linux-stable/drivers/tty
Peter Hurley ddc7b758a6 tty: Move tty->closing from port lock critical section
tty->closing informs the line discipline that the hardware will
be shutting down imminently, and to disable further input other
than soft flow control (but to still allow additional output).

However, the tty lock is the necessary lock for preventing
concurrent changes to tty->closing. As shown by the call-tree
audit [1] of functions that modify tty->closing, the tty lock
is already held for those functions.

[1]
Call-tree audit of functions that modify tty->closing
* does not include call tree to tty_port_close(), tty_port_close_start(),
  or tty_port_close_end() which is already documented in
  'tty: Document locking for tty_port_close{,start,end}' that shows
  callers to those 3 functions hold the tty lock

tty_release()
  tty->ops->close() --+
                      |
__tty_hangup()        |
  tty->ops->close() --+
                      |
        mp_close():drivers/staging/sb105x/sb_pci_mp.c
        dngc_tty_close():drivers/staging/dgnc/dgnc_tty.c
        dgap_tty_close():drivers/staging/dgap/dgap_tty.c
        dgrp_tty_close():drivers/staging/dgrp/dgrp_tty.c
        rp_close():drivers/tty/rocket.c
        hvsi_close():drivers/tty/hvc/hvsi.c
        rs_close():drivers/tty/serial/68328serial.c
        rs_close():drivers/tty/serial/crisv10.c
        uart_close():drivers/tty/serial/serial_core.c
        isdn_tty_close():drivers/isdn/i4l/isdn_tty.c
        tty3215_close():drivers/s390/char/con3215.c

tty_open()
  tty_ldisc_setup() ----+
                        |
__tty_hangup()          |
  tty_ldisc_hangup() ---+
                        |
tty_set_ldisc() --------+
  tty_ldisc_restore() --+
                        |
                        +- tty_ldisc_open()
                             ld->ops->open() --+
                                               |
                                               +- n_tty_open()

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 16:06:48 -07:00
..
hvc Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2014-06-11 16:50:01 -07:00
ipwireless tty: Fix low_latency BUG 2014-02-28 16:31:00 -08:00
serial tty: Move tty->closing from port lock critical section 2014-07-10 16:06:48 -07:00
vt Merge tag 'drm-intel-fixes-2014-06-17' of git://anongit.freedesktop.org/drm-intel into drm-next 2014-06-19 10:54:35 +10:00
amiserial.c
bfin_jtag_comm.c
cyclades.c
ehv_bytechan.c
goldfish.c goldfish: clean up the checkpatch warnings 2014-05-15 13:20:42 -07:00
isicom.c
Kconfig
Makefile
metag_da.c
moxa.c
moxa.h
mxser.c
mxser.h
n_gsm.c
n_hdlc.c drivers/tty/n_hdlc.c: replace kmalloc/memset by kzalloc 2014-05-28 13:33:18 -07:00
n_r3964.c
n_tracerouter.c
n_tracesink.c
n_tracesink.h
n_tty.c tty: Correct INPCK handling 2014-06-19 13:04:52 -07:00
nozomi.c
pty.c
rocket.c
rocket.h
rocket_int.h
synclink.c synclink: fix info leak in ioctl 2014-03-17 16:13:23 -07:00
synclink_gt.c
synclinkmp.c synclink: fix info leak in ioctl 2014-03-17 16:13:23 -07:00
sysrq.c sysrq,rcu: suppress RCU stall warnings while sysrq runs 2014-06-06 16:08:17 -07:00
tty_audit.c audit: anchor all pid references in the initial pid namespace 2014-03-20 10:11:55 -04:00
tty_buffer.c Staging: speakup: Update __speakup_paste_selection() tty (ab)usage to match vt 2014-05-24 02:25:11 +09:00
tty_io.c tty: fix memleak in alloc_pid 2014-04-16 14:31:13 -07:00
tty_ioctl.c
tty_ldisc.c
tty_ldsem.c
tty_mutex.c
tty_port.c tty: Move tty->closing from port lock critical section 2014-07-10 16:06:48 -07:00