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path: root/drivers/char/tty_io.c
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* TTY: create drivers/tty and move the tty core files thereGreg Kroah-Hartman2010-11-05
| | | | | | | | | | | | 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>
* tty: Make tiocgicount a handlerAlan Cox2010-10-22
| | | | | | | | | | | | | Dan Rosenberg noted that various drivers return the struct with uncleared fields. Instead of spending forever trying to stomp all the drivers that get it wrong (and every new driver) do the job in one place. This first patch adds the needed operations and hooks them up, including the needed USB midlayer and serial core plumbing. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty_io: check return code of tty_register_deviceVasiliy Kulikov2010-10-22
| | | | | | | | Function tty_register_device may return ERR_PTR(...). Check for it. Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Remove __GFP_NOFAIL from tty_add_file()Pekka Enberg2010-10-22
| | | | | | | | | | | | | This patch removes __GFP_NOFAIL use from tty_add_file() and adds proper error handling to the call-sites of the function. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Pekka Enberg <penberg@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: add tty_struct->dev pointer to corresponding device instanceDmitry Eremin-Solenikov2010-10-22
| | | | | | | | | | | | Some device drivers (mostly tty line disciplines) would like to have way know a struct device instance corresponding to passed tty_struct. Add a struct device pointer to struct tty_struct and populate it during initialize_tty_struct(). Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: fix tty_line must not be equal to number of allocated tty pointers in ↵Nathael Pajani2010-09-03
| | | | | | | | | | | | | | | | | | | | | | | | | | tty driver I found a bug "by chance" in drivers/char/tty_io.c I mean "by chance" because I was just reading the code of the tty_find_polling_driver() to make a new tty_find_by_name() function. In tty_find_polling_driver() the driver actually test "tty_line <= p->num" while num refers to the number of struct tty_struct pointers allocated for the p->ttys (p is a tty_driver), and tty_line is scanned in a tty name, which can be for example ttyS2. Then tty_line equals 2. And if p->num is 2, we have only p->ttys[0] and p->ttys[1], but no p->ttys[2]. This is actually unharmful, for tty_find_polling_driver() is used only in drivers/serial/kgdboc.c, and there's a test over there to find a console with a matching index, which will never happen. This is still a bug anyway. Signed-off-by: Nathael Pajani <nathael.pajani@ed3l.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: fix fu_list abuseNick Piggin2010-08-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tty: fix fu_list abuse tty code abuses fu_list, which causes a bug in remount,ro handling. If a tty device node is opened on a filesystem, then the last link to the inode removed, the filesystem will be allowed to be remounted readonly. This is because fs_may_remount_ro does not find the 0 link tty inode on the file sb list (because the tty code incorrectly removed it to use for its own purpose). This can result in a filesystem with errors after it is marked "clean". Taking idea from Christoph's initial patch, allocate a tty private struct at file->private_data and put our required list fields in there, linking file and tty. This makes tty nodes behave the same way as other device nodes and avoid meddling with the vfs, and avoids this bug. The error handling is not trivial in the tty code, so for this bugfix, I take the simple approach of using __GFP_NOFAIL and don't worry about memory errors. This is not a problem because our allocator doesn't fail small allocs as a rule anyway. So proper error handling is left as an exercise for tty hackers. [ Arguably filesystem's device inode would ideally be divorced from the driver's pseudo inode when it is opened, but in practice it's not clear whether that will ever be worth implementing. ] Cc: linux-kernel@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Nick Piggin <npiggin@kernel.dk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: cleanup files_lock lockingNick Piggin2010-08-18
| | | | | | | | | | | | | | | fs: cleanup files_lock locking Lock tty_files with a new spinlock, tty_files_lock; provide helpers to manipulate the per-sb files list; unexport the files_lock spinlock. Cc: linux-kernel@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Andi Kleen <ak@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Nick Piggin <npiggin@kernel.dk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* tty_io: remove casts from void*Kulikov Vasiliy2010-08-10
| | | | | | | | Remove unnesessary casts from void*. Signed-off-by: Kulikov Vasiliy <segooon@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: avoid recursive BTM in pty_closeArnd Bergmann2010-08-10
| | | | | | | | | | | | | | | | | | | | | | | When the console has been redirected, a hangup of the tty will cause tty_release to be called under the big tty_mutex, which leads to a deadlock because hangup is also called under the BTM. This moves the BTM deeper into the tty_hangup function so we can close the redirected tty without holding the BTM. In case of pty, we now need to drop the BTM before calling tty_vhangup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Tony Luck <tony.luck@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: John Kacur <jkacur@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: remove tty_lock_nestedArnd Bergmann2010-08-10
| | | | | | | | | | | | This changes all remaining users of tty_lock_nested to be non-recursive, which lets us kill this function. As a consequence, we won't need to keep the lock count any more, which allows more simplifications later. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: never hold BTM while getting tty_mutexArnd Bergmann2010-08-10
| | | | | | | | | | | | | | tty_mutex is never taken with the BTM held, except for two corner cases that are worked around here. We give up the BTM before calling tty_release() in the error path of tty_open(). Similarly, we reorder the locking in ptmx_open() to get tty_mutex before the BTM. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: replace BKL with a new tty_lockArnd Bergmann2010-08-10
| | | | | | | | | | | As a preparation for replacing the big kernel lock in the TTY layer, wrap all the callers in new macros tty_lock, tty_lock_nested and tty_unlock. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Fix init ordering of /dev/console vs callers of modprobeDavid Howells2010-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make /dev/console get initialised before any initialisation routine that invokes modprobe because if modprobe fails, it's going to want to open /dev/console, presumably to write an error message to. The problem with that is that if the /dev/console driver is not yet initialised, the chardev handler will call request_module() to invoke modprobe, which will fail, because we never compile /dev/console as a module. This will lead to a modprobe loop, showing the following in the kernel log: request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 This can happen, for example, when the built in md5 module can't find the built in cryptomgr module (because the latter fails to initialise). The md5 module comes before the call to tty_init(), presumably because 'crypto' comes before 'drivers' alphabetically. Fix this by calling tty_init() from chrdev_init(). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Fix unbalanced BKL handling in error pathAlan Cox2010-05-13
| | | | | | | | | | | | | | | | Arnd noted: After the "retry_open:" label, we first get the tty_mutex and then the BKL. However a the end of tty_open, we jump back to retry_open with the BKL still held. If we run into this case, the tty_open function will be left with the BKL still held. Signed-off-by: Alan Cox <alan@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: release_one_tty() forgets to put pidsOleg Nesterov2010-04-02
| | | | | | | | | | | | release_one_tty(tty) can be called when tty still has a reference to pgrp/session. In this case we leak the pid. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Catalin Marinas <catalin.marinas@arm.com> Reported-and-tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 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>
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