summaryrefslogtreecommitdiff
path: root/drivers/pci/proc.c
diff options
context:
space:
mode:
authorDavid Woodhouse <dwmw@amazon.co.uk>2017-04-12 15:25:52 +0300
committerBjorn Helgaas <bhelgaas@google.com>2017-04-18 21:00:49 +0300
commitcef4d02305a06be581bb7f4353446717a1b319ec (patch)
treec806c699401ede0d5ca0894d33f84bac80e7e99e /drivers/pci/proc.c
parent17caf56731311c9596e7d38a70c88fcb6afa6a1b (diff)
downloadlinux-cef4d02305a06be581bb7f4353446717a1b319ec.tar.xz
PCI: Only allow WC mmap on prefetchable resources
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: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/pci/proc.c')
-rw-r--r--drivers/pci/proc.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
index 62a0c3e788d3..dc8912e2d4a1 100644
--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -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;
- else
- write_combine = 0;
+ if (fpriv->mmap_state == pci_mmap_mem &&
+ fpriv->write_combine) {
+ if (dev->resource[i].flags & IORESOURCE_PREFETCH)
+ write_combine = 1;
+ else
+ return -EINVAL;
+ }
ret = pci_mmap_page_range(dev, vma,
fpriv->mmap_state, write_combine);
if (ret < 0)