Dmitry Safonov a13520e0d5 tty: Don't hold ldisc lock in tty_reopen() if ldisc present ...

commit d3736d82e8 upstream.

Try to get reference for ldisc during tty_reopen().
If ldisc present, we don't need to do tty_ldisc_reinit() and lock the
write side for line discipline semaphore.
Effectively, it optimizes fast-path for tty_reopen(), but more
importantly it won't interrupt ongoing IO on the tty as no ldisc change
is needed.
Fixes user-visible issue when tty_reopen() interrupted login process for
user with a long password, observed and reported by Lukas.

Fixes: c96cf923a9 ("tty: Don't block on IO when ldisc change is pending")
Fixes: 83d817f410 ("tty: Hold tty_ldisc_lock() during tty_reopen()")
Cc: Jiri Slaby <jslaby@suse.com>
Reported-by: Lukas F. Hartmann <lukas@mntmn.com>
Tested-by: Lukas F. Hartmann <lukas@mntmn.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2019-01-22 21:40:28 +01:00

..

hvc

tty: hvc: hvc_write() fix break condition

2018-09-10 18:04:31 +02:00

ipwireless

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serdev

serdev: add dev_pm_domain_attach|detach()

2018-07-15 12:23:53 +02:00

serial

serial/sunsu: fix refcount leak

2019-01-13 09:51:03 +01:00

vt

vt: fix broken display when running aptitude

2018-11-13 11:09:00 -08:00

amiserial.c

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cyclades.c

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ehv_bytechan.c

treewide: kzalloc() -> kcalloc()

2018-06-12 16:19:22 -07:00

goldfish.c

headers: separate linux/mod_devicetable.h from linux/platform_device.h

2018-07-07 17:52:26 +02:00

isicom.c

treewide: kmalloc() -> kmalloc_array()

2018-06-12 16:19:22 -07:00

Kconfig

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Makefile

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mips_ejtag_fdc.c

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moxa.c

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moxa.h

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mxser.c

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mxser.h

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n_gsm.c

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n_hdlc.c

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n_null.c

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n_r3964.c

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n_tracerouter.c

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n_tracesink.c

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n_tracesink.h

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n_tty.c

tty: wipe buffer if not echoing data

2018-12-01 09:37:34 +01:00

nozomi.c

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pty.c

pty: fix O_CLOEXEC for TIOCGPTPEER

2018-07-21 09:08:47 +02:00

rocket_int.h

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rocket.c

tty: rocket: Fix possible buffer overwrite on register_PCI

2018-08-02 10:11:32 +02:00

rocket.h

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synclink_gt.c

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synclink.c

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synclinkmp.c

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sysrq.c

signal: Pass pid type into do_send_sig_info

2018-07-21 12:57:35 -05:00

tty_audit.c

audit: eliminate audit_enabled magic number comparison

2018-06-19 10:43:55 -04:00

tty_baudrate.c

termios, tty/tty_baudrate.c: fix buffer overrun

2018-11-21 09:19:20 +01:00

tty_buffer.c

tty: wipe buffer.

2018-12-01 09:37:34 +01:00

tty_io.c

tty: Don't hold ldisc lock in tty_reopen() if ldisc present

2019-01-22 21:40:28 +01:00

tty_ioctl.c

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tty_jobctrl.c

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tty_ldisc.c

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tty_ldsem.c

tty/ldsem: Wake up readers after timed out down_write()

2019-01-22 21:40:28 +01:00

tty_mutex.c

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tty_port.c

tty: do not set TTY_IO_ERROR flag if console port

2018-12-13 09:16:22 +01:00

vcc.c

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