diff options
| -rw-r--r-- | drivers/misc/open-dice.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/drivers/misc/open-dice.c b/drivers/misc/open-dice.c index c61be3404c6f..9dda47b3fd70 100644 --- a/drivers/misc/open-dice.c +++ b/drivers/misc/open-dice.c @@ -90,15 +90,13 @@ static int open_dice_mmap(struct file *filp, struct vm_area_struct *vma) { struct open_dice_drvdata *drvdata = to_open_dice_drvdata(filp); - /* Do not allow userspace to modify the underlying data. */ - if ((vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_SHARED)) - return -EPERM; - - /* Ensure userspace cannot acquire VM_WRITE + VM_SHARED later. */ - if (vma->vm_flags & VM_WRITE) - vma->vm_flags &= ~VM_MAYSHARE; - else if (vma->vm_flags & VM_SHARED) + if (vma->vm_flags & VM_MAYSHARE) { + /* Do not allow userspace to modify the underlying data. */ + if (vma->vm_flags & VM_WRITE) + return -EPERM; + /* Ensure userspace cannot acquire VM_WRITE later. */ vma->vm_flags &= ~VM_MAYWRITE; + } /* Create write-combine mapping so all clients observe a wipe. */ vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); |