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path: root/drivers/tty/tty_ioctl.c
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2021-04-15tty: move some tty-only functions to drivers/tty/tty.hGreg Kroah-Hartman
The flow change and restricted_tty_write() logic is internal to the tty core only, so move it out of the include/linux/tty.h file. Cc: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20210408125134.3016837-12-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10tty: fix return value for unsupported termiox ioctlsJohan Hovold
Drivers should return -ENOTTY ("Inappropriate I/O control operation") when an ioctl isn't supported, while -EINVAL is used for invalid arguments. Support for termiox was added by commit 1d65b4a088de ("tty: Add termiox") in 2008 but no driver support ever followed and it was recently ripped out by commit e0efb3168d34 ("tty: Remove dead termiox code"). Fix the return value for the unsupported termiox ioctls, which have always returned -EINVAL, by explicitly returning -ENOTTY rather than removing them completely and falling back to the default unrecognised- ioctl handling. Fixes: 1d65b4a088de ("tty: Add termiox") Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210407095208.31838-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10tty: cleanup tty_chars_in_bufferJiri Slaby
There is no need for 'else' when the 'if' part already returned. This makes tty_chars_in_buffer similar to tty_write_room too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210302062214.29627-42-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-04tty: Remove dead termiox codeJann Horn
set_termiox() and the TCGETX handler bail out with -EINVAL immediately if ->termiox is NULL, but there are no code paths that can set ->termiox to a non-NULL pointer; and no such code paths seem to have existed since the termiox mechanism was introduced back in commit 1d65b4a088de ("tty: Add termiox") in v2.6.28. Similarly, no driver actually implements .set_termiox; and it looks like no driver ever has. Delete this dead code; but leave the definition of struct termiox in the UAPI headers intact. Signed-off-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/r/20201203020331.2394754-1-jannh@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2018-09-14move compat handling of tty ioctls to tty_compat_ioctl()Al Viro
ioctls that are * callable only via tty_ioctl() * not driver-specific * not demand data structure conversions * either always need passing arg as is or always demand compat_ptr() get intercepted in tty_compat_ioctl() from the very beginning and redirecter to tty_ioctl(). As the result, their entries in fs/compat_ioctl.c (some of those had been missing, BTW) got removed, as well as n_tty_compat_ioctl_helper() (now it's never called with any cmd it would accept). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-22tty: add missing const to termios hw-change helperJohan Hovold
Add missing const qualifiers to the parameters of the termios hw-change helper, which is used by a few USB serial drivers. This specifically allows the pl2303 driver to use const arguments in one of its helper as well. Cc: Jiri Slaby <jslaby@suse.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org>
2017-11-08tty: add SPDX identifiers to all remaining files in drivers/tty/Greg Kroah-Hartman
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-18tty: move baudrate handling code to a file of its ownNicolas Pitre
To allow reuse without the rest of the tty_ioctl code. No logical changes from this patch. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-30tty: Replace TTY_THROTTLED bit tests with tty_throttled()Peter Hurley
Abstract TTY_THROTTLED bit tests with tty_throttled(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-28tty: Use termios c_*flag macrosPeter Hurley
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>
2015-12-13tty: Remove __func__ from tty_debug() macroPeter Hurley
Now that tty_debug() macro uses pr_debug(), the function name can be printed when using dynamic debug; printing the function name within the format string is redundant. Remove the __func__ parameter and print specifier from the format string. Add context to messages for when the function name is not printed by dynamic debug, or when dynamic debug is not enabled. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-13tty: core: Prefer pr_* to printk(*)Peter Hurley
Convert remaining printk() use to pr_*() when tty is unknown or unsafe to use. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-13tty: Remove unset_locked_termios() error messagePeter Hurley
With the refactor of 'locked' from parameter to local, it's now obvious locked cannot be NULL. Remove entire conditional. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-13tty: core: Refactor parameters for unset_locked_termios() helperPeter Hurley
Add tty as parameter to unset_locked_termios() and extract former parameters, termios and locked, as locals. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20tty: Fix tty_send_xchar() lock order inversionPeter Hurley
The correct lock order is atomic_write_lock => termios_rwsem, as established by tty_write() => n_tty_write(). Fixes: c274f6ef1c666 ("tty: Hold termios_rwsem for tcflow(TCIxxx)") Reported-and-Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> # v3.18+ Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-23tty: Replace inline #ifdef TTY_DEBUG_WAIT_UNTIL_SENTPeter Hurley
Add tty_debug_wait_until_sent() macro which uses tty_debug() to print the debug message; remove inlined #ifdef. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06tty: remove buf parameter from tty_name()Rasmus Villemoes
tty_name no longer uses the buf parameter, so remove it along with all the 64 byte stack buffers that used to be passed in. Mostly generated by the coccinelle script @depends on patch@ identifier buf; constant C; expression tty; @@ - char buf[C]; <+... - tty_name(tty, buf) + tty_name(tty) ...+> allmodconfig compiles, so I'm fairly confident the stack buffers weren't used for other purposes as well. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-28tty: Re-add external interface for tty_set_termios()Frederic Danis
This is needed by Bluetooth hci_uart module to be able to change speed of Bluetooth controller and local UART. Signed-off-by: Frederic Danis <frederic.danis@linux.intel.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Cc: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07TTY: fix tty_wait_until_sent maximum timeoutJohan Hovold
Currently tty_wait_until_sent may take up to twice as long as the requested timeout while waiting for driver and hardware buffers to drain. Fix this by taking the remaining number of jiffies after waiting for driver buffers to drain into account so that the timeout actually becomes a maximum timeout as it is documented to be. Note that this specifically implies tighter timings when closing a port as a consequence of actually honouring the port closing-wait setting for drivers relying on tty_wait_until_sent_from_close (e.g. via tty_port_close_start). Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07TTY: fix tty_wait_until_sent on 64-bit machinesJohan Hovold
Fix overflow bug in tty_wait_until_sent on 64-bit machines, where an infinite timeout (0) would be passed to the underlying tty-driver's wait_until_sent-operation as a negative timeout (-1), causing it to return immediately. This manifests itself for example as tcdrain() returning immediately, drivers not honouring the drain flags when setting terminal attributes, or even dropped data on close as a requested infinite closing-wait timeout would be ignored. The first symptom was reported by Asier LLANO who noted that tcdrain() returned prematurely when using the ftdi_sio usb-serial driver. Fix this by passing 0 rather than MAX_SCHEDULE_TIMEOUT (LONG_MAX) to the underlying tty driver. Note that the serial-core wait_until_sent-implementation is not affected by this bug due to a lucky chance (comparison to an unsigned maximum timeout), and neither is the cyclades one that had an explicit check for negative timeouts, but all other tty drivers appear to be affected. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable <stable@vger.kernel.org> # v2.6.12 Reported-by: ZIV-Asier Llano Palacios <asier.llano@cgglobal.com> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02tty: Remove external interface for tty_set_termios()Peter Hurley
tty_set_termios() is an internal helper intended for file scope use. UART drivers which are capable of driving the RTS pin must properly handle the tiocmset() method, regardless of termios settings. A failure to do so is a UART driver bug and should be fixed there. Do not use this interface to workaround UART driver bugs. Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: <linux-bluetooth@vger.kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05tty: Call methods in modern stylePeter Hurley
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 <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05tty: Move pty-specific set_termios() handling to pty driverPeter Hurley
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 <peter@hurleysoftware.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05tty: WARN for attempted set_termios() of pty masterPeter Hurley
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 <peter@hurleysoftware.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23tty: Hold termios_rwsem for tcflow(TCIxxx)Peter Hurley
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 <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23tty: Move and rename send_prio_char() as tty_send_xchar()Peter Hurley
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 <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23tty: Serialize tcflow() with other tty flow control changesPeter Hurley
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 <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-08tty: fix typo in comment of tty_termios_encode_baud_rateMatthias Brugger
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-25tty: Fix SIGTTOU not sent with tcflush()Peter Hurley
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 <oleg@redhat.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-23tty: Only guarantee termios read safety for throttle/unthrottlePeter Hurley
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 <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-23tty: Convert termios_mutex to termios_rwsemPeter Hurley
termios is commonly accessed unsafely (especially by N_TTY) because the existing mutex forces exclusive access. Convert existing usage. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-15tty: Fix unsafe bit ops in tty_throttle_safe/unthrottle_safePeter Hurley
tty->flags needs to be atomically modified. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Fix recursive deadlock in tty_perform_flush()Peter Hurley
tty_perform_flush() can deadlock when called while holding a line discipline reference. By definition, all ldisc drivers hold a ldisc reference, so calls originating from ldisc drivers must not block for a ldisc reference. The deadlock can occur when: CPU 0 | CPU 1 | tty_ldisc_ref(tty) | .... | <line discipline halted> tty_ldisc_ref_wait(tty) | | CPU 0 cannot progess because it cannot obtain an ldisc reference with the line discipline has been halted (thus no new references are granted). CPU 1 cannot progress because an outstanding ldisc reference has not been released. An in-tree call-tree audit of tty_perform_flush() [1] shows 5 ldisc drivers calling tty_perform_flush() indirectly via n_tty_ioctl_helper() and 2 ldisc drivers calling directly. A single tty driver safely uses the function. [1] Recursive usage: /* These functions are line discipline ioctls and thus * recursive wrt line discipline references */ tty_perform_flush() - ./drivers/tty/tty_ioctl.c n_tty_ioctl_helper() hci_uart_tty_ioctl(default) - drivers/bluetooth/hci_ldisc.c (N_HCI) n_hdlc_tty_ioctl(default) - drivers/tty/n_hdlc.c (N_HDLC) gsmld_ioctl(default) - drivers/tty/n_gsm.c (N_GSM0710) n_tty_ioctl(default) - drivers/tty/n_tty.c (N_TTY) gigaset_tty_ioctl(default) - drivers/isdn/gigaset/ser-gigaset.c (N_GIGASET_M101) ppp_synctty_ioctl(TCFLSH) - drivers/net/ppp/pps_synctty.c ppp_asynctty_ioctl(TCFLSH) - drivers/net/ppp/ppp_async.c Non-recursive use: tty_perform_flush() - drivers/tty/tty_ioctl.c ipw_ioctl(TCFLSH) - drivers/tty/ipwireless/tty.c /* This function is a tty i/o ioctl method, which * is invoked by tty_ioctl() */ Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: do not warn about setting speed via SPD_*Jiri Slaby
The warning is there since 2.1.69 and we have not seen anybody reporting it in the past decade. Remove the warning now. tty_get_baud_rate can now be inline. This gives us one less EXPORT_SYMBOL. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Add safe tty throttle/unthrottle functionsPeter Hurley
The tty driver can become stuck throttled due to race conditions between throttle and unthrottle, when the decision to throttle or unthrottle is conditional. The following example helps to illustrate the race: CPU 0 | CPU 1 | if (condition A) | | <processing such that A not true> | if (!condition A) | unthrottle() throttle() | | Note the converse is also possible; ie., CPU 0 | CPU 1 | | if (!condition A) <processing such that A true> | if (condition A) | throttle() | | unthrottle() | Add new throttle/unthrottle functions based on the familiar model of task state and schedule/wake. For example, while (1) { tty_set_flow_change(tty, TTY_THROTTLE_SAFE); if (!condition) break; if (!tty_throttle_safe(tty)) break; } __tty_set_flow_change(tty, 0); In this example, if an unthrottle occurs after the condition is evaluated but before tty_throttle_safe(), then tty_throttle_safe() will return non-zero, looping and forcing the re-evaluation of condition. Reported-by: Vincent Pillet <vincentx.pillet@intel.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-04tty: set_termios/set_termiox should not return -EINTROleg Nesterov
See https://bugzilla.redhat.com/show_bug.cgi?id=904907 read command causes bash to abort with double free or corruption (out). A simple test-case from Roman: // Compile the reproducer and send sigchld ti that process. // EINTR occurs even if SA_RESTART flag is set. void handler(int sig) { } main() { struct sigaction act; act.sa_handler = handler; act.sa_flags = SA_RESTART; sigaction (SIGCHLD, &act, 0); struct termio ttp; ioctl(0, TCGETA, &ttp); while(1) { if (ioctl(0, TCSETAW, ttp) < 0) { if (errno == EINTR) { fprintf(stderr, "BUG!"); return(1); } } } } Change set_termios/set_termiox to return -ERESTARTSYS to fix this particular problem. I didn't dare to change other EINTR's in drivers/tty/, but they look equally wrong. Reported-by: Roman Rakus <rrakus@redhat.com> Reported-by: Lingzhu Xiang <lxiang@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-18tty: Add driver unthrottle in ioctl(...,TCFLSH,..).Ilya Zykov
Regression 'tty: fix "IRQ45: nobody cared"' Regression commit 7b292b4bf9a9d6098440d85616d6ca4c608b8304 Function reset_buffer_flags() also invoked during the ioctl(...,TCFLSH,..). At the time of request we can have full buffers and throttled driver too. If we don't unthrottle driver, we can get forever throttled driver, because, after request, we will have empty buffers and throttled driver and there is no place to unthrottle driver. It simple reproduce with "pty" pair then one side sleep on tty->write_wait, and other side do ioctl(...,TCFLSH,..). Then there is no place to do writers wake up. Signed-off-by: Ilya Zykov <ilya@ilyx.ru> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-25tty: pty - Move TIOCPKT handling into pty.cCyrill Gorcunov
Since this ioctl is for pty devices only move it to pty.c. v2: - drop PTY_TYPE_MASTER test since it's master peer ioctl anyway (by jslaby@) Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Pavel Emelyanov <xemul@parallels.com> CC: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17tty: Fix up PPC fallout from the termios moveAlan Cox
This fixes up the problem Stephen Rothwell reported when trying to merge -next Signed-off-by: Alan Cox <alan@linux.intel.com> Reported-by: Stephen Rothwell <sfr@cab.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16tty: move the termios object into the ttyAlan Cox
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>
2012-03-28Remove all #inclusions of asm/system.hDavid Howells
Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
2011-10-18tty: Support compat_ioctl get/set termios_lockedThomas Meyer
When running a Fedora 15 (x86) on an x86_64 kernel, in the boot process plymouthd complains about those two missing ioctls: [ 2.581783] ioctl32(plymouthd:186): Unknown cmd fd(10) cmd(00005457){t:'T';sz:0} arg(ffb6a5d0) on /dev/tty1 [ 2.581803] ioctl32(plymouthd:186): Unknown cmd fd(10) cmd(00005456){t:'T';sz:0} arg(ffb6a680) on /dev/tty1 both ioctl functions work on the 'struct termios' resp. 'struct termios2', which has the same size (36 bytes resp. 44 bytes) on x86 and x86_64, so it's just a matter of converting the pointer from userland. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-23Merge branch 'tty-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6 * 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (48 commits) serial: 8250_pci: add support for Cronyx Omega PCI multiserial board. tty/serial: Fix break handling for PORT_TEGRA tty/serial: Add explicit PORT_TEGRA type n_tracerouter and n_tracesink ldisc additions. Intel PTI implementaiton of MIPI 1149.7. Kernel documentation for the PTI feature. export kernel call get_task_comm(). tty: Remove to support serial for S5P6442 pch_phub: Support new device ML7223 8250_pci: Add support for the Digi/IBM PCIe 2-port Adapter ASoC: Update cx20442 for TTY API change pch_uart: Support new device ML7223 IOH parport: Use request_muxed_region for IT87 probe and lock tty/serial: add support for Xilinx PS UART n_gsm: Use print_hex_dump_bytes drivers/tty/moxa.c: Put correct tty value TTY: tty_io, annotate locking functions TTY: serial_core, remove superfluous set_task_state TTY: serial_core, remove invalid test Char: moxa, fix locking in moxa_write ... Fix up trivial conflicts in drivers/bluetooth/hci_ldisc.c and drivers/tty/serial/Makefile. I did the hci_ldisc thing as an evil merge, cleaning things up.
2011-04-26Merge branch 'master' into for-nextJiri Kosina
Fast-forwarded to current state of Linus' tree as there are patches to be applied for files that didn't exist on the old branch.
2011-04-19tty: remove invalid location line in file headerJovi Zhang
remove invalid location line in each file header after location moved from driver/char to driver/tty Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-12tty: fix typo in descripton of tty_termios_encode_baud_rateUwe Kleine-König
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>