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, 506 insertions, 0 deletions

diff --git a/drivers/parport/daisy.c b/drivers/parport/daisy.c
new file mode 100644
index 000000000..0f15c5de8
--- /dev/null
+++ b/drivers/parport/daisy.c
@@ -0,0 +1,506 @@
+/*
+ * IEEE 1284.3 Parallel port daisy chain and multiplexor code
+ * 
+ * Copyright (C) 1999, 2000  Tim Waugh <tim@cyberelk.demon.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * ??-12-1998: Initial implementation.
+ * 31-01-1999: Make port-cloning transparent.
+ * 13-02-1999: Move DeviceID technique from parport_probe.
+ * 13-03-1999: Get DeviceID from non-IEEE 1284.3 devices too.
+ * 22-02-2000: Count devices that are actually detected.
+ *
+ * Any part of this program may be used in documents licensed under
+ * the GNU Free Documentation License, Version 1.1 or any later version
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/parport.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+
+#include <asm/current.h>
+#include <linux/uaccess.h>
+
+#undef DEBUG
+
+static struct daisydev {
+	struct daisydev *next;
+	struct parport *port;
+	int daisy;
+	int devnum;
+} *topology = NULL;
+static DEFINE_SPINLOCK(topology_lock);
+
+static int numdevs;
+static bool daisy_init_done;
+
+/* Forward-declaration of lower-level functions. */
+static int mux_present(struct parport *port);
+static int num_mux_ports(struct parport *port);
+static int select_port(struct parport *port);
+static int assign_addrs(struct parport *port);
+
+/* Add a device to the discovered topology. */
+static void add_dev(int devnum, struct parport *port, int daisy)
+{
+	struct daisydev *newdev, **p;
+	newdev = kmalloc_obj(struct daisydev);
+	if (newdev) {
+		newdev->port = port;
+		newdev->daisy = daisy;
+		newdev->devnum = devnum;
+		spin_lock(&topology_lock);
+		for (p = &topology; *p && (*p)->devnum<devnum; p = &(*p)->next)
+			;
+		newdev->next = *p;
+		*p = newdev;
+		spin_unlock(&topology_lock);
+	}
+}
+
+/* Clone a parport (actually, make an alias). */
+static struct parport *clone_parport(struct parport *real, int muxport)
+{
+	struct parport *extra = parport_register_port(real->base,
+						       real->irq,
+						       real->dma,
+						       real->ops);
+	if (extra) {
+		extra->portnum = real->portnum;
+		extra->physport = real;
+		extra->muxport = muxport;
+		real->slaves[muxport-1] = extra;
+	}
+
+	return extra;
+}
+
+static int daisy_drv_probe(struct pardevice *par_dev)
+{
+	struct device_driver *drv = par_dev->dev.driver;
+
+	if (strcmp(drv->name, "daisy_drv"))
+		return -ENODEV;
+	if (strcmp(par_dev->name, daisy_dev_name))
+		return -ENODEV;
+
+	return 0;
+}
+
+static struct parport_driver daisy_driver = {
+	.name = "daisy_drv",
+	.probe = daisy_drv_probe,
+};
+
+/* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains.
+ * Return value is number of devices actually detected. */
+int parport_daisy_init(struct parport *port)
+{
+	int detected = 0;
+	char *deviceid;
+	static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" };
+	int num_ports;
+	int i;
+	int last_try = 0;
+
+	if (!daisy_init_done) {
+		/*
+		 * flag should be marked true first as
+		 * parport_register_driver() might try to load the low
+		 * level driver which will lead to announcing new ports
+		 * and which will again come back here at
+		 * parport_daisy_init()
+		 */
+		daisy_init_done = true;
+		i = parport_register_driver(&daisy_driver);
+		if (i) {
+			pr_err("daisy registration failed\n");
+			daisy_init_done = false;
+			return i;
+		}
+	}
+
+again:
+	/* Because this is called before any other devices exist,
+	 * we don't have to claim exclusive access.  */
+
+	/* If mux present on normal port, need to create new
+	 * parports for each extra port. */
+	if (port->muxport < 0 && mux_present(port) &&
+	    /* don't be fooled: a mux must have 2 or 4 ports. */
+	    ((num_ports = num_mux_ports(port)) == 2 || num_ports == 4)) {
+		/* Leave original as port zero. */
+		port->muxport = 0;
+		pr_info("%s: 1st (default) port of %d-way multiplexor\n",
+			port->name, num_ports);
+		for (i = 1; i < num_ports; i++) {
+			/* Clone the port. */
+			struct parport *extra = clone_parport(port, i);
+			if (!extra) {
+				if (signal_pending(current))
+					break;
+
+				schedule();
+				continue;
+			}
+
+			pr_info("%s: %d%s port of %d-way multiplexor on %s\n",
+				extra->name, i + 1, th[i + 1], num_ports,
+				port->name);
+
+			/* Analyse that port too.  We won't recurse
+			   forever because of the 'port->muxport < 0'
+			   test above. */
+			parport_daisy_init(extra);
+		}
+	}
+
+	if (port->muxport >= 0)
+		select_port(port);
+
+	parport_daisy_deselect_all(port);
+	detected += assign_addrs(port);
+
+	/* Count the potential legacy device at the end. */
+	add_dev(numdevs++, port, -1);
+
+	/* Find out the legacy device's IEEE 1284 device ID. */
+	deviceid = kmalloc(1024, GFP_KERNEL);
+	if (deviceid) {
+		if (parport_device_id(numdevs - 1, deviceid, 1024) > 2)
+			detected++;
+
+		kfree(deviceid);
+	}
+
+	if (!detected && !last_try) {
+		/* No devices were detected.  Perhaps they are in some
+                   funny state; let's try to reset them and see if
+                   they wake up. */
+		parport_daisy_fini(port);
+		parport_write_control(port, PARPORT_CONTROL_SELECT);
+		udelay(50);
+		parport_write_control(port,
+				       PARPORT_CONTROL_SELECT |
+				       PARPORT_CONTROL_INIT);
+		udelay(50);
+		last_try = 1;
+		goto again;
+	}
+
+	return detected;
+}
+
+/* Forget about devices on a physical port. */
+void parport_daisy_fini(struct parport *port)
+{
+	struct daisydev **p;
+
+	spin_lock(&topology_lock);
+	p = &topology;
+	while (*p) {
+		struct daisydev *dev = *p;
+		if (dev->port != port) {
+			p = &dev->next;
+			continue;
+		}
+		*p = dev->next;
+		kfree(dev);
+	}
+
+	/* Gaps in the numbering could be handled better.  How should
+           someone enumerate through all IEEE1284.3 devices in the
+           topology?. */
+	if (!topology) numdevs = 0;
+	spin_unlock(&topology_lock);
+	return;
+}
+
+/**
+ *	parport_open - find a device by canonical device number
+ *	@devnum: canonical device number
+ *	@name: name to associate with the device
+ *
+ *	This function is similar to parport_register_device(), except
+ *	that it locates a device by its number rather than by the port
+ *	it is attached to.
+ *
+ *	All parameters except for @devnum are the same as for
+ *	parport_register_device().  The return value is the same as
+ *	for parport_register_device().
+ **/
+
+struct pardevice *parport_open(int devnum, const char *name)
+{
+	struct daisydev *p = topology;
+	struct pardev_cb par_cb;
+	struct parport *port;
+	struct pardevice *dev;
+	int daisy;
+
+	memset(&par_cb, 0, sizeof(par_cb));
+	spin_lock(&topology_lock);
+	while (p && p->devnum != devnum)
+		p = p->next;
+
+	if (!p) {
+		spin_unlock(&topology_lock);
+		return NULL;
+	}
+
+	daisy = p->daisy;
+	port = parport_get_port(p->port);
+	spin_unlock(&topology_lock);
+
+	dev = parport_register_dev_model(port, name, &par_cb, devnum);
+	parport_put_port(port);
+	if (!dev)
+		return NULL;
+
+	dev->daisy = daisy;
+
+	/* Check that there really is a device to select. */
+	if (daisy >= 0) {
+		int selected;
+		parport_claim_or_block(dev);
+		selected = port->daisy;
+		parport_release(dev);
+
+		if (selected != daisy) {
+			/* No corresponding device. */
+			parport_unregister_device(dev);
+			return NULL;
+		}
+	}
+
+	return dev;
+}
+
+/**
+ *	parport_close - close a device opened with parport_open()
+ *	@dev: device to close
+ *
+ *	This is to parport_open() as parport_unregister_device() is to
+ *	parport_register_device().
+ **/
+
+void parport_close(struct pardevice *dev)
+{
+	parport_unregister_device(dev);
+}
+
+/* Send a daisy-chain-style CPP command packet. */
+static int cpp_daisy(struct parport *port, int cmd)
+{
+	unsigned char s;
+
+	parport_data_forward(port);
+	parport_write_data(port, 0xaa); udelay(2);
+	parport_write_data(port, 0x55); udelay(2);
+	parport_write_data(port, 0x00); udelay(2);
+	parport_write_data(port, 0xff); udelay(2);
+	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
+					  | PARPORT_STATUS_PAPEROUT
+					  | PARPORT_STATUS_SELECT
+					  | PARPORT_STATUS_ERROR);
+	if (s != (PARPORT_STATUS_BUSY
+		  | PARPORT_STATUS_PAPEROUT
+		  | PARPORT_STATUS_SELECT
+		  | PARPORT_STATUS_ERROR)) {
+		pr_debug("%s: cpp_daisy: aa5500ff(%02x)\n", port->name, s);
+		return -ENXIO;
+	}
+
+	parport_write_data(port, 0x87); udelay(2);
+	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
+					  | PARPORT_STATUS_PAPEROUT
+					  | PARPORT_STATUS_SELECT
+					  | PARPORT_STATUS_ERROR);
+	if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
+		pr_debug("%s: cpp_daisy: aa5500ff87(%02x)\n", port->name, s);
+		return -ENXIO;
+	}
+
+	parport_write_data(port, 0x78); udelay(2);
+	parport_write_data(port, cmd); udelay(2);
+	parport_frob_control(port,
+			      PARPORT_CONTROL_STROBE,
+			      PARPORT_CONTROL_STROBE);
+	udelay(1);
+	s = parport_read_status(port);
+	parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
+	udelay(1);
+	parport_write_data(port, 0xff); udelay(2);
+
+	return s;
+}
+
+/* Send a mux-style CPP command packet. */
+static int cpp_mux(struct parport *port, int cmd)
+{
+	unsigned char s;
+	int rc;
+
+	parport_data_forward(port);
+	parport_write_data(port, 0xaa); udelay(2);
+	parport_write_data(port, 0x55); udelay(2);
+	parport_write_data(port, 0xf0); udelay(2);
+	parport_write_data(port, 0x0f); udelay(2);
+	parport_write_data(port, 0x52); udelay(2);
+	parport_write_data(port, 0xad); udelay(2);
+	parport_write_data(port, cmd); udelay(2);
+
+	s = parport_read_status(port);
+	if (!(s & PARPORT_STATUS_ACK)) {
+		pr_debug("%s: cpp_mux: aa55f00f52ad%02x(%02x)\n",
+			 port->name, cmd, s);
+		return -EIO;
+	}
+
+	rc = (((s & PARPORT_STATUS_SELECT   ? 1 : 0) << 0) |
+	      ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) |
+	      ((s & PARPORT_STATUS_BUSY     ? 0 : 1) << 2) |
+	      ((s & PARPORT_STATUS_ERROR    ? 0 : 1) << 3));
+
+	return rc;
+}
+
+void parport_daisy_deselect_all(struct parport *port)
+{
+	cpp_daisy(port, 0x30);
+}
+
+int parport_daisy_select(struct parport *port, int daisy, int mode)
+{
+	switch (mode)
+	{
+		// For these modes we should switch to EPP mode:
+		case IEEE1284_MODE_EPP:
+		case IEEE1284_MODE_EPPSL:
+		case IEEE1284_MODE_EPPSWE:
+			return !(cpp_daisy(port, 0x20 + daisy) &
+				 PARPORT_STATUS_ERROR);
+
+		// For these modes we should switch to ECP mode:
+		case IEEE1284_MODE_ECP:
+		case IEEE1284_MODE_ECPRLE:
+		case IEEE1284_MODE_ECPSWE: 
+			return !(cpp_daisy(port, 0xd0 + daisy) &
+				 PARPORT_STATUS_ERROR);
+
+		// Nothing was told for BECP in Daisy chain specification.
+		// May be it's wise to use ECP?
+		case IEEE1284_MODE_BECP:
+		// Others use compat mode
+		case IEEE1284_MODE_NIBBLE:
+		case IEEE1284_MODE_BYTE:
+		case IEEE1284_MODE_COMPAT:
+		default:
+			return !(cpp_daisy(port, 0xe0 + daisy) &
+				 PARPORT_STATUS_ERROR);
+	}
+}
+
+static int mux_present(struct parport *port)
+{
+	return cpp_mux(port, 0x51) == 3;
+}
+
+static int num_mux_ports(struct parport *port)
+{
+	return cpp_mux(port, 0x58);
+}
+
+static int select_port(struct parport *port)
+{
+	int muxport = port->muxport;
+	return cpp_mux(port, 0x60 + muxport) == muxport;
+}
+
+static int assign_addrs(struct parport *port)
+{
+	unsigned char s;
+	unsigned char daisy;
+	int thisdev = numdevs;
+	int detected;
+	char *deviceid;
+
+	parport_data_forward(port);
+	parport_write_data(port, 0xaa); udelay(2);
+	parport_write_data(port, 0x55); udelay(2);
+	parport_write_data(port, 0x00); udelay(2);
+	parport_write_data(port, 0xff); udelay(2);
+	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
+					  | PARPORT_STATUS_PAPEROUT
+					  | PARPORT_STATUS_SELECT
+					  | PARPORT_STATUS_ERROR);
+	if (s != (PARPORT_STATUS_BUSY
+		  | PARPORT_STATUS_PAPEROUT
+		  | PARPORT_STATUS_SELECT
+		  | PARPORT_STATUS_ERROR)) {
+		pr_debug("%s: assign_addrs: aa5500ff(%02x)\n", port->name, s);
+		return 0;
+	}
+
+	parport_write_data(port, 0x87); udelay(2);
+	s = parport_read_status(port) & (PARPORT_STATUS_BUSY
+					  | PARPORT_STATUS_PAPEROUT
+					  | PARPORT_STATUS_SELECT
+					  | PARPORT_STATUS_ERROR);
+	if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) {
+		pr_debug("%s: assign_addrs: aa5500ff87(%02x)\n", port->name, s);
+		return 0;
+	}
+
+	parport_write_data(port, 0x78); udelay(2);
+	s = parport_read_status(port);
+
+	for (daisy = 0;
+	     (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT))
+		     == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)
+		     && daisy < 4;
+	     ++daisy) {
+		parport_write_data(port, daisy);
+		udelay(2);
+		parport_frob_control(port,
+				      PARPORT_CONTROL_STROBE,
+				      PARPORT_CONTROL_STROBE);
+		udelay(1);
+		parport_frob_control(port, PARPORT_CONTROL_STROBE, 0);
+		udelay(1);
+
+		add_dev(numdevs++, port, daisy);
+
+		/* See if this device thought it was the last in the
+		 * chain. */
+		if (!(s & PARPORT_STATUS_BUSY))
+			break;
+
+		/* We are seeing pass through status now. We see
+		   last_dev from next device or if last_dev does not
+		   work status lines from some non-daisy chain
+		   device. */
+		s = parport_read_status(port);
+	}
+
+	parport_write_data(port, 0xff); udelay(2);
+	detected = numdevs - thisdev;
+	pr_debug("%s: Found %d daisy-chained devices\n", port->name, detected);
+
+	/* Ask the new devices to introduce themselves. */
+	deviceid = kmalloc(1024, GFP_KERNEL);
+	if (!deviceid) return 0;
+
+	for (daisy = 0; thisdev < numdevs; thisdev++, daisy++)
+		parport_device_id(thisdev, deviceid, 1024);
+
+	kfree(deviceid);
+	return detected;
+}