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, 509 insertions, 0 deletions

diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
new file mode 100644
index 000000000..7ecdd774a
--- /dev/null
+++ b/drivers/pps/pps.c
@@ -0,0 +1,509 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PPS core file
+ *
+ * Copyright (C) 2005-2009   Rodolfo Giometti <giometti@linux.it>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+#include <linux/idr.h>
+#include <linux/mutex.h>
+#include <linux/cdev.h>
+#include <linux/poll.h>
+#include <linux/pps_kernel.h>
+#include <linux/slab.h>
+
+#include "kc.h"
+
+/*
+ * Local variables
+ */
+
+static int pps_major;
+static const struct class pps_class = {
+	.name		= "pps",
+	.dev_groups	= pps_groups
+};
+
+static DEFINE_MUTEX(pps_idr_lock);
+static DEFINE_IDR(pps_idr);
+
+/*
+ * Char device methods
+ */
+
+static __poll_t pps_cdev_poll(struct file *file, poll_table *wait)
+{
+	struct pps_device *pps = file->private_data;
+
+	poll_wait(file, &pps->queue, wait);
+
+	if (pps->last_fetched_ev == pps->last_ev)
+		return 0;
+
+	return EPOLLIN | EPOLLRDNORM;
+}
+
+static int pps_cdev_fasync(int fd, struct file *file, int on)
+{
+	struct pps_device *pps = file->private_data;
+	return fasync_helper(fd, file, on, &pps->async_queue);
+}
+
+static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata)
+{
+	unsigned int ev = pps->last_ev;
+	int err = 0;
+
+	/* Manage the timeout */
+	if (fdata->timeout.flags & PPS_TIME_INVALID)
+		err = wait_event_interruptible(pps->queue,
+				ev != pps->last_ev);
+	else {
+		struct timespec64 ts;
+		unsigned long ticks;
+
+		dev_dbg(&pps->dev, "timeout %lld.%09d\n",
+				(long long) fdata->timeout.sec,
+				fdata->timeout.nsec);
+
+		if (fdata->timeout.sec < 0)
+			return -ETIMEDOUT;
+
+		ts.tv_sec = fdata->timeout.sec;
+		ts.tv_nsec = fdata->timeout.nsec;
+		ticks = timespec64_to_jiffies(&ts);
+
+		if (ticks != 0) {
+			err = wait_event_interruptible_timeout(
+					pps->queue,
+					ev != pps->last_ev,
+					ticks);
+			if (err == 0)
+				return -ETIMEDOUT;
+		}
+	}
+
+	/* Check for pending signals */
+	if (err == -ERESTARTSYS) {
+		dev_dbg(&pps->dev, "pending signal caught\n");
+		return -EINTR;
+	}
+
+	return 0;
+}
+
+static long pps_cdev_ioctl(struct file *file,
+		unsigned int cmd, unsigned long arg)
+{
+	struct pps_device *pps = file->private_data;
+	struct pps_kparams params;
+	void __user *uarg = (void __user *) arg;
+	int __user *iuarg = (int __user *) arg;
+	int err;
+
+	switch (cmd) {
+	case PPS_GETPARAMS:
+		dev_dbg(&pps->dev, "PPS_GETPARAMS\n");
+
+		spin_lock_irq(&pps->lock);
+
+		/* Get the current parameters */
+		params = pps->params;
+
+		spin_unlock_irq(&pps->lock);
+
+		err = copy_to_user(uarg, &params, sizeof(struct pps_kparams));
+		if (err)
+			return -EFAULT;
+
+		break;
+
+	case PPS_SETPARAMS:
+		dev_dbg(&pps->dev, "PPS_SETPARAMS\n");
+
+		/* Check the capabilities */
+		if (!capable(CAP_SYS_TIME))
+			return -EPERM;
+
+		err = copy_from_user(&params, uarg, sizeof(struct pps_kparams));
+		if (err)
+			return -EFAULT;
+		if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) {
+			dev_dbg(&pps->dev, "capture mode unspecified (%x)\n",
+								params.mode);
+			return -EINVAL;
+		}
+
+		/* Check for supported capabilities */
+		if ((params.mode & ~pps->info.mode) != 0) {
+			dev_dbg(&pps->dev, "unsupported capabilities (%x)\n",
+								params.mode);
+			return -EINVAL;
+		}
+
+		spin_lock_irq(&pps->lock);
+
+		/* Save the new parameters */
+		pps->params = params;
+
+		/* Restore the read only parameters */
+		if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
+			/* section 3.3 of RFC 2783 interpreted */
+			dev_dbg(&pps->dev, "time format unspecified (%x)\n",
+								params.mode);
+			pps->params.mode |= PPS_TSFMT_TSPEC;
+		}
+		if (pps->info.mode & PPS_CANWAIT)
+			pps->params.mode |= PPS_CANWAIT;
+		pps->params.api_version = PPS_API_VERS;
+
+		/*
+		 * Clear unused fields of pps_kparams to avoid leaking
+		 * uninitialized data of the PPS_SETPARAMS caller via
+		 * PPS_GETPARAMS
+		 */
+		pps->params.assert_off_tu.flags = 0;
+		pps->params.clear_off_tu.flags = 0;
+
+		spin_unlock_irq(&pps->lock);
+
+		break;
+
+	case PPS_GETCAP:
+		dev_dbg(&pps->dev, "PPS_GETCAP\n");
+
+		err = put_user(pps->info.mode, iuarg);
+		if (err)
+			return -EFAULT;
+
+		break;
+
+	case PPS_FETCH: {
+		struct pps_fdata fdata;
+
+		dev_dbg(&pps->dev, "PPS_FETCH\n");
+
+		err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
+		if (err)
+			return -EFAULT;
+
+		err = pps_cdev_pps_fetch(pps, &fdata);
+		if (err)
+			return err;
+
+		/* Return the fetched timestamp and save last fetched event  */
+		spin_lock_irq(&pps->lock);
+
+		pps->last_fetched_ev = pps->last_ev;
+
+		fdata.info.assert_sequence = pps->assert_sequence;
+		fdata.info.clear_sequence = pps->clear_sequence;
+		fdata.info.assert_tu = pps->assert_tu;
+		fdata.info.clear_tu = pps->clear_tu;
+		fdata.info.current_mode = pps->current_mode;
+
+		spin_unlock_irq(&pps->lock);
+
+		err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
+		if (err)
+			return -EFAULT;
+
+		break;
+	}
+	case PPS_KC_BIND: {
+		struct pps_bind_args bind_args;
+
+		dev_dbg(&pps->dev, "PPS_KC_BIND\n");
+
+		/* Check the capabilities */
+		if (!capable(CAP_SYS_TIME))
+			return -EPERM;
+
+		if (copy_from_user(&bind_args, uarg,
+					sizeof(struct pps_bind_args)))
+			return -EFAULT;
+
+		/* Check for supported capabilities */
+		if ((bind_args.edge & ~pps->info.mode) != 0) {
+			dev_err(&pps->dev, "unsupported capabilities (%x)\n",
+					bind_args.edge);
+			return -EINVAL;
+		}
+
+		/* Validate parameters roughly */
+		if (bind_args.tsformat != PPS_TSFMT_TSPEC ||
+				(bind_args.edge & ~PPS_CAPTUREBOTH) != 0 ||
+				bind_args.consumer != PPS_KC_HARDPPS) {
+			dev_err(&pps->dev, "invalid kernel consumer bind"
+					" parameters (%x)\n", bind_args.edge);
+			return -EINVAL;
+		}
+
+		err = pps_kc_bind(pps, &bind_args);
+		if (err < 0)
+			return err;
+
+		break;
+	}
+	default:
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_COMPAT
+static long pps_cdev_compat_ioctl(struct file *file,
+		unsigned int cmd, unsigned long arg)
+{
+	struct pps_device *pps = file->private_data;
+	void __user *uarg = (void __user *) arg;
+
+	cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *));
+
+	if (cmd == PPS_FETCH) {
+		struct pps_fdata_compat compat;
+		struct pps_fdata fdata;
+		int err;
+
+		dev_dbg(&pps->dev, "PPS_FETCH\n");
+
+		err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat));
+		if (err)
+			return -EFAULT;
+
+		memcpy(&fdata.timeout, &compat.timeout,
+					sizeof(struct pps_ktime_compat));
+
+		err = pps_cdev_pps_fetch(pps, &fdata);
+		if (err)
+			return err;
+
+		/* Return the fetched timestamp and save last fetched event  */
+		spin_lock_irq(&pps->lock);
+
+		pps->last_fetched_ev = pps->last_ev;
+
+		compat.info.assert_sequence = pps->assert_sequence;
+		compat.info.clear_sequence = pps->clear_sequence;
+		compat.info.current_mode = pps->current_mode;
+
+		memcpy(&compat.info.assert_tu, &pps->assert_tu,
+				sizeof(struct pps_ktime_compat));
+		memcpy(&compat.info.clear_tu, &pps->clear_tu,
+				sizeof(struct pps_ktime_compat));
+
+		spin_unlock_irq(&pps->lock);
+
+		return copy_to_user(uarg, &compat,
+				sizeof(struct pps_fdata_compat)) ? -EFAULT : 0;
+	}
+
+	return pps_cdev_ioctl(file, cmd, arg);
+}
+#else
+#define pps_cdev_compat_ioctl	NULL
+#endif
+
+static struct pps_device *pps_idr_get(unsigned long id)
+{
+	struct pps_device *pps;
+
+	mutex_lock(&pps_idr_lock);
+	pps = idr_find(&pps_idr, id);
+	if (pps)
+		get_device(&pps->dev);
+
+	mutex_unlock(&pps_idr_lock);
+	return pps;
+}
+
+static int pps_cdev_open(struct inode *inode, struct file *file)
+{
+	struct pps_device *pps = pps_idr_get(iminor(inode));
+
+	if (!pps)
+		return -ENODEV;
+
+	file->private_data = pps;
+	return 0;
+}
+
+static int pps_cdev_release(struct inode *inode, struct file *file)
+{
+	struct pps_device *pps = file->private_data;
+
+	WARN_ON(pps->id != iminor(inode));
+	put_device(&pps->dev);
+	return 0;
+}
+
+/*
+ * Char device stuff
+ */
+
+static const struct file_operations pps_cdev_fops = {
+	.owner		= THIS_MODULE,
+	.poll		= pps_cdev_poll,
+	.fasync		= pps_cdev_fasync,
+	.compat_ioctl	= pps_cdev_compat_ioctl,
+	.unlocked_ioctl	= pps_cdev_ioctl,
+	.open		= pps_cdev_open,
+	.release	= pps_cdev_release,
+};
+
+static void pps_device_destruct(struct device *dev)
+{
+	struct pps_device *pps = dev_get_drvdata(dev);
+
+	pr_debug("deallocating pps%d\n", pps->id);
+	kfree(pps);
+}
+
+int pps_register_cdev(struct pps_device *pps)
+{
+	int err;
+
+	mutex_lock(&pps_idr_lock);
+	/*
+	 * Get new ID for the new PPS source.  After idr_alloc() calling
+	 * the new source will be freely available into the kernel.
+	 */
+	err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL);
+	if (err < 0) {
+		if (err == -ENOSPC) {
+			pr_err("%s: too many PPS sources in the system\n",
+			       pps->info.name);
+			err = -EBUSY;
+		}
+		kfree(pps);
+		goto out_unlock;
+	}
+	pps->id = err;
+
+	pps->dev.class = &pps_class;
+	pps->dev.parent = pps->info.dev;
+	pps->dev.devt = MKDEV(pps_major, pps->id);
+	dev_set_drvdata(&pps->dev, pps);
+	dev_set_name(&pps->dev, "pps%d", pps->id);
+	pps->dev.release = pps_device_destruct;
+	err = device_register(&pps->dev);
+	if (err)
+		goto free_idr;
+
+	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, pps_major,
+		 pps->id);
+
+	get_device(&pps->dev);
+	mutex_unlock(&pps_idr_lock);
+	return 0;
+
+free_idr:
+	idr_remove(&pps_idr, pps->id);
+	put_device(&pps->dev);
+out_unlock:
+	mutex_unlock(&pps_idr_lock);
+	return err;
+}
+
+void pps_unregister_cdev(struct pps_device *pps)
+{
+	pr_debug("unregistering pps%d\n", pps->id);
+	pps->lookup_cookie = NULL;
+	device_destroy(&pps_class, pps->dev.devt);
+
+	/* Now we can release the ID for re-use */
+	mutex_lock(&pps_idr_lock);
+	idr_remove(&pps_idr, pps->id);
+	put_device(&pps->dev);
+	mutex_unlock(&pps_idr_lock);
+}
+
+/*
+ * Look up a pps device by magic cookie.
+ * The cookie is usually a pointer to some enclosing device, but this
+ * code doesn't care; you should never be dereferencing it.
+ *
+ * This is a bit of a kludge that is currently used only by the PPS
+ * serial line discipline.  It may need to be tweaked when a second user
+ * is found.
+ *
+ * There is no function interface for setting the lookup_cookie field.
+ * It's initialized to NULL when the pps device is created, and if a
+ * client wants to use it, just fill it in afterward.
+ *
+ * The cookie is automatically set to NULL in pps_unregister_source()
+ * so that it will not be used again, even if the pps device cannot
+ * be removed from the idr due to pending references holding the minor
+ * number in use.
+ *
+ * Since pps_idr holds a reference to the device, the returned
+ * pps_device is guaranteed to be valid until pps_unregister_cdev() is
+ * called on it. But after calling pps_unregister_cdev(), it may be
+ * freed at any time.
+ */
+struct pps_device *pps_lookup_dev(void const *cookie)
+{
+	struct pps_device *pps;
+	unsigned id;
+
+	rcu_read_lock();
+	idr_for_each_entry(&pps_idr, pps, id)
+		if (cookie == pps->lookup_cookie)
+			break;
+	rcu_read_unlock();
+	return pps;
+}
+EXPORT_SYMBOL(pps_lookup_dev);
+
+/*
+ * Module stuff
+ */
+
+static void __exit pps_exit(void)
+{
+	class_unregister(&pps_class);
+	__unregister_chrdev(pps_major, 0, PPS_MAX_SOURCES, "pps");
+}
+
+static int __init pps_init(void)
+{
+	int err;
+
+	err = class_register(&pps_class);
+	if (err) {
+		pr_err("failed to register class\n");
+		return err;
+	}
+
+	pps_major = __register_chrdev(0, 0, PPS_MAX_SOURCES, "pps",
+				      &pps_cdev_fops);
+	if (pps_major < 0) {
+		pr_err("failed to allocate char device region\n");
+		goto remove_class;
+	}
+
+	pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
+	pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
+		"<giometti@linux.it>\n", PPS_VERSION);
+
+	return 0;
+
+remove_class:
+	class_unregister(&pps_class);
+	return pps_major;
+}
+
+subsys_initcall(pps_init);
+module_exit(pps_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
+MODULE_LICENSE("GPL");