Char/Misc fixes for 4.18-rc5

Here are a few char/misc driver fixes for 4.18-rc5.
 
 The "largest" stuff here is fixes for the UIO changes in 4.18-rc1 that
 caused breakages for some people.  Thanks to Xiubo Li for fixing them
 quickly.  Other than that, minor fixes for thunderbolt, vmw_balloon,
 nvmem, mei, ibmasm, and mei drivers.  There's also a MAINTAINERS update
 where Rafael is offering to help out with reviewing driver core patches.
 
 All of these have been in linux-next with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc fixes from Greg KH:
 "Here are a few char/misc driver fixes for 4.18-rc5.

  The "largest" stuff here is fixes for the UIO changes in 4.18-rc1 that
  caused breakages for some people. Thanks to Xiubo Li for fixing them
  quickly. Other than that, minor fixes for thunderbolt, vmw_balloon,
  nvmem, mei, ibmasm, and mei drivers. There's also a MAINTAINERS update
  where Rafael is offering to help out with reviewing driver core
  patches.

  All of these have been in linux-next with no reported issues"

* tag 'char-misc-4.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  nvmem: Don't let a NULL cell_id for nvmem_cell_get() crash us
  thunderbolt: Notify userspace when boot_acl is changed
  uio: fix crash after the device is unregistered
  uio: change to use the mutex lock instead of the spin lock
  uio: use request_threaded_irq instead
  fpga: altera-cvp: Fix an error handling path in 'altera_cvp_probe()'
  ibmasm: don't write out of bounds in read handler
  MAINTAINERS: Add myself as driver core changes reviewer
  mei: discard messages from not connected client during power down.
  vmw_balloon: fix inflation with batching

MAINTAINERS

@@ -4460,6 +4460,7 @@ F:	Documentation/blockdev/drbd/
 
 DRIVER CORE, KOBJECTS, DEBUGFS AND SYSFS
 M:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+R:	"Rafael J. Wysocki" <rafael@kernel.org>
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
 S:	Supported
 F:	Documentation/kobject.txt

drivers/fpga/altera-cvp.c

@@ -455,8 +455,10 @@ static int altera_cvp_probe(struct pci_dev *pdev,
 
 	mgr = fpga_mgr_create(&pdev->dev, conf->mgr_name,
 			      &altera_cvp_ops, conf);
-	if (!mgr)
-		return -ENOMEM;
+	if (!mgr) {
+		ret = -ENOMEM;
+		goto err_unmap;
+	}
 
 	pci_set_drvdata(pdev, mgr);
 

drivers/misc/ibmasm/ibmasmfs.c

@@ -507,35 +507,14 @@ static int remote_settings_file_close(struct inode *inode, struct file *file)
 static ssize_t remote_settings_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
 {
 	void __iomem *address = (void __iomem *)file->private_data;
-	unsigned char *page;
-	int retval;
 	int len = 0;
 	unsigned int value;
-
-	if (*offset < 0)
-		return -EINVAL;
-	if (count == 0 || count > 1024)
-		return 0;
-	if (*offset != 0)
-		return 0;
-
-	page = (unsigned char *)__get_free_page(GFP_KERNEL);
-	if (!page)
-		return -ENOMEM;
+	char lbuf[20];
 
 	value = readl(address);
-	len = sprintf(page, "%d\n", value);
+	len = snprintf(lbuf, sizeof(lbuf), "%d\n", value);
 
-	if (copy_to_user(buf, page, len)) {
-		retval = -EFAULT;
-		goto exit;
-	}
-	*offset += len;
-	retval = len;
-
-exit:
-	free_page((unsigned long)page);
-	return retval;
+	return simple_read_from_buffer(buf, count, offset, lbuf, len);
 }
 
 static ssize_t remote_settings_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)

drivers/misc/mei/interrupt.c

@@ -310,8 +310,11 @@ int mei_irq_read_handler(struct mei_device *dev,
 	if (&cl->link == &dev->file_list) {
 		/* A message for not connected fixed address clients
 		 * should be silently discarded
+		 * On power down client may be force cleaned,
+		 * silently discard such messages
 		 */
-		if (hdr_is_fixed(mei_hdr)) {
+		if (hdr_is_fixed(mei_hdr) ||
+		    dev->dev_state == MEI_DEV_POWER_DOWN) {
 			mei_irq_discard_msg(dev, mei_hdr);
 			ret = 0;
 			goto reset_slots;

drivers/misc/vmw_balloon.c

@@ -467,7 +467,7 @@ static int vmballoon_send_batched_lock(struct vmballoon *b,
 		unsigned int num_pages, bool is_2m_pages, unsigned int *target)
 {
 	unsigned long status;
-	unsigned long pfn = page_to_pfn(b->page);
+	unsigned long pfn = PHYS_PFN(virt_to_phys(b->batch_page));
 
 	STATS_INC(b->stats.lock[is_2m_pages]);
 
@@ -515,7 +515,7 @@ static bool vmballoon_send_batched_unlock(struct vmballoon *b,
 		unsigned int num_pages, bool is_2m_pages, unsigned int *target)
 {
 	unsigned long status;
-	unsigned long pfn = page_to_pfn(b->page);
+	unsigned long pfn = PHYS_PFN(virt_to_phys(b->batch_page));
 
 	STATS_INC(b->stats.unlock[is_2m_pages]);
 

drivers/nvmem/core.c

@@ -936,6 +936,10 @@ struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id)
 			return cell;
 	}
 
+	/* NULL cell_id only allowed for device tree; invalid otherwise */
+	if (!cell_id)
+		return ERR_PTR(-EINVAL);
+
 	return nvmem_cell_get_from_list(cell_id);
 }
 EXPORT_SYMBOL_GPL(nvmem_cell_get);

drivers/thunderbolt/domain.c

@@ -213,6 +213,10 @@ static ssize_t boot_acl_store(struct device *dev, struct device_attribute *attr,
 		goto err_free_acl;
 	}
 	ret = tb->cm_ops->set_boot_acl(tb, acl, tb->nboot_acl);
+	if (!ret) {
+		/* Notify userspace about the change */
+		kobject_uevent(&tb->dev.kobj, KOBJ_CHANGE);
+	}
 	mutex_unlock(&tb->lock);
 
 err_free_acl:

drivers/uio/uio.c

@@ -215,7 +215,20 @@ static ssize_t name_show(struct device *dev,
 			 struct device_attribute *attr, char *buf)
 {
 	struct uio_device *idev = dev_get_drvdata(dev);
-	return sprintf(buf, "%s\n", idev->info->name);
+	int ret;
+
+	mutex_lock(&idev->info_lock);
+	if (!idev->info) {
+		ret = -EINVAL;
+		dev_err(dev, "the device has been unregistered\n");
+		goto out;
+	}
+
+	ret = sprintf(buf, "%s\n", idev->info->name);
+
+out:
+	mutex_unlock(&idev->info_lock);
+	return ret;
 }
 static DEVICE_ATTR_RO(name);
 
@@ -223,7 +236,20 @@ static ssize_t version_show(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
 	struct uio_device *idev = dev_get_drvdata(dev);
-	return sprintf(buf, "%s\n", idev->info->version);
+	int ret;
+
+	mutex_lock(&idev->info_lock);
+	if (!idev->info) {
+		ret = -EINVAL;
+		dev_err(dev, "the device has been unregistered\n");
+		goto out;
+	}
+
+	ret = sprintf(buf, "%s\n", idev->info->version);
+
+out:
+	mutex_unlock(&idev->info_lock);
+	return ret;
 }
 static DEVICE_ATTR_RO(version);
 
@@ -415,11 +441,15 @@ EXPORT_SYMBOL_GPL(uio_event_notify);
 static irqreturn_t uio_interrupt(int irq, void *dev_id)
 {
 	struct uio_device *idev = (struct uio_device *)dev_id;
-	irqreturn_t ret = idev->info->handler(irq, idev->info);
+	irqreturn_t ret;
 
+	mutex_lock(&idev->info_lock);
+
+	ret = idev->info->handler(irq, idev->info);
 	if (ret == IRQ_HANDLED)
 		uio_event_notify(idev->info);
 
+	mutex_unlock(&idev->info_lock);
 	return ret;
 }
 
@@ -433,7 +463,6 @@ static int uio_open(struct inode *inode, struct file *filep)
 	struct uio_device *idev;
 	struct uio_listener *listener;
 	int ret = 0;
-	unsigned long flags;
 
 	mutex_lock(&minor_lock);
 	idev = idr_find(&uio_idr, iminor(inode));
@@ -460,10 +489,16 @@ static int uio_open(struct inode *inode, struct file *filep)
 	listener->event_count = atomic_read(&idev->event);
 	filep->private_data = listener;
 
-	spin_lock_irqsave(&idev->info_lock, flags);
+	mutex_lock(&idev->info_lock);
+	if (!idev->info) {
+		mutex_unlock(&idev->info_lock);
+		ret = -EINVAL;
+		goto err_alloc_listener;
+	}
+
 	if (idev->info && idev->info->open)
 		ret = idev->info->open(idev->info, inode);
-	spin_unlock_irqrestore(&idev->info_lock, flags);
+	mutex_unlock(&idev->info_lock);
 	if (ret)
 		goto err_infoopen;
 
@@ -495,12 +530,11 @@ static int uio_release(struct inode *inode, struct file *filep)
 	int ret = 0;
 	struct uio_listener *listener = filep->private_data;
 	struct uio_device *idev = listener->dev;
-	unsigned long flags;
 
-	spin_lock_irqsave(&idev->info_lock, flags);
+	mutex_lock(&idev->info_lock);
 	if (idev->info && idev->info->release)
 		ret = idev->info->release(idev->info, inode);
-	spin_unlock_irqrestore(&idev->info_lock, flags);
+	mutex_unlock(&idev->info_lock);
 
 	module_put(idev->owner);
 	kfree(listener);
@@ -513,12 +547,11 @@ static __poll_t uio_poll(struct file *filep, poll_table *wait)
 	struct uio_listener *listener = filep->private_data;
 	struct uio_device *idev = listener->dev;
 	__poll_t ret = 0;
-	unsigned long flags;
 
-	spin_lock_irqsave(&idev->info_lock, flags);
+	mutex_lock(&idev->info_lock);
 	if (!idev->info || !idev->info->irq)
 		ret = -EIO;
-	spin_unlock_irqrestore(&idev->info_lock, flags);
+	mutex_unlock(&idev->info_lock);
 
 	if (ret)
 		return ret;
@@ -537,12 +570,11 @@ static ssize_t uio_read(struct file *filep, char __user *buf,
 	DECLARE_WAITQUEUE(wait, current);
 	ssize_t retval = 0;
 	s32 event_count;
-	unsigned long flags;
 
-	spin_lock_irqsave(&idev->info_lock, flags);
+	mutex_lock(&idev->info_lock);
 	if (!idev->info || !idev->info->irq)
 		retval = -EIO;
-	spin_unlock_irqrestore(&idev->info_lock, flags);
+	mutex_unlock(&idev->info_lock);
 
 	if (retval)
 		return retval;
@@ -592,9 +624,13 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
 	struct uio_device *idev = listener->dev;
 	ssize_t retval;
 	s32 irq_on;
-	unsigned long flags;
 
-	spin_lock_irqsave(&idev->info_lock, flags);
+	mutex_lock(&idev->info_lock);
+	if (!idev->info) {
+		retval = -EINVAL;
+		goto out;
+	}
+
 	if (!idev->info || !idev->info->irq) {
 		retval = -EIO;
 		goto out;
@@ -618,7 +654,7 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
 	retval = idev->info->irqcontrol(idev->info, irq_on);
 
 out:
-	spin_unlock_irqrestore(&idev->info_lock, flags);
+	mutex_unlock(&idev->info_lock);
 	return retval ? retval : sizeof(s32);
 }
 
@@ -640,10 +676,20 @@ static vm_fault_t uio_vma_fault(struct vm_fault *vmf)
 	struct page *page;
 	unsigned long offset;
 	void *addr;
+	int ret = 0;
+	int mi;
 
-	int mi = uio_find_mem_index(vmf->vma);
-	if (mi < 0)
-		return VM_FAULT_SIGBUS;
+	mutex_lock(&idev->info_lock);
+	if (!idev->info) {
+		ret = VM_FAULT_SIGBUS;
+		goto out;
+	}
+
+	mi = uio_find_mem_index(vmf->vma);
+	if (mi < 0) {
+		ret = VM_FAULT_SIGBUS;
+		goto out;
+	}
 
 	/*
 	 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
@@ -658,7 +704,11 @@ static vm_fault_t uio_vma_fault(struct vm_fault *vmf)
 		page = vmalloc_to_page(addr);
 	get_page(page);
 	vmf->page = page;
-	return 0;
+
+out:
+	mutex_unlock(&idev->info_lock);
+
+	return ret;
 }
 
 static const struct vm_operations_struct uio_logical_vm_ops = {
@@ -683,6 +733,7 @@ static int uio_mmap_physical(struct vm_area_struct *vma)
 	struct uio_device *idev = vma->vm_private_data;
 	int mi = uio_find_mem_index(vma);
 	struct uio_mem *mem;
+
 	if (mi < 0)
 		return -EINVAL;
 	mem = idev->info->mem + mi;
@@ -724,30 +775,46 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
 
 	vma->vm_private_data = idev;
 
+	mutex_lock(&idev->info_lock);
+	if (!idev->info) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	mi = uio_find_mem_index(vma);
-	if (mi < 0)
-		return -EINVAL;
+	if (mi < 0) {
+		ret = -EINVAL;
+		goto out;
+	}
 
 	requested_pages = vma_pages(vma);
 	actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
 			+ idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
-	if (requested_pages > actual_pages)
-		return -EINVAL;
+	if (requested_pages > actual_pages) {
+		ret = -EINVAL;
+		goto out;
+	}
 
 	if (idev->info->mmap) {
 		ret = idev->info->mmap(idev->info, vma);
-		return ret;
+		goto out;
 	}
 
 	switch (idev->info->mem[mi].memtype) {
 		case UIO_MEM_PHYS:
-			return uio_mmap_physical(vma);
+			ret = uio_mmap_physical(vma);
+			break;
 		case UIO_MEM_LOGICAL:
 		case UIO_MEM_VIRTUAL:
-			return uio_mmap_logical(vma);
+			ret = uio_mmap_logical(vma);
+			break;
 		default:
-			return -EINVAL;
+			ret = -EINVAL;
 	}
+
+out:
+	mutex_unlock(&idev->info_lock);
+	return 0;
 }
 
 static const struct file_operations uio_fops = {
@@ -865,7 +932,7 @@ int __uio_register_device(struct module *owner,
 
 	idev->owner = owner;
 	idev->info = info;
-	spin_lock_init(&idev->info_lock);
+	mutex_init(&idev->info_lock);
 	init_waitqueue_head(&idev->wait);
 	atomic_set(&idev->event, 0);
 
@@ -902,8 +969,9 @@ int __uio_register_device(struct module *owner,
 		 * FDs at the time of unregister and therefore may not be
 		 * freed until they are released.
 		 */
-		ret = request_irq(info->irq, uio_interrupt,
-				  info->irq_flags, info->name, idev);
+		ret = request_threaded_irq(info->irq, NULL, uio_interrupt,
+					   info->irq_flags, info->name, idev);
+
 		if (ret)
 			goto err_request_irq;
 	}
@@ -928,7 +996,6 @@ EXPORT_SYMBOL_GPL(__uio_register_device);
 void uio_unregister_device(struct uio_info *info)
 {
 	struct uio_device *idev;
-	unsigned long flags;
 
 	if (!info || !info->uio_dev)
 		return;
@@ -937,14 +1004,14 @@ void uio_unregister_device(struct uio_info *info)
 
 	uio_free_minor(idev);
 
+	mutex_lock(&idev->info_lock);
 	uio_dev_del_attributes(idev);
 
 	if (info->irq && info->irq != UIO_IRQ_CUSTOM)
 		free_irq(info->irq, idev);
 
-	spin_lock_irqsave(&idev->info_lock, flags);
 	idev->info = NULL;
-	spin_unlock_irqrestore(&idev->info_lock, flags);
+	mutex_unlock(&idev->info_lock);
 
 	device_unregister(&idev->dev);
 

include/linux/uio_driver.h

@@ -75,7 +75,7 @@ struct uio_device {
         struct fasync_struct    *async_queue;
         wait_queue_head_t       wait;
         struct uio_info         *info;
-	spinlock_t		info_lock;
+	struct mutex		info_lock;
         struct kobject          *map_dir;
         struct kobject          *portio_dir;
 };