[PATCH 4.9 58/93] PCI: Update BARs using property bits appropriate for type

From: Greg Kroah-Hartman
Date: Mon Mar 20 2017 - 14:26:36 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

[ Upstream commit 45d004f4afefdd8d79916ee6d97a9ecd94bb1ffe ]

The BAR property bits (0-3 for memory BARs, 0-1 for I/O BARs) are supposed
to be read-only, but we do save them in res->flags and include them when
updating the BAR.

Mask the I/O property bits with ~PCI_BASE_ADDRESS_IO_MASK (0x3) instead of
PCI_REGION_FLAG_MASK (0xf) to make it obvious that we can't corrupt bits
2-3 of I/O addresses.

Use PCI_ROM_ADDRESS_MASK for ROM BARs. This means we'll only check the top
21 bits (instead of the 28 bits we used to check) of a ROM BAR to see if
the update was successful.

Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/setup-res.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -58,12 +58,17 @@ static void pci_std_update_resource(stru
return;

pcibios_resource_to_bus(dev->bus, &region, res);
+ new = region.start;

- new = region.start | (res->flags & PCI_REGION_FLAG_MASK);
- if (res->flags & IORESOURCE_IO)
+ if (res->flags & IORESOURCE_IO) {
mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
- else
+ new |= res->flags & ~PCI_BASE_ADDRESS_IO_MASK;
+ } else if (resno == PCI_ROM_RESOURCE) {
+ mask = (u32)PCI_ROM_ADDRESS_MASK;
+ } else {
mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
+ new |= res->flags & ~PCI_BASE_ADDRESS_MEM_MASK;
+ }

if (resno < PCI_ROM_RESOURCE) {
reg = PCI_BASE_ADDRESS_0 + 4 * resno;