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path: root/drivers/char/tty_io.c
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* Merge branch 'for-next' into for-linusJiri Kosina2010-03-08
|\ | | | | | | | | | | | | | | | | Conflicts: Documentation/filesystems/proc.txt arch/arm/mach-u300/include/mach/debug-macro.S drivers/net/qlge/qlge_ethtool.c drivers/net/qlge/qlge_main.c drivers/net/typhoon.c
| * tree-wide: Assorted spelling fixesDaniel Mack2010-02-09
| | | | | | | | | | | | | | | | | | | | | | In particular, several occurances of funny versions of 'success', 'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address', 'beginning', 'desirable', 'separate' and 'necessary' are fixed. Signed-off-by: Daniel Mack <daniel@caiaq.de> Cc: Joe Perches <joe@perches.com> Cc: Junio C Hamano <gitster@pobox.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | Fix race in tty_fasync() properlyLinus Torvalds2010-02-07
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 703625118069 ("tty: fix race in tty_fasync") and commit b04da8bfdfbb ("fnctl: f_modown should call write_lock_irqsave/ restore") that tried to fix up some of the fallout but was incomplete. It turns out that we really cannot hold 'tty->ctrl_lock' over calling __f_setown, because not only did that cause problems with interrupt disables (which the second commit fixed), it also causes a potential ABBA deadlock due to lock ordering. Thanks to Tetsuo Handa for following up on the issue, and running lockdep to show the problem. It goes roughly like this: - f_getown gets filp->f_owner.lock for reading without interrupts disabled, so an interrupt that happens while that lock is held can cause a lockdep chain from f_owner.lock -> sighand->siglock. - at the same time, the tty->ctrl_lock -> f_owner.lock chain that commit 703625118069 introduced, together with the pre-existing sighand->siglock -> tty->ctrl_lock chain means that we have a lock dependency the other way too. So instead of extending tty->ctrl_lock over the whole __f_setown() call, we now just take a reference to the 'pid' structure while holding the lock, and then release it after having done the __f_setown. That still guarantees that 'struct pid' won't go away from under us, which is all we really ever needed. Reported-and-tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Américo Wang <xiyou.wangcong@gmail.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: fix race in tty_fasyncGreg Kroah-Hartman2010-01-20
| | | | | | | | | | | | | | | | | | | We need to keep the lock held over the call to __f_setown() to prevent a PID race. Thanks to Al Viro for pointing out the problem, and to Travis for making us look here in the first place. Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tavis Ormandy <taviso@google.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Julien Tinnes <jln@google.com> Cc: Matt Mackall <mpm@selenic.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Fix BKL taken under a spinlock bug introduced in the BKL splitAlan Cox2009-12-12
| | | | | | | | | | | | | | The fasync path takes the BKL (it probably doesn't need to in fact) while holding the file_list spinlock. You can't do that with the kernel lock: it causes lock inversions and deadlocks. Leave the BKL over that bit for the moment. Identified by AKPM. Signed-off-by: Alan Cox <alan@linux.intel.com> Acked-and-Tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: split the lock up a bit furtherAlan Cox2009-12-11
| | | | | | | | | | | The tty count sanity check may need the BKL, that isn't clear. However it is clear that the count use of the lock is internal and independant of the bigger use of the lock. Furthermore the file list locking is also separately locked already Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Move the leader test in disassociateAlan Cox2009-12-11
| | | | | | | | | There are two call points, both want to check that tty->signal->leader is set. Move the test into disassociate_ctty() as that will make locking changes easier in a bit Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Push the bkl down a bit in the hangup codeAlan Cox2009-12-11
| | | | | | | | We know that the redirect field is handled via its own locking in all places Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Push the lock down further into the ldisc codeAlan Cox2009-12-11
| | | | | Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: push the BKL down into the handlers a bitAlan Cox2009-12-11
| | | | | | | | | Start trying to untangle the remaining BKL mess Updated to fix missing unlock_kernel noted by Dan Carpenter Signed-off-by: Alan "I must be out of my tree" Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Fix regressions caused by commit b50989dcDave Young2009-09-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following commit made console open fails while booting: commit b50989dc444599c8b21edc23536fc305f4e9b7d5 Author: Alan Cox <alan@linux.intel.com> Date: Sat Sep 19 13:13:22 2009 -0700 tty: make the kref destructor occur asynchronously Due to tty release routines run in a workqueue now, error like the following will be reported while booting: INIT open /dev/console Input/output error It also causes hibernation regression to appear as reported at http://bugzilla.kernel.org/show_bug.cgi?id=14229 The reason is that now there's latency issue with closing, but when we open a "closing not finished" tty, -EIO will be returned. Fix it as per the following Alan's suggestion: Fun but it's actually not a bug and the fix is wrong in itself as the port may be closing but not yet being destructed, in which case it seems to do the wrong thing. Opening a tty that is closing (and could be closing for long periods) is supposed to return -EIO. I suspect a better way to deal with this and keep the old console timing is to split tty->shutdown into two functions. tty->shutdown() - called synchronously just before we dump the tty onto the waitqueue for destruction tty->cleanup() - called when the destructor runs. We would then do the shutdown part which can occur in IRQ context fine, before queueing the rest of the release (from tty->magic = 0 ... the end) to occur asynchronously The USB update in -next would then need a call like if (tty->cleanup) tty->cleanup(tty); at the top of the async function and the USB shutdown to be split between shutdown and cleanup as the USB resource cleanup and final tidy cannot occur synchronously as it needs to sleep. In other words the logic becomes final kref put make object unfindable async clean it up Signed-off-by: Dave Young <hidave.darkstar@gmail.com> [ rjw: Rebased on top of 2.6.31-git, reworked the changelog. ] Signed-off-by: "Rafael J. Wysocki" <rjw@sisk.pl> [ Changed serial naming to match new rules, dropped tty_shutdown as per comments from Alan Stern - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6Linus Torvalds2009-09-20
|\ | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: Driver-Core: extend devnode callbacks to provide permissions
| * Driver-Core: extend devnode callbacks to provide permissionsKay Sievers2009-09-19
| | | | | | | | | | | | | | | | | | | | | | | | | | This allows subsytems to provide devtmpfs with non-default permissions for the device node. Instead of the default mode of 0600, null, zero, random, urandom, full, tty, ptmx now have a mode of 0666, which allows non-privileged processes to access standard device nodes in case no other userspace process applies the expected permissions. This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | tty: USB serial termios bitsAlan Cox2009-09-19
| | | | | | | | | | | | | | | | | | Various drivers have hacks to mangle termios structures. This stems from the fact there is no nice setup hook for configuring the termios settings when the port is created Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | tty: make the kref destructor occur asynchronouslyAlan Cox2009-09-19
| | | | | | | | | | | | | | | | | | We want to be able to sleep in the destructor for USB at least. It isn't a hot path so just pushing it to a work queue doesn't really cause any difficulty. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | tty: Fix a typo noted in passingAlan Cox2009-09-19
|/ | | | | Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: fix sanity checkAlan Cox2009-06-16
| | | | | | | | | | | | | | | | The WARN_ON() that was added to tty_reopen can be triggered in the specific case of a hangup occurring during a re-open of a tty which is not in the middle of being otherwise closed. In that case however the WARN() is bogus as we don't hold the neccessary locks to make a correct decision. The case we should be checking is "if the ldisc is not changing and reopen is occuring". We could drop the WARN_ON but for the moment the debug is more valuable even if it means taking a mutex as it will find any other cases. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Move ldisc_flushAlan Cox2009-06-11
| | | | | | | We have a tty_ldisc file now so put tty_ldisc_flush in the right place Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: rewrite the ldisc lockingAlan Cox2009-06-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several pretty much unfixable races in the old ldisc code, especially with respect to pty behaviour and also to hangup. It's easier to rewrite the code than simply try and patch it up. This patch - splits the ldisc from the tty (so we will be able to refcount it more cleanly later) - introduces a mutex lock for ldisc changing on an active device - fixes the complete mess that hangup caused - implements hopefully correct setldisc/close/hangup locking There are still some problems around pty pairs that have always been there but at least it is now possible to understand the code and fix further problems. This fixes the following known bugs - hang up can leak ldisc references - hang up may not call open/close on ldisc in a matched way - pty/tty pairs can deadlock during an ldisc change - reading the ldisc proc files can cause every ldisc to be loaded and probably a few other of the mysterious ldisc race reports. I'm sure it also adds the odd new one. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Extract various bits of ldisc codeAlan Cox2009-06-11
| | | | | | | | Before trying to tackle the ldisc bugs the code needs to be a good deal more readable, so do the simple extractions of routines first. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Fix oops when scanning the polling list for kgdbAlan Cox2009-06-11
| | | | | | | | | | Costantino Leandro found a bug in tty_find_polling_driver and provided a patch that fixed the crash but not the underlying bug. This fixes the underlying bug where the list walk corrupts the values it is using on a match but then reuses them if the open fails. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pids: kill signal_struct-> __pgrp/__session and friendsOleg Nesterov2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are wasting 2 words in signal_struct without any reason to implement task_pgrp_nr() and task_session_nr(). task_session_nr() has no callers since 2e2ba22ea4fd4bb85f0fa37c521066db6775cbef, we can remove it. task_pgrp_nr() is still (I believe wrongly) used in fs/autofsX and fs/coda. This patch reimplements task_pgrp_nr() via task_pgrp_nr_ns(), and kills __pgrp/__session and the related helpers. The change in drivers/char/tty_io.c is cosmetic, but hopefully makes sense anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Alan Cox <number6@the-village.bc.nu> [tty parts] Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* __tty_open(): use the correct type for saved_flagsAndrew Morton2009-04-02
| | | | | | | | filp->f_flags is unsigned, so use that type for the local copy. Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* epoll keyed wakeups: make tty use keyed wakeupsDavide Libenzi2009-04-01
| | | | | | | | | | | | Introduce keyed event wakeups inside the TTY code. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: William Lee Irwin III <wli@movementarian.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Use f_lock to protect f_flagsJonathan Corbet2009-03-16
| | | | | | | | | | | | Traditionally, changes to struct file->f_flags have been done under BKL protection, or with no protection at all. This patch causes all f_flags changes after file open/creation time to be done under protection of f_lock. This allows the removal of some BKL usage and fixes a number of longstanding (if microscopic) races. Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* tty_open can return to userspace holding tty_mutexEric Paris2009-01-27
| | | | | | | | | | | | | | | __tty_open could return (to userspace) holding the tty_mutex thanks to a regression introduced by 4a2b5fddd53b80efcb3266ee36e23b8de28e761a ("Move tty lookup/reopen to caller"). This was found by bisecting an fsfuzzer problem. Admittedly I have no idea how it managed to tickle this 100% reliably, but it is clearly a regression and when hit leaves the box in a completely unusable state. This patch lets the fsfuzzer test complete every time. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pty: simplify resizeAlan Cox2009-01-02
| | | | | | | | We have special case logic for resizing pty/tty pairs. We also have a per driver resize method so for the pty case we should use it. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Fix sparse static warning for tty_driver_lookup_ttyJason Wessel2009-01-02
| | | | | | | | | Fixed sparse warning: drivers/char/tty_io.c:1216:19: warning: symbol 'tty_driver_lookup_tty' was not declared. Should it be static? Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* n_tty: Fix loss of echoed characters and remove bkl from n_ttyJoe Peterson2009-01-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes the loss of echoed (and other ldisc-generated characters) when the tty is stopped or when the driver output buffer is full (happens frequently for input during continuous program output, such as ^C) and removes the Big Kernel Lock from the N_TTY line discipline. Adds an "echo buffer" to the N_TTY line discipline that handles all ldisc-generated output (including echoed characters). Along with the loss of characters, this also fixes the associated loss of sync between tty output and the ldisc state when characters cannot be immediately written to the tty driver. The echo buffer stores (in addition to characters) state operations that need to be done at the time of character output (like management of the column position). This allows echo to cooperate correctly with program output, since the ldisc state remains consistent with actual characters written. Since the echo buffer code now isolates the tty column state code to the process_out* and process_echoes functions, we can remove the Big Kernel Lock (BKL) and replace it with mutex locks. Highlights are: * Handles echo (and other ldisc output) when tty driver buffer is full - continuous program output can block echo * Saves echo when tty is in stopped state (e.g. ^S) - (e.g.: ^Q will correctly cause held characters to be released for output) * Control character pairs (e.g. "^C") are treated atomically and not split up by interleaved program output * Line discipline state is kept consistent with characters sent to the tty driver * Remove the big kernel lock (BKL) from N_TTY line discipline Signed-off-by: Joe Peterson <joe@skyrush.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Audit: Log TIOCSTIAl Viro2008-12-09
| | | | | | | | | | | | | | | | | AUDIT_TTY records currently log all data read by processes marked for TTY input auditing, even if the data was "pushed back" using the TIOCSTI ioctl, not typed by the user. This patch records all TIOCSTI calls to disambiguate the input. It generates one audit message per character pushed back; considering TIOCSTI is used very rarely, this simple solution is probably good enough. (The only program I could find that uses TIOCSTI is mailx/nail in "header editing" mode, e.g. using the ~h escape. mailx is used very rarely, and the escapes are used even rarer.) Signed-Off-By: Miloslav Trmac <mitr@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: James Morris <jmorris@namei.org>
* drivers/char/tty_io.c: Avoid panic when no console is configured.Will Newton2008-12-01
| | | | | | | | | When no console is configured tty_open tries to call kref_get on a NULL pointer, return ENODEV instead. Signed-off-by: Will Newton <will.newton@gmail.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* device create: char: convert device_create_drvdata to device_createGreg Kroah-Hartman2008-10-16
| | | | | | | | Now that device_create() has been audited, rename things back to the original call to be sane. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: make sure that proc_clear_tty stores the cpu flagsArjan van de Ven2008-10-15
| | | | | | | | | | | | proc_clear_tty() gets called with interrupts off (while holding the task list lock) from sys_setid. This means that it needs the _irqsave version of the locking primitives. Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com> Tested-by: Marcin Slusarz <marcin.slusarz@gmail.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: tty_io.c shadows sparse fixJason Wessel2008-10-13
| | | | | | | | | drivers/char/tty_io.c:1413:17: warning: symbol 'buf' shadows an earlier one drivers/char/tty_io.c:1379:20: originally declared here Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: simplify ktermios allocationAlan Cox2008-10-13
| | | | | | | | | | Copy the simplification from the pty unix98 special case to the generic one. This allows us to kill off driver->termios_locked entirely which is nice. We have to whack bits of the cris driver as it meddles in places it shouldn't providing its own arrays that were never used anyway. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add an instance parameter devpts interfacesSukadev Bhattiprolu2008-10-13
| | | | | | | | | | | | | | | | | Pass-in 'inode' or 'tty' parameter to devpts interfaces. With multiple devpts instances, these parameters will be used in subsequent patches to identify the instance of devpts mounted. The parameters also help simplify devpts implementation. Changelog[v3]: - minor changes due to merge with ttydev updates - rename parameters to emphasize they are ptmx or pts inodes - pass-in tty_struct * to devpts_pty_kill() (this will help cleanup the get_node() call in a subsequent patch) Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Move tty lookup/reopen to callerSukadev Bhattiprolu2008-10-13
| | | | | | | | | | | | | | | Move tty_driver_lookup_tty() and tty_reopen() from tty_init_dev() into tty_open() (one of the two callers of tty_init_dev()). These calls are not really required in ptmx_open(), the other caller, since ptmx_open() would be setting up a new tty. Changelog[v2]: - remove the lookup and reopen calls from ptmx_open - merge with recent changes to ttydev tree Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: extract the pty init time special casesAlan Cox2008-10-13
| | | | | | | | The majority of the remaining init_dev code is pty special cases. We refactor this code into the driver->install method. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Finish fixing up the init_dev interface to use ERR_PTRAlan Cox2008-10-13
| | | | | | | Original suggestion and proposal from Sukadev Bhattiprolu. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: More driver operationsAlan Cox2008-10-13
| | | | | | | | | | We have the lookup operation abstracted which is nice for pty cleanup but we really want to abstract the add/remove entries as well so that we can pull the pty code out of the tty core and create a clear defined interface for the tty driver table. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: kref the tty driver objectAlan Cox2008-10-13
| | | | | Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Clean up the tty_init_dev changes furtherAlan Cox2008-10-13
| | | | | | | | Fix up the naming, style and extract some bits of code into the driver specific code Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Move parts of tty_init_dev into new functionsSukadev Bhattiprolu2008-10-13
| | | | | | | | | Move the 'find-tty' and 'fast-track-open' parts of init_dev() to separate functions. Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Remove more special casing and out of place codeAlan Cox2008-10-13
| | | | | | | | | Carry on pushing code out of tty_io when it belongs to other drivers. I'm not 100% happy with some of this and it will be worth revisiting some of the exports later when the restructuring work is done. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: shutdown methodAlan Cox2008-10-13
| | | | | | | | | | | | | | | | | | | Right now there are various drivers that try to use tty->count to know when they get the final close. Aristeau Rozanski showed while debugging the vt sysfs race that this isn't entirely safe. Instead of driver side tricks to work around this introduce a shutdown which is called when the tty is being destructed. This also means that the shutdown method is tied into the refcounting. Use this to rework the console close/sysfs logic. Remove lots of special case code from the tty core code. The pty code can now have a shutdown() method that replaces the special case hackery in the tree free up paths. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pty: If the administrator creates a device for a ptmx slave we should not errorAlan Cox2008-10-13
| | | | | | | | | The open path for ptmx slaves is via the ptmx device. Opening them any other way is not allowed. Vegard Nossum found that previously this was not the case and mknod foo c 128 42; cat foo would produce nasty diagnostics Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Redo current tty lockingAlan Cox2008-10-13
| | | | | | | | | Currently it is sometimes locked by the tty mutex and sometimes by the sighand lock. The latter is in fact correct and now we can hand back referenced objects we can fix this up without problems around sleeping functions. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: the vhangup syscall is racyAlan Cox2008-10-13
| | | | | | | | We now have the infrastructure to sort this out but rather than teaching the syscall tty lock rules we move the hard work into a tty helper Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Move tty_write_message out of kernel/printkAlan Cox2008-10-13
| | | | | | | | This is pure tty code so put it in the tty layer where it can be with the locking relevant material it uses Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Make get_current_tty use a krefAlan Cox2008-10-13
| | | | | | | | | | | | | We now return a kref covered tty reference. That ensures the tty structure doesn't go away when you have a return from get_current_tty. This is not enough to protect you from most of the resources being freed behind your back - yet. [Updated to include fixes for SELinux problems found by Andrew Morton and an s390 leak found while debugging the former] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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