From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752149AbdHGGuw (ORCPT <rfc822;w@1wt.eu>);
        Mon, 7 Aug 2017 02:50:52 -0400
Received: from mail-wr0-f169.google.com ([209.85.128.169]:37371 "EHLO
        mail-wr0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1752122AbdHGGuv (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 7 Aug 2017 02:50:51 -0400
MIME-Version: 1.0
In-Reply-To: <20170807044912.18146-1-kai.heng.feng@canonical.com>
References: <20170807044912.18146-1-kai.heng.feng@canonical.com>
From: Kai-Heng Feng <kai.heng.feng@canonical.com>
Date: Mon, 7 Aug 2017 14:50:49 +0800
Message-ID: <CAAd53p5c+MHuviVjEi0=oJ0eEE3atW181PsHpCjfqnhtHBy=GA@mail.gmail.com>
Subject: Re: [PATCH] thunderbolt: icm: Remove Apple check for Alpine Ridge
To: LKML <linux-kernel@vger.kernel.org>
Cc: andreas.noever@gmail.com, michael.jamet@intel.com,
        yehezkel.bernat@intel.com, Kai-Heng Feng <kai.heng.feng@canonical.com>,
        mika.westerberg@linux.intel.com
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, Aug 7, 2017 at 12:49 PM, Kai-Heng Feng
<kai.heng.feng@canonical.com> wrote:
> In icm_ar_is_supported(), icm->upstream_port will be uninitialized if
> the hardware is not an Apple one.
>
> The uninitialized icm->upstream_port will later be dereferenced in
> pcie2cio_write(), causes a NULL pointer dereference issue.
>
> Commit f67cf491175a ("thunderbolt: Add support for Internal Connection
> Manager (ICM)") states that all Alpine Ridge will use ICM, so I guess
> it's safe to remove the Apple check.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
>  drivers/thunderbolt/icm.c | 7 -------
>  1 file changed, 7 deletions(-)
>
> diff --git a/drivers/thunderbolt/icm.c b/drivers/thunderbolt/icm.c
> index bdaac1ff00a5..2ab25aac5446 100644
> --- a/drivers/thunderbolt/icm.c
> +++ b/drivers/thunderbolt/icm.c
> @@ -514,13 +514,6 @@ static bool icm_ar_is_supported(struct tb *tb)
>         struct icm *icm = tb_priv(tb);
>
>         /*
> -        * Starting from Alpine Ridge we can use ICM on Apple machines
> -        * as well. We just need to reset and re-enable it first.
> -        */
> -       if (!is_apple())
> -               return true;
> -
> -       /*
>          * Find the upstream PCIe port in case we need to do reset
>          * through its vendor specific registers.
>          */
> --
> 2.13.4
>

Forgot to CC LKML...