linux-stable.git/drivers/tty/tty_ioctl.c, branch v3.19

tty: Call methods in modern style

2014-11-06T04:18:30+00:00

The use of older function ptr calling style, (*fn)(), makes static
analysis more error-prone; replace with modern fn() style.

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: Move pty-specific set_termios() handling to pty driver

2014-11-06T00:34:36+00:00

Packet mode is unique to the pty driver; move the packet mode state
change code from the generic tty ioctl handler to the pty driver.

Signed-off-by: Peter Hurley 
Reviewed-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

tty: WARN for attempted set_termios() of pty master

2014-11-06T00:34:36+00:00

The pty master's termios should never be set; currently, all code
paths which call the driver's set_termios() method ensure that the
pty slave's termios is being set.

Signed-off-by: Peter Hurley 
Reviewed-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

tty: Hold termios_rwsem for tcflow(TCIxxx)

2014-09-24T04:19:36+00:00

While transmitting a START/STOP char for tcflow(TCION/TCIOFF), prevent
a termios change. Otherwise, a garbage in-band flow control char
may be sent, if the termios change overlaps the transmission setup.

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: Move and rename send_prio_char() as tty_send_xchar()

2014-09-24T04:19:35+00:00

Relocate the file-scope function, send_prio_char(), as a global
helper tty_send_xchar(). Remove the global declarations for
tty_write_lock()/tty_write_unlock(), as these are file-scope only now.

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: Serialize tcflow() with other tty flow control changes

2014-09-24T04:19:35+00:00

Use newly-introduced tty->flow_lock to serialize updates to
tty->flow_stopped (via tcflow()) and with concurrent tty flow
control changes from other sources.

Merge the storage for ->stopped and ->flow_stopped, now that both
flags are serialized by ->flow_lock.

The padding bits are necessary to force the compiler to allocate the
type specified; otherwise, gcc will ignore the type specifier and
allocate the minimum number of bytes necessary to store the bitfield.
In turn, this would allow Alpha EV4 and EV5 cpus to corrupt adjacent
byte storage because those cpus use RMW to store byte and short data.

gcc versions < 4.7.2 will also corrupt storage adjacent to bitfields
smaller than unsigned long on ia64, ppc64, hppa64 and sparc64, thus
requiring more than unsigned int storage (which would otherwise be
sufficient to workaround the Alpha non-atomic byte/short storage problem).

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: fix typo in comment of tty_termios_encode_baud_rate

2014-09-08T22:32:05+00:00

Signed-off-by: Matthias Brugger 
Signed-off-by: Greg Kroah-Hartman

tty: Fix SIGTTOU not sent with tcflush()

2013-09-26T00:52:17+00:00

Commit 'e7f3880cd9b98c5bf9391ae7acdec82b75403776'
  tty: Fix recursive deadlock in tty_perform_flush()
introduced a regression where tcflush() does not generate
SIGTTOU for background process groups.

Make sure ioctl(TCFLSH) calls tty_check_change() when
invoked from the line discipline.

Cc: stable@vger.kernel.org # v3.10+
Reported-by: Oleg Nesterov 
Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: Only guarantee termios read safety for throttle/unthrottle

2013-07-23T23:43:02+00:00

No tty driver modifies termios during throttle() or unthrottle().
Therefore, only read safety is required.

However, tty_throttle_safe and tty_unthrottle_safe must still be
mutually exclusive; introduce throttle_mutex for that purpose.

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: Convert termios_mutex to termios_rwsem

2013-07-23T23:43:01+00:00

termios is commonly accessed unsafely (especially by N_TTY)
because the existing mutex forces exclusive access.
Convert existing usage.

Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman