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, 564 insertions, 0 deletions

diff --git a/drivers/misc/phantom.c b/drivers/misc/phantom.c
new file mode 100644
index 000000000..331cae539
--- /dev/null
+++ b/drivers/misc/phantom.c
@@ -0,0 +1,564 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (C) 2005-2007 Jiri Slaby <jirislaby@gmail.com>
+ *
+ *  You need a userspace library to cooperate with this driver. It (and other
+ *  info) may be obtained here:
+ *  http://www.fi.muni.cz/~xslaby/phantom.html
+ *  or alternatively, you might use OpenHaptics provided by Sensable.
+ */
+
+#include <linux/compat.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/pci.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/interrupt.h>
+#include <linux/cdev.h>
+#include <linux/slab.h>
+#include <linux/phantom.h>
+#include <linux/sched.h>
+#include <linux/mutex.h>
+
+#include <linux/atomic.h>
+#include <asm/io.h>
+
+#define PHANTOM_VERSION		"n0.9.8"
+
+#define PHANTOM_MAX_MINORS	8
+
+#define PHN_IRQCTL		0x4c    /* irq control in caddr space */
+
+#define PHB_RUNNING		1
+#define PHB_NOT_OH		2
+
+static DEFINE_MUTEX(phantom_mutex);
+static int phantom_major;
+
+static const struct class phantom_class = {
+	.name = "phantom",
+};
+
+struct phantom_device {
+	unsigned int opened;
+	void __iomem *caddr;
+	u32 __iomem *iaddr;
+	u32 __iomem *oaddr;
+	unsigned long status;
+	atomic_t counter;
+
+	wait_queue_head_t wait;
+	struct cdev cdev;
+
+	struct mutex open_lock;
+	spinlock_t regs_lock;
+
+	/* used in NOT_OH mode */
+	struct phm_regs oregs;
+	u32 ctl_reg;
+};
+
+static unsigned char phantom_devices[PHANTOM_MAX_MINORS];
+
+static int phantom_status(struct phantom_device *dev, unsigned long newstat)
+{
+	pr_debug("phantom_status %lx %lx\n", dev->status, newstat);
+
+	if (!(dev->status & PHB_RUNNING) && (newstat & PHB_RUNNING)) {
+		atomic_set(&dev->counter, 0);
+		iowrite32(PHN_CTL_IRQ, dev->iaddr + PHN_CONTROL);
+		iowrite32(0x43, dev->caddr + PHN_IRQCTL);
+		ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */
+	} else if ((dev->status & PHB_RUNNING) && !(newstat & PHB_RUNNING)) {
+		iowrite32(0, dev->caddr + PHN_IRQCTL);
+		ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */
+	}
+
+	dev->status = newstat;
+
+	return 0;
+}
+
+/*
+ * File ops
+ */
+
+static long phantom_ioctl(struct file *file, unsigned int cmd,
+		unsigned long arg)
+{
+	struct phantom_device *dev = file->private_data;
+	struct phm_regs rs;
+	struct phm_reg r;
+	void __user *argp = (void __user *)arg;
+	unsigned long flags;
+	unsigned int i;
+
+	switch (cmd) {
+	case PHN_SETREG:
+	case PHN_SET_REG:
+		if (copy_from_user(&r, argp, sizeof(r)))
+			return -EFAULT;
+
+		if (r.reg > 7)
+			return -EINVAL;
+
+		spin_lock_irqsave(&dev->regs_lock, flags);
+		if (r.reg == PHN_CONTROL && (r.value & PHN_CTL_IRQ) &&
+				phantom_status(dev, dev->status | PHB_RUNNING)){
+			spin_unlock_irqrestore(&dev->regs_lock, flags);
+			return -ENODEV;
+		}
+
+		pr_debug("phantom: writing %x to %u\n", r.value, r.reg);
+
+		/* preserve amp bit (don't allow to change it when in NOT_OH) */
+		if (r.reg == PHN_CONTROL && (dev->status & PHB_NOT_OH)) {
+			r.value &= ~PHN_CTL_AMP;
+			r.value |= dev->ctl_reg & PHN_CTL_AMP;
+			dev->ctl_reg = r.value;
+		}
+
+		iowrite32(r.value, dev->iaddr + r.reg);
+		ioread32(dev->iaddr); /* PCI posting */
+
+		if (r.reg == PHN_CONTROL && !(r.value & PHN_CTL_IRQ))
+			phantom_status(dev, dev->status & ~PHB_RUNNING);
+		spin_unlock_irqrestore(&dev->regs_lock, flags);
+		break;
+	case PHN_SETREGS:
+	case PHN_SET_REGS:
+		if (copy_from_user(&rs, argp, sizeof(rs)))
+			return -EFAULT;
+
+		pr_debug("phantom: SRS %u regs %x\n", rs.count, rs.mask);
+		spin_lock_irqsave(&dev->regs_lock, flags);
+		if (dev->status & PHB_NOT_OH)
+			memcpy(&dev->oregs, &rs, sizeof(rs));
+		else {
+			u32 m = min(rs.count, 8U);
+			for (i = 0; i < m; i++)
+				if (rs.mask & BIT(i))
+					iowrite32(rs.values[i], dev->oaddr + i);
+			ioread32(dev->iaddr); /* PCI posting */
+		}
+		spin_unlock_irqrestore(&dev->regs_lock, flags);
+		break;
+	case PHN_GETREG:
+	case PHN_GET_REG:
+		if (copy_from_user(&r, argp, sizeof(r)))
+			return -EFAULT;
+
+		if (r.reg > 7)
+			return -EINVAL;
+
+		r.value = ioread32(dev->iaddr + r.reg);
+
+		if (copy_to_user(argp, &r, sizeof(r)))
+			return -EFAULT;
+		break;
+	case PHN_GETREGS:
+	case PHN_GET_REGS: {
+		u32 m;
+
+		if (copy_from_user(&rs, argp, sizeof(rs)))
+			return -EFAULT;
+
+		m = min(rs.count, 8U);
+
+		pr_debug("phantom: GRS %u regs %x\n", rs.count, rs.mask);
+		spin_lock_irqsave(&dev->regs_lock, flags);
+		for (i = 0; i < m; i++)
+			if (rs.mask & BIT(i))
+				rs.values[i] = ioread32(dev->iaddr + i);
+		atomic_set(&dev->counter, 0);
+		spin_unlock_irqrestore(&dev->regs_lock, flags);
+
+		if (copy_to_user(argp, &rs, sizeof(rs)))
+			return -EFAULT;
+		break;
+	} case PHN_NOT_OH:
+		spin_lock_irqsave(&dev->regs_lock, flags);
+		if (dev->status & PHB_RUNNING) {
+			printk(KERN_ERR "phantom: you need to set NOT_OH "
+					"before you start the device!\n");
+			spin_unlock_irqrestore(&dev->regs_lock, flags);
+			return -EINVAL;
+		}
+		dev->status |= PHB_NOT_OH;
+		spin_unlock_irqrestore(&dev->regs_lock, flags);
+		break;
+	default:
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_COMPAT
+static long phantom_compat_ioctl(struct file *filp, unsigned int cmd,
+		unsigned long arg)
+{
+	if (_IOC_NR(cmd) <= 3 && _IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
+		cmd &= ~(_IOC_SIZEMASK << _IOC_SIZESHIFT);
+		cmd |= sizeof(void *) << _IOC_SIZESHIFT;
+	}
+	return phantom_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
+}
+#else
+#define phantom_compat_ioctl NULL
+#endif
+
+static int phantom_open(struct inode *inode, struct file *file)
+{
+	struct phantom_device *dev = container_of(inode->i_cdev,
+			struct phantom_device, cdev);
+
+	mutex_lock(&phantom_mutex);
+	nonseekable_open(inode, file);
+
+	if (mutex_lock_interruptible(&dev->open_lock)) {
+		mutex_unlock(&phantom_mutex);
+		return -ERESTARTSYS;
+	}
+
+	if (dev->opened) {
+		mutex_unlock(&dev->open_lock);
+		mutex_unlock(&phantom_mutex);
+		return -EINVAL;
+	}
+
+	WARN_ON(dev->status & PHB_NOT_OH);
+
+	file->private_data = dev;
+
+	atomic_set(&dev->counter, 0);
+	dev->opened++;
+	mutex_unlock(&dev->open_lock);
+	mutex_unlock(&phantom_mutex);
+	return 0;
+}
+
+static int phantom_release(struct inode *inode, struct file *file)
+{
+	struct phantom_device *dev = file->private_data;
+
+	mutex_lock(&dev->open_lock);
+
+	dev->opened = 0;
+	phantom_status(dev, dev->status & ~PHB_RUNNING);
+	dev->status &= ~PHB_NOT_OH;
+
+	mutex_unlock(&dev->open_lock);
+
+	return 0;
+}
+
+static __poll_t phantom_poll(struct file *file, poll_table *wait)
+{
+	struct phantom_device *dev = file->private_data;
+	__poll_t mask = 0;
+
+	pr_debug("phantom_poll: %d\n", atomic_read(&dev->counter));
+	poll_wait(file, &dev->wait, wait);
+
+	if (!(dev->status & PHB_RUNNING))
+		mask = EPOLLERR;
+	else if (atomic_read(&dev->counter))
+		mask = EPOLLIN | EPOLLRDNORM;
+
+	pr_debug("phantom_poll end: %x/%d\n", mask, atomic_read(&dev->counter));
+
+	return mask;
+}
+
+static const struct file_operations phantom_file_ops = {
+	.open = phantom_open,
+	.release = phantom_release,
+	.unlocked_ioctl = phantom_ioctl,
+	.compat_ioctl = phantom_compat_ioctl,
+	.poll = phantom_poll,
+};
+
+static irqreturn_t phantom_isr(int irq, void *data)
+{
+	struct phantom_device *dev = data;
+	unsigned int i;
+	u32 ctl;
+
+	spin_lock(&dev->regs_lock);
+	ctl = ioread32(dev->iaddr + PHN_CONTROL);
+	if (!(ctl & PHN_CTL_IRQ)) {
+		spin_unlock(&dev->regs_lock);
+		return IRQ_NONE;
+	}
+
+	iowrite32(0, dev->iaddr);
+	iowrite32(0xc0, dev->iaddr);
+
+	if (dev->status & PHB_NOT_OH) {
+		struct phm_regs *r = &dev->oregs;
+		u32 m = min(r->count, 8U);
+
+		for (i = 0; i < m; i++)
+			if (r->mask & BIT(i))
+				iowrite32(r->values[i], dev->oaddr + i);
+
+		dev->ctl_reg ^= PHN_CTL_AMP;
+		iowrite32(dev->ctl_reg, dev->iaddr + PHN_CONTROL);
+	}
+	spin_unlock(&dev->regs_lock);
+
+	ioread32(dev->iaddr); /* PCI posting */
+
+	atomic_inc(&dev->counter);
+	wake_up_interruptible(&dev->wait);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Init and deinit driver
+ */
+
+static unsigned int phantom_get_free(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < PHANTOM_MAX_MINORS; i++)
+		if (phantom_devices[i] == 0)
+			break;
+
+	return i;
+}
+
+static int phantom_probe(struct pci_dev *pdev,
+	const struct pci_device_id *pci_id)
+{
+	struct phantom_device *pht;
+	unsigned int minor;
+	int retval;
+
+	retval = pci_enable_device(pdev);
+	if (retval) {
+		dev_err(&pdev->dev, "pci_enable_device failed!\n");
+		goto err;
+	}
+
+	minor = phantom_get_free();
+	if (minor == PHANTOM_MAX_MINORS) {
+		dev_err(&pdev->dev, "too many devices found!\n");
+		retval = -EIO;
+		goto err_dis;
+	}
+
+	phantom_devices[minor] = 1;
+
+	retval = pci_request_regions(pdev, "phantom");
+	if (retval) {
+		dev_err(&pdev->dev, "pci_request_regions failed!\n");
+		goto err_null;
+	}
+
+	retval = -ENOMEM;
+	pht = kzalloc_obj(*pht);
+	if (pht == NULL) {
+		dev_err(&pdev->dev, "unable to allocate device\n");
+		goto err_reg;
+	}
+
+	pht->caddr = pci_iomap(pdev, 0, 0);
+	if (pht->caddr == NULL) {
+		dev_err(&pdev->dev, "can't remap conf space\n");
+		goto err_fr;
+	}
+	pht->iaddr = pci_iomap(pdev, 2, 0);
+	if (pht->iaddr == NULL) {
+		dev_err(&pdev->dev, "can't remap input space\n");
+		goto err_unmc;
+	}
+	pht->oaddr = pci_iomap(pdev, 3, 0);
+	if (pht->oaddr == NULL) {
+		dev_err(&pdev->dev, "can't remap output space\n");
+		goto err_unmi;
+	}
+
+	mutex_init(&pht->open_lock);
+	spin_lock_init(&pht->regs_lock);
+	init_waitqueue_head(&pht->wait);
+	cdev_init(&pht->cdev, &phantom_file_ops);
+	pht->cdev.owner = THIS_MODULE;
+
+	iowrite32(0, pht->caddr + PHN_IRQCTL);
+	ioread32(pht->caddr + PHN_IRQCTL); /* PCI posting */
+	retval = request_irq(pdev->irq, phantom_isr,
+			IRQF_SHARED, "phantom", pht);
+	if (retval) {
+		dev_err(&pdev->dev, "can't establish ISR\n");
+		goto err_unmo;
+	}
+
+	retval = cdev_add(&pht->cdev, MKDEV(phantom_major, minor), 1);
+	if (retval) {
+		dev_err(&pdev->dev, "chardev registration failed\n");
+		goto err_irq;
+	}
+
+	if (IS_ERR(device_create(&phantom_class, &pdev->dev,
+				 MKDEV(phantom_major, minor), NULL,
+				 "phantom%u", minor)))
+		dev_err(&pdev->dev, "can't create device\n");
+
+	pci_set_drvdata(pdev, pht);
+
+	return 0;
+err_irq:
+	free_irq(pdev->irq, pht);
+err_unmo:
+	pci_iounmap(pdev, pht->oaddr);
+err_unmi:
+	pci_iounmap(pdev, pht->iaddr);
+err_unmc:
+	pci_iounmap(pdev, pht->caddr);
+err_fr:
+	kfree(pht);
+err_reg:
+	pci_release_regions(pdev);
+err_null:
+	phantom_devices[minor] = 0;
+err_dis:
+	pci_disable_device(pdev);
+err:
+	return retval;
+}
+
+static void phantom_remove(struct pci_dev *pdev)
+{
+	struct phantom_device *pht = pci_get_drvdata(pdev);
+	unsigned int minor = MINOR(pht->cdev.dev);
+
+	device_destroy(&phantom_class, MKDEV(phantom_major, minor));
+
+	cdev_del(&pht->cdev);
+
+	iowrite32(0, pht->caddr + PHN_IRQCTL);
+	ioread32(pht->caddr + PHN_IRQCTL); /* PCI posting */
+	free_irq(pdev->irq, pht);
+
+	pci_iounmap(pdev, pht->oaddr);
+	pci_iounmap(pdev, pht->iaddr);
+	pci_iounmap(pdev, pht->caddr);
+
+	kfree(pht);
+
+	pci_release_regions(pdev);
+
+	phantom_devices[minor] = 0;
+
+	pci_disable_device(pdev);
+}
+
+static int __maybe_unused phantom_suspend(struct device *dev_d)
+{
+	struct phantom_device *dev = dev_get_drvdata(dev_d);
+
+	iowrite32(0, dev->caddr + PHN_IRQCTL);
+	ioread32(dev->caddr + PHN_IRQCTL); /* PCI posting */
+
+	synchronize_irq(to_pci_dev(dev_d)->irq);
+
+	return 0;
+}
+
+static int __maybe_unused phantom_resume(struct device *dev_d)
+{
+	struct phantom_device *dev = dev_get_drvdata(dev_d);
+
+	iowrite32(0, dev->caddr + PHN_IRQCTL);
+
+	return 0;
+}
+
+static struct pci_device_id phantom_pci_tbl[] = {
+	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050,
+			 PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050),
+	  .class = PCI_CLASS_BRIDGE_OTHER << 8, .class_mask = 0xffff00 },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, phantom_pci_tbl);
+
+static SIMPLE_DEV_PM_OPS(phantom_pm_ops, phantom_suspend, phantom_resume);
+
+static struct pci_driver phantom_pci_driver = {
+	.name = "phantom",
+	.id_table = phantom_pci_tbl,
+	.probe = phantom_probe,
+	.remove = phantom_remove,
+	.driver.pm = &phantom_pm_ops,
+};
+
+static CLASS_ATTR_STRING(version, 0444, PHANTOM_VERSION);
+
+static int __init phantom_init(void)
+{
+	int retval;
+	dev_t dev;
+
+	retval = class_register(&phantom_class);
+	if (retval) {
+		printk(KERN_ERR "phantom: can't register phantom class\n");
+		goto err;
+	}
+	retval = class_create_file(&phantom_class, &class_attr_version.attr);
+	if (retval) {
+		printk(KERN_ERR "phantom: can't create sysfs version file\n");
+		goto err_class;
+	}
+
+	retval = alloc_chrdev_region(&dev, 0, PHANTOM_MAX_MINORS, "phantom");
+	if (retval) {
+		printk(KERN_ERR "phantom: can't register character device\n");
+		goto err_attr;
+	}
+	phantom_major = MAJOR(dev);
+
+	retval = pci_register_driver(&phantom_pci_driver);
+	if (retval) {
+		printk(KERN_ERR "phantom: can't register pci driver\n");
+		goto err_unchr;
+	}
+
+	printk(KERN_INFO "Phantom Linux Driver, version " PHANTOM_VERSION ", "
+			"init OK\n");
+
+	return 0;
+err_unchr:
+	unregister_chrdev_region(dev, PHANTOM_MAX_MINORS);
+err_attr:
+	class_remove_file(&phantom_class, &class_attr_version.attr);
+err_class:
+	class_unregister(&phantom_class);
+err:
+	return retval;
+}
+
+static void __exit phantom_exit(void)
+{
+	pci_unregister_driver(&phantom_pci_driver);
+
+	unregister_chrdev_region(MKDEV(phantom_major, 0), PHANTOM_MAX_MINORS);
+
+	class_remove_file(&phantom_class, &class_attr_version.attr);
+	class_unregister(&phantom_class);
+
+	pr_debug("phantom: module successfully removed\n");
+}
+
+module_init(phantom_init);
+module_exit(phantom_exit);
+
+MODULE_AUTHOR("Jiri Slaby <jirislaby@gmail.com>");
+MODULE_DESCRIPTION("Sensable Phantom driver (PCI devices)");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(PHANTOM_VERSION);