netdev - Re: [PATCH net] net: sched: check netif_xmit_frozen_or_stopped() in sch_direct

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <9CCB235F-A3AB-41A3-AE1B-97A241DBB686@fb.com>
Date:   Tue, 29 May 2018 16:51:15 +0000
From:   Song Liu <songliubraving@...com>
To:     David Miller <davem@...emloft.net>
CC:     Networking <netdev@...r.kernel.org>,
        Kernel Team <Kernel-team@...com>,
        "john.fastabend@...il.com" <john.fastabend@...il.com>
Subject: Re: [PATCH net] net: sched: check netif_xmit_frozen_or_stopped() in
 sch_direct_xmit()



> On May 29, 2018, at 7:02 AM, David Miller <davem@...emloft.net> wrote:
> 
> From: Song Liu <songliubraving@...com>
> Date: Fri, 25 May 2018 11:11:44 -0700
> 
>> Summary:
>> 
>> At the end of sch_direct_xmit(), we are in the else path of
>> !dev_xmit_complete(ret), which means ret == NETDEV_TX_OK. The following
>> condition will always fail and netif_xmit_frozen_or_stopped() is not
>> checked at all.
>> 
>>    if (ret && netif_xmit_frozen_or_stopped(txq))
>>         return false;
>> 
>> In this patch, this condition is fixed as:
>> 
>>    if (netif_xmit_frozen_or_stopped(txq))
>>         return false;
>> 
>> and further simplifies the code as:
>> 
>>    return !netif_xmit_frozen_or_stopped(txq);
>> 
>> Fixes: 29b86cdac00a ("net: sched: remove remaining uses for qdisc_qlen in xmit path")
>> Cc: John Fastabend <john.fastabend@...il.com>
>> Cc: David S. Miller <davem@...emloft.net>
>> Signed-off-by: Song Liu <songliubraving@...com>
> 
> I expect a new version of this patch which removes the test entirely.

The new version of it is here: http://patchwork.ozlabs.org/patch/921708/

Thanks,
Song