[PATCH 3.16 043/134] PCI: Fix pci_mmap_fits() for HAVE_PCI_RESOURCE_TO_USER platforms

Ben Hutchings
2017-08-18T13:15:45Z

From: David Woodhouse <dwmw@amazon.co.uk>

commit 6bccc7f426abd640f08d8c75fb22f99483f201b4 upstream.

In the PCI_MMAP_PROCFS case when the address being passed by the user is a
'user visible' resource address based on the bus window, and not the actual
contents of the resource, that's what we need to be checking it against.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/pci/pci-sysfs.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -965,15 +965,19 @@ void pci_remove_legacy_files(struct pci_
int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
enum pci_mmap_api mmap_api)
{
- unsigned long nr, start, size, pci_start;
+ unsigned long nr, start, size;
+ resource_size_t pci_start = 0, pci_end;

if (pci_resource_len(pdev, resno) == 0)
return 0;
nr = vma_pages(vma);
start = vma->vm_pgoff;
size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1;
- pci_start = (mmap_api == PCI_MMAP_PROCFS) ?
- pci_resource_start(pdev, resno) >> PAGE_SHIFT : 0;
+ if (mmap_api == PCI_MMAP_PROCFS) {
+ pci_resource_to_user(pdev, resno, &pdev->resource[resno],
+ &pci_start, &pci_end);
+ pci_start >>= PAGE_SHIFT;
+ }
if (start >= pci_start && start < pci_start + size &&
start + nr <= pci_start + size)
return 1;