diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2017-04-12 13:25:52 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-25 15:44:47 +0200 |
| commit | 9ad81ecb28d611a07b59d8e899e0bd79a423aee2 (patch) | |
| tree | 6f8b32d97361d06530e56efb1ba03ed17e32caa2 | |
| parent | 6bec009a2f690c69239ab8c002aa1f5eca8c480e (diff) | |
PCI: Only allow WC mmap on prefetchable resources
commit cef4d02305a06be581bb7f4353446717a1b319ec 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: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 78802ee42878..66c886365fbc 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) |