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path: root/drivers/char/tty_io.c
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2007-03-01[PATCH] tty_io: fix race in master pty close/slave pty close pathAristeu Sergio Rozanski Filho
This patch fixes a possible race that leads to double freeing an idr index. When the master begin to close, release_dev() is called and then pty_close() is called: if (tty->driver->close) tty->driver->close(tty, filp); This is done without helding any locks other than BKL. Inside pty_close(), being a master close, the devpts entry will be removed: #ifdef CONFIG_UNIX98_PTYS if (tty->driver == ptm_driver) devpts_pty_kill(tty->index); #endif But devpts_pty_kill() will call get_node() that may sleep while waiting for &devpts_root->d_inode->i_sem. When this happens and the slave is being opened, tty_open() just found the driver and index: driver = get_tty_driver(device, &index); if (!driver) { mutex_unlock(&tty_mutex); return -ENODEV; } This part of the code is already protected under tty_mute. The problem is that the slave close already got an index. Then init_dev() is called and blocks waiting for the same &devpts_root->d_inode->i_sem. When the master close resumes, it removes the devpts entry, and the relation between idr index and the tty is gone. The master then sleeps waiting for the tty_mutex on release_dev(). Slave open resumes and found no tty for that index. As result, a NULL tty is returned and init_dev() doesn't flow to fast_track: /* check whether we're reopening an existing tty */ if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { tty = devpts_get_tty(idx); if (tty && driver->subtype == PTY_TYPE_MASTER) tty = tty->link; } else { tty = driver->ttys[idx]; } if (tty) goto fast_track; The result of this, is that a new tty will be created and init_dev() returns sucessfull. After returning, tty_mutex is dropped and master close may resume. Master close finds it's the only use and both sides are closing, then releases the tty and the index. At this point, the idr index is free, but slave still has it. Slave open then calls pty_open() and finds that tty->link->count is 0, because there's no master and returns error. Then tty_open() calls release_dev() which executes without any warning, as it was a case of last slave close when the master is already closed (master->count == 0, slave->count == 1). The tty is then released with the already released idr index. This normally would only issue a warning on idr_remove() but in case of a customer's critical application, it's never too simple: thread1: opens master, gets index X thread1: begin closing master thread2: begin opening slave with index X thread1: finishes closing master, index X released thread3: opens master, gets index X, just released thread2: fails opening slave, releases index X <---- thread4: opens master, gets index X, init_dev() then find an already in use and healthy tty and fails If no more indexes are released, ptmx_open() will keep failing, as the first free index available is X, and it will make init_dev() fail because you're trying to "reopen a master" which isn't valid. The patch notices when this race happens and make init_dev() fail imediately. The init_dev() function is called with tty_mutex held, so it's safe to continue with tty till the end of function because release_dev() won't make any further changes without grabbing the tty_mutex. Without the patch, on some machines it's possible get easily idr warnings like this one: idr_remove called for id=15 which is not allocated. [<c02555b9>] idr_remove+0x139/0x170 [<c02a1b62>] release_mem+0x182/0x230 [<c02a28e7>] release_dev+0x4b7/0x700 [<c02a0ea7>] tty_ldisc_enable+0x27/0x30 [<c02a1e64>] init_dev+0x254/0x580 [<c02a0d64>] check_tty_count+0x14/0xb0 [<c02a4f05>] tty_open+0x1c5/0x340 [<c02a4d40>] tty_open+0x0/0x340 [<c017388f>] chrdev_open+0xaf/0x180 [<c017c2ac>] open_namei+0x8c/0x760 [<c01737e0>] chrdev_open+0x0/0x180 [<c0167bc9>] __dentry_open+0xc9/0x210 [<c0167e2c>] do_filp_open+0x5c/0x70 [<c0167a91>] get_unused_fd+0x61/0xd0 [<c0167e93>] do_sys_open+0x53/0x100 [<c0167f97>] sys_open+0x27/0x30 [<c010303b>] syscall_call+0x7/0xb using this test application available on: http://www.ruivo.org/~aris/pty_sodomizer.c Signed-off-by: Aristeu Sergio Rozanski Filho <aris@ruivo.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20[PATCH] tty: use NULL for ptrsRandy Dunlap
Fix sparse warning in tty_io: drivers/char/tty_io.c:1536:34: warning: Using plain integer as NULL pointer Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20[PATCH] tty_register_driver: Remove incorrect and superfluous castGeert Uytterhoeven
tty_register_driver: Remove incorrect and superfluous cast (expected and passed types are both const char *) Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-13[PATCH] Fix SAK_work workqueue initialization.Eric W. Biederman
Somewhere in the rewrite of the work queues my cleanup of SAK handling got broken. Maybe I didn't retest it properly or possibly the API was changing so fast I missed something. Regardless currently triggering a SAK now generates an ugly BUG_ON and kills the kernel. Thanks to Alexey Dobriyan <adobriyan@openvz.org> for spotting this. This modifies the use of SAK_work to initialize it when the data structure it resides in is initialized, and to simply call schedule_work when we need to generate a SAK. I update both data structures that have a SAK_work member for consistency. All of the old PREPARE_WORK calls that are now gone. If we call schedule_work again before it has processed it has generated the first SAK it will simply ignore the duplicate schedule_work request. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] tty: update the tty layer to work with struct pidEric W. Biederman
Of kernel subsystems that work with pids the tty layer is probably the largest consumer. But it has the nice virtue that the assiation with a session only lasts until the session leader exits. Which means that no reference counting is required. So using struct pid winds up being a simple optimization to avoid hash table lookups. In the long term the use of pid_nr also ensures that when we have multiple pid spaces mixed everything will work correctly. Signed-off-by: Eric W. Biederman <eric@maxwell.lnxi.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] pid: replace is_orphaned_pgrp with is_current_pgrp_orphanedEric W. Biederman
Every call to is_orphaned_pgrp passed in process_group(current) which is racy with respect to another thread changing our process group. It didn't bite us because we were dealing with integers and the worse we would get would be a stale answer. In switching the checks to use struct pid to be a little more efficient and prepare the way for pid namespaces this race became apparent. So I simplified the calls to the more specialized is_current_pgrp_orphaned so I didn't have to worry about making logic changes to avoid the race. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] pid: make session_of_pgrp use struct pid instead of pid_tEric W. Biederman
To properly implement a pid namespace I need to deal exclusively in terms of struct pid, because pid_t values become ambiguous. To this end session_of_pgrp is transformed to take and return a struct pid pointer. To avoid the need to worry about reference counting I now require my caller to hold the appropriate locks. Leaving callers repsonsible for increasing the reference count if they need access to the result outside of the locks. Since session_of_pgrp currently only has one caller and that caller simply uses only test the result for equality with another process group, the locking change means I don't actually have to acquire the tasklist_lock at all. tiocspgrp is also modified to take and release the lock. The logic there is a little more complicated but nothing I won't need when I convert pgrp of a tty to a struct pid pointer. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] tty: fix the locking for signal->session in disassociate_cttyEric W. Biederman
commit 24ec839c431eb79bb8f6abc00c4e1eb3b8c4d517 while fixing the locking for signal->tty got the locking wrong for signal->session. This places our accesses of signal->session back under the tasklist_lock where they belong. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] tty: clarify disassociate_cttyEric W. Biederman
The code to look at tty_old_pgrp and send SIGHUP and SIGCONT when it is present only executes when disassociate_ctty is called from do_exit. Make this clear by adding an explict on_exit check, and explicitly setting tty_old_pgrp to 0. In addition fix the locking by reading tty_old_pgrp under the siglock. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] tty: make __proc_set_tty staticEric W. Biederman
The aim of this patch set is to start wrapping up the struct pid conversions. As such this patchset culminates with the removal of kill_pg, kill_pg_info, __kill_pg_info, do_each_task_pid, and while_each_task_pid. kill_proc, daemonize, and kernel_thread are still in my sights but there is still work to get to them. The first three are basic cleanups around disassociate_ctty, while working on converting it I found several issues. tty_old_pgrp can be a tricky concept to wrap your head around. 1 tty: Make __proc_set_tty static. 2 tty: Clarify disassociate_ctty 3 tty: Fix the locking for signal->session in disassociate_ctty These just stop using the old helper functions. 4 signal: Use kill_pgrp not kill_pg in the sunos compatibility code. 5 signal: Rewrite kill_something_info so it uses newer helpers. Then the grind to convert the tty layer and all of it's helper functions to struct pid. 6 pid: Make session_of_pgrp use struct pid instead of pid_t. 7 pid: Use struct pid for talking about process groups in exit.c 8 pid: Replace is_orphaned_pgrp with is_current_pgrp_orphaned 9 tty: Update the tty layer to work with struct pid. A final helper function update. 10 pid: Replace do/while_each_task_pid with do/while_each_pid_task And the removal of the functions that are now unused. 11 pid: Remove now unused do_each_task_pid and while_each_task_pid 12 pid: Remove the now unused kill_pg kill_pg_info and __kill_pg_info All of these should be fairly simple and to the point. This patch: Currently all users of __proc_set_tty are in tty_io.c so make the function static. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] tty: cleanup release_memChristoph Hellwig
release_mem contains two copies of exactly the same code. Refactor these into a new helper, release_tty. The only change in behaviour is that the driver reference count is now decremented after the master tty has been freed instead of before. [penberg@cs.helsinki.fi: fix use-after-free in release_tty.] Cc: Alan Cox <alan@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] Char: tty, delete wake_up_interruptible after tty_wakeupJiri Slaby
tty_wakeup calls wake_up_interruptible(&tty->write_wait) itself, it's not needed to wake up again after tty_wakeup returns. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> 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>
2007-02-11[PATCH] vt: refactor console SAK processingEric W. Biederman
This does several things. - It moves looking up of the current foreground console into process context where we can safely take the semaphore that protects this operation. - It uses the new flavor of work queue processing. - This generates a factor of do_SAK, __do_SAK that runs immediately. - This calls __do_SAK with the console semaphore held ensuring nothing else happens to the console while we process the SAK operation. - With the console SAK processing moved into process context this patch removes the xchg operations that I used to attempt to attomically update struct pid, because of the strange locking used in the SAK processing. With SAK using the normal console semaphore nothing special is needed. Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-13[PATCH] tty_io.c balance tty_ldisc_ref()Dan Carpenter
tty_ldisc_deref() should only be called when tty_ldisc_ref() succeeds otherwise it triggers a BUG(). There's already a function tty_ldisc_flush() that flushes properly. Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13[PATCH] tty: export get_current_ttyHeiko Carstens
24ec839c431eb79bb8f6abc00c4e1eb3b8c4d517 causes this: WARNING: "get_current_tty" [drivers/s390/char/fs3270.ko] undefined! Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] tty: switch to ktermios and new frameworkAlan Cox
This is the core of the switch to the new framework. I've split it from the driver patches which are mostly search/replace and would encourage people to give this one a good hard stare. The references to BOTHER and ISHIFT are the termios values that must be defined by a platform once it wants to turn on "new style" ioctl support. The code patches here ensure that providing 1. The termios overlays the ktermios in memory 2. The only new kernel only fields are c_ispeed/c_ospeed (or none) the existing behaviour is retained. This is true for the patches at this point in time. Future patches will define BOTHER, ISHIFT and enable newer termios structures for each architecture, and once they are all done some of the ifdefs also vanish. [akpm@osdl.org: warning fix] [akpm@osdl.org: IRDA fix] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] add process_session() helper routine: deprecate old fieldCedric Le Goater
Add an anonymous union and ((deprecated)) to catch direct usage of the session field. [akpm@osdl.org: fix various missed conversions] [jdike@addtoit.com: fix UML bug] Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] add process_session() helper routineCedric Le Goater
Replace occurences of task->signal->session by a new process_session() helper routine. It will be useful for pid namespaces to abstract the session pid number. Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] struct path: convert char-driversJosef Sipek
Signed-off-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] tty: ->signal->tty lockingPeter Zijlstra
Fix the locking of signal->tty. Use ->sighand->siglock to protect ->signal->tty; this lock is already used by most other members of ->signal/->sighand. And unless we are 'current' or the tasklist_lock is held we need ->siglock to access ->signal anyway. (NOTE: sys_unshare() is broken wrt ->sighand locking rules) Note that tty_mutex is held over tty destruction, so while holding tty_mutex any tty pointer remains valid. Otherwise the lifetime of ttys are governed by their open file handles. This leaves some holes for tty access from signal->tty (or any other non file related tty access). It solves the tty SLAB scribbles we were seeing. (NOTE: the change from group_send_sig_info to __group_send_sig_info needs to be examined by someone familiar with the security framework, I think it is safe given the SEND_SIG_PRIV from other __group_send_sig_info invocations) [schwidefsky@de.ibm.com: 3270 fix] [akpm@osdl.org: various post-viro fixes] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Alan Cox <alan@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Roland McGrath <roland@redhat.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Jan Kara <jack@ucw.cz> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-05Merge branch 'master' of ↵David Howells
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: drivers/infiniband/core/iwcm.c drivers/net/chelsio/cxgb2.c drivers/net/wireless/bcm43xx/bcm43xx_main.c drivers/net/wireless/prism54/islpci_eth.c drivers/usb/core/hub.h drivers/usb/input/hid-core.c net/core/netpoll.c Fix up merge failures with Linus's head and fix new compilation failures. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-12-01Driver core: convert tty core to use struct deviceGreg Kroah-Hartman
Converts from using struct "class_device" to "struct device" making everything show up properly in /sys/devices/ with symlinks from the /sys/class directory. Also fixes up the isdn drivers that were putting something in the class device's directory. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-11-22WorkStruct: Pass the work_struct pointer instead of context dataDavid Howells
Pass the work_struct pointer to the work function rather than context data. The work function can use container_of() to work out the data. For the cases where the container of the work_struct may go away the moment the pending bit is cleared, it is made possible to defer the release of the structure by deferring the clearing of the pending bit. To make this work, an extra flag is introduced into the management side of the work_struct. This governs auto-release of the structure upon execution. Ordinarily, the work queue executor would release the work_struct for further scheduling or deallocation by clearing the pending bit prior to jumping to the work function. This means that, unless the driver makes some guarantee itself that the work_struct won't go away, the work function may not access anything else in the work_struct or its container lest they be deallocated.. This is a problem if the auxiliary data is taken away (as done by the last patch). However, if the pending bit is *not* cleared before jumping to the work function, then the work function *may* access the work_struct and its container with no problems. But then the work function must itself release the work_struct by calling work_release(). In most cases, automatic release is fine, so this is the default. Special initiators exist for the non-auto-release case (ending in _NAR). Signed-Off-By: David Howells <dhowells@redhat.com>
2006-11-22WorkStruct: Separate delayable and non-delayable events.David Howells
Separate delayable work items from non-delayable work items be splitting them into a separate structure (delayed_work), which incorporates a work_struct and the timer_list removed from work_struct. The work_struct struct is huge, and this limits it's usefulness. On a 64-bit architecture it's nearly 100 bytes in size. This reduces that by half for the non-delayable type of event. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-10-02[PATCH] const struct tty_operationsJeff Dike
As part of an SMP cleanliness pass over UML, I consted a bunch of structures in order to not have to document their locking. One of these structures was a struct tty_operations. In order to const it in UML without introducing compiler complaints, the declaration of tty_set_operations needs to be changed, and then all of its callers need to be fixed. This patch declares all struct tty_operations in the tree as const. In all cases, they are static and used only as input to tty_set_operations. As an extra check, I ran an i386 allyesconfig build which produced no extra warnings. 53 drivers are affected. I checked the history of a bunch of them, and in most cases, there have been only a handful of maintenance changes in the last six months. serial_core.c was the busiest one that I looked at. Signed-off-by: Jeff Dike <jdike@addtoit.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] rate limiting for the ldisc open failure messagesAkinobu Mita
This patch limits the messages when ldisc open faulures happen. It happens under memory pressure. Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] tty: Fix bits and note more bits to fixAlan Cox
If your driver implements "break on" and "break off" this ensures you won't get multiple overlapping requests or requests in parallel. If your driver has its own break handling then its still your problem as the driver author. Break is also now serialized against writes from user space properly but no new guarantees are made driver level about writes from the line discipline itself (eg flow control or echo) Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] solaris emulation: incorrect tty lockingAlan Cox
[akpm@osdl.org: build fix] [akpm@osdl.org: warning fix] Signed-off-by: Alan Cox <alan@redhat.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] tty: make termios_sem a mutexArjan van de Ven
[akpm@osdl.org: fix] Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] tty: lock ticogwinszAlan Cox
Now we lock the set ioctl its trivial to lock the get one so the data copied is consistent. At the moment we have the BKL here but this removes the need for it and is a step in the right direction Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] tty: trivial kzalloc opportunityAlan Cox
Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] tty locking on resizeAlan Cox
The current kernel serializes console resizes but does not serialize the resize against the tty structure updates. This means that while two parallel resizes cannot mess up the console you can get incorrect results reported. Secondly while doing this I added vc_lock_resize() to lock and resize the console. This leaves all knowledge of the console_sem in the vt/console driver and kicks it out of the tty layer, which is good Thirdly while doing this I decided I couldn't stand "disallocate" any longer so I switched it to "deallocate". Signed-off-by: Alan Cox <alan@redhat.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] tty_io.c: keep davej saneAlexey Dobriyan
Just comment and next "while" look _very_ wrong. Place { correctly to hint unsuspecting ones that it's the end of the loop actually. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Dave Jones <davej@redhat.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27[PATCH] Fix tty layer DoS and comment relevant codeAlan Cox
Unlike the other tty comment patch this one has code changes. Specifically it limits the queue size for a tty to 64K characters (128Kbytes) worst case even if the tty is ignoring tty->throttle. This is because certain drivers don't honour the throttle value correctly, although it is a useful safeguard anyway. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27[PATCH] tty layer comment the locking assumptions and functions somewhatAlan Cox
Doesn't fix them but does show up some interesting areas that need review and fixing. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27[PATCH] tty: remove bogus call to cdev_del()Rolf Eike Beer
When cdev_add() failed there is no reason to call cdev_del(). Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] sched: cleanup, remove task_t, convert to struct task_structIngo Molnar
cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] make more file_operation structs staticArjan van de Ven
Mark the static struct file_operations in drivers/char as const. Making them const prevents accidental bugs, and moves them to the .rodata section so that they no longer do any false sharing; in addition with the proper debug option they are then protected against corruption.. [akpm@osdl.org: build fix] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6: (22 commits) [PATCH] devfs: Remove it from the feature_removal.txt file [PATCH] devfs: Last little devfs cleanups throughout the kernel tree. [PATCH] devfs: Rename TTY_DRIVER_NO_DEVFS to TTY_DRIVER_DYNAMIC_DEV [PATCH] devfs: Remove the tty_driver devfs_name field as it's no longer needed [PATCH] devfs: Remove the line_driver devfs_name field as it's no longer needed [PATCH] devfs: Remove the videodevice devfs_name field as it's no longer needed [PATCH] devfs: Remove the gendisk devfs_name field as it's no longer needed [PATCH] devfs: Remove the miscdevice devfs_name field as it's no longer needed [PATCH] devfs: Remove the devfs_fs_kernel.h file from the tree [PATCH] devfs: Remove devfs_remove() function from the kernel tree [PATCH] devfs: Remove devfs_mk_cdev() function from the kernel tree [PATCH] devfs: Remove devfs_mk_bdev() function from the kernel tree [PATCH] devfs: Remove devfs_mk_symlink() function from the kernel tree [PATCH] devfs: Remove devfs_mk_dir() function from the kernel tree [PATCH] devfs: Remove devfs_*_tape() functions from the kernel tree [PATCH] devfs: Remove devfs support from the sound subsystem [PATCH] devfs: Remove devfs support from the ide subsystem. [PATCH] devfs: Remove devfs support from the serial subsystem [PATCH] devfs: Remove devfs from the init code [PATCH] devfs: Remove devfs from the partition code ...
2006-06-28[PATCH] remove active field from tty buffer structurePaul Fulghum
Remove 'active' field from tty buffer structure. This was added in 2.6.16 as part of a patch to make the new tty buffering SMP safe. This field is unnecessary with the more intelligently written flush_to_ldisc that adds receive_room handling. Removing this field reverts to simpler logic where the tail buffer is always the 'active' buffer, which should not be freed by flush_to_ldisc. (active == buffer being filled with new data) The result is simpler, smaller, and faster tty buffer code. Signed-off-by: Paul Fulghum <paulkf@microgate.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-28[PATCH] add receive_room flow control to flush_to_ldiscPaul Fulghum
Flush data serially to line discipline in blocks no larger than tty->receive_room to avoid losing data if line discipline is busy (such as N_TTY operating at high speed on heavily loaded system) or does not accept data in large blocks (such as N_MOUSE). Signed-off-by: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-28[PATCH] remove TTY_DONT_FLIPPaul Fulghum
Remove TTY_DONT_FLIP tty flag. This flag was introduced in 2.1.X kernels to prevent the N_TTY line discipline functions read_chan() and n_tty_receive_buf() from running at the same time. 2.2.15 introduced tty->read_lock to protect access to the N_TTY read buffer, which is the only state requiring protection between these two functions. The current TTY_DONT_FLIP implementation is broken for SMP, and is not universally honored by drivers that send data directly to the line discipline receive_buf function. Because TTY_DONT_FLIP is not necessary, is broken in implementation, and is not universally honored, it is removed. Signed-off-by: Paul Fulghum <paulkf@microgate.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27[PATCH] tty: fix TCSBRK commentPaul Fulghum
Fix TCSBRK comment to prevent confusion or accidental removal. Signed-off-by: Paul Fulghum <paulkf@microgate.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] devfs: Rename TTY_DRIVER_NO_DEVFS to TTY_DRIVER_DYNAMIC_DEVGreg Kroah-Hartman
I've always found this flag confusing. Now that devfs is no longer around, it has been renamed, and the documentation for when this flag should be used has been updated. Also fixes all drivers that use this flag. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26[PATCH] devfs: Remove the devfs_fs_kernel.h file from the treeGreg Kroah-Hartman
Also fixes up all files that #include it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26[PATCH] devfs: Remove devfs_remove() function from the kernel treeGreg Kroah-Hartman
Removes the devfs_remove() function and all callers of it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26[PATCH] devfs: Remove devfs_mk_cdev() function from the kernel treeGreg Kroah-Hartman
Removes the devfs_mk_cdev() function and all callers of it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-21[PATCH] TTY: return class device pointer from tty_register_device()Hansjoerg Lipp
Let tty_register_device() return a pointer to the class device it creates. This allows registrants to add their own sysfs files under the class device node. Signed-off-by: Hansjoerg Lipp <hjlipp@web.de> Signed-off-by: Tilman Schmidt <tilman@imap.cc> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-05-23[PATCH] tty_insert_flip_string_flags() license fixTobias Powalowski
We still don't have the tty layer licensing compatibility quite right. tty_insert_flip_char() used to be inlined in include/linux/tty_flip.h. It is now out-of-lined and hence needs EXPORT_SYMBOL() to be back-compatible. One known offender is the Intel Modem driver. Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>