Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

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");