linux-kernel - [BUG? -next] login prompt of tty2~6 displayed slowly

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-next>] [day] [month] [year] [list]

Message-ID: <4AB31B87.2040007@np.css.fujitsu.com>
Date:	Fri, 18 Sep 2009 14:32:55 +0900
From:	Jin Dongming <jin.dongming@...css.fujitsu.com>
To:	LKLM <linux-kernel@...r.kernel.org>
Cc:	Alan Cox <alan@...ux.intel.com>,
	Greg Kroah-Hartman <gregkh@...e.de>,
	Kenji Kaneshige <kaneshige.kenji@...fujitsu.com>,
	Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>
Subject: [BUG? -next] login prompt of tty2~6 displayed slowly

Hi, all

I have a trouble on tty of -next.
After the system booted and login prompt of tty1 was displayed, I tried to
change tty1 to tty2 or other console with Ctrl+Alt+FN(N:2~6). The changed screen
was black and there was not login prompt. After a few(2~3) minutes the prompt
was displayed. I checked the message of klog and there were some errors of tty
listed as following:

Sep 15 10:02:44 iridium /sbin/mingetty[3062]: tty2: cannot open tty: Input/output error
Sep 15 10:02:44 iridium /sbin/mingetty[3063]: tty3: cannot open tty: Input/output error
Sep 15 10:02:44 iridium /sbin/mingetty[3060]: tty4: cannot open tty: Input/output error
Sep 15 10:02:44 iridium /sbin/mingetty[3061]: tty5: cannot open tty: Input/output error
Sep 15 10:02:44 iridium /sbin/mingetty[3066]: tty6: cannot open tty: Input/output error
Sep 15 10:02:49 iridium init: tty2 main process (3062) terminated with status 1
Sep 15 10:02:49 iridium init: tty2 main process ended, respawning
Sep 15 10:02:49 iridium init: tty3 main process (3063) terminated with status 1
Sep 15 10:02:49 iridium init: tty3 main process ended, respawning
Sep 15 10:02:49 iridium /sbin/mingetty[3107]: tty3: cannot open tty: Input/output error
Sep 15 10:02:49 iridium init: tty4 main process (3060) terminated with status 1
Sep 15 10:02:49 iridium init: tty4 main process ended, respawning
Sep 15 10:02:49 iridium /sbin/mingetty[3106]: tty2: cannot open tty: Input/output error
Sep 15 10:02:49 iridium /sbin/mingetty[3108]: tty4: cannot open tty: Input/output error
Sep 15 10:02:49 iridium init: tty5 main process (3061) terminated with status 1
Sep 15 10:02:49 iridium init: tty5 main process ended, respawning
Sep 15 10:02:49 iridium /sbin/mingetty[3109]: tty5: cannot open tty: Input/output error
Sep 15 10:02:49 iridium init: tty6 main process (3066) terminated with status 1
Sep 15 10:02:49 iridium init: tty6 main process ended, respawning
Sep 15 10:02:49 iridium /sbin/mingetty[3110]: tty6: cannot open tty: Input/output error


And I find out that the root cause of this problem is the following patch:
    commit 236cce0066f9c6a4856bc0404e541d3db3b0255e
    Titled "tty: make the kref destructor occur asynchronously"

When the tty is closed, the content of tty is not released immediately. And the
flag of tty is set with TTY_CLOSING. So when the tty is reopened, the tty may
not be released yet. Because the TTY_CLOSING in flag of tty is still valid. The
kernel returns "-EIO" error. And the message
    "/sbin/mingetty[3062]: tty2: cannot open tty: Input/output error"
is displayed at the user land.

Best Regards
Jin Dongming
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/