Thread (198 messages) 198 messages, 4 authors, 2016-07-26
STALE3640d

[PATCH 4.6 144/203] PCI: Fix unaligned accesses in VC code

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2016-07-25 21:41:45
Also in: lkml

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

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

From: David Miller <davem@davemloft.net>

commit ef0dab4aae14e25efddf1577736f8450132800c5 upstream.

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 <redacted>
Reported-by: Anatoly Pugachev <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/pci/vc.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/pci/vc.c
+++ b/drivers/pci/vc.c
@@ -221,9 +221,9 @@ static int pci_vc_do_save_buffer(struct
 		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

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