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, 395 insertions, 0 deletions

diff --git a/drivers/usb/misc/usbsevseg.c b/drivers/usb/misc/usbsevseg.c
new file mode 100644
index 000000000..89d25fcef
--- /dev/null
+++ b/drivers/usb/misc/usbsevseg.c
@@ -0,0 +1,395 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USB 7 Segment Driver
+ *
+ * Copyright (C) 2008 Harrison Metzger <harrisonmetz@gmail.com>
+ * Based on usbled.c by Greg Kroah-Hartman (greg@kroah.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/usb.h>
+
+
+#define DRIVER_AUTHOR "Harrison Metzger <harrisonmetz@gmail.com>"
+#define DRIVER_DESC "USB 7 Segment Driver"
+
+#define VENDOR_ID	0x0fc5
+#define PRODUCT_ID	0x1227
+#define MAXLEN		8
+
+/* table of devices that work with this driver */
+static const struct usb_device_id id_table[] = {
+	{ USB_DEVICE(VENDOR_ID, PRODUCT_ID) },
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+/* the different text display modes the device is capable of */
+static const char *display_textmodes[] = {"raw", "hex", "ascii"};
+
+struct usb_sevsegdev {
+	struct usb_device *udev;
+	struct usb_interface *intf;
+
+	u8 powered;
+	u8 mode_msb;
+	u8 mode_lsb;
+	u8 decimals[MAXLEN];
+	u8 textmode;
+	u8 text[MAXLEN];
+	u16 textlength;
+
+	u8 shadow_power; /* for PM */
+	u8 has_interface_pm;
+};
+
+/* sysfs_streq can't replace this completely
+ * If the device was in hex mode, and the user wanted a 0,
+ * if str commands are used, we would assume the end of string
+ * so mem commands are used.
+ */
+static inline size_t my_memlen(const char *buf, size_t count)
+{
+	if (count > 0 && buf[count-1] == '\n')
+		return count - 1;
+	else
+		return count;
+}
+
+static void update_display_powered(struct usb_sevsegdev *mydev)
+{
+	int rc;
+
+	if (mydev->powered && !mydev->has_interface_pm) {
+		rc = usb_autopm_get_interface(mydev->intf);
+		if (rc < 0)
+			return;
+		mydev->has_interface_pm = 1;
+	}
+
+	if (mydev->shadow_power != 1)
+		return;
+
+	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
+				  (80 * 0x100) + 10, /*  (power mode) */
+				  (0x00 * 0x100) + (mydev->powered ? 1 : 0),
+				  NULL, 0, 2000, GFP_KERNEL);
+	if (rc < 0)
+		dev_dbg(&mydev->udev->dev, "power retval = %d\n", rc);
+
+	if (!mydev->powered && mydev->has_interface_pm) {
+		usb_autopm_put_interface(mydev->intf);
+		mydev->has_interface_pm = 0;
+	}
+}
+
+static void update_display_mode(struct usb_sevsegdev *mydev)
+{
+	int rc;
+
+	if(mydev->shadow_power != 1)
+		return;
+
+	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
+				  (82 * 0x100) + 10, /* (set mode) */
+				  (mydev->mode_msb * 0x100) + mydev->mode_lsb,
+				  NULL, 0, 2000, GFP_NOIO);
+
+	if (rc < 0)
+		dev_dbg(&mydev->udev->dev, "mode retval = %d\n", rc);
+}
+
+static void update_display_visual(struct usb_sevsegdev *mydev, gfp_t mf)
+{
+	int rc;
+	int i;
+	unsigned char buffer[MAXLEN] = {0};
+	u8 decimals = 0;
+
+	if(mydev->shadow_power != 1)
+		return;
+
+	/* The device is right to left, where as you write left to right */
+	for (i = 0; i < mydev->textlength; i++)
+		buffer[i] = mydev->text[mydev->textlength-1-i];
+
+	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
+				  (85 * 0x100) + 10, /* (write text) */
+				  (0 * 0x100) + mydev->textmode, /* mode  */
+				  &buffer, mydev->textlength, 2000, mf);
+
+	if (rc < 0)
+		dev_dbg(&mydev->udev->dev, "write retval = %d\n", rc);
+
+	/* The device is right to left, where as you write left to right */
+	for (i = 0; i < sizeof(mydev->decimals); i++)
+		decimals |= mydev->decimals[i] << i;
+
+	rc = usb_control_msg_send(mydev->udev, 0, 0x12, 0x48,
+				  (86 * 0x100) + 10, /* (set decimal) */
+				  (0 * 0x100) + decimals, /* decimals */
+				  NULL, 0, 2000, mf);
+
+	if (rc < 0)
+		dev_dbg(&mydev->udev->dev, "decimal retval = %d\n", rc);
+}
+
+#define MYDEV_ATTR_SIMPLE_UNSIGNED(name, update_fcn)		\
+static ssize_t name##_show(struct device *dev,			\
+	struct device_attribute *attr, char *buf) 		\
+{								\
+	struct usb_interface *intf = to_usb_interface(dev);	\
+	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);	\
+								\
+	return sprintf(buf, "%u\n", mydev->name);		\
+}								\
+								\
+static ssize_t name##_store(struct device *dev,			\
+	struct device_attribute *attr, const char *buf, size_t count) \
+{								\
+	struct usb_interface *intf = to_usb_interface(dev);	\
+	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);	\
+								\
+	mydev->name = simple_strtoul(buf, NULL, 10);		\
+	update_fcn(mydev); 					\
+								\
+	return count;						\
+}								\
+static DEVICE_ATTR_RW(name);
+
+static ssize_t text_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
+
+	return sysfs_emit(buf, "%s\n", mydev->text);
+}
+
+static ssize_t text_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
+	size_t end = my_memlen(buf, count);
+
+	if (end > sizeof(mydev->text))
+		return -EINVAL;
+
+	memset(mydev->text, 0, sizeof(mydev->text));
+	mydev->textlength = end;
+
+	if (end > 0)
+		memcpy(mydev->text, buf, end);
+
+	update_display_visual(mydev, GFP_KERNEL);
+	return count;
+}
+
+static DEVICE_ATTR_RW(text);
+
+static ssize_t decimals_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
+	int i;
+	int pos;
+
+	for (i = 0; i < sizeof(mydev->decimals); i++) {
+		pos = sizeof(mydev->decimals) - 1 - i;
+		if (mydev->decimals[i] == 0)
+			buf[pos] = '0';
+		else if (mydev->decimals[i] == 1)
+			buf[pos] = '1';
+		else
+			buf[pos] = 'x';
+	}
+
+	buf[sizeof(mydev->decimals)] = '\n';
+	return sizeof(mydev->decimals) + 1;
+}
+
+static ssize_t decimals_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
+	size_t end = my_memlen(buf, count);
+	int i;
+
+	if (end > sizeof(mydev->decimals))
+		return -EINVAL;
+
+	for (i = 0; i < end; i++)
+		if (buf[i] != '0' && buf[i] != '1')
+			return -EINVAL;
+
+	memset(mydev->decimals, 0, sizeof(mydev->decimals));
+	for (i = 0; i < end; i++)
+		if (buf[i] == '1')
+			mydev->decimals[end-1-i] = 1;
+
+	update_display_visual(mydev, GFP_KERNEL);
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(decimals);
+
+static ssize_t textmode_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
+	int i;
+
+	buf[0] = 0;
+
+	for (i = 0; i < ARRAY_SIZE(display_textmodes); i++) {
+		if (mydev->textmode == i) {
+			strcat(buf, " [");
+			strcat(buf, display_textmodes[i]);
+			strcat(buf, "] ");
+		} else {
+			strcat(buf, " ");
+			strcat(buf, display_textmodes[i]);
+			strcat(buf, " ");
+		}
+	}
+	strcat(buf, "\n");
+
+
+	return strlen(buf);
+}
+
+static ssize_t textmode_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
+	int i;
+
+	i = sysfs_match_string(display_textmodes, buf);
+	if (i < 0)
+		return i;
+
+	mydev->textmode = i;
+	update_display_visual(mydev, GFP_KERNEL);
+	return count;
+}
+
+static DEVICE_ATTR_RW(textmode);
+
+
+MYDEV_ATTR_SIMPLE_UNSIGNED(powered, update_display_powered);
+MYDEV_ATTR_SIMPLE_UNSIGNED(mode_msb, update_display_mode);
+MYDEV_ATTR_SIMPLE_UNSIGNED(mode_lsb, update_display_mode);
+
+static struct attribute *sevseg_attrs[] = {
+	&dev_attr_powered.attr,
+	&dev_attr_text.attr,
+	&dev_attr_textmode.attr,
+	&dev_attr_decimals.attr,
+	&dev_attr_mode_msb.attr,
+	&dev_attr_mode_lsb.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(sevseg);
+
+static int sevseg_probe(struct usb_interface *interface,
+	const struct usb_device_id *id)
+{
+	struct usb_device *udev = interface_to_usbdev(interface);
+	struct usb_sevsegdev *mydev;
+	int rc = -ENOMEM;
+
+	mydev = kzalloc_obj(struct usb_sevsegdev);
+	if (!mydev)
+		goto error_mem;
+
+	mydev->udev = udev;
+	mydev->intf = interface;
+	usb_set_intfdata(interface, mydev);
+
+	/* PM */
+	mydev->shadow_power = 1; /* currently active */
+	mydev->has_interface_pm = 0; /* have not issued autopm_get */
+
+	/*set defaults */
+	mydev->textmode = 0x02; /* ascii mode */
+	mydev->mode_msb = 0x06; /* 6 characters */
+	mydev->mode_lsb = 0x3f; /* scanmode for 6 chars */
+
+	dev_info(&interface->dev, "USB 7 Segment device now attached\n");
+	return 0;
+
+error_mem:
+	return rc;
+}
+
+static void sevseg_disconnect(struct usb_interface *interface)
+{
+	struct usb_sevsegdev *mydev;
+
+	mydev = usb_get_intfdata(interface);
+	usb_set_intfdata(interface, NULL);
+	kfree(mydev);
+	dev_info(&interface->dev, "USB 7 Segment now disconnected\n");
+}
+
+static int sevseg_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct usb_sevsegdev *mydev;
+
+	mydev = usb_get_intfdata(intf);
+	mydev->shadow_power = 0;
+
+	return 0;
+}
+
+static int sevseg_resume(struct usb_interface *intf)
+{
+	struct usb_sevsegdev *mydev;
+
+	mydev = usb_get_intfdata(intf);
+	mydev->shadow_power = 1;
+	update_display_mode(mydev);
+	update_display_visual(mydev, GFP_NOIO);
+
+	return 0;
+}
+
+static int sevseg_reset_resume(struct usb_interface *intf)
+{
+	struct usb_sevsegdev *mydev;
+
+	mydev = usb_get_intfdata(intf);
+	mydev->shadow_power = 1;
+	update_display_mode(mydev);
+	update_display_visual(mydev, GFP_NOIO);
+
+	return 0;
+}
+
+static struct usb_driver sevseg_driver = {
+	.name =		"usbsevseg",
+	.probe =	sevseg_probe,
+	.disconnect =	sevseg_disconnect,
+	.suspend =	sevseg_suspend,
+	.resume =	sevseg_resume,
+	.reset_resume =	sevseg_reset_resume,
+	.id_table =	id_table,
+	.dev_groups =	sevseg_groups,
+	.supports_autosuspend = 1,
+};
+
+module_usb_driver(sevseg_driver);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");