Return-path: Received: from mail-wm0-f45.google.com ([74.125.82.45]:38325 "EHLO mail-wm0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751441AbdD0Ezu (ORCPT ); Thu, 27 Apr 2017 00:55:50 -0400 Received: by mail-wm0-f45.google.com with SMTP id r190so7031837wme.1 for ; Wed, 26 Apr 2017 21:55:49 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <1493111408-27692-1-git-send-email-arend.vanspriel@broadcom.com> <20170426085337.181AA61493@smtp.codeaurora.org> <4d7ced43-4a95-f626-b66e-285c133c48c1@broadcom.com> From: Steve deRosier Date: Wed, 26 Apr 2017 21:55:48 -0700 Message-ID: (sfid-20170427_065559_604687_5DB3DD9D) Subject: Re: ath6kl: assure headroom of skbuff is writable in .start_xmit() To: James Hughes Cc: Arend Van Spriel , Kalle Valo , linux-wireless Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, Apr 26, 2017 at 12:54 PM, James Hughes wrote: > On 26 April 2017 at 19:03, Arend Van Spriel > wrote: >> >> >> On 26-4-2017 17:44, Steve deRosier wrote: >>> On Wed, Apr 26, 2017 at 1:53 AM, Kalle Valo wrote: >>>> Arend Van Spriel wrote: >>>>> An issue was found brcmfmac driver in which a skbuff in .start_xmit() >>>>> callback was actually cloned. So instead of checking for sufficient >>>>> headroom it should also be writable. Hence use skb_cow_head() to >>>>> check and expand the headroom appropriately. >>>>> >>>>> Signed-off-by: Arend van Spriel >>>> >>>> Steve, would you have time to run a quick test with this? >>>> >>>> Patch set to Deferred. >>>> >>> >>> Happy to give it a quick spin on both of my platforms. >>> @ Arend and James, thanks for the info. I understand it, but unfortunately I can't seem to replicate the problems on my platforms with the limited time I have available to test it. It also may have to do with my platforms having special custom bridging related code, or just me having setup too simple of a test. That said... @Kalle: I have tested on both my 6004 and 6003 platforms. I didn't notice any incorrect behavior in my testing. But I don't have a test setup that would have shown the original problem as reported on the brcm driver so I can't say that the change actually _fixes_ anything. Only that in my testing it doesn't seem to break anything. Tested-by: Steve deRosier - Steve