From: Xie He <xie.he.0141@gmail.com>
To: Martin Schiller <ms@dev.tdt.de>
Cc: "David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux X25 <linux-x25@vger.kernel.org>,
Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
Brian Norris <briannorris@chromium.org>,
netdev-owner@vger.kernel.org
Subject: Re: [net v3] drivers/net/wan/lapbether: Use needed_headroom instead of hard_header_len
Date: Wed, 5 Aug 2020 01:57:25 -0700 [thread overview]
Message-ID: <CAJht_EMf5i1qykEP6sZjLBcPAN9u9oQoZ34dfJ68Z5XL6rKuDQ@mail.gmail.com> (raw)
In-Reply-To: <9975370f14b8ddeafc8dec7bc6c0878a@dev.tdt.de>
On Tue, Aug 4, 2020 at 10:23 PM Martin Schiller <ms@dev.tdt.de> wrote:
>
> > Adding skb_cow before these skb_push calls would indeed help
> > preventing kernel panics, but that might not be the essential issue
> > here, and it might also prevent us from discovering the real issue. (I
> > guess this is also the reason skb_cow is not included in skb_push
> > itself.)
>
> Well, you are right that the panic is "useful" to discover the real
> problem. But on the other hand, if it is possible to prevent a panic, I
> think we should do so. Maybe with adding a warning, when skb_cow() needs
> to reallocate memory.
>
> But this is getting a little bit off topic. For this patch I can say:
>
> LGTM.
>
> Reviewed-by: Martin Schiller <ms@dev.tdt.de>
Thank you so much!
Yes, it might be better to use skb_cow with a warning so that we can
prevent kernel panic while still being able to discover the problem.
If we want to do this, there are 2 more places in addition to
lapbeth_data_transmit that need to be guarded with skb_cow:
lapb_send_iframe and lapb_transmit_buffer in net/lapb/lapb_out.c.
Maybe we can address this in a separate patch.
next prev parent reply other threads:[~2020-08-05 8:57 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-02 19:50 [net v3] drivers/net/wan/lapbether: Use needed_headroom instead of hard_header_len Xie He
2020-08-03 9:49 ` Willem de Bruijn
2020-08-03 17:25 ` Xie He
2020-08-04 12:43 ` Martin Schiller
2020-08-04 19:20 ` Xie He
2020-08-05 5:23 ` Martin Schiller
2020-08-05 8:57 ` Xie He [this message]
2020-08-05 9:33 ` Willem de Bruijn
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=CAJht_EMf5i1qykEP6sZjLBcPAN9u9oQoZ34dfJ68Z5XL6rKuDQ@mail.gmail.com \
--to=xie.he.0141@gmail.com \
--cc=briannorris@chromium.org \
--cc=davem@davemloft.net \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-x25@vger.kernel.org \
--cc=ms@dev.tdt.de \
--cc=netdev-owner@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=willemdebruijn.kernel@gmail.com \
/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).