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drm: fix up mmap locking in preparation for ttm changes 

This change is needed to protect againt disappearing maps which aren't common.
The map lists are protected using sturct_mutex but drm_mmap never locked it.

Signed-off-by: Dave Airlie <airlied@linux.ie>
This commit is contained in:
Thomas Hellstrom 2007-03-24 17:52:49 +11:00 committed by Dave Airlie
parent 040ac32048
commit d7d8aac79d
1 changed files with 26 additions and 9 deletions
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35
drivers/char/drm/drm_vm.c
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@ -413,7 +413,7 @@ static struct vm_operations_struct drm_vm_sg_ops = {
* Create a new drm_vma_entry structure as the \p vma private data entry and
* add it to drm_device::vmalist.
*/
static void drm_vm_open(struct vm_area_struct *vma)
static void drm_vm_open_locked(struct vm_area_struct *vma)
{
drm_file_t *priv = vma->vm_file->private_data;
drm_device_t *dev = priv->head->dev;
@ -425,15 +425,23 @@ static void drm_vm_open(struct vm_area_struct *vma)
vma_entry = drm_alloc(sizeof(*vma_entry), DRM_MEM_VMAS);
if (vma_entry) {
mutex_lock(&dev->struct_mutex);
vma_entry->vma = vma;
vma_entry->next = dev->vmalist;
vma_entry->pid = current->pid;
dev->vmalist = vma_entry;
mutex_unlock(&dev->struct_mutex);
}
}
static void drm_vm_open(struct vm_area_struct *vma)
{
drm_file_t *priv = vma->vm_file->private_data;
drm_device_t *dev = priv->head->dev;
mutex_lock(&dev->struct_mutex);
drm_vm_open_locked(vma);
mutex_unlock(&dev->struct_mutex);
}
/**
* \c close method for all virtual memory types.
*
@ -484,7 +492,6 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
drm_device_dma_t *dma;
unsigned long length = vma->vm_end - vma->vm_start;
lock_kernel();
dev = priv->head->dev;
dma = dev->dma;
DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
@ -492,10 +499,8 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
/* Length must match exact page count */
if (!dma || (length >> PAGE_SHIFT) != dma->page_count) {
unlock_kernel();
return -EINVAL;
}
unlock_kernel();
if (!capable(CAP_SYS_ADMIN) &&
(dma->flags & _DRM_DMA_USE_PCI_RO)) {
@ -518,7 +523,7 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
vma->vm_flags |= VM_RESERVED; /* Don't swap */
vma->vm_file = filp; /* Needed for drm_vm_open() */
drm_vm_open(vma);
drm_vm_open_locked(vma);
return 0;
}
@ -553,7 +558,7 @@ EXPORT_SYMBOL(drm_core_get_reg_ofs);
* according to the mapping type and remaps the pages. Finally sets the file
* pointer and calls vm_open().
*/
int drm_mmap(struct file *filp, struct vm_area_struct *vma)
static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->dev;
@ -667,8 +672,20 @@ int drm_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_flags |= VM_RESERVED; /* Don't swap */
vma->vm_file = filp; /* Needed for drm_vm_open() */
drm_vm_open(vma);
drm_vm_open_locked(vma);
return 0;
}
int drm_mmap(struct file *filp, struct vm_area_struct *vma)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->dev;
int ret;
mutex_lock(&dev->struct_mutex);
ret = drm_mmap_locked(filp, vma);
mutex_unlock(&dev->struct_mutex);
return ret;
}
EXPORT_SYMBOL(drm_mmap);