Commit f21143a5 authored by David Woodhouse's avatar David Woodhouse Committed by Greg Kroah-Hartman

PCI: Only allow WC mmap on prefetchable resources

commit cef4d023 upstream.

The /proc/bus/pci mmap interface allows the user to specify whether they
want WC or not.  Don't let them do so on non-prefetchable BARs.
Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent bee38f0f
......@@ -231,7 +231,7 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
{
struct pci_dev *dev = PDE_DATA(file_inode(file));
struct pci_filp_private *fpriv = file->private_data;
int i, ret, write_combine, res_bit;
int i, ret, write_combine = 0, res_bit;
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
......@@ -251,10 +251,13 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
if (i >= PCI_ROM_RESOURCE)
return -ENODEV;
if (fpriv->mmap_state == pci_mmap_mem)
write_combine = fpriv->write_combine;
if (fpriv->mmap_state == pci_mmap_mem &&
fpriv->write_combine) {
if (dev->resource[i].flags & IORESOURCE_PREFETCH)
write_combine = 1;
else
write_combine = 0;
return -EINVAL;
}
ret = pci_mmap_page_range(dev, vma,
fpriv->mmap_state, write_combine);
if (ret < 0)
......
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