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path: root/drivers/tty/tty_io.c
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2013-11-25tty: Reset hupped state on openPeter Hurley
A common security idiom is to hangup the current tty (via vhangup()) after forking but before execing a root shell. This hangs up any existing opens which other processes may have and ensures subsequent opens have the necessary permissions to open the root shell tty/pty. Reset the TTY_HUPPED state after the driver has successfully returned the opened tty (perform the reset while the tty is locked to avoid racing with concurrent hangups). Reported-by: Heorhi Valakhanovich <valahanovich@tut.by> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Cc: stable <stable@vger.kernel.org> # 3.12 Tested-by: Heorhi Valakhanovich <valahanovich@tut.by> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-17tty: disassociate_ctty() sends the extra SIGCONTOleg Nesterov
Starting from v3.10 (probably commit f91e2590410b: "tty: Signal foreground group processes in hangup") disassociate_ctty() sends SIGCONT if tty && on_exit. This breaks LSB test-suite, in particular test8 in _exit.c and test40 in sigcon5.c. Put the "!on_exit" check back to restore the old behaviour. Review by Peter Hurley: "Yes, this regression was introduced by me in that commit. The effect of the regression is that ptys will receive a SIGCONT when, in similar circumstances, ttys would not. The fact that two test vectors accidentally tripped over this regression suggests that some other apps may as well. Thanks for catching this" Cc: stable@vger.kernel.org # v3.10+ Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Karel Srot <ksrot@redhat.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-08-02tty: Only hangup oncePeter Hurley
Instrumented testing shows a tty can be hungup multiple times [1]. Although concurrent hangups are properly serialized, multiple hangups for the same tty should be prevented. If tty has already been HUPPED, abort hangup. Note it is not necessary to cleanup file *redirect on subsequent hangups, as only TIOCCONS can set that value and ioctls are disabled after hangup. [1] Test performed by simulating a concurrent async hangup via tty_hangup() with a sync hangup via tty_vhangup(), while __tty_hangup() was instrumented with: diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 26bb78c..fe8b061 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -629,6 +629,8 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session) tty_lock(tty); + WARN_ON(test_bit(TTY_HUPPED, &tty->flags)); + /* some functions below drop BTM, so we need this bit */ set_bit(TTY_HUPPING, &tty->flags); Test result: WARNING: at /home/peter/src/kernels/mainline/drivers/tty/tty_io.c:632 __tty_hangup+0x459/0x460() Modules linked in: ip6table_filter ip6_tables ebtable_nat <...snip...> CPU: 6 PID: 1197 Comm: kworker/6:2 Not tainted 3.10.0-0+rfcomm-xeon #0+rfcomm Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012 Workqueue: events do_tty_hangup 0000000000000009 ffff8802b16d7d18 ffffffff816b553e ffff8802b16d7d58 ffffffff810407e0 ffff880254f95c00 ffff880254f95c00 ffff8802bfd92b00 ffff8802bfd96b00 ffff880254f95e40 0000000000000180 ffff8802b16d7d68 Call Trace: [<ffffffff816b553e>] dump_stack+0x19/0x1b [<ffffffff810407e0>] warn_slowpath_common+0x70/0xa0 [<ffffffff8104082a>] warn_slowpath_null+0x1a/0x20 [<ffffffff813fb279>] __tty_hangup+0x459/0x460 [<ffffffff8107409c>] ? finish_task_switch+0xbc/0xe0 [<ffffffff813fb297>] do_tty_hangup+0x17/0x20 [<ffffffff8105fd6f>] process_one_work+0x16f/0x450 [<ffffffff8106007c>] process_scheduled_works+0x2c/0x40 [<ffffffff8106060a>] worker_thread+0x26a/0x380 [<ffffffff810603a0>] ? rescuer_thread+0x310/0x310 [<ffffffff810698a0>] kthread+0xc0/0xd0 [<ffffffff816b0000>] ? destroy_compound_page+0x65/0x92 [<ffffffff810697e0>] ? kthread_create_on_node+0x130/0x130 [<ffffffff816c495c>] ret_from_fork+0x7c/0xb0 [<ffffffff810697e0>] ? kthread_create_on_node+0x130/0x130 ---[ end trace 98d9f01536cf411e ]--- Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-24tty: Fix lock order in tty_do_resize()Peter Hurley
Commits 6a1c0680cf3ba94356ecd58833e1540c93472a57 and 9356b535fcb71db494fc434acceb79f56d15bda2, respectively 'tty: Convert termios_mutex to termios_rwsem' and 'n_tty: Access termios values safely' introduced a circular lock dependency with console_lock and termios_rwsem. The lockdep report [1] shows that n_tty_write() will attempt to claim console_lock while holding the termios_rwsem, whereas tty_do_resize() may already hold the console_lock while claiming the termios_rwsem. Since n_tty_write() and tty_do_resize() do not contend over the same data -- the tty->winsize structure -- correct the lock dependency by introducing a new lock which specifically serializes access to tty->winsize only. [1] Lockdep report ====================================================== [ INFO: possible circular locking dependency detected ] 3.10.0-0+tip-xeon+lockdep #0+tip Not tainted ------------------------------------------------------- modprobe/277 is trying to acquire lock: (&tty->termios_rwsem){++++..}, at: [<ffffffff81452656>] tty_do_resize+0x36/0xe0 but task is already holding lock: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((fb_notifier_list).rwsem){.+.+.+}: [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff8175b797>] down_read+0x47/0x5c [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b -> #1 (console_lock){+.+.+.}: [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff810430a7>] console_lock+0x77/0x80 [<ffffffff8146b2a1>] con_flush_chars+0x31/0x50 [<ffffffff8145780c>] n_tty_write+0x1ec/0x4d0 [<ffffffff814541b9>] tty_write+0x159/0x2e0 [<ffffffff814543f5>] redirected_tty_write+0xb5/0xc0 [<ffffffff811ab9d5>] vfs_write+0xc5/0x1f0 [<ffffffff811abec5>] SyS_write+0x55/0xa0 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b -> #0 (&tty->termios_rwsem){++++..}: [<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30 [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff8175b724>] down_write+0x44/0x70 [<ffffffff81452656>] tty_do_resize+0x36/0xe0 [<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0 [<ffffffff8146c99f>] vc_resize+0x1f/0x30 [<ffffffff813e4535>] fbcon_init+0x385/0x5a0 [<ffffffff8146a4bc>] visual_init+0xbc/0x120 [<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320 [<ffffffff8146cfa1>] do_take_over_console+0x61/0x70 [<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0 [<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820 [<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110 [<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b other info that might help us debug this: Chain exists of: &tty->termios_rwsem --> console_lock --> (fb_notifier_list).rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((fb_notifier_list).rwsem); lock(console_lock); lock((fb_notifier_list).rwsem); lock(&tty->termios_rwsem); *** DEADLOCK *** 7 locks held by modprobe/277: #0: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b5b>] __driver_attach+0x5b/0xb0 #1: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b69>] __driver_attach+0x69/0xb0 #2: (drm_global_mutex){+.+.+.}, at: [<ffffffffa008a6dd>] drm_get_pci_dev+0xbd/0x2a0 [drm] #3: (registration_lock){+.+.+.}, at: [<ffffffff813d93f5>] register_framebuffer+0x25/0x320 #4: (&fb_info->lock){+.+.+.}, at: [<ffffffff813d8116>] lock_fb_info+0x26/0x60 #5: (console_lock){+.+.+.}, at: [<ffffffff813d95a4>] register_framebuffer+0x1d4/0x320 #6: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 stack backtrace: CPU: 0 PID: 277 Comm: modprobe Not tainted 3.10.0-0+tip-xeon+lockdep #0+tip Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012 ffffffff8213e5e0 ffff8802aa2fb298 ffffffff81755f19 ffff8802aa2fb2e8 ffffffff8174f506 ffff8802aa2fa000 ffff8802aa2fb378 ffff8802aa2ea8e8 ffff8802aa2ea910 ffff8802aa2ea8e8 0000000000000006 0000000000000007 Call Trace: [<ffffffff81755f19>] dump_stack+0x19/0x1b [<ffffffff8174f506>] print_circular_bug+0x1fb/0x20c [<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30 [<ffffffff810b775e>] ? mark_held_locks+0xae/0x120 [<ffffffff810b78d5>] ? trace_hardirqs_on_caller+0x105/0x1d0 [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff81452656>] ? tty_do_resize+0x36/0xe0 [<ffffffff8175b724>] down_write+0x44/0x70 [<ffffffff81452656>] ? tty_do_resize+0x36/0xe0 [<ffffffff81452656>] tty_do_resize+0x36/0xe0 [<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0 [<ffffffff8146c99f>] vc_resize+0x1f/0x30 [<ffffffff813e4535>] fbcon_init+0x385/0x5a0 [<ffffffff8146a4bc>] visual_init+0xbc/0x120 [<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320 [<ffffffff8146cfa1>] do_take_over_console+0x61/0x70 [<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0 [<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820 [<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110 [<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffff8173cbcb>] ? kmemleak_alloc+0x5b/0xc0 [<ffffffff81198874>] ? kmem_cache_alloc_trace+0x104/0x290 [<ffffffffa01035e1>] ? drm_fb_helper_single_add_all_connectors+0x81/0xf0 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff8175f162>] ? _raw_spin_unlock_irqrestore+0x42/0x80 [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff81497b00>] ? driver_probe_device+0x3a0/0x3a0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff81399a50>] ? ddebug_proc_open+0xb0/0xb0 [<ffffffff813855ae>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-23n_tty: Fix EOF push handlingPeter Hurley
In canonical mode, an EOF which is not the first character of the line causes read() to complete and return the number of characters read so far (commonly referred to as EOF push). However, if the previous read() returned because the user buffer was full _and_ the next character is an EOF not at the beginning of the line, read() must not return 0, thus mistakenly indicating the end-of-file condition. The TTY_PUSH flag is used to indicate an EOF was received which is not at the beginning of the line. Because the EOF push condition is evaluated by a thread other than the read(), multiple EOF pushes can cause a premature end-of-file to be indicated. Instead, discover the 'EOF push as first read character' condition from the read() thread itself, and restart the i/o loop if detected. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-23tty: Only guarantee termios read safety for throttle/unthrottlePeter Hurley
No tty driver modifies termios during throttle() or unthrottle(). Therefore, only read safety is required. However, tty_throttle_safe and tty_unthrottle_safe must still be mutually exclusive; introduce throttle_mutex for that purpose. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-23tty: Convert termios_mutex to termios_rwsemPeter Hurley
termios is commonly accessed unsafely (especially by N_TTY) because the existing mutex forces exclusive access. Convert existing usage. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-23tty: Replace ldisc locking with ldisc_semPeter Hurley
Line discipline locking was performed with a combination of a mutex, a status bit, a count, and a waitqueue -- basically, a rw semaphore. Replace the existing combination with an ld_semaphore. Fixes: 1) the 'reference acquire after ldisc locked' bug 2) the over-complicated halt mechanism 3) lock order wrt. tty_lock() 4) dropping locks while changing ldisc 5) previously unidentified deadlock while locking ldisc from both linked ttys concurrently 6) previously unidentified recursive deadlocks Adds much-needed lockdep diagnostics. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-23tty: Fix tty_ldisc_lock name collisionPeter Hurley
The file scope spinlock identifier, tty_ldisc_lock, will collide with the file scope lock function tty_ldisc_lock() so rename it. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-17tty: Reset itty for other ptyPeter Hurley
Commit 19ffd68f816878aed456d5e87697f43bd9e3bd2b ('pty: Remove redundant itty reset') introduced a regression whereby the other pty's linkage is not cleared on teardown. This triggers a false positive diagnostic in testing. Properly reset the itty linkage. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Cc: stable <stable@vger.kernel.org> # 3.10 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-17n_tty: Encapsulate minimum_to_wake within N_TTYPeter Hurley
minimum_to_wake is unique to N_TTY processing, and belongs in per-ldisc data. Add the ldisc method, ldisc_ops::fasync(), to notify line disciplines when signal-driven I/O is enabled or disabled. When enabled for N_TTY (by fcntl(F_SETFL, O_ASYNC)), blocking reader/polls will be woken for any readable input. When disabled, blocking reader/polls are not woken until the read buffer is full. Canonical mode (L_ICANON(tty), n_tty_data::icanon) is not affected by the minimum_to_wake setting. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-01tty: fix up atime/mtime mess, take threeLinus Torvalds
We first tried to avoid updating atime/mtime entirely (commit b0de59b5733d: "TTY: do not update atime/mtime on read/write"), and then limited it to only update it occasionally (commit 37b7f3c76595: "TTY: fix atime/mtime regression"), but it turns out that this was both insufficient and overkill. It was insufficient because we let people attach to the shared ptmx node to see activity without even reading atime/mtime, and it was overkill because the "only once a minute" means that you can't really tell an idle person from an active one with 'w'. So this tries to fix the problem properly. It marks the shared ptmx node as un-notifiable, and it lowers the "only once a minute" to a few seconds instead - still long enough that you can't time individual keystrokes, but short enough that you can tell whether somebody is active or not. Reported-by: Simon Kirby <sim@hostway.ca> Acked-by: Jiri Slaby <jslaby@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29Merge tag 'tty-3.10-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver update from Greg Kroah-Hartman: "Here's the big tty/serial driver merge request for 3.10-rc1 Once again, Jiri has a number of TTY driver fixes and cleanups, and Peter Hurley came through with a bunch of ldisc fixes that resolve a number of reported issues. There are some other serial driver cleanups as well. All of these have been in the linux-next tree for a while" * tag 'tty-3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (117 commits) tty/serial/sirf: fix MODULE_DEVICE_TABLE serial: mxs: drop superfluous {get|put}_device serial: mxs: fix buffer overflow ARM: PL011: add support for extended FIFO-size of PL011-r1p5 serial_core.c: add put_device() after device_find_child() tty: Fix unsafe bit ops in tty_throttle_safe/unthrottle_safe serial: sccnxp: Replace pdata.init/exit with regulator API serial: sccnxp: Do not override device name TTY: pty, fix compilation warning TTY: rocket, fix compilation warning TTY: ircomm: fix DTR being raised on hang up TTY: synclinkmp: fix DTR being raised on hang up TTY: synclink_gt: fix DTR being raised on hang up TTY: synclink: fix DTR being raised on hang up serial: 8250_dw: Fix the stub for dw8250_probe_acpi() serial: 8250_dw: Convert to devm_ioremap() serial: 8250_dw: Set port capabilities based on CPR register serial: 8250_dw: Let ACPI code extract the DMA client info serial: 8250_dw: Support clk framework also with ACPI serial: 8250_dw: Enable runtime PM ...
2013-04-26TTY: fix atime/mtime regressionJiri Slaby
In commit b0de59b5733d ("TTY: do not update atime/mtime on read/write") we removed timestamps from tty inodes to fix a security issue and waited if something breaks. Well, 'w', the utility to find out logged users and their inactivity time broke. It shows that users are inactive since the time they logged in. To revert to the old behaviour while still preventing attackers to guess the password length, we update the timestamps in one-minute intervals by this patch. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-25tty: tty_vhangup_session can be staticChanglong Xie
Reported-by: Fengguang Wu <fengguang.wu@intel.com> Acked-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Don't protect atomic operation with mutexPeter Hurley
test_bit() is already atomic; drop mutex lock/unlock. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Bracket ldisc release with TTY_DEBUG_HANGUP messagesPeter Hurley
Expected typical log output: [ 2.437211] tty_open: opening pts1... [ 2.443376] tty_open: opening pts5... [ 2.447830] tty_release: ptm0 (tty count=1)... [ 2.447849] pts0 vhangup... [ 2.447865] tty_release: ptm0: final close [ 2.447876] tty_release: ptm0: freeing structure... [ 2.451634] tty_release: tty1 (tty count=1)... [ 2.451638] tty_release: tty1: final close [ 2.451654] tty_release: tty1: freeing structure... [ 2.452505] tty_release: pts5 (tty count=2)... [ 2.453029] tty_open: opening pts0... Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Make core responsible for synchronizing its workPeter Hurley
The tty core relies on the ldisc layer for synchronizing destruction of the tty. Instead, the final tty release must wait for any pending tty work to complete prior to tty destruction. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Complete ownership transfer of flip buffersPeter Hurley
Waiting for buffer work to complete is not required for safely performing changes to the line discipline, once the line discipline is halted. The buffer work routine, flush_to_ldisc(), will be unable to acquire an ldisc ref and all existing references were waited until released (so it can't already have one). Ensure running buffer work which may reference the soon-to-be-gone tty completes and any buffer work running after this point retrieves a NULL tty. Also, ensure all buffer work is cancelled on port destruction. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18tty: Don't reenable already enabled ldiscPeter Hurley
tty_ldisc_hangup() guarantees the ldisc is enabled (or that there is no ldisc). Since __tty_hangup() was the only user, re-define tty_ldisc_enable() in file-scope. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15tty: Signal SIGHUP before hanging up ldiscPeter Hurley
An exiting session leader can hang if a foreground process is blocking for line discipline i/o, eg. in n_tty_read(). This happens because the blocking reader is holding an ldisc reference (indicating the line discipline is in-use) which prevents __tty_hangup() from recycling the line discipline. Although waiters are woken before attempting to gain exclusive access for changing the ldisc, the blocking reader in this case will not exit the i/o loop since it has not yet received SIGHUP (because it has not been sent). Instead, perform signalling first, then recycle the line discipline. Fixes: INFO: task init:1 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. init D 00000000001d7180 2688 1 0 0x00000002 ffff8800b9acfba8 0000000000000002 00000000001d7180 ffff8800b9b10048 ffff8800b94cb000 ffff8800b9b10000 00000000001d7180 00000000001d7180 ffff8800b9b10000 ffff8800b9acffd8 00000000001d7180 00000000001d7180 Call Trace: [<ffffffff83db9909>] __schedule+0x2e9/0x3b0 [<ffffffff83db9b35>] schedule+0x55/0x60 [<ffffffff83db74ba>] schedule_timeout+0x3a/0x370 [<ffffffff81182349>] ? mark_held_locks+0xf9/0x130 [<ffffffff83dbab38>] ? down_failed+0x108/0x200 [<ffffffff83dbb7ab>] ? _raw_spin_unlock_irq+0x2b/0x80 [<ffffffff81182608>] ? trace_hardirqs_on_caller+0x128/0x160 [<ffffffff83dbab61>] down_failed+0x131/0x200 [<ffffffff83dbbfad>] ? tty_ldisc_lock_pair_timeout+0xcd/0x120 [<ffffffff83dbae03>] ldsem_down_write+0xd3/0x113 [<ffffffff83dbbfad>] ? tty_ldisc_lock_pair_timeout+0xcd/0x120 [<ffffffff8118264d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff83dbbfad>] tty_ldisc_lock_pair_timeout+0xcd/0x120 [<ffffffff81c3df60>] tty_ldisc_hangup+0xd0/0x220 [<ffffffff81c35bd7>] __tty_hangup+0x137/0x4f0 [<ffffffff81c37c7c>] disassociate_ctty+0x6c/0x230 [<ffffffff8111290c>] do_exit+0x41c/0x590 [<ffffffff8107ad34>] ? syscall_trace_enter+0x24/0x2e0 [<ffffffff81112b4a>] do_group_exit+0x8a/0xc0 [<ffffffff81112b92>] sys_exit_group+0x12/0x20 [<ffffffff83dc49d8>] tracesys+0xe1/0xe6 1 lock held by init/1: #0: (&tty->ldisc_sem){++++++}, at: [<ffffffff83dbbfad>] tty_ldisc_lock_pair_timeout+0xcd/0x120 Reported-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15tty: Signal foreground group processes in hangupPeter Hurley
When the session leader is exiting, signal the foreground group processes as part of the hangup sequence, instead of after the hangup is complete. This prepares for hanging up the line discipline _after_ signalling processes which may be blocking on ldisc i/o. Parameterize __tty_hangup() to distinguish between when the session leader is exiting and all other hangups; signal the foreground group after signalling the session leader and its process group, which preserves the original signal order. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15tty: Use spin_lock() inside existing critical regionPeter Hurley
The interrupt state does not need to be saved, disabled and restored here; interrupts are already off because this lock is bracketed by spin_lock_irq/spin_unlock_irq. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15tty: Fix spinlock flavor in non-atomic __tty_hangup()Peter Hurley
__tty_hangup() and tty_vhangup() cannot be called from atomic context, so locks do not need to preserve the interrupt state (although, still disable interrupts). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15tty: Refactor session leader SIGHUP from __tty_hangup()Peter Hurley
Reduce complexity of __tty_hangup(); separate SIGHUP signalling into tty_signal_session_leader(). Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-27more file_inode() open-coded instancesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-21Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 update from Martin Schwidefsky: "The most prominent change in this patch set is the software dirty bit patch for s390. It removes __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY and the page_test_and_clear_dirty primitive which makes the common memory management code a bit less obscure. Heiko fixed most of the PCI related fallout, more often than not missing GENERIC_HARDIRQS dependencies. Notable is one of the 3270 patches which adds an export to tty_io to be able to resize a tty. The rest is the usual bunch of cleanups and bug fixes." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits) s390/module: Add missing R_390_NONE relocation type drivers/gpio: add missing GENERIC_HARDIRQ dependency drivers/input: add couple of missing GENERIC_HARDIRQS dependencies s390/cleanup: rename SPP to LPP s390/mm: implement software dirty bits s390/mm: Fix crst upgrade of mmap with MAP_FIXED s390/linker skript: discard exit.data at runtime drivers/media: add missing GENERIC_HARDIRQS dependency s390/bpf,jit: add vlan tag support drivers/net,AT91RM9200: add missing GENERIC_HARDIRQS dependency iucv: fix kernel panic at reboot s390/Kconfig: sort list of arch selected config options phylib: remove !S390 dependeny from Kconfig uio: remove !S390 dependency from Kconfig dasd: fix sysfs cleanup in dasd_generic_remove s390/pci: fix hotplug module init s390/pci: cleanup clp page allocation s390/pci: cleanup clp inline assembly s390/perf: cpum_cf: fallback to software sampling events s390/mm: provide PAGE_SHARED define ...
2013-02-21Merge tag 'tty-3.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial patches from Greg Kroah-Hartman: "Here's the big tty/serial driver patches for 3.9-rc1. More tty port rework and fixes from Jiri here, as well as lots of individual serial driver updates and fixes. All of these have been in the linux-next tree for a while." * tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits) tty: mxser: improve error handling in mxser_probe() and mxser_module_init() serial: imx: fix uninitialized variable warning serial: tegra: assume CONFIG_OF TTY: do not update atime/mtime on read/write lguest: select CONFIG_TTY to build properly. ARM defconfigs: add missing inclusions of linux/platform_device.h fb/exynos: include platform_device.h ARM: sa1100/assabet: include platform_device.h directly serial: imx: Fix recursive locking bug pps: Fix build breakage from decoupling pps from tty tty: Remove ancient hardpps() pps: Additional cleanups in uart_handle_dcd_change pps: Move timestamp read into PPS code proper pps: Don't crash the machine when exiting will do pps: Fix a use-after free bug when unregistering a source. pps: Use pps_lookup_dev to reduce ldisc coupling pps: Add pps_lookup_dev() function tty: serial: uartlite: Support uartlite on big and little endian systems tty: serial: uartlite: Fix sparse and checkpatch warnings serial/arc-uart: Miscll DT related updates (Grant's review comments) ... Fix up trivial conflicts, mostly just due to the TTY config option clashing with the EXPERIMENTAL removal.
2013-02-15TTY: do not update atime/mtime on read/writeJiri Slaby
On http://vladz.devzero.fr/013_ptmx-timing.php, we can see how to find out length of a password using timestamps of /dev/ptmx. It is documented in "Timing Analysis of Keystrokes and Timing Attacks on SSH". To avoid that problem, do not update time when reading from/writing to a TTY. I am afraid of regressions as this is a behavior we have since 0.97 and apps may expect the time to be current, e.g. for monitoring whether there was a change on the TTY. Now, there is no change. So this would better have a lot of testing before it goes upstream. References: CVE-2013-0160 Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: stable <stable@vger.kernel.org> # after 3.9 is out Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14s390/3270: asynchronous size sensingMartin Schwidefsky
Convert the synchronous size sense code to an interrupt driven approach. This allows to set the device online even if the terminal is not connected. With the new code views can be registered without a connected terminal, the tty can be opened as soon as the device is online. After the terminal has been connected and the size has been determined the tty is resized to match the device characteristics.. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-02-06TTY: mark tty_get_device call with the proper const valuesGreg Kroah-Hartman
Michał's previous patch missed this tty check to fix up the class_find_device() arguments. Reported-by: kbuild test robot <fengguang.wu@intel.com> Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15tty: Fix comments that reference BKL, eventd, old pathsKevin Cernekee
Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-21tty: Mark tty_del_file and __tty_hangup staticJosh Triplett
Nothing outside of drivers/tty/tty_io.c references these functions, so mark them static. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-25tty: Add get- ioctls to fetch tty status v3Cyrill Gorcunov
For checkpoint/restore we need to know if tty has exclusive or packet mode set, as well as if pty is currently locked. Just to be able to restore this characteristics. For this sake the following ioctl codes are introduced - TIOCGPKT to get packet mode state - TIOCGPTLCK to get Pty locked state - TIOCGEXCL to get Exclusive mode state Note this ioctls are a bit unsafe in terms of data obtained consistency. The tty characteristics might be changed right after ioctl complete. Keep it in mind and use this ioctl carefully. v2: - Use TIOC prefix for ioctl codes (by jslaby@) Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> CC: Alan Cox <alan@lxorguk.ukuu.org.uk> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Pavel Emelyanov <xemul@parallels.com> CC: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move tty buffers to tty_portJiri Slaby
So this is it. The big step why we did all the work over the past kernel releases. Now everything is prepared, so nothing protects us from doing that big step. | | \ \ nnnn/^l | | | | \ / / | | | '-,.__ => \/ ,-` => | '-,.__ | O __.´´) ( .` | O __.´´) ~~~ ~~ `` ~~~ ~~ The buffers are now in the tty_port structure and we can start teaching the buffer helpers (insert char/string, flip etc.) to use tty_port instead of tty_struct all around. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: add port -> tty linkJiri Slaby
For that purpose we have to temporarily introduce a second tty back pointer into tty_port. It is because serial layer, and maybe others, still do not use tty_port_tty_set/get. So that we cannot set the tty_port->tty to NULL at will now. Yes, the fix would be to convert whole serial layer and all its users to tty_port_tty_set/get. However we are in the process of removing the need of tty in most of the call sites, so this would lead to a duplicated work. Instead we have now tty_port->itty (internal tty) which will be used only in flush_to_ldisc. For that one it is ensured that itty is valid wherever the work is run. IOW, the work is synchronously cancelled before we set itty to NULL and also before hangup is processed. After we need only tty_port and not tty_struct in most code, this shall be changed to tty_port_tty_set/get and itty removed completely. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move ldisc data from tty_struct: locksJiri Slaby
atomic_write_lock is not n_tty specific, so move it up in the tty_struct. And since these are the last ones to move, remove also the comment saying there are some ldisc' members. There are none now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move ldisc data from tty_struct: simple membersJiri Slaby
Here we start moving all the n_tty related bits from tty_struct to the newly defined n_tty_data struct in n_tty proper. In this patch primitive members and bits are moved. The rest will be done per-partes in the next patches. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move devpts kill to ptyJiri Slaby
Now that we have control over tty->driver_data in pty, we can just kill the /dev/pts/ in pty code too. Namely, in ->shutdown hook of tty. For pty, this is called only once, for whichever end is closed last. But we don't care, both driver_data are the inode as it used to be till now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs update from Al Viro: - big one - consolidation of descriptor-related logics; almost all of that is moved to fs/file.c (BTW, I'm seriously tempted to rename the result to fd.c. As it is, we have a situation when file_table.c is about handling of struct file and file.c is about handling of descriptor tables; the reasons are historical - file_table.c used to be about a static array of struct file we used to have way back). A lot of stray ends got cleaned up and converted to saner primitives, disgusting mess in android/binder.c is still disgusting, but at least doesn't poke so much in descriptor table guts anymore. A bunch of relatively minor races got fixed in process, plus an ext4 struct file leak. - related thing - fget_light() partially unuglified; see fdget() in there (and yes, it generates the code as good as we used to have). - also related - bits of Cyrill's procfs stuff that got entangled into that work; _not_ all of it, just the initial move to fs/proc/fd.c and switch of fdinfo to seq_file. - Alex's fs/coredump.c spiltoff - the same story, had been easier to take that commit than mess with conflicts. The rest is a separate pile, this was just a mechanical code movement. - a few misc patches all over the place. Not all for this cycle, there'll be more (and quite a few currently sit in akpm's tree)." Fix up trivial conflicts in the android binder driver, and some fairly simple conflicts due to two different changes to the sock_alloc_file() interface ("take descriptor handling from sock_alloc_file() to callers" vs "net: Providing protocol type via system.sockprotoname xattr of /proc/PID/fd entries" adding a dentry name to the socket) * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits) MAX_LFS_FILESIZE should be a loff_t compat: fs: Generic compat_sys_sendfile implementation fs: push rcu_barrier() from deactivate_locked_super() to filesystems btrfs: reada_extent doesn't need kref for refcount coredump: move core dump functionality into its own file coredump: prevent double-free on an error path in core dumper usb/gadget: fix misannotations fcntl: fix misannotations ceph: don't abuse d_delete() on failure exits hypfs: ->d_parent is never NULL or negative vfs: delete surplus inode NULL check switch simple cases of fget_light to fdget new helpers: fdget()/fdput() switch o2hb_region_dev_write() to fget_light() proc_map_files_readdir(): don't bother with grabbing files make get_file() return its argument vhost_set_vring(): turn pollstart/pollstop into bool switch prctl_set_mm_exe_file() to fget_light() switch xfs_find_handle() to fget_light() switch xfs_swapext() to fget_light() ...
2012-09-26make get_file() return its argumentAl Viro
simplifies a bunch of callers... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26new helper: iterate_fd()Al Viro
iterates through the opened files in given descriptor table, calling a supplied function; we stop once non-zero is returned. Callback gets struct file *, descriptor number and const void * argument passed to iterator. It is called with files->file_lock held, so it is not allowed to block. tty_io, netprio_cgroup and selinux flush_unauthorized_files() converted to its use. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-06tty_register_device_attr updated for tty-nextTomas Hlavacek
Added tty_device_create_release() and bound to dev->release in tty_register_device_attr(). Added tty_port_register_device_attr() and used in uart_add_one_port() instead of tty_register_device_attr(). Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-06tty: uartclk value from serial_core exposed to sysfsTomas Hlavacek
Added file /sys/devices/.../tty/ttySX/uartclk to allow reading uartclk value in struct uart_port in serial_core via sysfs. tty_register_device() has been generalized and refactored in order to add support for setting drvdata and attribute_group to the device. Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-05drivers:tty:fix up ENOIOCTLCMD error handlingWanlong Gao
At commit 07d106d0, Linus pointed out that ENOIOCTLCMD should be translated as ENOTTY to user mode. For example: fd = open("/dev/tty", O_RDWR); ioctl(fd, -1, &argp); then the errno should be ENOTTY but not EINVAL. Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-17TTY: check if tty->port is assignedJiri Slaby
And if not, complain loudly. None in-kernel module should trigger that, but let us find out for sure. On the other hand, all the out-of-tree modules will hit that. Give them some time (maybe one release) to catch up. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-13TTY: move cdev_add to tty_register_deviceJiri Slaby
We need the /dev/ node not to be available before we call tty_register_device. Otherwise we might race with open and tty_struct->port might not be available at that time. This is not an issue now, but would be a problem after "TTY: use tty_port_register_device" is applied. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-13TTY: add support for unnumbered device nodesJiri Slaby
This allows drivers like ttyprintk to avoid hacks to create an unnumbered node in /dev. It used to set TTY_DRIVER_DYNAMIC_DEV in flags and call device_create on its own. That is incorrect, because TTY_DRIVER_DYNAMIC_DEV may be set only if tty_register_device is called explicitly. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-13TTY: move allocations to tty_alloc_driverJiri Slaby
So now, that we have flags and know everything needed, keep a promise and move all the tables and ports allocation from tty_register_driver to tty_alloc_driver. Not only that it makes sense, but we need this for tty_port_link_device which needs tty_driver->ports but is to be called before tty_register_driver. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-10TTY: pass flags to alloc_tty_driverJiri Slaby
We need to allow drivers that use neither tty_port_install nor tty_port_register_device to link a tty_port to a tty somehow. To avoid a race with open, this has to be performed before tty_register_device. But currently tty_driver->ports is allocated even in tty_register_device because we do not know whether this is the PTY driver. The PTY driver is special here due to an excessive count of lines it declares to handle. We cannot handle tty_ports there this way. To circumvent this, we start passing tty_driver flags to alloc_tty_driver already and we create tty_alloc_driver for this purpose. There we can allocate tty_driver->ports and do all the magic between tty_alloc_driver and tty_register_device. Later we will introduce tty_port_link_device function for that purpose. All drivers should eventually switch to this new tty driver allocation interface. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-18 04:49:36 +0000