diff options
Diffstat (limited to 'drivers/uio/uio.c')
-rw-r--r-- | drivers/uio/uio.c | 151 |
1 files changed, 104 insertions, 47 deletions
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index e8f4ac9400ea..70a7981b94b3 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * drivers/uio/uio.c * @@ -9,8 +10,6 @@ * Userspace IO * * Base Functions - * - * Licensed under the GPLv2 only. */ #include <linux/module.h> @@ -215,7 +214,20 @@ 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 +235,20 @@ 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); @@ -415,8 +440,9 @@ 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; + ret = idev->info->handler(irq, idev->info); if (ret == IRQ_HANDLED) uio_event_notify(idev->info); @@ -433,7 +459,6 @@ 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 +485,16 @@ 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 +526,11 @@ 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 +543,11 @@ 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 +566,11 @@ 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; @@ -592,33 +620,33 @@ 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); - if (!idev->info || !idev->info->irq) { - retval = -EIO; - goto out; - } + if (count != sizeof(s32)) + return -EINVAL; - if (count != sizeof(s32)) { + if (copy_from_user(&irq_on, buf, count)) + return -EFAULT; + + mutex_lock(&idev->info_lock); + if (!idev->info) { retval = -EINVAL; goto out; } - if (!idev->info->irqcontrol) { - retval = -ENOSYS; + if (!idev->info || !idev->info->irq) { + retval = -EIO; goto out; } - if (copy_from_user(&irq_on, buf, count)) { - retval = -EFAULT; + if (!idev->info->irqcontrol) { + retval = -ENOSYS; goto out; } 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 +668,20 @@ 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 +696,11 @@ 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 +725,7 @@ 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 +767,46 @@ 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 ret; } static const struct file_operations uio_fops = { @@ -865,7 +924,7 @@ 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); @@ -891,8 +950,6 @@ int __uio_register_device(struct module *owner, if (ret) goto err_uio_dev_add_attributes; - info->uio_dev = idev; - if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { /* * Note that we deliberately don't use devm_request_irq @@ -908,6 +965,7 @@ int __uio_register_device(struct module *owner, goto err_request_irq; } + info->uio_dev = idev; return 0; err_request_irq: @@ -928,7 +986,6 @@ 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 +994,14 @@ 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); |