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path: root/drivers/char/pty.c
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2010-08-18tty: fix fu_list abuseNick Piggin
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>
2010-08-18fs: cleanup files_lock lockingNick Piggin
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>
2010-08-10tty: avoid recursive BTM in pty_closeArnd Bergmann
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>
2010-08-10tty: remove tty_lock_nestedArnd Bergmann
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>
2010-08-10tty: never hold BTM while getting tty_mutexArnd Bergmann
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>
2010-08-10tty: replace BKL with a new tty_lockArnd Bergmann
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>
2010-08-10tty: Add EXTPROC support for LINEMODEhyc@symas.com
This patch is against the 2.6.34 source. Paraphrased from the 1989 BSD patch by David Borman @ cray.com: These are the changes needed for the kernel to support LINEMODE in the server. There is a new bit in the termios local flag word, EXTPROC. When this bit is set, several aspects of the terminal driver are disabled. Input line editing, character echo, and mapping of signals are all disabled. This allows the telnetd to turn off these functions when in linemode, but still keep track of what state the user wants the terminal to be in. New ioctl: TIOCSIG Generate a signal to processes in the current process group of the pty. There is a new mode for packet driver, the TIOCPKT_IOCTL bit. When packet mode is turned on in the pty, and the EXTPROC bit is set, then whenever the state of the pty is changed, the next read on the master side of the pty will have the TIOCPKT_IOCTL bit set. This allows the process on the server side of the pty to know when the state of the terminal has changed; it can then issue the appropriate ioctl to retrieve the new state. Since the original BSD patches accompanied the source code for telnet I've left that reference here, but obviously the feature is useful for any remote terminal protocol, including ssh. The corresponding feature has existed in the BSD tty driver since 1989. For historical reference, a good copy of the relevant files can be found here: http://anonsvn.mit.edu/viewvc/krb5/trunk/src/appl/telnet/?pathrev=17741 Signed-off-by: Howard Chu <hyc@symas.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-02-09tree-wide: Assorted spelling fixesDaniel Mack
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>
2009-12-11tty: push the BKL down into the handlers a bitAlan Cox
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>
2009-11-18sysctl: Drop & in front of every proc_handler.Eric W. Biederman
For consistency drop & in front of every proc_handler. Explicity taking the address is unnecessary and it prevents optimizations like stubbing the proc_handlers to NULL. Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Joe Perches <joe@perches.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-12sysctl drivers: Remove dead binary sysctl supportEric W. Biederman
Now that sys_sysctl is a wrapper around /proc/sys all of the binary sysctl support elsewhere in the tree is dead code. Cc: Jens Axboe <axboe@kernel.dk> Cc: Corey Minyard <minyard@acm.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Neil Brown <neilb@suse.de> Cc: "James E.J. Bottomley" <James.Bottomley@suse.de> Acked-by: Clemens Ladisch <clemens@ladisch.de> for drivers/char/hpet.c Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-10-11headers: remove sched.h from interrupt.hAlexey Dobriyan
After m68k's task_thread_info() doesn't refer to current, it's possible to remove sched.h from interrupt.h and not break m68k! Many thanks to Heiko Carstens for allowing this. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-09-30pty: reconnect the BSD TIOCSPTLCK handling to legacy ptysLinus Torvalds
David Howells noticed (due to the compiler warning about an unused 'pty_ops_bsd' variable) that we haven't actually been using the code that implements TIOCSPTLCK for legacy pty handling. It's been that way since 2.6.26, commit 3e8e88ca053150efdbecb45d8f481cf560ec808d to be exact ("pty: prepare for tty->ops changes"). DavidH initially submitted a patch just removing the dead code entirely, and since nobody has apparently ever complained, I'm not entirely sure that wouldn't be the right thing to do. But since the whole and only point of the legacy pty code is to be compatible with legacy distros that don't use the new unix98 pty model, let's just wire it up again. And clean it up a bit while we're at it. Acked-by: David Howells <dhowells@redhat.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-18pty_write: don't do a tty_wakeup() when the buffers are fullLinus Torvalds
Commit ac89a9174 ("pty: don't limit the writes to 'pty_space()' inside 'pty_write()'") removed the pty_space() checking, in order to let the regular tty buffer code limit the buffering itself. That was all good, but as a subtle side effect it meant that we'd be doing a tty_wakeup() even in the case where the buffers were all filled up, and didn't actually make any progress on the write. Which sounds innocuous, but it interacts very badly with the ppp_async code, which has an infinite loop in ppp_async_push() that tries to push out data to the tty. When we call tty_wakeup(), that loop ends up thinking that progress was made (see the subtle interactions between XMIT_WAKEUP and 'tty_stuffed' for details). End result: one unhappy ppp user. Fixed by noticing when tty_insert_flip_string() didn't actually do anything, and then not doing any more processing (including, very much not calling tty_wakeup()). Bisected-and-tested-by: Peter Volkov <pva@gentoo.org> Cc: stable@kernel.org (2.6.31) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05pty: don't limit the writes to 'pty_space()' inside 'pty_write()'Linus Torvalds
The whole write-room thing is something that is up to the _caller_ to worry about, not the pty layer itself. The total buffer space will still be limited by the buffering routines themselves, so there is no advantage or need in having pty_write() artificially limit the size somehow. And what happened was that the caller (the n_tty line discipline, in this case) may have verified that there is room for 2 bytes to be written (for NL -> CRNL expansion), and it used to then do those writes as two single-byte writes. And if the first byte written (CR) then caused a new tty buffer to be allocated, pty_space() may have returned zero when trying to write the second byte (LF), and then incorrectly failed the write - leading to a lost newline character. This should finally fix http://bugzilla.kernel.org/show_bug.cgi?id=14015 Reported-by: Mikael Pettersson <mikpe@it.uu.se> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-10pty: fix data loss when stopped (^S/^Q)Linus Torvalds
Commit d945cb9cc ("pty: Rework the pty layer to use the normal buffering logic") dropped the test for 'tty->stopped' in pty_write_room(), which then causes the n_tty line discipline thing to not throttle the data properly when the tty is stopped. So instead of pausing the write due to the tty being stopped, the ldisc layer would go ahead and push it down to the pty. The pty write() routine would then refuse to take the data (because it _did_ check 'stopped'), and the data wouldn't actually be written. This whole stopped test should eventually be moved into the tty ldisc layer rather than have low-level tty drivers care about these things, but right now the fix is to just re-instate the missing pty 'stopped' handling. Reported-and-tested-by: Artur Skawina <art.08.09@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-29pty: avoid forcing 'low_latency' tty flagOGAWA Hirofumi
We really don't want to mark the pty as a low-latency device, because as Alan points out, the ->write method can be called from an IRQ (ppp?), and that means we can't use ->low_latency=1 as we take mutexes in the low_latency case. So rather than using low_latency to force the written data to be pushed to the ldisc handling at 'write()' time, just make the reader side (or the poll function) do the flush when it checks whether there is data to be had. This also fixes the problem with lost data in an emacs compile buffer (bugzilla 13815), and we can thus revert the low_latency pty hack (commit 3a54297478e6578f96fd54bf4daa1751130aca86: "pty: quickfix for the pty ENXIO timing problems"). Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [ Modified to do the tty_flush_to_ldisc() inside input_available_p() so that it triggers for both read and poll() - Linus] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-27pty: quickfix for the pty ENXIO timing problemsAlan Cox
This also makes close stall in the normal case which is apparently needed to fix emacs Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-12headers: smp_lock.h reduxAlexey Dobriyan
* Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-08pty: Rework the pty layer to use the normal buffering logicAlan Cox
This fixes the ppp problems and various other issues with call locking caused by one side of a pty called in one locking context trying to match another with differing rules on the other side. We also get a big slack space to work with that means we can bury the flow control deadlock case for any conceivable real world situation. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16pty: Narrow the race on ldisc lockingAlan Cox
The pty code has always been buggy on its ldisc handling. The recent changes made the window for the race much bigger. Pending fixing it properly which is not at all trivial, at least make the race small again so we don't disrupt other dev work. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11tty: rewrite the ldisc lockingAlan Cox
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>
2009-06-11pty: Fix a commentAlan Cox
We fixed the globals, so now fix the comment Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-12pty: Fix documentationAlan Cox
The pty changes and updates for window sizing forgot to correct the kerneldoc Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08Make various things staticRoel Kluin
Building an allnoconfig kernel, sparse asked whether these could be static, so I checked, and they are only used in the file where they are declared. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02tty: PTYs set TTY_DO_WRITE_WAKEUP when they don't need toAlan Cox
The write wakeup is done anyway for the poll while DO_WRITE_WAKUP is cleared, set and managed by the ldisc layer and is no business of the pty code. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02pty: simplify resizeAlan Cox
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>
2008-10-13pty: simplify unix98 allocationAlan Cox
We need both termios and termios_locked so allocate them as one Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13pty: Fix allocation failure double freeAlan Cox
The updating and moving around of the pty code added a bug where both the helper and caller free the main tty struct (the pty driver must free the o_tty pair itself however). Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13pty: Coding style and polishAlan Cox
We've done the heavy lifting now its time to mop up a bit Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13Add an instance parameter devpts interfacesSukadev Bhattiprolu
Pass-in 'inode' or 'tty' parameter to devpts interfaces. With multiple devpts instances, these parameters will be used in subsequent patches to identify the instance of devpts mounted. The parameters also help simplify devpts implementation. Changelog[v3]: - minor changes due to merge with ttydev updates - rename parameters to emphasize they are ptmx or pts inodes - pass-in tty_struct * to devpts_pty_kill() (this will help cleanup the get_node() call in a subsequent patch) Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13tty: extract the pty init time special casesAlan Cox
The majority of the remaining init_dev code is pty special cases. We refactor this code into the driver->install method. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13tty: Finish fixing up the init_dev interface to use ERR_PTRAlan Cox
Original suggestion and proposal from Sukadev Bhattiprolu. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13tty: More driver operationsAlan Cox
We have the lookup operation abstracted which is nice for pty cleanup but we really want to abstract the add/remove entries as well so that we can pull the pty code out of the tty core and create a clear defined interface for the tty driver table. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13tty: kref the tty driver objectAlan Cox
Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13tty: Clean up the tty_init_dev changes furtherAlan Cox
Fix up the naming, style and extract some bits of code into the driver specific code Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13tty: Remove more special casing and out of place codeAlan Cox
Carry on pushing code out of tty_io when it belongs to other drivers. I'm not 100% happy with some of this and it will be worth revisiting some of the exports later when the restructuring work is done. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13tty: shutdown methodAlan Cox
Right now there are various drivers that try to use tty->count to know when they get the final close. Aristeau Rozanski showed while debugging the vt sysfs race that this isn't entirely safe. Instead of driver side tricks to work around this introduce a shutdown which is called when the tty is being destructed. This also means that the shutdown method is tied into the refcounting. Use this to rework the console close/sysfs logic. Remove lots of special case code from the tty core code. The pty code can now have a shutdown() method that replaces the special case hackery in the tree free up paths. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20tty: Ldisc revampAlan Cox
Move the line disciplines towards a conventional ->ops arrangement. For the moment the actual 'tty_ldisc' struct in the tty is kept as part of the tty struct but this can then be changed if it turns out that when it all settles down we want to refcount ldiscs separately to the tty. Pull the ldisc code out of /proc and put it with our ldisc code. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30pty: prepare for tty->ops changesAlan Cox
We are about to change the tty layer to avoid keeping private copies of all the methods in each tty. We have to update the pty layer first as it currently patches the ioctl method according to the tty type. Use multiple tty operations sets instead. Signed-off-by: Alan Cox <alan@redhat.com> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30tty: BKL pushdownAlan Cox
- Push the BKL down into the line disciplines - Switch the tty layer to unlocked_ioctl - Introduce a new ctrl_lock spin lock for the control bits - Eliminate much of the lock_kernel use in n_tty - Prepare to (but don't yet) call the drivers with the lock dropped on the paths that historically held the lock BKL now primarily protects open/close/ldisc change in the tty layer [jirislaby@gmail.com: a couple of fixes] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18sysctl: simplify the pty sysctl logicEric W. Biederman
Instead of having a bunch of ifdefs in sysctl.c move all of the pty sysctl logic into drivers/char/pty.c As well as cleaning up the logic this prevents sysctl_check_table from complaining that the root table has a NULL data pointer on something with generic methods. 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>
2007-10-12PTY: add kernel parameter to overwrite legacy pty countKay Sievers
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-14[PATCH] remove many unneeded #includes of sched.hTim Schmielau
After Al Viro (finally) succeeded in removing the sched.h #include in module.h recently, it makes sense again to remove other superfluous sched.h includes. There are quite a lot of files which include it but don't actually need anything defined in there. Presumably these includes were once needed for macros that used to live in sched.h, but moved to other header files in the course of cleaning it up. To ease the pain, this time I did not fiddle with any header files and only removed #includes from .c-files, which tend to cause less trouble. Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha, arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig, allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all configs in arch/arm/configs on arm. I also checked that no new warnings were introduced by the patch (actually, some warnings are removed that were emitted by unnecessarily included header files). Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-08[PATCH] tty: switch to ktermiosAlan Cox
This is the grungy swap all the occurrences in the right places patch that goes with the updates. At this point we have the same functionality as before (except that sgttyb() returns speeds not zero) and are ready to begin turning new stuff on providing nobody reports lots of bugs If you are a tty driver author converting an out of tree driver the only impact should be termios->ktermios name changes for the speed/property setting functions from your upper layers. If you are implementing your own TCGETS function before then your driver was broken already and its about to get a whole lot more painful for you so please fix it 8) Also fill in c_ispeed/ospeed on init for most devices, although the current code will do this for you anyway but I'd like eventually to lose that extra paranoia [akpm@osdl.org: bluetooth fix] [mp3@de.ibm.com: sclp fix] [mp3@de.ibm.com: warning fix for tty3270] [hugh@veritas.com: fix tty_ioctl powerpc build] [jdike@addtoit.com: uml: fix ->set_termios declaration] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Martin Peschke <mp3@de.ibm.com> Acked-by: Peter Oberparleiter <oberpar@de.ibm.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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>
2006-06-30Remove 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 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>