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path: root/drivers/char/tty_io.c
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* [PATCH] Fix tty layer DoS and comment relevant codeAlan Cox2006-08-27
| | | | | | | | | | | | 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>
* [PATCH] tty layer comment the locking assumptions and functions somewhatAlan Cox2006-08-27
| | | | | | | | | 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>
* [PATCH] tty: remove bogus call to cdev_del()Rolf Eike Beer2006-08-27
| | | | | | | | | 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>
* [PATCH] sched: cleanup, remove task_t, convert to struct task_structIngo Molnar2006-07-03
| | | | | | | | | | | | 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>
* [PATCH] make more file_operation structs staticArjan van de Ven2006-07-03
| | | | | | | | | | | | 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>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6Linus Torvalds2006-06-29
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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 ...
| * [PATCH] devfs: Rename TTY_DRIVER_NO_DEVFS to TTY_DRIVER_DYNAMIC_DEVGreg Kroah-Hartman2006-06-26
| | | | | | | | | | | | | | | | | | | | 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>
| * [PATCH] devfs: Remove the devfs_fs_kernel.h file from the treeGreg Kroah-Hartman2006-06-26
| | | | | | | | | | | | Also fixes up all files that #include it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * [PATCH] devfs: Remove devfs_remove() function from the kernel treeGreg Kroah-Hartman2006-06-26
| | | | | | | | | | | | Removes the devfs_remove() function and all callers of it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * [PATCH] devfs: Remove devfs_mk_cdev() function from the kernel treeGreg Kroah-Hartman2006-06-26
| | | | | | | | | | | | Removes the devfs_mk_cdev() function and all callers of it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | [PATCH] remove active field from tty buffer structurePaul Fulghum2006-06-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | [PATCH] add receive_room flow control to flush_to_ldiscPaul Fulghum2006-06-28
| | | | | | | | | | | | | | | | | | | | | | 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>
* | [PATCH] remove TTY_DONT_FLIPPaul Fulghum2006-06-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | [PATCH] tty: fix TCSBRK commentPaul Fulghum2006-06-27
|/ | | | | | | | | 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>
* [PATCH] TTY: return class device pointer from tty_register_device()Hansjoerg Lipp2006-06-21
| | | | | | | | | | 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>
* [PATCH] tty_insert_flip_string_flags() license fixTobias Powalowski2006-05-23
| | | | | | | | | | | | | 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>
* [PATCH] Fix file lookup without refDipankar Sarma2006-04-19
| | | | | | | | | | | | | | There are places in the kernel where we look up files in fd tables and access the file structure without holding refereces to the file. So, we need special care to avoid the race between looking up files in the fd table and tearing down of the file in another CPU. Otherwise, one might see a NULL f_dentry or such torn down version of the file. This patch fixes those special places where such a race may happen. Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] do_SAK: Don't recursively take the tasklist_lockEric W. Biederman2006-04-13
| | | | | | | | | | | | | By calling send_sig do_SAK is recursively taking the tasklist_lock, which is silly. In addition I just audited the kernel and this was the only place where tasklist_lock is taken inside of task_lock. So this one line change is a general worthwhile cleanup and it increases our options on how to fix the ptrace_attach races. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] tty release_dev(): remove dead codePaul Fulghum2006-04-11
| | | | | | | Remove dead code from tty_io.c release_dev() Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] ptmx: fix duplicate idr_removePaul Fulghum2006-04-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove duplicate call to idr_remove() in ptmx_open. Error during open can result in call to release_dev() followed by call to idr_remove(). release_dev already calls idr_remove so the second call can cause a stack dump in idr_remove()->sub_remove() flagging an attempt to release an already released entry. I reproduces this on a machine with a misconfigured X server (attempting to restart multiple times rapidly) getting the same error as the 1st link below. This also seems to be related to: http://marc.theaimsgroup.com/?l=selinux&m=110536513426735&w=2 http://marc.theaimsgroup.com/?l=selinux&m=110596994916785&w=2 The stack dump can occur on close (as well as open) as shown in the 1st instance above, possible from something like: process A - open (index=0), open fail to out1, release_dev calls idr_remove (index 0), down(sem) sleeps process B - open (index=0), open OK (idr allocated) process A - wake and call idr_remove on index 0 ... process B - close, release_dev, stack dump on idr_remove (index=0) because entry already removed Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] make tty_insert_flip_string_flags() a non gpl exportAndrew Morton2006-04-11
| | | | | | | | | | | | We changed the wrong symbol. It's tty_insert_flip_string_flags() which is called from the previously-non-GPL'ed now-inlined tty_insert_flip_char(). Fix that up, and uninline tty_schedule_flip() while we're there. Cc: Tobias Powalowski <t.powa@gmx.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>
* [PATCH] make tty_insert_flip_string a non-GPL exportAndrew Morton2006-03-31
| | | | | | | | | | | | | | | | | Alan sayeth "Based on Linus original comments about _GPL we should export tty_insert_flip_char as EXPORT_SYMBOL because it used to be EXPORT_SYMBOL equivalent (trivial inline). The other features are new extensions are were not available to drivers before so need not be provided except as _GPL functionality as far as I can see." Addresses http://bugzilla.kernel.org/show_bug.cgi?id=6294 Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Fulghum <paulkf@microgate.com> Cc: Philippe Vouters <Philippe.Vouters@laposte.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] do_SAK: don't depend on session ID 0Eric W. Biederman2006-03-28
| | | | | | | | | | | | | | | I'm not really certain what the thinking was but the code obviously wanted to walk processes other than just those in it's session, for purposes of do_SAK. Just walking those tasks that don't have a session assigned sounds at the very least incomplete. So modify the code to kill everything in the session and anything else that might have the tty open. Hopefully this helps if the do_SAK functionality is ever finished. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] do_tty_hangup: use group_send_sig_info not send_group_sig_infoEric W. Biederman2006-03-28
| | | | | | | | | | We already have the tasklist_lock so there is no need for us to reacquire it with send_group_sig_info. reader/writer locks allow multiple readers and thus recursion so the old code was ok just wastful. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* BUG_ON() Conversion in drivers/charEric Sesterhenn2006-03-26
| | | | | | | | this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] constify tty flip buffer handlingThomas Koeller2006-03-25
| | | | | | | | | | Add a couple of 'const' qualifiers to the TTY flip buffer APIs, where appropriate. Signed-off-by: Thomas Koeller <thomas@koeller.dyndns.org> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sem2mutex: ttyIngo Molnar2006-03-23
| | | | | | | | | | | | | Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] tty buffering: comment out debug codePaul Fulghum2006-02-28
| | | | | | | | | | Comment out debug code in tty receive buffering. For performance reasons (I'll keep it enabled in -mm). 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>
* [PATCH] tty reference count fixPaul Fulghum2006-02-14
| | | | | | | | | | | | | | | | | | | | | | Fix hole where tty structure can be released when reference count is non zero. Existing code can sleep without tty_sem protection between deciding to release the tty structure (setting local variables tty_closing and otty_closing) and setting TTY_CLOSING to prevent further opens. An open can occur during this interval causing release_dev() to free the tty structure while it is still referenced. This should fix bugzilla.kernel.org [Bug 6041] New: Unable to handle kernel paging request In Bug 6041, tty_open() oopes on accessing the tty structure it has successfully claimed. Bug was on SMP machine with the same tty being opened and closed by multiple processes, and DEBUG_PAGEALLOC enabled. Signed-off-by: Paul Fulghum <paulkf@microgate.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] tty buffering stall fixPaul Fulghum2006-02-10
| | | | | | | | | | | | Prevent stalled processing of received data when a driver allocates tty buffer space but does not immediately follow the allocation with more data and a call to schedule receive tty processing. (example: hvc_console) This bug was introduced by the first locking patch for the new tty buffering. 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>
* [PATCH] new tty buffering locking fixPaul Fulghum2006-02-03
| | | | | | | | | | | | | | | | | | | Change locking in the new tty buffering facility from using tty->read_lock, which is currently ignored by drivers and thus ineffective. New locking uses a new tty buffering specific lock enforced centrally in the tty buffering code. Two drivers (esp and cyclades) are updated to use the tty buffering functions instead of accessing tty buffering internals directly. This is required for the new locking to work. Minor checks for NULL buffers added to tty_prepare_flip_string/tty_prepare_flip_string_flags 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>
* [PATCH] new tty buffering access fixPaul Fulghum2006-01-11
| | | | | | | | | Fix typos in new tty buffering that incorrectly access and update buffers in pending queue. Signed-off-by: Paul Fulghum <paulkf@microgate.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] TTY layer buffering revampAlan Cox2006-01-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The API and code have been through various bits of initial review by serial driver people but they definitely need to live somewhere for a while so the unconverted drivers can get knocked into shape, existing drivers that have been updated can be better tuned and bugs whacked out. This replaces the tty flip buffers with kmalloc objects in rings. In the normal situation for an IRQ driven serial port at typical speeds the behaviour is pretty much the same, two buffers end up allocated and the kernel cycles between them as before. When there are delays or at high speed we now behave far better as the buffer pool can grow a bit rather than lose characters. This also means that we can operate at higher speeds reliably. For drivers that receive characters in blocks (DMA based, USB and especially virtualisation) the layer allows a lot of driver specific code that works around the tty layer with private secondary queues to be removed. The IBM folks need this sort of layer, the smart serial port people do, the virtualisers do (because a virtualised tty typically operates at infinite speed rather than emulating 9600 baud). Finally many drivers had invalid and unsafe attempts to avoid buffer overflows by directly invoking tty methods extracted out of the innards of work queue structs. These are no longer needed and all go away. That fixes various random hangs with serial ports on overflow. The other change in here is to optimise the receive_room path that is used by some callers. It turns out that only one ldisc uses receive room except asa constant and it updates it far far less than the value is read. We thus make it a variable not a function call. I expect the code to contain bugs due to the size alone but I'll be watching and squashing them and feeding out new patches as it goes. Because the buffers now dynamically expand you should only run out of buffering when the kernel runs out of memory for real. That means a lot of the horrible hacks high performance drivers used to do just aren't needed any more. Description: tty_insert_flip_char is an old API and continues to work as before, as does tty_flip_buffer_push() [this is why many drivers dont need modification]. It does now also return the number of chars inserted There are also tty_buffer_request_room(tty, len) which asks for a buffer block of the length requested and returns the space found. This improves efficiency with hardware that knows how much to transfer. and tty_insert_flip_string_flags(tty, str, flags, len) to insert a string of characters and flags For a smart interface the usual code is len = tty_request_buffer_room(tty, amount_hardware_says); tty_insert_flip_string(tty, buffer_from_card, len); More description! At the moment tty buffers are attached directly to the tty. This is causing a lot of the problems related to tty layer locking, also problems at high speed and also with bursty data (such as occurs in virtualised environments) I'm working on ripping out the flip buffers and replacing them with a pool of dynamically allocated buffers. This allows both for old style "byte I/O" devices and also helps virtualisation and smart devices where large blocks of data suddenely materialise and need storing. So far so good. Lots of drivers reference tty->flip.*. Several of them also call directly and unsafely into function pointers it provides. This will all break. Most drivers can use tty_insert_flip_char which can be kept as an API but others need more. At the moment I've added the following interfaces, if people think more will be needed now is a good time to say int tty_buffer_request_room(tty, size) Try and ensure at least size bytes are available, returns actual room (may be zero). At the moment it just uses the flipbuf space but that will change. Repeated calls without characters being added are not cumulative. (ie if you call it with 1, 1, 1, and then 4 you'll have four characters of space. The other functions will also try and grow buffers in future but this will be a more efficient way when you know block sizes. int tty_insert_flip_char(tty, ch, flag) As before insert a character if there is room. Now returns 1 for success, 0 for failure. int tty_insert_flip_string(tty, str, len) Insert a block of non error characters. Returns the number inserted. int tty_prepare_flip_string(tty, strptr, len) Adjust the buffer to allow len characters to be added. Returns a buffer pointer in strptr and the length available. This allows for hardware that needs to use functions like insl or mencpy_fromio. Signed-off-by: Alan Cox <alan@redhat.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kfree cleanup: drivers/charJesper Juhl2005-11-07
| | | | | | | | | | This is the drivers/char/ part of the big kfree cleanup patch. Remove pointless checks for NULL prior to calling kfree() in drivers/char/. Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] reduce sizeof(struct file)Eric Dumazet2005-10-30
| | | | | | | | | | | | | | | Now that RCU applied on 'struct file' seems stable, we can place f_rcuhead in a memory location that is not anymore used at call_rcu(&f->f_rcuhead, file_free_rcu) time, to reduce the size of this critical kernel object. The trick I used is to move f_rcuhead and f_list in an union called f_u The callers are changed so that f_rcuhead becomes f_u.fu_rcuhead and f_list becomes f_u.f_list Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Driver Core: fix up all callers of class_device_create()Greg Kroah-Hartman2005-10-28
| | | | | | | | The previous patch adding the ability to nest struct class_device changed the paramaters to the call class_device_create(). This patch fixes up all in-kernel users of the function. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] files: lock-free fd look-upDipankar Sarma2005-09-09
| | | | | | | | | | | | With the use of RCU in files structure, the look-up of files using fds can now be lock-free. The lookup is protected by rcu_read_lock()/rcu_read_unlock(). This patch changes the readers to use lock-free lookup. Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Ravikiran Thirumalai <kiran_th@gmail.com> Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] files: break up files structDipankar Sarma2005-09-09
| | | | | | | | | | | | | | | In order for the RCU to work, the file table array, sets and their sizes must be updated atomically. Instead of ensuring this through too many memory barriers, we put the arrays and their sizes in a separate structure. This patch takes the first step of putting the file table elements in a separate structure fdtable that is embedded withing files_struct. It also changes all the users to refer to the file table using files_fdtable() macro. Subsequent applciation of RCU becomes easier after this. Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] pty_chars_in_buffer oops fixJason Baron2005-09-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The idea of this patch is to lock both sides of a ptmx/pty pair during line discipline changing. This is needed to ensure that say a poll on one side of the pty doesn't occur while the line discipline is actively being changed. This resulted in an oops reported on lkml, see: http://marc.theaimsgroup.com/?l=linux-kernel&m=111342171410005&w=2 A 'hacky' approach was previously implmemented which served to eliminate the poll vs. line discipline changing race. However, this patch takes a more general approach to the issue. The patch only adds locking on a less often used path, the line-discipline changing path, as opposed to locking the ptmx/pty pair on read/write/poll paths. The patch below, takes both ldisc locks in either order b/c the locks are both taken under the same spinlock(). I thought about locking the ptmx/pty separately, such as master always first but that introduces a 3 way deadlock. For example, process 1 does a blocking read on the slave side. Then, process 2 does an ldisc change on the slave side, which acquires the master ldisc lock but not the slave's. Finally, process 3 does a write which blocks on the process 2's ldisc reference. This patch does introduce some changes in semantics. For example, a line discipline change on side 'a' of a ptmx/pty pair, will now wait for a read/write to complete on the other side, or side 'b'. The current behavior is to simply wait for any read/writes on only side 'a', not both sides 'a' and 'b'. I think this behavior makes sense, but I wanted to point it out. I've tested the patch with a bunch of read/write/poll while changing the line discipline out from underneath. This patch obviates the need for the above "hide the problem" patch. Signed-off-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] move 68360serial.c over use initcallsChristoph Hellwig2005-09-07
| | | | | | | | | this is the last serial driver not using initcalls. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: <jeff@uclinux.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] char/tty_io: replace schedule_timeout() with msleep_interruptible()Domen Puncer2005-06-25
| | | | | | | | | | | | Use msleep_interruptible() instead of schedule_timeout() in send_break() to guarantee the task delays as expected. Change @duration's units to milliseconds, and modify arguments in callers appropriately. Patch is compile-tested. Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Domen Puncer <domen@coderock.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Introduce tty_unregister_ldisc()Alexey Dobriyan2005-06-23
| | | | | | | | | It's a bit strange to see tty_register_ldisc call in modules' exit functions. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] tty: move to use the new class code, instead of class_simplegregkh@suse.de2005-06-20
| | | | Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] uninline tty_paranoia_check()Andrew Morton2005-05-05
| | | | | | | Has lots of callsites. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-16
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!