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, 1126 insertions, 0 deletions

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
new file mode 100644
index 000000000..24417a00d
--- /dev/null
+++ b/drivers/char/lp.c
@@ -0,0 +1,1126 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Generic parallel printer driver
+ *
+ * Copyright (C) 1992 by Jim Weigand and Linus Torvalds
+ * Copyright (C) 1992,1993 by Michael K. Johnson
+ * - Thanks much to Gunter Windau for pointing out to me where the error
+ *   checking ought to be.
+ * Copyright (C) 1993 by Nigel Gamble (added interrupt code)
+ * Copyright (C) 1994 by Alan Cox (Modularised it)
+ * LPCAREFUL, LPABORT, LPGETSTATUS added by Chris Metcalf, metcalf@lcs.mit.edu
+ * Statistics and support for slow printers by Rob Janssen, rob@knoware.nl
+ * "lp=" command line parameters added by Grant Guenther, grant@torque.net
+ * lp_read (Status readback) support added by Carsten Gross,
+ *                                             carsten@sol.wohnheim.uni-ulm.de
+ * Support for parport by Philip Blundell <philb@gnu.org>
+ * Parport sharing hacking by Andrea Arcangeli
+ * Fixed kernel_(to/from)_user memory copy to check for errors
+ * 				by Riccardo Facchetti <fizban@tin.it>
+ * 22-JAN-1998  Added support for devfs  Richard Gooch <rgooch@atnf.csiro.au>
+ * Redesigned interrupt handling for handle printers with buggy handshake
+ *				by Andrea Arcangeli, 11 May 1998
+ * Full efficient handling of printer with buggy irq handshake (now I have
+ * understood the meaning of the strange handshake). This is done sending new
+ * characters if the interrupt is just happened, even if the printer say to
+ * be still BUSY. This is needed at least with Epson Stylus Color. To enable
+ * the new TRUST_IRQ mode read the `LP OPTIMIZATION' section below...
+ * Fixed the irq on the rising edge of the strobe case.
+ * Obsoleted the CAREFUL flag since a printer that doesn' t work with
+ * CAREFUL will block a bit after in lp_check_status().
+ *				Andrea Arcangeli, 15 Oct 1998
+ * Obsoleted and removed all the lowlevel stuff implemented in the last
+ * month to use the IEEE1284 functions (that handle the _new_ compatibilty
+ * mode fine).
+ */
+
+/* This driver should, in theory, work with any parallel port that has an
+ * appropriate low-level driver; all I/O is done through the parport
+ * abstraction layer.
+ *
+ * If this driver is built into the kernel, you can configure it using the
+ * kernel command-line.  For example:
+ *
+ *	lp=parport1,none,parport2	(bind lp0 to parport1, disable lp1 and
+ *					 bind lp2 to parport2)
+ *
+ *	lp=auto				(assign lp devices to all ports that
+ *				         have printers attached, as determined
+ *					 by the IEEE-1284 autoprobe)
+ *
+ *	lp=reset			(reset the printer during
+ *					 initialisation)
+ *
+ *	lp=off				(disable the printer driver entirely)
+ *
+ * If the driver is loaded as a module, similar functionality is available
+ * using module parameters.  The equivalent of the above commands would be:
+ *
+ *	# insmod lp.o parport=1,none,2
+ *
+ *	# insmod lp.o parport=auto
+ *
+ *	# insmod lp.o reset=1
+ */
+
+/* COMPATIBILITY WITH OLD KERNELS
+ *
+ * Under Linux 2.0 and previous versions, lp devices were bound to ports at
+ * particular I/O addresses, as follows:
+ *
+ *	lp0		0x3bc
+ *	lp1		0x378
+ *	lp2		0x278
+ *
+ * The new driver, by default, binds lp devices to parport devices as it
+ * finds them.  This means that if you only have one port, it will be bound
+ * to lp0 regardless of its I/O address.  If you need the old behaviour, you
+ * can force it using the parameters described above.
+ */
+
+/*
+ * The new interrupt handling code take care of the buggy handshake
+ * of some HP and Epson printer:
+ * ___
+ * ACK    _______________    ___________
+ *                       |__|
+ * ____
+ * BUSY   _________              _______
+ *                 |____________|
+ *
+ * I discovered this using the printer scanner that you can find at:
+ *
+ *	ftp://e-mind.com/pub/linux/pscan/
+ *
+ *					11 May 98, Andrea Arcangeli
+ *
+ * My printer scanner run on an Epson Stylus Color show that such printer
+ * generates the irq on the _rising_ edge of the STROBE. Now lp handle
+ * this case fine too.
+ *
+ *					15 Oct 1998, Andrea Arcangeli
+ *
+ * The so called `buggy' handshake is really the well documented
+ * compatibility mode IEEE1284 handshake. They changed the well known
+ * Centronics handshake acking in the middle of busy expecting to not
+ * break drivers or legacy application, while they broken linux lp
+ * until I fixed it reverse engineering the protocol by hand some
+ * month ago...
+ *
+ *                                     14 Dec 1998, Andrea Arcangeli
+ *
+ * Copyright (C) 2000 by Tim Waugh (added LPSETTIMEOUT ioctl)
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/fcntl.h>
+#include <linux/delay.h>
+#include <linux/poll.h>
+#include <linux/console.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+#include <linux/jiffies.h>
+#include <linux/mutex.h>
+#include <linux/compat.h>
+
+#include <linux/parport.h>
+#undef LP_STATS
+#include <linux/lp.h>
+
+#include <asm/irq.h>
+#include <linux/uaccess.h>
+
+/* if you have more than 8 printers, remember to increase LP_NO */
+#define LP_NO 8
+
+static DEFINE_MUTEX(lp_mutex);
+static struct lp_struct lp_table[LP_NO];
+static int port_num[LP_NO];
+
+static unsigned int lp_count = 0;
+static const struct class lp_class = {
+	.name = "printer",
+};
+
+#ifdef CONFIG_LP_CONSOLE
+static struct parport *console_registered;
+#endif /* CONFIG_LP_CONSOLE */
+
+#undef LP_DEBUG
+
+/* Bits used to manage claiming the parport device */
+#define LP_PREEMPT_REQUEST 1
+#define LP_PARPORT_CLAIMED 2
+
+/* --- low-level port access ----------------------------------- */
+
+#define r_dtr(x)	(parport_read_data(lp_table[(x)].dev->port))
+#define r_str(x)	(parport_read_status(lp_table[(x)].dev->port))
+#define w_ctr(x,y)	do { parport_write_control(lp_table[(x)].dev->port, (y)); } while (0)
+#define w_dtr(x,y)	do { parport_write_data(lp_table[(x)].dev->port, (y)); } while (0)
+
+/* Claim the parport or block trying unless we've already claimed it */
+static void lp_claim_parport_or_block(struct lp_struct *this_lp)
+{
+	if (!test_and_set_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
+		parport_claim_or_block(this_lp->dev);
+	}
+}
+
+/* Claim the parport or block trying unless we've already claimed it */
+static void lp_release_parport(struct lp_struct *this_lp)
+{
+	if (test_and_clear_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
+		parport_release(this_lp->dev);
+	}
+}
+
+
+
+static int lp_preempt(void *handle)
+{
+	struct lp_struct *this_lp = (struct lp_struct *)handle;
+	set_bit(LP_PREEMPT_REQUEST, &this_lp->bits);
+	return 1;
+}
+
+
+/*
+ * Try to negotiate to a new mode; if unsuccessful negotiate to
+ * compatibility mode.  Return the mode we ended up in.
+ */
+static int lp_negotiate(struct parport *port, int mode)
+{
+	if (parport_negotiate(port, mode) != 0) {
+		mode = IEEE1284_MODE_COMPAT;
+		parport_negotiate(port, mode);
+	}
+
+	return mode;
+}
+
+static int lp_reset(int minor)
+{
+	int retval;
+	lp_claim_parport_or_block(&lp_table[minor]);
+	w_ctr(minor, LP_PSELECP);
+	udelay(LP_DELAY);
+	w_ctr(minor, LP_PSELECP | LP_PINITP);
+	retval = r_str(minor);
+	lp_release_parport(&lp_table[minor]);
+	return retval;
+}
+
+static void lp_error(int minor)
+{
+	DEFINE_WAIT(wait);
+	int polling;
+
+	if (LP_F(minor) & LP_ABORT)
+		return;
+
+	polling = lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE;
+	if (polling)
+		lp_release_parport(&lp_table[minor]);
+	prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
+	schedule_timeout(LP_TIMEOUT_POLLED);
+	finish_wait(&lp_table[minor].waitq, &wait);
+	if (polling)
+		lp_claim_parport_or_block(&lp_table[minor]);
+	else
+		parport_yield_blocking(lp_table[minor].dev);
+}
+
+static int lp_check_status(int minor)
+{
+	int error = 0;
+	unsigned int last = lp_table[minor].last_error;
+	unsigned char status = r_str(minor);
+	if ((status & LP_PERRORP) && !(LP_F(minor) & LP_CAREFUL))
+		/* No error. */
+		last = 0;
+	else if ((status & LP_POUTPA)) {
+		if (last != LP_POUTPA) {
+			last = LP_POUTPA;
+			printk(KERN_INFO "lp%d out of paper\n", minor);
+		}
+		error = -ENOSPC;
+	} else if (!(status & LP_PSELECD)) {
+		if (last != LP_PSELECD) {
+			last = LP_PSELECD;
+			printk(KERN_INFO "lp%d off-line\n", minor);
+		}
+		error = -EIO;
+	} else if (!(status & LP_PERRORP)) {
+		if (last != LP_PERRORP) {
+			last = LP_PERRORP;
+			printk(KERN_INFO "lp%d on fire\n", minor);
+		}
+		error = -EIO;
+	} else {
+		last = 0; /* Come here if LP_CAREFUL is set and no
+			     errors are reported. */
+	}
+
+	lp_table[minor].last_error = last;
+
+	if (last != 0)
+		lp_error(minor);
+
+	return error;
+}
+
+static int lp_wait_ready(int minor, int nonblock)
+{
+	int error = 0;
+
+	/* If we're not in compatibility mode, we're ready now! */
+	if (lp_table[minor].current_mode != IEEE1284_MODE_COMPAT) {
+		return 0;
+	}
+
+	do {
+		error = lp_check_status(minor);
+		if (error && (nonblock || (LP_F(minor) & LP_ABORT)))
+			break;
+		if (signal_pending(current)) {
+			error = -EINTR;
+			break;
+		}
+	} while (error);
+	return error;
+}
+
+static ssize_t lp_write(struct file *file, const char __user *buf,
+			size_t count, loff_t *ppos)
+{
+	unsigned int minor = iminor(file_inode(file));
+	struct parport *port = lp_table[minor].dev->port;
+	char *kbuf = lp_table[minor].lp_buffer;
+	ssize_t retv = 0;
+	ssize_t written;
+	size_t copy_size = count;
+	int nonblock = ((file->f_flags & O_NONBLOCK) ||
+			(LP_F(minor) & LP_ABORT));
+
+#ifdef LP_STATS
+	if (time_after(jiffies, lp_table[minor].lastcall + LP_TIME(minor)))
+		lp_table[minor].runchars = 0;
+
+	lp_table[minor].lastcall = jiffies;
+#endif
+
+	/* Need to copy the data from user-space. */
+	if (copy_size > LP_BUFFER_SIZE)
+		copy_size = LP_BUFFER_SIZE;
+
+	if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
+		return -EINTR;
+
+	if (copy_from_user(kbuf, buf, copy_size)) {
+		retv = -EFAULT;
+		goto out_unlock;
+	}
+
+	/* Claim Parport or sleep until it becomes available
+	 */
+	lp_claim_parport_or_block(&lp_table[minor]);
+	/* Go to the proper mode. */
+	lp_table[minor].current_mode = lp_negotiate(port,
+						    lp_table[minor].best_mode);
+
+	parport_set_timeout(lp_table[minor].dev,
+			    (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
+			     : lp_table[minor].timeout));
+
+	if ((retv = lp_wait_ready(minor, nonblock)) == 0)
+	do {
+		/* Write the data. */
+		written = parport_write(port, kbuf, copy_size);
+		if (written > 0) {
+			copy_size -= written;
+			count -= written;
+			buf  += written;
+			retv += written;
+		}
+
+		if (signal_pending(current)) {
+			if (retv == 0)
+				retv = -EINTR;
+
+			break;
+		}
+
+		if (copy_size > 0) {
+			/* incomplete write -> check error ! */
+			int error;
+
+			parport_negotiate(lp_table[minor].dev->port,
+					  IEEE1284_MODE_COMPAT);
+			lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
+
+			error = lp_wait_ready(minor, nonblock);
+
+			if (error) {
+				if (retv == 0)
+					retv = error;
+				break;
+			} else if (nonblock) {
+				if (retv == 0)
+					retv = -EAGAIN;
+				break;
+			}
+
+			parport_yield_blocking(lp_table[minor].dev);
+			lp_table[minor].current_mode
+			  = lp_negotiate(port,
+					 lp_table[minor].best_mode);
+
+		} else if (need_resched())
+			schedule();
+
+		if (count) {
+			copy_size = count;
+			if (copy_size > LP_BUFFER_SIZE)
+				copy_size = LP_BUFFER_SIZE;
+
+			if (copy_from_user(kbuf, buf, copy_size)) {
+				if (retv == 0)
+					retv = -EFAULT;
+				break;
+			}
+		}
+	} while (count > 0);
+
+	if (test_and_clear_bit(LP_PREEMPT_REQUEST,
+			       &lp_table[minor].bits)) {
+		printk(KERN_INFO "lp%d releasing parport\n", minor);
+		parport_negotiate(lp_table[minor].dev->port,
+				  IEEE1284_MODE_COMPAT);
+		lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
+		lp_release_parport(&lp_table[minor]);
+	}
+out_unlock:
+	mutex_unlock(&lp_table[minor].port_mutex);
+
+	return retv;
+}
+
+#ifdef CONFIG_PARPORT_1284
+
+/* Status readback conforming to ieee1284 */
+static ssize_t lp_read(struct file *file, char __user *buf,
+		       size_t count, loff_t *ppos)
+{
+	DEFINE_WAIT(wait);
+	unsigned int minor=iminor(file_inode(file));
+	struct parport *port = lp_table[minor].dev->port;
+	ssize_t retval = 0;
+	char *kbuf = lp_table[minor].lp_buffer;
+	int nonblock = ((file->f_flags & O_NONBLOCK) ||
+			(LP_F(minor) & LP_ABORT));
+
+	if (count > LP_BUFFER_SIZE)
+		count = LP_BUFFER_SIZE;
+
+	if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
+		return -EINTR;
+
+	lp_claim_parport_or_block(&lp_table[minor]);
+
+	parport_set_timeout(lp_table[minor].dev,
+			    (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
+			     : lp_table[minor].timeout));
+
+	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
+	if (parport_negotiate(lp_table[minor].dev->port,
+			      IEEE1284_MODE_NIBBLE)) {
+		retval = -EIO;
+		goto out;
+	}
+
+	while (retval == 0) {
+		retval = parport_read(port, kbuf, count);
+
+		if (retval > 0)
+			break;
+
+		if (nonblock) {
+			retval = -EAGAIN;
+			break;
+		}
+
+		/* Wait for data. */
+
+		if (lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE) {
+			parport_negotiate(lp_table[minor].dev->port,
+					  IEEE1284_MODE_COMPAT);
+			lp_error(minor);
+			if (parport_negotiate(lp_table[minor].dev->port,
+					      IEEE1284_MODE_NIBBLE)) {
+				retval = -EIO;
+				goto out;
+			}
+		} else {
+			prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
+			schedule_timeout(LP_TIMEOUT_POLLED);
+			finish_wait(&lp_table[minor].waitq, &wait);
+		}
+
+		if (signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+
+		cond_resched();
+	}
+	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
+ out:
+	lp_release_parport(&lp_table[minor]);
+
+	if (retval > 0 && copy_to_user(buf, kbuf, retval))
+		retval = -EFAULT;
+
+	mutex_unlock(&lp_table[minor].port_mutex);
+
+	return retval;
+}
+
+#endif /* IEEE 1284 support */
+
+static int lp_open(struct inode *inode, struct file *file)
+{
+	unsigned int minor = iminor(inode);
+	int ret = 0;
+
+	mutex_lock(&lp_mutex);
+	if (minor >= LP_NO) {
+		ret = -ENXIO;
+		goto out;
+	}
+	if ((LP_F(minor) & LP_EXIST) == 0) {
+		ret = -ENXIO;
+		goto out;
+	}
+	if (test_and_set_bit(LP_BUSY_BIT_POS, &LP_F(minor))) {
+		ret = -EBUSY;
+		goto out;
+	}
+	/* If ABORTOPEN is set and the printer is offline or out of paper,
+	   we may still want to open it to perform ioctl()s.  Therefore we
+	   have commandeered O_NONBLOCK, even though it is being used in
+	   a non-standard manner.  This is strictly a Linux hack, and
+	   should most likely only ever be used by the tunelp application. */
+	if ((LP_F(minor) & LP_ABORTOPEN) && !(file->f_flags & O_NONBLOCK)) {
+		int status;
+		lp_claim_parport_or_block(&lp_table[minor]);
+		status = r_str(minor);
+		lp_release_parport(&lp_table[minor]);
+		if (status & LP_POUTPA) {
+			printk(KERN_INFO "lp%d out of paper\n", minor);
+			LP_F(minor) &= ~LP_BUSY;
+			ret = -ENOSPC;
+			goto out;
+		} else if (!(status & LP_PSELECD)) {
+			printk(KERN_INFO "lp%d off-line\n", minor);
+			LP_F(minor) &= ~LP_BUSY;
+			ret = -EIO;
+			goto out;
+		} else if (!(status & LP_PERRORP)) {
+			printk(KERN_ERR "lp%d printer error\n", minor);
+			LP_F(minor) &= ~LP_BUSY;
+			ret = -EIO;
+			goto out;
+		}
+	}
+	lp_table[minor].lp_buffer = kmalloc(LP_BUFFER_SIZE, GFP_KERNEL);
+	if (!lp_table[minor].lp_buffer) {
+		LP_F(minor) &= ~LP_BUSY;
+		ret = -ENOMEM;
+		goto out;
+	}
+	/* Determine if the peripheral supports ECP mode */
+	lp_claim_parport_or_block(&lp_table[minor]);
+	if ((lp_table[minor].dev->port->modes & PARPORT_MODE_ECP) &&
+	     !parport_negotiate(lp_table[minor].dev->port,
+				 IEEE1284_MODE_ECP)) {
+		printk(KERN_INFO "lp%d: ECP mode\n", minor);
+		lp_table[minor].best_mode = IEEE1284_MODE_ECP;
+	} else {
+		lp_table[minor].best_mode = IEEE1284_MODE_COMPAT;
+	}
+	/* Leave peripheral in compatibility mode */
+	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
+	lp_release_parport(&lp_table[minor]);
+	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
+out:
+	mutex_unlock(&lp_mutex);
+	return ret;
+}
+
+static int lp_release(struct inode *inode, struct file *file)
+{
+	unsigned int minor = iminor(inode);
+
+	lp_claim_parport_or_block(&lp_table[minor]);
+	parport_negotiate(lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
+	lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
+	lp_release_parport(&lp_table[minor]);
+	kfree(lp_table[minor].lp_buffer);
+	lp_table[minor].lp_buffer = NULL;
+	LP_F(minor) &= ~LP_BUSY;
+	return 0;
+}
+
+static int lp_do_ioctl(unsigned int minor, unsigned int cmd,
+	unsigned long arg, void __user *argp)
+{
+	int status;
+	int retval = 0;
+
+#ifdef LP_DEBUG
+	printk(KERN_DEBUG "lp%d ioctl, cmd: 0x%x, arg: 0x%lx\n", minor, cmd, arg);
+#endif
+	if (minor >= LP_NO)
+		return -ENODEV;
+	if ((LP_F(minor) & LP_EXIST) == 0)
+		return -ENODEV;
+	switch (cmd) {
+		case LPTIME:
+			if (arg > UINT_MAX / HZ)
+				return -EINVAL;
+			LP_TIME(minor) = arg * HZ/100;
+			break;
+		case LPCHAR:
+			LP_CHAR(minor) = arg;
+			break;
+		case LPABORT:
+			if (arg)
+				LP_F(minor) |= LP_ABORT;
+			else
+				LP_F(minor) &= ~LP_ABORT;
+			break;
+		case LPABORTOPEN:
+			if (arg)
+				LP_F(minor) |= LP_ABORTOPEN;
+			else
+				LP_F(minor) &= ~LP_ABORTOPEN;
+			break;
+		case LPCAREFUL:
+			if (arg)
+				LP_F(minor) |= LP_CAREFUL;
+			else
+				LP_F(minor) &= ~LP_CAREFUL;
+			break;
+		case LPWAIT:
+			LP_WAIT(minor) = arg;
+			break;
+		case LPSETIRQ:
+			return -EINVAL;
+		case LPGETIRQ:
+			if (copy_to_user(argp, &LP_IRQ(minor),
+					sizeof(int)))
+				return -EFAULT;
+			break;
+		case LPGETSTATUS:
+			if (mutex_lock_interruptible(&lp_table[minor].port_mutex))
+				return -EINTR;
+			lp_claim_parport_or_block(&lp_table[minor]);
+			status = r_str(minor);
+			lp_release_parport(&lp_table[minor]);
+			mutex_unlock(&lp_table[minor].port_mutex);
+
+			if (copy_to_user(argp, &status, sizeof(int)))
+				return -EFAULT;
+			break;
+		case LPRESET:
+			lp_reset(minor);
+			break;
+#ifdef LP_STATS
+		case LPGETSTATS:
+			if (copy_to_user(argp, &LP_STAT(minor),
+					sizeof(struct lp_stats)))
+				return -EFAULT;
+			if (capable(CAP_SYS_ADMIN))
+				memset(&LP_STAT(minor), 0,
+						sizeof(struct lp_stats));
+			break;
+#endif
+		case LPGETFLAGS:
+			status = LP_F(minor);
+			if (copy_to_user(argp, &status, sizeof(int)))
+				return -EFAULT;
+			break;
+
+		default:
+			retval = -EINVAL;
+	}
+	return retval;
+}
+
+static int lp_set_timeout(unsigned int minor, s64 tv_sec, long tv_usec)
+{
+	long to_jiffies;
+
+	/* Convert to jiffies, place in lp_table */
+	if (tv_sec < 0 || tv_usec < 0)
+		return -EINVAL;
+
+	/*
+	 * we used to not check, so let's not make this fatal,
+	 * but deal with user space passing a 32-bit tv_nsec in
+	 * a 64-bit field, capping the timeout to 1 second
+	 * worth of microseconds, and capping the total at
+	 * MAX_JIFFY_OFFSET.
+	 */
+	if (tv_usec > 999999)
+		tv_usec = 999999;
+
+	if (tv_sec >= MAX_SEC_IN_JIFFIES - 1) {
+		to_jiffies = MAX_JIFFY_OFFSET;
+	} else {
+		to_jiffies = DIV_ROUND_UP(tv_usec, 1000000/HZ);
+		to_jiffies += tv_sec * (long) HZ;
+	}
+
+	if (to_jiffies <= 0) {
+		return -EINVAL;
+	}
+	lp_table[minor].timeout = to_jiffies;
+	return 0;
+}
+
+static int lp_set_timeout32(unsigned int minor, void __user *arg)
+{
+	s32 karg[2];
+
+	if (copy_from_user(karg, arg, sizeof(karg)))
+		return -EFAULT;
+
+	return lp_set_timeout(minor, karg[0], karg[1]);
+}
+
+static int lp_set_timeout64(unsigned int minor, void __user *arg)
+{
+	s64 karg[2];
+
+	if (copy_from_user(karg, arg, sizeof(karg)))
+		return -EFAULT;
+
+	/* sparc64 suseconds_t is 32-bit only */
+	if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
+		karg[1] >>= 32;
+
+	return lp_set_timeout(minor, karg[0], karg[1]);
+}
+
+static long lp_ioctl(struct file *file, unsigned int cmd,
+			unsigned long arg)
+{
+	unsigned int minor;
+	int ret;
+
+	minor = iminor(file_inode(file));
+	mutex_lock(&lp_mutex);
+	switch (cmd) {
+	case LPSETTIMEOUT_OLD:
+		if (BITS_PER_LONG == 32) {
+			ret = lp_set_timeout32(minor, (void __user *)arg);
+			break;
+		}
+		fallthrough;	/* for 64-bit */
+	case LPSETTIMEOUT_NEW:
+		ret = lp_set_timeout64(minor, (void __user *)arg);
+		break;
+	default:
+		ret = lp_do_ioctl(minor, cmd, arg, (void __user *)arg);
+		break;
+	}
+	mutex_unlock(&lp_mutex);
+
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static long lp_compat_ioctl(struct file *file, unsigned int cmd,
+			unsigned long arg)
+{
+	unsigned int minor;
+	int ret;
+
+	minor = iminor(file_inode(file));
+	mutex_lock(&lp_mutex);
+	switch (cmd) {
+	case LPSETTIMEOUT_OLD:
+		if (!COMPAT_USE_64BIT_TIME) {
+			ret = lp_set_timeout32(minor, (void __user *)arg);
+			break;
+		}
+		fallthrough;	/* for x32 mode */
+	case LPSETTIMEOUT_NEW:
+		ret = lp_set_timeout64(minor, (void __user *)arg);
+		break;
+#ifdef LP_STATS
+	case LPGETSTATS:
+		/* FIXME: add an implementation if you set LP_STATS */
+		ret = -EINVAL;
+		break;
+#endif
+	default:
+		ret = lp_do_ioctl(minor, cmd, arg, compat_ptr(arg));
+		break;
+	}
+	mutex_unlock(&lp_mutex);
+
+	return ret;
+}
+#endif
+
+static const struct file_operations lp_fops = {
+	.owner		= THIS_MODULE,
+	.write		= lp_write,
+	.unlocked_ioctl	= lp_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= lp_compat_ioctl,
+#endif
+	.open		= lp_open,
+	.release	= lp_release,
+#ifdef CONFIG_PARPORT_1284
+	.read		= lp_read,
+#endif
+	.llseek		= noop_llseek,
+};
+
+/* --- support for console on the line printer ----------------- */
+
+#ifdef CONFIG_LP_CONSOLE
+
+#define CONSOLE_LP 0
+
+/* If the printer is out of paper, we can either lose the messages or
+ * stall until the printer is happy again.  Define CONSOLE_LP_STRICT
+ * non-zero to get the latter behaviour. */
+#define CONSOLE_LP_STRICT 1
+
+/* The console must be locked when we get here. */
+
+static void lp_console_write(struct console *co, const char *s,
+			     unsigned count)
+{
+	struct pardevice *dev = lp_table[CONSOLE_LP].dev;
+	struct parport *port = dev->port;
+	ssize_t written;
+
+	if (parport_claim(dev))
+		/* Nothing we can do. */
+		return;
+
+	parport_set_timeout(dev, 0);
+
+	/* Go to compatibility mode. */
+	parport_negotiate(port, IEEE1284_MODE_COMPAT);
+
+	do {
+		/* Write the data, converting LF->CRLF as we go. */
+		ssize_t canwrite = count;
+		char *lf = memchr(s, '\n', count);
+		if (lf)
+			canwrite = lf - s;
+
+		if (canwrite > 0) {
+			written = parport_write(port, s, canwrite);
+
+			if (written <= 0)
+				continue;
+
+			s += written;
+			count -= written;
+			canwrite -= written;
+		}
+
+		if (lf && canwrite <= 0) {
+			const char *crlf = "\r\n";
+			int i = 2;
+
+			/* Dodge the original '\n', and put '\r\n' instead. */
+			s++;
+			count--;
+			do {
+				written = parport_write(port, crlf, i);
+				if (written > 0) {
+					i -= written;
+					crlf += written;
+				}
+			} while (i > 0 && (CONSOLE_LP_STRICT || written > 0));
+		}
+	} while (count > 0 && (CONSOLE_LP_STRICT || written > 0));
+
+	parport_release(dev);
+}
+
+static struct console lpcons = {
+	.name		= "lp",
+	.write		= lp_console_write,
+	.flags		= CON_PRINTBUFFER,
+};
+
+#endif /* console on line printer */
+
+/* --- initialisation code ------------------------------------- */
+
+static int parport_nr[LP_NO] = { [0 ... LP_NO-1] = LP_PARPORT_UNSPEC };
+static char *parport[LP_NO];
+static bool reset;
+
+module_param_array(parport, charp, NULL, 0);
+module_param(reset, bool, 0);
+
+#ifndef MODULE
+static int __init lp_setup(char *str)
+{
+	static int parport_ptr;
+	int x;
+
+	if (get_option(&str, &x)) {
+		if (x == 0) {
+			/* disable driver on "lp=" or "lp=0" */
+			parport_nr[0] = LP_PARPORT_OFF;
+		} else {
+			printk(KERN_WARNING "warning: 'lp=0x%x' is deprecated, ignored\n", x);
+			return 0;
+		}
+	} else if (!strncmp(str, "parport", 7)) {
+		int n = simple_strtoul(str+7, NULL, 10);
+		if (parport_ptr < LP_NO)
+			parport_nr[parport_ptr++] = n;
+		else
+			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
+			       str);
+	} else if (!strcmp(str, "auto")) {
+		parport_nr[0] = LP_PARPORT_AUTO;
+	} else if (!strcmp(str, "none")) {
+		if (parport_ptr < LP_NO)
+			parport_nr[parport_ptr++] = LP_PARPORT_NONE;
+		else
+			printk(KERN_INFO "lp: too many ports, %s ignored.\n",
+			       str);
+	} else if (!strcmp(str, "reset")) {
+		reset = true;
+	}
+	return 1;
+}
+#endif
+
+static int lp_register(int nr, struct parport *port)
+{
+	struct pardev_cb ppdev_cb;
+
+	memset(&ppdev_cb, 0, sizeof(ppdev_cb));
+	ppdev_cb.preempt = lp_preempt;
+	ppdev_cb.private = &lp_table[nr];
+	lp_table[nr].dev = parport_register_dev_model(port, "lp",
+						      &ppdev_cb, nr);
+	if (lp_table[nr].dev == NULL)
+		return 1;
+	lp_table[nr].flags |= LP_EXIST;
+
+	if (reset)
+		lp_reset(nr);
+
+	device_create(&lp_class, port->dev, MKDEV(LP_MAJOR, nr), NULL,
+		      "lp%d", nr);
+
+	printk(KERN_INFO "lp%d: using %s (%s).\n", nr, port->name,
+	       (port->irq == PARPORT_IRQ_NONE)?"polling":"interrupt-driven");
+
+#ifdef CONFIG_LP_CONSOLE
+	if (!nr) {
+		if (port->modes & PARPORT_MODE_SAFEININT) {
+			register_console(&lpcons);
+			console_registered = port;
+			printk(KERN_INFO "lp%d: console ready\n", CONSOLE_LP);
+		} else
+			printk(KERN_ERR "lp%d: cannot run console on %s\n",
+			       CONSOLE_LP, port->name);
+	}
+#endif
+	port_num[nr] = port->number;
+
+	return 0;
+}
+
+static void lp_attach(struct parport *port)
+{
+	unsigned int i;
+
+	switch (parport_nr[0]) {
+	case LP_PARPORT_UNSPEC:
+	case LP_PARPORT_AUTO:
+		if (parport_nr[0] == LP_PARPORT_AUTO &&
+		    port->probe_info[0].class != PARPORT_CLASS_PRINTER)
+			return;
+		if (lp_count == LP_NO) {
+			printk(KERN_INFO "lp: ignoring parallel port (max. %d)\n",LP_NO);
+			return;
+		}
+		for (i = 0; i < LP_NO; i++)
+			if (port_num[i] == -1)
+				break;
+
+		if (!lp_register(i, port))
+			lp_count++;
+		break;
+
+	default:
+		for (i = 0; i < LP_NO; i++) {
+			if (port->number == parport_nr[i]) {
+				if (!lp_register(i, port))
+					lp_count++;
+				break;
+			}
+		}
+		break;
+	}
+}
+
+static void lp_detach(struct parport *port)
+{
+	int n;
+
+	/* Write this some day. */
+#ifdef CONFIG_LP_CONSOLE
+	if (console_registered == port) {
+		unregister_console(&lpcons);
+		console_registered = NULL;
+	}
+#endif /* CONFIG_LP_CONSOLE */
+
+	for (n = 0; n < LP_NO; n++) {
+		if (port_num[n] == port->number) {
+			port_num[n] = -1;
+			lp_count--;
+			device_destroy(&lp_class, MKDEV(LP_MAJOR, n));
+			parport_unregister_device(lp_table[n].dev);
+		}
+	}
+}
+
+static struct parport_driver lp_driver = {
+	.name = "lp",
+	.match_port = lp_attach,
+	.detach = lp_detach,
+};
+
+static int __init lp_init(void)
+{
+	int i, err;
+
+	if (parport_nr[0] == LP_PARPORT_OFF)
+		return 0;
+
+	for (i = 0; i < LP_NO; i++) {
+		lp_table[i].dev = NULL;
+		lp_table[i].flags = 0;
+		lp_table[i].chars = LP_INIT_CHAR;
+		lp_table[i].time = LP_INIT_TIME;
+		lp_table[i].wait = LP_INIT_WAIT;
+		lp_table[i].lp_buffer = NULL;
+#ifdef LP_STATS
+		lp_table[i].lastcall = 0;
+		lp_table[i].runchars = 0;
+		memset(&lp_table[i].stats, 0, sizeof(struct lp_stats));
+#endif
+		lp_table[i].last_error = 0;
+		init_waitqueue_head(&lp_table[i].waitq);
+		init_waitqueue_head(&lp_table[i].dataq);
+		mutex_init(&lp_table[i].port_mutex);
+		lp_table[i].timeout = 10 * HZ;
+		port_num[i] = -1;
+	}
+
+	if (register_chrdev(LP_MAJOR, "lp", &lp_fops)) {
+		printk(KERN_ERR "lp: unable to get major %d\n", LP_MAJOR);
+		return -EIO;
+	}
+
+	err = class_register(&lp_class);
+	if (err)
+		goto out_reg;
+
+	if (parport_register_driver(&lp_driver)) {
+		printk(KERN_ERR "lp: unable to register with parport\n");
+		err = -EIO;
+		goto out_class;
+	}
+
+	if (!lp_count) {
+		printk(KERN_INFO "lp: driver loaded but no devices found\n");
+#ifndef CONFIG_PARPORT_1284
+		if (parport_nr[0] == LP_PARPORT_AUTO)
+			printk(KERN_INFO "lp: (is IEEE 1284 support enabled?)\n");
+#endif
+	}
+
+	return 0;
+
+out_class:
+	class_unregister(&lp_class);
+out_reg:
+	unregister_chrdev(LP_MAJOR, "lp");
+	return err;
+}
+
+static int __init lp_init_module(void)
+{
+	if (parport[0]) {
+		/* The user gave some parameters.  Let's see what they were.  */
+		if (!strncmp(parport[0], "auto", 4))
+			parport_nr[0] = LP_PARPORT_AUTO;
+		else {
+			int n;
+			for (n = 0; n < LP_NO && parport[n]; n++) {
+				if (!strncmp(parport[n], "none", 4))
+					parport_nr[n] = LP_PARPORT_NONE;
+				else {
+					char *ep;
+					unsigned long r = simple_strtoul(parport[n], &ep, 0);
+					if (ep != parport[n])
+						parport_nr[n] = r;
+					else {
+						printk(KERN_ERR "lp: bad port specifier `%s'\n", parport[n]);
+						return -ENODEV;
+					}
+				}
+			}
+		}
+	}
+
+	return lp_init();
+}
+
+static void lp_cleanup_module(void)
+{
+	parport_unregister_driver(&lp_driver);
+
+#ifdef CONFIG_LP_CONSOLE
+	unregister_console(&lpcons);
+#endif
+
+	unregister_chrdev(LP_MAJOR, "lp");
+	class_unregister(&lp_class);
+}
+
+__setup("lp=", lp_setup);
+module_init(lp_init_module);
+module_exit(lp_cleanup_module);
+
+MODULE_ALIAS_CHARDEV_MAJOR(LP_MAJOR);
+MODULE_DESCRIPTION("Generic parallel printer driver");
+MODULE_LICENSE("GPL");