From: Bjorn Helgaas <helgaas@kernel.org>
To: David Miller <davem@davemloft.net>
Cc: bhelgaas@google.com, linux-pci@vger.kernel.org
Subject: Re: [PATCH] pci: Fix unaligned accesses in VC code.
Date: Mon, 20 Jun 2016 13:34:28 -0500 [thread overview]
Message-ID: <20160620183428.GA31564@localhost> (raw)
In-Reply-To: <20160618.235225.1591502152749272620.davem@davemloft.net>
On Sat, Jun 18, 2016 at 11:52:25PM -0700, David Miller wrote:
>
> 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.
>
> Reported-by: Meelis Roos <mroos@linux.ee>
> Reported-by: Anatoly Pugachev <matorola@gmail.com>
> Signed-off-by: David S. Miller <davem@davemloft.net>
Applied to for-linus for v4.7, thanks.
I'm pretty sure this problem was introduced by 5f8fc43217a0 ("PCI:
Include pci/pcie/Kconfig directly from pci/Kconfig"), which appeared
in v4.6. This effectively made PCIe services, including VC, available
on sparc.
I added a stable tag for v4.6.
> diff --git a/drivers/pci/vc.c b/drivers/pci/vc.c
> index dfbab61..1fa3a32 100644
> --- 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
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
prev parent reply other threads:[~2016-06-20 18:35 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-19 6:52 [PATCH] pci: Fix unaligned accesses in VC code David Miller
2016-06-20 18:34 ` Bjorn Helgaas [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160620183428.GA31564@localhost \
--to=helgaas@kernel.org \
--cc=bhelgaas@google.com \
--cc=davem@davemloft.net \
--cc=linux-pci@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).