata(iface, pdata);
+
+	printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
+
+	return 0;
+
+error:
+	if (pdata) {
+		if (pdata->urb) {
+			usb_kill_urb(pdata->urb);
+			cancel_delayed_work_sync(&pdata->work);
+			usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
+					pdata->urbdata, pdata->urb->transfer_dma);
+			usb_free_urb(pdata->urb);
+		}
+		if (!IS_ERR(pdata->bd))
+			backlight_device_unregister(pdata->bd);
+		kfree(pdata->msgdata);
+	}
+	usb_set_intfdata(iface, NULL);
+	kfree(pdata);
+	return retval;
+}
+
+static void appledisplay_disconnect(struct usb_interface *iface)
+{
+	struct appledisplay *pdata = usb_get_intfdata(iface);
+
+	if (pdata) {
+		usb_kill_urb(pdata->urb);
+		cancel_delayed_work_sync(&pdata->work);
+		backlight_device_unregister(pdata->bd);
+		usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
+			pdata->urbdata, pdata->urb->transfer_dma);
+		usb_free_urb(pdata->urb);
+		kfree(pdata->msgdata);
+		kfree(pdata);
+	}
+
+	printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
+}
+
+static struct usb_driver appledisplay_driver = {
+	.name		= "appledisplay",
+	.probe		= appledisplay_probe,
+	.disconnect	= appledisplay_disconnect,
+	.id_table	= appledisplay_table,
+};
+module_usb_driver(appledisplay_driver);
+
+MODULE_AUTHOR("Michael Hanselmann");
+MODULE_DESCRIPTION("Apple Cinema Display driver");
+MODULE_LICENSE("GPL");