From: Takashi Yano <takashi.yano@nifty.ne.jp>
To: cygwin@cygwin.com
Subject: Re: SSHD causes 100% CPU load
Date: Fri, 6 Aug 2021 10:55:07 +0900 [thread overview]
Message-ID: <20210806105507.47c573639b0762ba91828023@nifty.ne.jp> (raw)
In-Reply-To: <20210806014331.899fb21f181e664663c328ae@nifty.ne.jp>
Hi Corinna,
On Fri, 6 Aug 2021 01:43:31 +0900
Takashi Yano wrote:
> Hi Corinna,
>
> On Thu, 5 Aug 2021 17:07:24 +0200
> Corinna Vinschen wrote:
> > Could you perhaps bisect the issue on your machine?
>
> In my environment, this does not happen with 8.4p1-1 and 8.4p1-2.
> However it happens with 8.5p1-1.
>
> > The fact that using Windows ssh is an issue makes me wonder if this is
> > some kind of pty problem.
>
> With command 'ssh user@localhost ls', pty does not allocated.
> It seems that this issue does not happen if -t option (allocate
> tty) is specified. So I think this is not a pty problem.
>
> In order to look into this problem, I tried to build openssh-8.5p1-1
> from source, however it cause the error in configure stage:
>
> ...
> checking for pkg-config... (cached) /usr/bin/pkg-config
> checking if /usr/bin/pkg-config knows about libfido2... no
> checking for fido_init in -lfido2... no
> configure: error: no usable libfido2 found
> *** ERROR: configure failed
>
> despite libfido2-devel had been installed.
>
> $ cygcheck -c libfido2-devel
> Cygwin Package Information
> Package Version Status
> libfido2-devel 1.5.0-1 OK
>
> How can I solve this error?
I looked into the openssh code and might find a calprit.
I guess the following patch solves the issue.
--- serverloop.c.orig 2021-03-02 19:31:47.000000000 +0900
+++ serverloop.c 2021-08-06 10:41:55.439357200 +0900
@@ -333,7 +333,7 @@
return -1;
} else if (len == -1) {
if (errno == EINTR || errno == EAGAIN ||
- errno != EWOULDBLOCK)
+ errno == EWOULDBLOCK)
return 0;
verbose("Read error from remote host %s port %d: %s",
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
This seems to be a upstream bug which has been already fixed.
Please refer to:
https://github.com/openssh/openssh-portable/commit/2dc328023f60212cd29504fc05d849133ae47355
--
Takashi Yano <takashi.yano@nifty.ne.jp>
next prev parent reply other threads:[~2021-08-06 1:55 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-26 10:42 Christoph Lüders
2021-04-28 4:23 ` Andrey Repin
2021-04-28 7:10 ` Christoph Lüders
2021-05-04 15:14 ` Andrey Repin
2021-05-04 21:56 ` Brian Inglis
2021-08-05 10:12 ` Takashi Yano
2021-08-05 15:07 ` Corinna Vinschen
2021-08-05 16:43 ` Takashi Yano
2021-08-06 1:55 ` Takashi Yano [this message]
2021-08-06 9:11 ` Corinna Vinschen
2021-08-06 11:14 ` Takashi Yano
2021-08-06 13:59 ` Corinna Vinschen
2021-08-06 11:30 ` Takashi Yano
2021-08-06 12:35 ` Takashi Yano
2021-08-06 13:57 ` Corinna Vinschen
2021-08-06 14:16 ` ASSI
2021-08-06 14:27 ` Corinna Vinschen
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