Re: commit 64ff3b938ec6782e6585a83d5459b98b0c3f6eb8 breaks rlogin

From: Jeff Chua
Date: Fri Feb 06 2009 - 00:39:38 EST


On Fri, Feb 6, 2009 at 7:29 AM, David Miller <davem@xxxxxxxxxxxxx> wrote:
> [ netdev CC:'d, please always do this for networking stuff ]

Will do.

> Oh well, what is running on each side of the rlogin attempt?

Nothing at all. Just a pure "rlogin remotehost" trying to get a login
prompt. Nothing inside .profile.

On Fri, Feb 6, 2009 at 11:10 AM, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
> Could you please try a strace on both sides, with and without
> this patch applied?

Attached are two strace. t1.good is a good rlogin run. t4.bad is bad
rlogin run where nothing is displayed but typing "~-." gets back to
the host.

With strace, it takes a bit more try to get it to hang. In fact, this
bug was quite to trigger and I've been having this problem on-and-off
since December, and but it was intermittent and didn't think it was a
kernel problem until serious chasing. Some network switches "mask" out
the problem, and some direct connect always has this problem. Some
servers occurred very frequent, some seldom.


On Fri, Feb 6, 2009 at 7:32 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> - even just a whiff of "breaks legacy app" just says "revert it".

I agree reverting is the right thing here.


Thanks,
Jeff.

Attachment: t1.good
Description: Binary data

Attachment: t4.bad
Description: Binary data