linux/drivers/tty
Dmitry Safonov 844fc57064 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>
History 2019-01-22 21:09:46 +01:00
..
hvc tty: hvc: hvc_write() fix break condition 2018-09-10 18:04:31 +02:00
ipwireless ipwireless: switch to ->[sg]et_serial() 2018-10-13 00:50:31 -04:00
serdev serdev: add dev_pm_domain_attach|detach() 2018-07-15 12:23:53 +02:00
serial serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly 2019-01-09 17:46:01 +01:00
vt TTY/Serial fixes for 4.20-rc2 2018-11-10 13:32:14 -06:00
amiserial.c kill TIOCSERGSTRUCT 2018-10-13 00:50:53 -04:00
cyclades.c cyclades: switch to ->[sg]et_serial() 2018-10-13 00:50:30 -04:00
ehv_bytechan.c tty: Convert to using %pOFn instead of device_node.name 2018-09-18 16:07:25 +02:00
goldfish.c headers: separate linux/mod_devicetable.h from linux/platform_device.h 2018-07-07 17:52:26 +02:00
isicom.c isicom: switch to ->[sg]et_serial() 2018-10-13 00:50:31 -04:00
Kconfig Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2018-04-09 09:04:10 -07:00
Makefile tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers 2018-03-26 15:57:24 +02:00
mips_ejtag_fdc.c tty: Remove redundant license text 2017-11-08 13:08:12 +01:00
moxa.c moxa: switch to ->[sg]et_serial() 2018-10-13 00:50:32 -04:00
moxa.h tty: moxa: Add support for CMSPAR 2017-11-28 15:32:33 +01:00
mxser.c mxser: switch to ->[sg]et_serial() 2018-10-13 00:50:32 -04:00
mxser.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
n_gsm.c change semantics of ldisc ->compat_ioctl() 2018-10-13 00:50:53 -04:00
n_hdlc.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
n_null.c tty: Remove redundant license text 2017-11-08 13:08:12 +01:00
n_r3964.c change semantics of ldisc ->compat_ioctl() 2018-10-13 00:50:53 -04:00
n_tracerouter.c tty: Remove redundant license text 2017-11-08 13:08:12 +01:00
n_tracesink.c tty: Remove redundant license text 2017-11-08 13:08:12 +01:00
n_tracesink.h tty: Remove redundant license text 2017-11-08 13:08:12 +01:00
n_tty.c tty: wipe buffer if not echoing data 2018-10-11 19:50:00 +02:00
nozomi.c tty/nozomi: fix inconsistent indentation 2018-04-25 14:54:26 +02:00
pty.c pty: fix compat ioctls 2018-10-13 00:50:51 -04:00
rocket.c tty: rocket: Fix possible buffer overwrite on register_PCI 2018-08-02 10:11:32 +02:00
rocket.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rocket_int.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
synclink.c synclink: reduce pointless checks in ->ioctl() 2018-10-13 00:50:43 -04:00
synclink_gt.c synclink_gt(): fix compat_ioctl() 2018-10-13 00:50:52 -04:00
synclinkmp.c synclink: reduce pointless checks in ->ioctl() 2018-10-13 00:50:43 -04:00
sysrq.c signal: send_sig_all no longer needs SEND_SIG_FORCED 2018-09-11 21:19:07 +02:00
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 2018-11-08 03:36:45 -08:00
tty_buffer.c tty: wipe buffer. 2018-10-11 19:50:00 +02:00
tty_io.c tty: Don't hold ldisc lock in tty_reopen() if ldisc present 2019-01-22 21:09:46 +01:00
tty_ioctl.c move compat handling of tty ioctls to tty_compat_ioctl() 2018-09-14 11:12:17 -04:00
tty_jobctrl.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
tty_ldisc.c proc: introduce proc_create_seq{,_data} 2018-05-16 07:23:35 +02:00
tty_ldsem.c tty/ldsem: Wake up readers after timed out down_write() 2019-01-22 21:09:45 +01:00
tty_mutex.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tty_port.c tty: do not set TTY_IO_ERROR flag if console port 2018-11-27 09:58:11 +01:00
vcc.c tty: vcc: Convert timers to use timer_setup() 2017-11-04 12:01:54 +01:00