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* tty: Revert the tty locking series, it needs more workLinus Torvalds2012-06-02
| | | | | | | | | | | | | | | | | | | | | | This reverts the tty layer change to use per-tty locking, because it's not correct yet, and fixing it will require some more deep surgery. The main revert is d29f3ef39be4 ("tty_lock: Localise the lock"), but there are several smaller commits that built upon it, they also get reverted here. The list of reverted commits is: fde86d310886 - tty: add lockdep annotations 8f6576ad476b - tty: fix ldisc lock inversion trace d3ca8b64b97e - pty: Fix lock inversion b1d679afd766 - tty: drop the pty lock during hangup abcefe5fc357 - tty/amiserial: Add missing argument for tty_unlock() fd11b42e3598 - cris: fix missing tty arg in wait_event_interruptible_tty call d29f3ef39be4 - tty_lock: Localise the lock The revert had a trivial conflict in the 68360serial.c staging driver that got removed in the meantime. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty_lock: Localise the lockAlan Cox2012-05-04
| | | | | | | | | | | | In each remaining case the tty_lock is associated with a specific tty. This means we can now lock on a per tty basis. We do need tty_lock_pair() for the pty case. Uglier but still a step in the right direction. [fixed up calls in 3 missing drivers - gregkh] Signed-off-by: Alan Cox <alan@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Remove all #inclusions of asm/system.hDavid Howells2012-03-28
| | | | | | | | | Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
* TTY: provide tty_standard_install helperJiri Slaby2012-02-02
| | | | | | | | | | | | There are currently many cut&paste copies of what tty_driver_install_tty does when custom ->install method is not provided. Let's get rid of the copies and create a helper with this setup code. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Havard Skinnemoen <hskinnemoen@google.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tty: rework pty count limitingKonstantin Khlebnikov2012-01-24
| | | | | | | | | | | | | | | | | | | | | After adding devpts multiple-insrances sysctl kernel.pty.max limit pty count for each devpts instance independently, while kernel.pty.nr shows total pty count. This patch restores sysctl kernel.pty.max as global limit (4096 by default), adds pty reseve for main devpts (mounted without "newinstance" argument), and new sysctl to tune it: kernel.pty.reserve (1024 by default) Also it adds devpts mount option "max=%d" to limit pty count for each devpts instance independently. (by default NR_UNIX98_PTY_MAX == 2^20) Thus devpts instances in containers cannot eat up all available pty even if we didn't set any limits, while with "max" argument we can adjust limits more precisely. Plus, now open("/dev/ptmx") return -ENOSPC in case lack of pty indexes, this is more informative than -EIO. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: cleanup prohibition of direct opening for unix98 pty masterKonstantin Khlebnikov2012-01-24
| | | | | | | | | | | | | | | | | | | | | | | cleanup hack added in v2.6.27-3203-g15582d3 comment from that patch: : pty: If the administrator creates a device for a ptmx slave we should not error : : The open path for ptmx slaves is via the ptmx device. Opening them any : other way is not allowed. Vegard Nossum found that previously this was not : the case and mknod foo c 128 42; cat foo would produce nasty diagnostics : : Signed-off-by: Alan Cox <alan@redhat.com> : Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> devpts_get_tty() returns non-null only for inodes on devpts, but there is no inodes for master-devices, /dev/ptmx (/dev/pts/ptmx) is the only way to open them. Thus we can completely forbid lookup for master-devices and eliminate that hack in tty_init_dev() because tty_open() will get EIO from tty_driver_lookup_tty(). Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Merge branch 'tty-next' of ↵Linus Torvalds2011-10-26
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty * 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (79 commits) TTY: serial_core: Fix crash if DCD drop during suspend tty/serial: atmel_serial: bootconsole removed from auto-enumerates Revert "TTY: call tty_driver_lookup_tty unconditionally" tty/serial: atmel_serial: add device tree support tty/serial: atmel_serial: auto-enumerate ports tty/serial: atmel_serial: whitespace and braces modifications tty/serial: atmel_serial: change platform_data variable name tty/serial: RS485 bindings for device tree TTY: call tty_driver_lookup_tty unconditionally TTY: pty, release tty in all ptmx_open fail paths TTY: make tty_add_file non-failing TTY: drop driver reference in tty_open fail path 8250_pci: Fix kernel panic when pch_uart is disabled h8300: drivers/serial/Kconfig was moved parport_pc: release IO region properly if unsupported ITE887x card is found tty: Support compat_ioctl get/set termios_locked hvc_console: display printk messages on console. TTY: snyclinkmp: forever loop in tx_load_dma_buffer() tty/n_gsm: avoid fifo overflow in gsm_dlci_data_output tty/n_gsm: fix a bug in gsm_dlci_data_output (adaption = 2 case) ... Fix up Conflicts in: - drivers/tty/serial/8250_pci.c Trivial conflict with removed duplicate device ID - drivers/tty/serial/atmel_serial.c Annoying silly conflict between "specify the port num via platform_data" and other changes to atmel_console_init
| * TTY: make tty_add_file non-failingJiri Slaby2011-10-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If tty_add_file fails at the point it is now, we have to revert all the changes we did to the tty. It means either decrease all refcounts if this was a tty reopen or delete the tty if it was newly allocated. There was a try to fix this in v3.0-rc2 using tty_release in 0259894c7 (TTY: fix fail path in tty_open). But instead it introduced a NULL dereference. It's because tty_release dereferences filp->private_data, but that one is set even in our tty_add_file. And when tty_add_file fails, it's still NULL/garbage. Hence tty_release cannot be called there. To circumvent the original leak (and the current NULL deref) we split tty_add_file into two functions, making the latter non-failing. In that case we may do the former early in open, where handling failures is easy. The latter stays as it is now. So there is no change in functionality. The original bug (leak) was introduced by f573bd176 (tty: Remove __GFP_NOFAIL from tty_add_file()). Thanks Dan for reporting this. Later, we may split tty_release into more functions and call only some of them in this fail path instead. (If at all possible.) Introduced-in: v2.6.37-rc2 Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable <stable@vger.kernel.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * tty: Support compat_ioctl get/set termios_lockedThomas Meyer2011-10-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running a Fedora 15 (x86) on an x86_64 kernel, in the boot process plymouthd complains about those two missing ioctls: [ 2.581783] ioctl32(plymouthd:186): Unknown cmd fd(10) cmd(00005457){t:'T';sz:0} arg(ffb6a5d0) on /dev/tty1 [ 2.581803] ioctl32(plymouthd:186): Unknown cmd fd(10) cmd(00005456){t:'T';sz:0} arg(ffb6a680) on /dev/tty1 both ioctl functions work on the 'struct termios' resp. 'struct termios2', which has the same size (36 bytes resp. 44 bytes) on x86 and x86_64, so it's just a matter of converting the pointer from userland. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * TTY: define tty_wait_until_sent_from_closeJiri Slaby2011-08-25
| | | | | | | | | | | | | | | | | | | | | | | | We need this helper to fix system stalls. The issue is that the rest of the system TTYs wait for us to finish waiting. This wasn't an issue with BKL. BKL used to unlock implicitly. This is based on the Arnd suggestion. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * TTY: remove tty_lockedJiri Slaby2011-08-23
| | | | | | | | | | | | | | | | | | | | | | | | We used it really only serial and ami_serial. The rest of the callsites were BUG/WARN_ONs to check if BTM is held. Now that we pruned tty_locked from both of the real users, we can get rid of tty_lock along with __big_tty_mutex_owner. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | TTY: pty, fix pty countingJiri Slaby2011-08-23
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tty_operations->remove is normally called like: queue_release_one_tty ->tty_shutdown ->tty_driver_remove_tty ->tty_operations->remove However tty_shutdown() is called from queue_release_one_tty() only if tty_operations->shutdown is NULL. But for pty, it is not. pty_unix98_shutdown() is used there as ->shutdown. So tty_operations->remove of pty (i.e. pty_unix98_remove()) is never called. This results in invalid pty_count. I.e. what can be seen in /proc/sys/kernel/pty/nr. I see this was already reported at: https://lkml.org/lkml/2009/11/5/370 But it was not fixed since then. This patch is kind of a hackish way. The problem lies in ->install. We allocate there another tty (so-called tty->link). So ->install is called once, but ->remove twice, for both tty and tty->link. The fix here is to count both tty and tty->link and divide the count by 2 for user. And to have ->remove called, let's make tty_driver_remove_tty() global and call that from pty_unix98_shutdown() (tty_operations->shutdown). While at it, let's document that when ->shutdown is defined, tty_shutdown() is not called. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: export NR_LDISC and N_* line discipline numbers to user-spaceFlorian Fainelli2011-06-07
| | | | | | | | | | | | | | | | | Since commit (4564f9e5: consolidate line discipline number definitions) the patch moved all line discipline number from a per-architecture termios.h to a shared one: tty.h. However, prior to this consolidation work, the line discipline numbers were outside of an ifdef __KERNEL__/endif block so these numbers used to be exported to user-space. Since such numbers are kernel ABI anyway, and tty.h is already included for user- space header processing, just move these relevant defines outside of the ifdef __KERNEL__/endif block in include/linux/tty.h. CC: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Florian Fainelli <ffainelli@freebox.fr> Acked-by: Tilman Schmidt <tilman@imap.cc> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* n_tracerouter and n_tracesink ldisc additions.J Freyensee2011-05-13
| | | | | | | | | | | | | | | The n_tracerouter and n_tracesink line discpline drivers use the Linux tty line discpline framework to route trace data coming from a tty port (say UART for example) to the trace sink line discipline driver and to another tty port(say USB). Those these two line discipline drivers can be used together, independently from pti.c, they are part of the original implementation solution of the MIPI P1149.7, compact JTAG, PTI solution for Intel mobile platforms starting with the Medfield platform. Signed-off-by: J Freyensee <james_p_freyensee@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* TTY: introduce deinit helpers for proper ldisc shutdownJiri Slaby2011-04-19
| | | | | | | | | | | | | | | | Introduce deinitialize_tty_struct which should be called after initialize_tty_struct and before successfull tty_ldisc_setup. It calls tty_ldisc_deinit which is opposite of tty_ldisc_init. It only puts a reference to ldisc and assigns NULL to tty->ldisc. It will be used to shut down ldisc when tty_release cannot be called yet. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Julian Anastasov <ja@ssi.bg> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: stop using "delayed_work" in the tty layerLinus Torvalds2011-03-22
| | | | | | | | | | | | | | | | | | | | | | | Using delayed-work for tty flip buffers ends up causing us to wait for the next tick to complete some actions. That's usually not all that noticeable, but for certain latency-critical workloads it ends up being totally unacceptable. As an extreme case of this, passing a token back-and-forth over a pty will take two ticks per iteration, so even just a thousand iterations will take 8 seconds assuming a common 250Hz configuration. Avoiding the whole delayed work issue brings that ping-pong test-case down to 0.009s on my machine. In more practical terms, this latency has been a performance problem for things like dive computer simulators (simulating the serial interface using the ptys) and for other environments (Alan mentions a CP/M emulator). Reported-by: Jef Driesen <jefdriesen@telenet.be> Acked-by: Greg KH <gregkh@suse.de> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: add a helper for setting termios data from kernel sideAlan Cox2011-02-17
| | | | | | | | | | | | | This basically encapsulates the small bit of locking knowledge needed. While we are at it make sure we blow up on any more abusers and unsafe misuses of ioctl for this kind of stuff. We change the function to return an argument as at some point it needs to honour the POSIX 'I asked for changes but got none of them' error reporting corner case. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: fix build error in vt_ioctl.c if CONFIG_COMPAT is enabledGreg Kroah-Hartman2011-02-17
| | | | | | | | This was caused by the previous patch to remove the file pointer from the tty ioctl handler. Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: now phase out the ioctl file pointer for goodAlan Cox2011-02-17
| | | | | | | | | Only oddities here are a couple of drivers that bogusly called the ldisc helpers instead of returning -ENOIOCTLCMD. Fix the bug and the rest goes away. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Merge branch 'tty-linus' of ↵Linus Torvalds2010-12-02
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6 * 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: serial: mfd: adjust the baud rate setting TTY: open/hangup race fixup TTY: don't allow reopen when ldisc is changing NET: wan/x25, fix ldisc->open retval TTY: ldisc, fix open flag handling serial8250: Mark console as CON_ANYTIME
| * TTY: open/hangup race fixupJiri Slaby2010-11-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Like in the "TTY: don't allow reopen when ldisc is changing" patch, this one fixes a TTY WARNING as described in the option 1) there: 1) __tty_hangup from tty_ldisc_hangup to tty_ldisc_enable. During this section tty_lock is held. However tty_lock is temporarily dropped in the middle of the function by tty_ldisc_hangup. The fix is to introduce a new flag which we set during the unlocked window and check it in tty_reopen too. The flag is TTY_HUPPING and is cleared after TTY_HUPPED is set. While at it, remove duplicate TTY_HUPPED set_bit. The one after calling ops->hangup seems to be more correct. But anyway, we hold tty_lock, so there should be no difference. Also document the function it does that kind of crap. Nicely reproducible with two forked children: static void do_work(const char *tty) { if (signal(SIGHUP, SIG_IGN) == SIG_ERR) exit(1); setsid(); while (1) { int fd = open(tty, O_RDWR|O_NOCTTY); if (fd < 0) continue; if (ioctl(fd, TIOCSCTTY)) continue; if (vhangup()) continue; close(fd); } exit(0); } Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: <Valdis.Kletnieks@vt.edu> Reported-by: Kyle McMartin <kyle@mcmartin.ca> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann2010-11-17
|/ | | | | | | | | | The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Fix formatting in tty.hAlan Cox2010-11-09
| | | | | | | | Someone added a new ldisc number and messed up the tabbing. Fix it before anyone else copies it. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* audit: Call tty_audit_push_task() outside preempt disabledThomas Gleixner2010-10-30
| | | | | | | | | | | | | | | | | | | | | | | | | | While auditing all tasklist_lock read_lock sites I stumbled over the following call chain: audit_prepare_user_tty() read_lock(&tasklist_lock); tty_audit_push_task(); mutex_lock(&buf->mutex); --> buf->mutex is locked with preemption disabled. Solve this by acquiring a reference to the task struct under rcu_read_lock and call tty_audit_push_task outside of the preempt disabled region. Move all code which needs to be protected by sighand lock into tty_audit_push_task() and use lock/unlock_sighand as we do not hold tasklist_lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge 'staging-next' to Linus's treeGreg Kroah-Hartman2010-10-28
|\ | | | | | | | | | | | | | | This merges the staging-next tree to Linus's tree and resolves some conflicts that were present due to changes in other trees that were affected by files here. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * tty.h: new ldisc for TI WiLink STPavan Savoy2010-10-05
| | | | | | | | | | | | | | | | | | | | | | | | | | Texas Instrument's WiLink7 connectivity devices pack wireless connectivity technologies like Bluetooth, FM Radio Receiver and Transmitter, GPS and WLAN into a single die. The BT, FM and GPS core on the chip are interfaced to application processors via a single UART. This line discipline driver allows such different technologies to be used simultaneous and independent of each other. Signed-off-by: Pavan Savoy <pavan_savoy@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | tty: Remove __GFP_NOFAIL from tty_add_file()Pekka Enberg2010-10-22
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes __GFP_NOFAIL use from tty_add_file() and adds proper error handling to the call-sites of the function. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Pekka Enberg <penberg@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | tty: add tty_struct->dev pointer to corresponding device instanceDmitry Eremin-Solenikov2010-10-22
|/ | | | | | | | | | | | Some device drivers (mostly tty line disciplines) would like to have way know a struct device instance corresponding to passed tty_struct. Add a struct device pointer to struct tty_struct and populate it during initialize_tty_struct(). Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: fix fu_list abuseNick Piggin2010-08-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tty: fix fu_list abuse tty code abuses fu_list, which causes a bug in remount,ro handling. If a tty device node is opened on a filesystem, then the last link to the inode removed, the filesystem will be allowed to be remounted readonly. This is because fs_may_remount_ro does not find the 0 link tty inode on the file sb list (because the tty code incorrectly removed it to use for its own purpose). This can result in a filesystem with errors after it is marked "clean". Taking idea from Christoph's initial patch, allocate a tty private struct at file->private_data and put our required list fields in there, linking file and tty. This makes tty nodes behave the same way as other device nodes and avoid meddling with the vfs, and avoids this bug. The error handling is not trivial in the tty code, so for this bugfix, I take the simple approach of using __GFP_NOFAIL and don't worry about memory errors. This is not a problem because our allocator doesn't fail small allocs as a rule anyway. So proper error handling is left as an exercise for tty hackers. [ Arguably filesystem's device inode would ideally be divorced from the driver's pseudo inode when it is opened, but in practice it's not clear whether that will ever be worth implementing. ] Cc: linux-kernel@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Nick Piggin <npiggin@kernel.dk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* fs: cleanup files_lock lockingNick Piggin2010-08-18
| | | | | | | | | | | | | | | fs: cleanup files_lock locking Lock tty_files with a new spinlock, tty_files_lock; provide helpers to manipulate the per-sb files list; unexport the files_lock spinlock. Cc: linux-kernel@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Andi Kleen <ak@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Nick Piggin <npiggin@kernel.dk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* tty: implement BTM as mutex instead of BKLArnd Bergmann2010-08-10
| | | | | | | | | | | | | | | | | | The tty locking now follows the rules for mutexes, so we can replace the BKL usage with a new subsystem wide mutex. Using a regular mutex here will change the behaviour when blocked on the BTM from spinning to sleeping, but that should not be visible to the user. Using the mutex also means that all the BTM is now covered by lockdep. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: remove tty_lock_nestedArnd Bergmann2010-08-10
| | | | | | | | | | | | This changes all remaining users of tty_lock_nested to be non-recursive, which lets us kill this function. As a consequence, we won't need to keep the lock count any more, which allows more simplifications later. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: introduce wait_event_interruptible_ttyArnd Bergmann2010-08-10
| | | | | | | | | | | | Calling wait_event_interruptible implicitly releases the BKL when it sleeps, but we need to do this explcitly when we have converted it to a mutex. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: replace BKL with a new tty_lockArnd Bergmann2010-08-10
| | | | | | | | | | | As a preparation for replacing the big kernel lock in the TTY layer, wrap all the callers in new macros tty_lock, tty_lock_nested and tty_unlock. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: Add EXTPROC support for LINEMODEhyc@symas.com2010-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Fix init ordering of /dev/console vs callers of modprobeDavid Howells2010-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make /dev/console get initialised before any initialisation routine that invokes modprobe because if modprobe fails, it's going to want to open /dev/console, presumably to write an error message to. The problem with that is that if the /dev/console driver is not yet initialised, the chardev handler will call request_module() to invoke modprobe, which will fail, because we never compile /dev/console as a module. This will lead to a modprobe loop, showing the following in the kernel log: request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 This can happen, for example, when the built in md5 module can't find the built in cryptomgr module (because the latter fails to initialise). The md5 module comes before the call to tty_init(), presumably because 'crypto' comes before 'drivers' alphabetically. Fix this by calling tty_init() from chrdev_init(). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: n_gsm line disciplineAlan Cox2010-05-21
| | | | | | | | | | | | | | | | | Add an implementation of GSM 0710 MUX. The implementation currently supports - Basic and advanced framing (as either end of the link) - UI or UIH data frames - Adaption layer 1-4 (1 and 2 via tty, 3 and 4 as skbuff lists) - Modem and control messages including the correct retry process - Flow control and exposes the MUX channels as a set of virtual tty devices including modem signals. This is an experimental driver. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* serial: TTY: new ldiscs for stagingPavan Savoy2010-05-21
| | | | | | | | | Push the max ldiscs by a few number to allow ldiscs to exist in the staging directory and elsewhere. Signed-off-by: Pavan Savoy <pavan_savoy@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Merge branch 'master' of ↵David S. Miller2010-04-07
|\ | | | | | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/bonding/bond_main.c drivers/net/via-velocity.c drivers/net/wireless/iwlwifi/iwl-agn.c
| * tty_port,usb-console: Fix usb serial console open/close regressionJason Wessel2010-03-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e1108a63e10d344284011cccc06328b2cd3e5da3 ("usb_serial: Use the shutdown() operation") breaks the ability to use a usb console starting in 2.6.33. This was observed when using console=ttyUSB0,115200 as a boot argument with an FTDI device. The error is: ftdi_sio ttyUSB0: ftdi_submit_read_urb - failed submitting read urb, error -22 The handling of the ASYNCB_INITIALIZED changed in 2.6.32 such that in tty_port_shutdown() it always clears the flag if it is set. The fix is to add a variable to the tty_port struct to indicate when the tty port is a console. CC: Alan Cox <alan@linux.intel.com> CC: Alan Stern <stern@rowland.harvard.edu> CC: Oliver Neukum <oliver@neukum.org> CC: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * tty: Take a 256 byte padding into account when buffering below sub-page unitsMel Gorman2010-03-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The TTY layer takes some care to ensure that only sub-page allocations are made with interrupts disabled. It does this by setting a goal of "TTY_BUFFER_PAGE" to allocate. Unfortunately, while TTY_BUFFER_PAGE takes the size of tty_buffer into account, it fails to account that tty_buffer_find() rounds the buffer size out to the next 256 byte boundary before adding on the size of the tty_buffer. This patch adjusts the TTY_BUFFER_PAGE calculation to take into account the size of the tty_buffer and the padding. Once applied, tty_buffer_alloc() should not require high-order allocations. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | net-caif-driver: add CAIF serial driver (ldisc)Sjur Braendeland2010-03-30
|/ | | | | | | | | | | Add CAIF Serial driver. This driver is implemented as a line discipline. caif_serial uses the following module parameters: ser_use_stx - specifies if STart of frame eXtension is in use. ser_loop - sets the interface in loopback mode. Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ldisc n_tty: add new method n_tty_inherit_ops()Rodolfo Giometti2010-03-12
| | | | | | | | | | | | | This new method can be used to init a new struct tty_ldisc_ops as the default tty_ldisc_N_TTY struct. Signed-off-by: Rodolfo Giometti <giometti@linux.it> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg KH <greg@kroah.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: Keep the default buffering to sub-page unitsAlan Cox2010-03-02
| | | | | | | | | | | | | | We allocate during interrupts so while our buffering is normally diced up small anyway on some hardware at speed we can pressure the VM excessively for page pairs. We don't really need big buffers to be linear so don't try so hard. In order to make this work well we will tidy up excess callers to request_room, which cannot itself enforce this break up. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty.h: make tty_port_get() static inlineRandy Dunlap2010-01-16
| | | | | | | | | | | | | | | | | I get a few dozen of these warnings when using gcc (GCC) 4.4.1 20090725 (Red Hat 4.4.1-2): In file included from mmotm-2010-0113-1217/init/do_mounts.c:5: mmotm-2010-0113-1217/include/linux/tty.h: In function 'tty_port_get': mmotm-2010-0113-1217/include/linux/tty.h:469: warning: '______f' is static but declared in inline function 'tty_port_get' which is not static so make the function static inline. [akpm@linux-foundation.org: may as well convert tty_port_users() also] Signed-off-by: Randy Dunlap <randy.dunlap@oracle.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>
* vt: introduce and use vt_kmsg_redirect() functionBernhard Walle2009-12-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel offers with TIOCL_GETKMSGREDIRECT ioctl() the possibility to redirect the kernel messages to a specific console. However, since it's not possible to switch to the kernel message console after a panic(), it would be nice if the kernel would print the panic message on the current console. This patch series adds a new interface to access the global kmsg_redirect variable by a function to be able to use it in code where CONFIG_VT_CONSOLE is not set (kernel/panic.c). This patch: Instead of using and exporting a global value kmsg_redirect, introduce a function vt_kmsg_redirect() that both can set and return the console where messages are printed. Change all users of kmsg_redirect (the VT code itself and kernel/power.c) to the new interface. The main advantage is that vt_kmsg_redirect() can also be used when CONFIG_VT_CONSOLE is not set. Signed-off-by: Bernhard Walle <bernhard@bwalle.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tty: push the BKL down into the handlers a bitAlan Cox2009-12-11
| | | | | | | | | Start trying to untangle the remaining BKL mess Updated to fix missing unlock_kernel noted by Dan Carpenter Signed-off-by: Alan "I must be out of my tree" Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: tty_port: Add a kref object to the tty portAlan Cox2009-12-11
| | | | | | | | Users of tty port need a way to refcount ports when hotplugging is involved. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty: tty_port: Change the buffer allocator lockingAlan Cox2009-12-11
| | | | | | | | | | We want to be able to do this without regard for the activate/own open method being used which causes a problem using port->mutex. Add another mutex for now. Once everything uses port_open to do buffer allocs we can kill it back off Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* tty_port: add "tty_port_open" helperAlan Cox2009-12-11
| | | | | | | | | | | | For the moment this just moves the USB logic over and fixes the 'what if we open and hangup at the same time' race noticed by Oliver Neukum. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oliver@neukum.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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