summaryrefslogtreecommitdiffstats
path: root/drivers/tty/tty_port.c
Commit message (Collapse)AuthorAgeFilesLines
* tty: Replace ASYNC_INITIALIZED bit and update atomicallyPeter Hurley2016-04-301-6/+7
| | | | | | | | | | | | | | Replace ASYNC_INITIALIZED bit in the tty_port::flags field with TTY_PORT_INITIALIZED bit in the tty_port::iflags field. Introduce helpers tty_port_set_initialized() and tty_port_initialized() to abstract atomic bit ops. Note: the transforms for test_and_set_bit() and test_and_clear_bit() are unnecessary as the state transitions are already mutually exclusive; the tty lock prevents concurrent open/close/hangup. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Replace ASYNC_NORMAL_ACTIVE bit and update atomicallyPeter Hurley2016-04-301-6/+6
| | | | | | | | | | | | | | Replace ASYNC_NORMAL_ACTIVE bit in the tty_port::flags field with TTY_PORT_ACTIVE bit in the tty_port::iflags field. Introduce helpers tty_port_set_active() and tty_port_active() to abstract atomic bit ops. Extract state changes from port lock sections, as this usage is broken and confused; the state transitions are protected by the tty lock (which mutually excludes parallel open/close/hangup), and no user tests the active state while holding the port lock. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Replace TTY_IO_ERROR bit tests with tty_io_error()Peter Hurley2016-04-301-1/+1
| | | | | | | | | Abstract TTY_IO_ERROR status test treewide with tty_io_error(). NB: tty->flags uses atomic bit ops; replace non-atomic bit test with test_bit(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Remove ASYNC_CLOSINGPeter Hurley2016-01-281-2/+1
| | | | | | | | | | | | | | | | | | | The tty core no longer provides nor uses ASYNC_CLOSING; remove from tty_port_close_start() and tty_port_close_end() as well as tty drivers which open-code these state changes. Unfortunately, even though the bit is masked from userspace, its inclusion in a uapi header precludes removing the macro. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: linux-cris-kernel@axis.com Cc: Samuel Ortiz <samuel@sortiz.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Use termios c_*flag macrosPeter Hurley2016-01-281-1/+1
| | | | | | | | | | | | Expressions of the form "tty->termios.c_*flag & FLAG" are more clearly expressed with the termios flags macros, I_FLAG(), C_FLAG(), O_FLAG(), and L_FLAG(). Convert treewide. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Allow unreadable mess to be > 80 charsPeter Hurley2016-01-281-4/+2
| | | | | Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Define tty_*() printk macrosPeter Hurley2015-12-131-5/+4
| | | | | | | | | | | | | Since not all ttys are devices (eg., SysV ptys), dev_*() printk macros cannot be used. Define tty_*() printk macros that output in similar format to dev_*() macros (ie., <driver> <tty>: .....). Transform the most-trivial printk( LEVEL ...) usage to tty_*() usage. NB: The function name has been eliminated from messages with unique context, or prefixed to the format when given. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Abstract tty buffer workPeter Hurley2015-10-171-1/+1
| | | | | | | | Introduce API functions to restart and cancel tty buffer work, rather than manipulate buffer work directly. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Remove tty_port::close_waitPeter Hurley2015-10-171-2/+0
| | | | | | | | | | | | With the removal of tty_wait_until_sent_from_close(), tty drivers no longer wait during open for parallel closes to complete (instead, the tty core waits before calling the driver open() method). Thus, the close_wait waitqueue is no longer used for waiting. Remove struct tty_port::close_wait. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Remove ASYNC_CLOSING checks in open()/hangup() methodsPeter Hurley2015-10-171-12/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Since at least before 2.6.30, tty drivers that do not drop the tty lock while closing cannot observe ASYNC_CLOSING set while holding the tty lock; this includes the tty driver's open() and hangup() methods, since the tty core calls these methods holding the tty lock. For these drivers, waiting for ASYNC_CLOSING to clear while opening is not required, since this condition cannot occur. Similarly, even when the open() method drops and reacquires the tty lock after blocking, ASYNC_CLOSING cannot be set (again, for drivers that do not drop the tty lock while closing). Now that tty port drivers no longer drop the tty lock while closing (since 'tty: Remove tty_wait_until_sent_from_close()'), the same conditions apply: waiting for ASYNC_CLOSING to clear while opening is not required, nor is re-checking ASYNC_CLOSING after dropping and reacquiring the tty lock while blocking (eg., in *_block_til_ready()). Note: The ASYNC_CLOSING flag state is still maintained since several bitrotting drivers use it for (dubious) other purposes. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Remove tty_wait_until_sent_from_close()Peter Hurley2015-10-171-9/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tty_wait_until_sent_from_close() drops the tty lock while waiting for the tty driver to finish sending previously accepted data (ie., data remaining in its write buffer and transmit fifo). tty_wait_until_sent_from_close() was added by commit a57a7bf3fc7e ("TTY: define tty_wait_until_sent_from_close") to prevent the entire tty subsystem from being unable to open new ttys while waiting for one tty to close while output drained. However, since commit 0911261d4cb6 ("tty: Don't take tty_mutex for tty count changes"), holding a tty lock while closing does not prevent other ttys from being opened/closed/hung up, but only prevents lifetime event changes for the tty under lock. Holding the tty lock while waiting for output to drain does prevent parallel non-blocking opens (O_NONBLOCK) from advancing or returning while the tty lock is held. However, all parallel opens _already_ block even if the tty lock is dropped while closing and the parallel open advances. Blocking in open has been in mainline since at least 2.6.29 (see tty_port_block_til_ready(); note the test for O_NONBLOCK is _after_ the wait while ASYNC_CLOSING). IOW, before this patch a non-blocking open will sleep anyway for the _entire_ duration of a parallel hardware shutdown, and when it wakes, the error return will cause a release of its tty, and it will restart with a fresh attempt to open. Similarly with a blocking open that is already waiting; when it's woken, the hardware shutdown has already completed to ASYNC_INITIALIZED is not set, which forces a release and restart as well. So, holding the tty lock across the _entire_ close (which is what this patch does), even while waiting for output to drain, is equivalent to the current outcome wrt parallel opens. Cc: Alan Cox <alan@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> CC: Arnd Bergmann <arnd@arndb.de> CC: Karsten Keil <isdn@linux-pingi.de> CC: linuxppc-dev@lists.ozlabs.org Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Deletion of unnecessary checks before two function callsMarkus Elfring2014-11-261-2/+1
| | | | | | | | | | | The functions put_device() and tty_kref_put() test whether their argument is NULL and then return immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Flush tty buffers after hardware shutdownPeter Hurley2014-11-061-0/+1
| | | | | | | | | | | | The line discipline buffer and the tty buffers must be flushed again after hardware shutdown; otherwise, a brief window exists between the ldisc flush in tty_port_close_start() and the subsequent tty_port_shutdown(), during which more data could be received into the tty buffers. A racing open might then be able to receive data from the previous session. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Move tty hung up check from port->lock critical sectionPeter Hurley2014-11-061-4/+2
| | | | | | | | | The port->lock does not protect the filp->f_op field; move the tty_hung_up_p() test outside the port->lock critical section in tty_port_close_start(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Remove tty_hung_up_p() tests from tty drivers' open()Peter Hurley2014-07-101-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since at least before 2.6.30, it has not been possible to observe a hung up file pointer in a tty driver's open() method unless/until the driver open() releases the tty_lock() (eg., before blocking). This is because tty_open() adds the file pointer while holding the tty_lock() _and_ doesn't release the lock until after calling the tty driver's open() method. [ Before tty_lock(), this was lock_kernel(). ] Since __tty_hangup() first waits on the tty_lock() before enumerating and hanging up the open file pointers, either __tty_hangup() will wait for the tty_lock() or tty_open() will not yet have added the file pointer. For example, CPU 0 | CPU 1 | tty_open | __tty_hangup .. | .. tty_lock | .. tty_reopen | tty_lock / blocks .. | tty_add_file(tty, filp) | .. | tty->ops->open(tty, filp) | tty_port_open | tty_port_block_til_ready | .. | while (1) | .. | tty_unlock | / unblocks schedule | for each filp on tty->tty_files | f_ops = tty_hung_up_fops; | .. | tty_unlock tty_lock | .. | tty_unlock | Note that since tty_port_block_til_ready() and similar drop the tty_lock while blocking, when woken, the file pointer must then be tested for having been hung up. Also, fix bit-rotted drivers that used extra_count to track the port->count bump. CC: Mikael Starvik <starvik@axis.com> CC: Samuel Ortiz <samuel@sortiz.org> CC: "David S. Miller" <davem@davemloft.net> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Move tty->closing from port lock critical sectionPeter Hurley2014-07-101-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* tty: Document locking for tty_port_hangup()Peter Hurley2014-07-101-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tty lock is held when the tty driver's hangup() method is called (from the lone call-site, __tty_hangup()). The call-tree audit [1] of tty_port_hangup() is a closed graph of the callers of tty_port_hangup(); ie., all callers originate only from __tty_hangup(). Of these callers, none drop the tty lock prior to calling tty_port_hangup(). [1] Call-tree audit of tty_port_hangup() __tty_hangup() tty->ops->hangup() --+ | rs_hangup():arch/ia64/hp/sim/simserial.c line_hangup():arch/um/drivers/line.c gdm_tty_hangup():drivers/staging/gdm724x/gdm_tty.c fwtty_hangup():drivers/staging/fwserial/fwserial.c acm_tty_hangup():drivers/usb/class/cdc-acm.c serial_hangup():drivers/usb/serial/usb-serial.c ipoctal_hangup():drivers/ipack/devices/ipoctal.c cy_hangup():drivers/tty/cyclades.c isicom_hangup():drivers/tty/isicom.c rp_hangup():drivers/tty/rocket.c dashtty_hangup():drivers/tty/metag_da.c moxa_hangup():drivers/tty/moxa.c gsmtty_hangup():drivers/tty/n_gsm.c goldfish_tty_hangup():drivers/tty/goldfish.c ehv_bc_tty_hangup():drivers/tty/ehv_bytechan.c mxser_hangup():drivers/tty/mxser.c kgdb_nmi_tty_hangup():drivers/tty/serial/kgdb_nmi.c ifx_spi_hangup():drivers/tty/serial/ifx6x60.c ntty_hangup():drivers/tty/nozomi.c capinc_tty_hangup():drivers/isdn/capi/capi.c mgslpc_hangup():drivers/char/pcmcia/synclink_cs.c sdio_uart_hangup():drivers/mmc/card/sdio_uart.c rfcomm_tty_hangup():net/bluetooth/rfcomm/tty.c | +- tty_port_hangup() Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Document locking for tty_port_block_til_ready()Peter Hurley2014-07-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tty lock is held when the tty driver's open() method is called (from tty_open()). The call-tree audit [1] of tty_port_block_til_ready() is a closed graph of the callers of tty_port_block_til_ready(); ie., all callers originate only from tty_open(). Of these callers, none drop the tty lock. Also, document tty_port_block_til_ready() may drop and reacquire the tty lock when blocking, which means the tty or tty_port may have changed state. [1] Call-tree audit of tty_port_block_til_ready() * does not include call tree of tty_port_open() which is already documented in 'tty: Document locking from tty_port_open()' tty_open() tty->ops->open() --+ | cy_open():drivers/tty/cyclades.c rp_open():drivers/tty/rocket.c rs_open():drivers/tty/amiserial.c moxa_open():drivers/tty/moxa.c gsmtty_open():drivers/tty/n_gsm.c rs_open():drivers/tty/serial/68328serial.c uart_open():drivers/tty/serial/serial_core.c isdn_tty_open():drivers/isdn/i4l/isdn_tty.c mgslpc_open():drivers/char/pcmcia/synclink_cs.c | +- tty_port_block_til_ready() Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Document locking for tty_port_open()Peter Hurley2014-07-101-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tty lock is held when the tty driver's open method is called (from the lone call-site, tty_open()). The call-tree audit [1] of tty_port_open() is a closed graph of the callers of tty_port_open(); ie., all callers originate from only tty_open(). Of these callers, none drop the tty lock. Also, document that tty_port_block_til_ready() may drop and reacquire the tty lock when blocking, which means the tty or tty_port may have changed state. [1] Call-tree audit of tty_port_open() tty_open() tty->ops->open() --+ | rs_open():arch/ia64/hp/sim/simserial.c *line_open():arch/um/drivers/line.c gdm_tty_open():drivers/staging/gdm724x/gdm_tty.c fwtty_open():drivers/staging/fwserial/fwserial.c acm_tty_open():drivers/usb/class/cdc-acm.c serial_open():drivers/usb/serial/usb-serial.c pti_tty_driver_open():drivers/misc/pti.c ipoctal_open():drivers/ipack/devices/ipoctal.c isicom_open():drivers/tty/isicom.c dashtty_open():drivers/tty/metag_da.c goldfish_tty_open():drivers/tty/goldfish.c ehv_bc_tty_open():drivers/tty/ehv_bytechan.c mxser_open():drivers/tty/mxser.c kgdb_nmi_tty_open():drivers/tty/serial/kgdb_nmi.c ifx_spi_open():drivers/tty/serial/ifx6x60.c smd_tty_open():drivers/tty/serial/msm_smd_tty.c ntty_open():drivers/tty/nozomi.c capinc_tty_open():drivers/isdn/capi/capi.c tpk_open():drivers/char/ttyprintk.c sdio_uart_open():drivers/mmc/card/sdio_uart.c rfcomm_tty_open():net/bluetooth/rfcomm/tty.c | +- tty_port_open() * line_open() is the .open method for 2 um drivers declared in ./arch/um/drivers/stdio_console.c and in ./arch/um/drivers/ssl.c, and not called directly Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Document locking for tty_port_close{,start,end}()Peter Hurley2014-07-101-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tty lock is held when the tty driver's .close method is called (from the two lone call-sites of tty_release() and __tty_hangup()). The call-tree audit[1] of tty_port_close(), tty_port_close_start, and tty_port_close_end() is a closed graph of the callers of these 3 functions; ie., all callers originate from only tty_release() or __tty_hangup(). Of these callers, none drop the tty lock. Also, document tty_port_close_start() may drop and reacquire the tty lock in tty_wait_until_sent_from_close(), which means the tty or tty_port may have changed state (but not reopened or hung up). [1] Call-tree audit of tty_port_close, tty_port_close_start, and tty_port_close_end() tty_release() tty->ops->close() --+ | __tty_hangup() | tty->ops->close() --+ | +- rp_close():drivers/tty/rocket.c -------------------+ +- uart_close():drivers/tty/serial/serial_core.c -----+ | +- tty_port_close_start() | | +- close():drivers/tty/synclinkmp.c ------------------+ +- rs_close():drivers/tty/amiserial.c ----------------+ +- gsmtty_close():drivers/tty/n_gsm.c ----------------+ +- mxser_close():drivers/tty/mxser.c -----------------+ +- close():drivers/tty/synclink_gt.c -----------------+ +- mgsl_close():drivers/tty/synclink.c ---------------+ +- isdn_tty_close():drivers/isdn/i4l/isdn_tty.c ------+ +- mgslpc_close():drivers/char/pcmcia/synclink_cs.c --+ +- ircomm_tty_close():net/irda/ircomm/ircomm_tty.c ---+ | | rs_close():arch/ia64/hp/sim/simserial.c | *line_close():arch/um/drivers/line.c | gdm_tty_close():drivers/staging/gdm724x/gdm_tty.c fwtty_close():drivers/staging/fwserial/fwserial.c acm_tty_close():drivers/usb/class/cdc-acm.c serial_close():drivers/usb/serial/usb-serial.c pti_tty_driver_close():drivers/misc/pti.c ipoctal_close():drivers/ipack/devices/ipoctal.c cy_close():drivers/tty/cyclades.c isicom_close():drivers/tty/isicom.c dashtty_close():drivers/tty/metag_da.c moxa_close():drivers/tty/moxa.c goldfish_tty_close():drivers/tty/goldfish.c ehv_bc_tty_close():drivers/tty/ehv_bytechan.c kgdb_nmi_tty_close():drivers/tty/serial/kgdb_nmi.c ifx_spi_close():drivers/tty/serial/ifx6x60.c smd_tty_close():drivers/tty/serial/msm_smd_tty.c ntty_close():drivers/tty/nozomi.c capinc_tty_close():drivers/isdn/capi/capi.c tpk_close():drivers/char/ttyprintk.c sdio_uart_close():drivers/mmc/card/sdio_uart.c | rfcomm_tty_close():net/bluetooth/rfcomm/tty.c | | | +- tty_port_close():drivers/tty/tty_port.c -----------+ | +- tty_port_close_start() +- tty_port_close_end() * line_close() is the .close method for 2 um drivers, declared in ./arch/um/drivers/stdio_console.c and in ./arch/um/drivers/ssl.c, and not called directly Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: delete non-required instances of include <linux/init.h>Paul Gortmaker2014-01-071-1/+0
| | | | | | | | | | None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Remove unused drop() method from tty_port interfacePeter Hurley2013-09-251-5/+1
| | | | | | | | Although originally conceived as a hook for port drivers to know when a port reference is dropped, no driver uses this method. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Prevent tty_port destruction if tty not releasedPeter Hurley2013-09-251-0/+4
| | | | | | | | | | | | If the tty driver mistakenly drops the last port reference before the tty has been released, issue a diagnostic and abort the port destruction. This will leak memory and may zombify the port, but might otherwise keep the machine in runnable state. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty_port: Fix refcounting leak in tty_port_tty_hangup()Gianluca Anzolin2013-07-261-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | The function tty_port_tty_hangup() could leak a reference to the tty_struct: struct tty_struct *tty = tty_port_tty_get(port); if (tty && (!check_clocal || !C_CLOCAL(tty))) { tty_hangup(tty); tty_kref_put(tty); } If tty != NULL and the second condition is false we never call tty_kref_put and the reference is leaked. Fix by always calling tty_kref_put() which accepts a NULL argument. The patch fixes a regression introduced by commit aa27a094. Acked-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it> Acked-by: Jiri Slaby <jslaby@suse.cz> Cc: stable <stable@vger.kernel.org> # 3.10 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Complete ownership transfer of flip buffersPeter Hurley2013-03-181-0/+1
| | | | | | | | | | | | | | | | | Waiting for buffer work to complete is not required for safely performing changes to the line discipline, once the line discipline is halted. The buffer work routine, flush_to_ldisc(), will be unable to acquire an ldisc ref and all existing references were waited until released (so it can't already have one). Ensure running buffer work which may reference the soon-to-be-gone tty completes and any buffer work running after this point retrieves a NULL tty. Also, ensure all buffer work is cancelled on port destruction. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: fix close of uninitialised portsJohan Hovold2013-03-181-8/+10
| | | | | | | | | | | | | | | | Make sure we do not make tty-driver callbacks or wait for port to drain on uninitialised ports (e.g. when open failed) in tty_port_close_start(). No callback, such as flush_buffer or wait_until_sent, needs to be made on a port that has never been opened. Neither does it make much sense to add drain delay for an uninitialised port. Currently a drain delay of up to two seconds could be added when a tty fails to open. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: clean up port drain-delay handlingJohan Hovold2013-03-181-11/+16
| | | | | | | Move port drain-delay handling to a separate function. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: fix DTR not being dropped on hang upJohan Hovold2013-03-181-12/+15
| | | | | | | | | | | | | | | | | | | | Move HUPCL handling to port shutdown so that DTR is dropped also on hang up (tty_port_close is a noop for hung-up ports). Also do not try to drop DTR for uninitialised ports where it has never been raised (e.g. after a failed open). Note that this is also the current behaviour of serial-core. Nine drivers currently call tty_port_close_start directly (rather than through tty_port_close) and seven of them lower DTR as part of their close (if the port has been initialised). Fixup the remaining two drivers so that it continues to be lowered also on normal (non-HUP) close. [ Note that most of those other seven drivers did not expect DTR to have been dropped by tty_port_close_start in the first place. ] Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: fix DTR being raised on hang upJohan Hovold2013-03-181-1/+1
| | | | | | | | | | | Make sure to check ASYNC_INITIALISED before raising DTR when waking up from blocked open in tty_port_block_til_ready. Currently DTR could get raised at hang up as a blocked process would raise DTR unconditionally before checking for hang up and returning. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: wake up processes last at hangupJohan Hovold2013-03-181-1/+1
| | | | | | | | | | | | | Move wake up of processes on blocked-open and modem-status wait queues to after port shutdown at hangup. This way the woken up processes can use the ASYNC_INITIALIZED flag to detect port shutdown. Note that this is the order currently used by serial-core. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: clean up port shutdownJohan Hovold2013-03-181-2/+7
| | | | | | | | Untangle port-shutdown logic and make sure the initialised flag is always cleared for non-console ports. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: add tty_port_tty_hangup helperJiri Slaby2013-03-181-0/+17
| | | | | | | | | | It allows for cleaning up on a considerable amount of places. They did port_get, hangup, kref_put. Now the only thing needed is to call tty_port_tty_hangup which does exactly that. And they can also decide whether to consider CLOCAL or completely ignore that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: add tty_port_tty_wakeup helperJiri Slaby2013-03-181-0/+16
| | | | | | | | | | | | It allows for cleaning up on a considerable amount of places. They did port_get, wakeup, kref_put. Now the only thing needed is to call tty_port_tty_wakeup which does exactly that. One exception is ifx6x60 where tty_wakeup was open-coded. We now call tty_wakeup properly there. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: introduce tty_port_destroyJiri Slaby2012-11-151-1/+15
| | | | | | | | | | | | | | After commit "TTY: move tty buffers to tty_port", the tty buffers are not freed in some drivers. This is because tty_port_destructor is not called whenever a tty_port is freed. This was an assumption I counted with but was unfortunately untrue. Those using refcounting are safe now, but for those which do not we introduce a function to be called right before the tty_port is freed by the drivers. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: pty, fix tty buffers leakJiri Slaby2012-11-151-1/+1
| | | | | | | | | | | | | | | After commit "TTY: move tty buffers to tty_port", the tty buffers are not freed in some drivers. This is because tty_port_destructor is not called whenever a tty_port is freed. This was an assumption I counted with but was unfortunately untrue. So fix the drivers to fulfil this assumption. PTY is one of those, here we just need to use tty_port_put instead of kfree. (Assuming tty_port_destructor does not need port->ops to be set which we change here too.) Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: move tty buffers to tty_portJiri Slaby2012-10-221-0/+2
| | | | | | | | | | | | | | | | | | | So this is it. The big step why we did all the work over the past kernel releases. Now everything is prepared, so nothing protects us from doing that big step. | | \ \ nnnn/^l | | | | \ / / | | | '-,.__ => \/ ,-` => | '-,.__ | O __.´´) ( .` | O __.´´) ~~~ ~~ `` ~~~ ~~ The buffers are now in the tty_port structure and we can start teaching the buffer helpers (insert char/string, flip etc.) to use tty_port instead of tty_struct all around. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty_register_device_attr updated for tty-nextTomas Hlavacek2012-09-061-0/+24
| | | | | | | | | | Added tty_device_create_release() and bound to dev->release in tty_register_device_attr(). Added tty_port_register_device_attr() and used in uart_add_one_port() instead of tty_register_device_attr(). Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: add tty_port_link_deviceJiri Slaby2012-08-131-1/+21
| | | | | | | | | | | | | This is for those drivers which do not have dynamic device creation (do not call tty_port_register_device) and do not want to implement tty->ops->install (will not call tty_port_install). They still have to provide the link somehow though. And this newly added function is exactly to serve that purpose. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: tty_port, add some documentationJiri Slaby2012-08-131-0/+21
| | | | | | | | | I forgot to document tty_port_register_device and tty_port_install when they were added. Fix it now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: localise the lockAlan Cox2012-08-101-3/+3
| | | | | | | | | | | | | | | The termios and other changes mean the other protections needed on the driver tty arrays should be adequate. Turn it all back on. This contains pieces folded in from the fixes made to the original patches | From: Geert Uytterhoeven <geert@linux-m68k.org> (fix m68k) | From: Paul Gortmaker <paul.gortmaker@windriver.com> (fix cris) | From: Jiri Kosina <jkosina@suze.cz> (lockdep) | From: Eric Dumazet <eric.dumazet@gmail.com> (lockdep) Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: move the termios object into the ttyAlan Cox2012-07-161-3/+3
| | | | | | | | | | | | This will let us sort out a whole pile of tty related races. The alternative would be to keep points and refcount the termios objects. However 1. They are tiny anyway 2. Many devices don't use the stored copies 3. We can remove a pty special case Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: revert incorrectly applied lock patchAlan Cox2012-07-161-3/+3
| | | | | | | | | | I sent GregKH this after the pre-requisites. He dropped the pre-requesites for good reason and unfortunately then applied this patch. Without this reverted you get random kernel memory corruption which will make bisecting anything between it and the properly applied patches a complete sod. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: localise the lockAlan Cox2012-07-061-3/+3
| | | | | | | | | | | | | | | The termios and other changes mean the other protections needed on the driver tty arrays should be adequate. Turn it all back on. This contains pieces folded in from the fixes made to the original patches | From: Geert Uytterhoeven <geert@linux-m68k.org> (fix m68k) | From: Paul Gortmaker <paul.gortmaker@windriver.com> (fix cris) | From: Jiri Kosina <jkosina@suze.cz> (lockdep) | From: Eric Dumazet <eric.dumazet@gmail.com> (lockdep) Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: add tty_port_register_device helperJiri Slaby2012-06-131-0/+9
| | | | | | | | | This will automatically assign tty_port to tty_driver's port array for later recall in tty_init_dev. This is intended to be called instead of tty_register_device. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: provide drivers with tty_port_installJiri Slaby2012-06-131-0/+8
| | | | | | | | This will be used in tty_ops->install to set tty->port (and to call tty_standard_install). Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: Revert the tty locking series, it needs more workLinus Torvalds2012-06-021-3/+3
| | | | | | | | | | | | | | | | | | | | | | This reverts the tty layer change to use per-tty locking, because it's not correct yet, and fixing it will require some more deep surgery. The main revert is d29f3ef39be4 ("tty_lock: Localise the lock"), but there are several smaller commits that built upon it, they also get reverted here. The list of reverted commits is: fde86d310886 - tty: add lockdep annotations 8f6576ad476b - tty: fix ldisc lock inversion trace d3ca8b64b97e - pty: Fix lock inversion b1d679afd766 - tty: drop the pty lock during hangup abcefe5fc357 - tty/amiserial: Add missing argument for tty_unlock() fd11b42e3598 - cris: fix missing tty arg in wait_event_interruptible_tty call d29f3ef39be4 - tty_lock: Localise the lock The revert had a trivial conflict in the 68360serial.c staging driver that got removed in the meantime. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty_lock: Localise the lockAlan Cox2012-05-041-3/+3
| | | | | | | | | | | | In each remaining case the tty_lock is associated with a specific tty. This means we can now lock on a per tty basis. We do need tty_lock_pair() for the pty case. Uglier but still a step in the right direction. [fixed up calls in 3 missing drivers - gregkh] Signed-off-by: Alan Cox <alan@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: fix UV serial console regressionJiri Slaby2012-01-241-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 74c2107759d (serial: Use block_til_ready helper) and its fixup 3f582b8c110 (serial: fix termios settings in open) introduced a regression on UV systems. The serial eventually freezes while being used. It's completely unpredictable and sometimes needs a heap of traffic to happen first. To reproduce this, yast installation was used as it turned out to be pretty reliable in reproducing. Especially during installation process where one doesn't have an SSH daemon running. And no monitor as the HW is completely headless. So this was fun to find. Given the machine doesn't boot on vanilla before 2.6.36 final. (And the commits above are older.) Unless there is some bad race in the code, the hardware seems to be pretty broken. Otherwise pure MSR read should not cause such a bug, or? So to prevent the bug, revert to the old behavior. I.e. read modem status only if we really have to -- for non-CLOCAL set serials. Non-CLOCAL works on this hardware OK, I tried. See? I don't. And document that shit. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: stable <stable@vger.kernel.org> References: https://lkml.org/lkml/2011/12/6/573 References: https://bugzilla.novell.com/show_bug.cgi?id=718518 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: use tty_wait_until_sent_from_close in tty_port_close_startJiri Slaby2011-08-251-1/+1
| | | | | | | | | | | | | Let's use the newly added helper to avoid stalls in drivers which are already ported to tty_port helpers. We have to ensure here, that there is no user of tty_port_close_start and tty_port_close which holds port->mutex (or other) lock over them. And sure, there is none. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: create drivers/tty and move the tty core files thereGreg Kroah-Hartman2010-11-051-0/+446
The tty code should be in its own subdirectory and not in the char driver with all of the cruft that is currently there. Based on work done by Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
OpenPOWER on IntegriCloud