diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2017-04-12 13:25:52 +0100 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2017-04-18 13:00:49 -0500 |
| commit | cef4d02305a06be581bb7f4353446717a1b319ec (patch) | |
| tree | c806c699401ede0d5ca0894d33f84bac80e7e99e | |
| parent | 17caf56731311c9596e7d38a70c88fcb6afa6a1b (diff) | |
| download | linux-stable-cef4d02305a06be581bb7f4353446717a1b319ec.tar.gz linux-stable-cef4d02305a06be581bb7f4353446717a1b319ec.tar.bz2 linux-stable-cef4d02305a06be581bb7f4353446717a1b319ec.zip | |
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
| -rw-r--r-- | drivers/pci/proc.c | 13 |
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) |