PCI: Fix unaligned accesses in VC code

The save/restore buffers for VC state is first composed of a 2-byte control
register, then a bunch of 4-byte words.

This causes unaligned accesses which trap on platform such as sparc.

This is easy to fix by simply moving the buffer pointer forward by 4 bytes
instead of 2 after dealing with the control register.  The length
adjustment needs to be changed likewise as well.

Fixes: 5f8fc43217a0 ("PCI: Include pci/pcie/Kconfig directly from pci/Kconfig")
Reported-by: Meelis Roos <mroos@linux.ee>
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org	# v4.6+

diff --git a/drivers/pci/vc.c b/drivers/pci/vc.c
index dfbab61a1b473d72cb6e631c6738d1c60fb99d96..1fa3a3219c454e23e0081b7073acd342909aacda 100644 (file)
--- a/drivers/pci/vc.c
+++ b/drivers/pci/vc.c
@@ -221,9 +221,9 @@ static int pci_vc_do_save_buffer(struct pci_dev *dev, int pos,
                else
                        pci_write_config_word(dev, pos + PCI_VC_PORT_CTRL,
                                              *(u16 *)buf);
-               buf += 2;
+               buf += 4;
        }
-       len += 2;
+       len += 4;
 
        /*
         * If we have any Low Priority VCs and a VC Arbitration Table Offset