kernel/linux.git/include/linux/tty.h, branch v3.13-rc5

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-11-12T01:20:12+00:00

Pull scheduler changes from Ingo Molnar: "The main changes in this cycle are: - (much) improved CONFIG_NUMA_BALANCING support from Mel Gorman, Rik van Riel, Peter Zijlstra et al. Yay! - optimize preemption counter handling: merge the NEED_RESCHED flag into the preempt_count variable, by Peter Zijlstra. - wait.h fixes and code reorganization from Peter Zijlstra - cfs_bandwidth fixes from Ben Segall - SMP load-balancer cleanups from Peter Zijstra - idle balancer improvements from Jason Low - other fixes and cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits) ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED stop_machine: Fix race between stop_two_cpus() and stop_cpus() sched: Remove unnecessary iteration over sched domains to update nr_busy_cpus sched: Fix asymmetric scheduling for POWER7 sched: Move completion code from core.c to completion.c sched: Move wait code from core.c to wait.c sched: Move wait.c into kernel/sched/ sched/wait: Fix __wait_event_interruptible_lock_irq_timeout() sched: Avoid throttle_cfs_rq() racing with period_timer stopping sched: Guarantee new group-entities always have weight sched: Fix hrtimer_cancel()/rq->lock deadlock sched: Fix cfs_bandwidth misuse of hrtimer_expires_remaining sched: Fix race on toggling cfs_bandwidth_used sched: Remove extra put_online_cpus() inside sched_setaffinity() sched/rt: Fix task_tick_rt() comment sched/wait: Fix build breakage sched/wait: Introduce prepare_to_wait_event() sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too sched: Remove get_online_cpus() usage sched: Fix race in migrate_swap_stop() ...

sched/wait: Make the __wait_event*() interface more friendly

2013-10-04T08:16:25+00:00

Change all __wait_event*() implementations to match the corresponding wait_event*() signature for convenience. In particular this does away with the weird 'ret' logic. Since there are __wait_event*() users this requires we update them too. Reviewed-by: Oleg Nesterov Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20131002092529.042563462@infradead.org Signed-off-by: Ingo Molnar

sched/wait: Collapse __wait_event_interruptible_tty()

2013-10-04T08:16:20+00:00

Reduce macro complexity by using the new ___wait_event() helper. No change in behaviour, identical generated code. Reviewed-by: Oleg Nesterov Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20131002092528.831085521@infradead.org Signed-off-by: Ingo Molnar

sched/wait: Make the signal_pending() checks consistent

2013-10-04T08:14:44+00:00

There's two patterns to check signals in the __wait_event*() macros: if (!signal_pending(current)) { schedule(); continue; } ret = -ERESTARTSYS; break; And the more natural: if (signal_pending(current)) { ret = -ERESTARTSYS; break; } schedule(); Change them all into the latter form. Reviewed-by: Oleg Nesterov Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20131002092527.956416254@infradead.org Signed-off-by: Ingo Molnar

tty: Remove unused drop() method from tty_port interface

2013-09-26T01:08:34+00:00

Although originally conceived as a hook for port drivers to know when a port reference is dropped, no driver uses this method. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Fix lock order in tty_do_resize()

2013-07-24T22:12:53+00:00

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: [] tty_do_resize+0x36/0xe0 but task is already holding lock: ((fb_notifier_list).rwsem){.+.+.+}, at: [] __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){.+.+.+}: [] lock_acquire+0x92/0x1f0 [] down_read+0x47/0x5c [] __blocking_notifier_call_chain+0x56/0xc0 [] blocking_notifier_call_chain+0x16/0x20 [] fb_notifier_call_chain+0x1b/0x20 [] register_framebuffer+0x1e2/0x320 [] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [] nouveau_fbcon_init+0x105/0x140 [nouveau] [] nouveau_drm_load+0x43f/0x610 [nouveau] [] drm_get_pci_dev+0x17e/0x2a0 [drm] [] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [] local_pci_probe+0x4b/0x80 [] pci_device_probe+0x111/0x120 [] driver_probe_device+0x8b/0x3a0 [] __driver_attach+0xab/0xb0 [] bus_for_each_dev+0x5d/0xa0 [] driver_attach+0x1e/0x20 [] bus_add_driver+0x111/0x290 [] driver_register+0x77/0x170 [] __pci_register_driver+0x64/0x70 [] drm_pci_init+0x11a/0x130 [drm] [] nouveau_drm_init+0x4d/0x1000 [nouveau] [] do_one_initcall+0xea/0x1a0 [] load_module+0x123b/0x1bf0 [] SyS_init_module+0xd7/0x120 [] system_call_fastpath+0x16/0x1b -> #1 (console_lock){+.+.+.}: [] lock_acquire+0x92/0x1f0 [] console_lock+0x77/0x80 [] con_flush_chars+0x31/0x50 [] n_tty_write+0x1ec/0x4d0 [] tty_write+0x159/0x2e0 [] redirected_tty_write+0xb5/0xc0 [] vfs_write+0xc5/0x1f0 [] SyS_write+0x55/0xa0 [] system_call_fastpath+0x16/0x1b -> #0 (&tty->termios_rwsem){++++..}: [] __lock_acquire+0x1c43/0x1d30 [] lock_acquire+0x92/0x1f0 [] down_write+0x44/0x70 [] tty_do_resize+0x36/0xe0 [] vc_do_resize+0x3e1/0x4c0 [] vc_resize+0x1f/0x30 [] fbcon_init+0x385/0x5a0 [] visual_init+0xbc/0x120 [] do_bind_con_driver+0x163/0x320 [] do_take_over_console+0x61/0x70 [] do_fbcon_takeover+0x63/0xc0 [] fbcon_event_notify+0x715/0x820 [] notifier_call_chain+0x5d/0x110 [] __blocking_notifier_call_chain+0x6c/0xc0 [] blocking_notifier_call_chain+0x16/0x20 [] fb_notifier_call_chain+0x1b/0x20 [] register_framebuffer+0x1e2/0x320 [] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [] nouveau_fbcon_init+0x105/0x140 [nouveau] [] nouveau_drm_load+0x43f/0x610 [nouveau] [] drm_get_pci_dev+0x17e/0x2a0 [drm] [] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [] local_pci_probe+0x4b/0x80 [] pci_device_probe+0x111/0x120 [] driver_probe_device+0x8b/0x3a0 [] __driver_attach+0xab/0xb0 [] bus_for_each_dev+0x5d/0xa0 [] driver_attach+0x1e/0x20 [] bus_add_driver+0x111/0x290 [] driver_register+0x77/0x170 [] __pci_register_driver+0x64/0x70 [] drm_pci_init+0x11a/0x130 [drm] [] nouveau_drm_init+0x4d/0x1000 [nouveau] [] do_one_initcall+0xea/0x1a0 [] load_module+0x123b/0x1bf0 [] SyS_init_module+0xd7/0x120 [] 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: [] __driver_attach+0x5b/0xb0 #1: (&__lockdep_no_validate__){......}, at: [] __driver_attach+0x69/0xb0 #2: (drm_global_mutex){+.+.+.}, at: [] drm_get_pci_dev+0xbd/0x2a0 [drm] #3: (registration_lock){+.+.+.}, at: [] register_framebuffer+0x25/0x320 #4: (&fb_info->lock){+.+.+.}, at: [] lock_fb_info+0x26/0x60 #5: (console_lock){+.+.+.}, at: [] register_framebuffer+0x1d4/0x320 #6: ((fb_notifier_list).rwsem){.+.+.+}, at: [] __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: [] dump_stack+0x19/0x1b [] print_circular_bug+0x1fb/0x20c [] __lock_acquire+0x1c43/0x1d30 [] ? mark_held_locks+0xae/0x120 [] ? trace_hardirqs_on_caller+0x105/0x1d0 [] lock_acquire+0x92/0x1f0 [] ? tty_do_resize+0x36/0xe0 [] down_write+0x44/0x70 [] ? tty_do_resize+0x36/0xe0 [] tty_do_resize+0x36/0xe0 [] vc_do_resize+0x3e1/0x4c0 [] vc_resize+0x1f/0x30 [] fbcon_init+0x385/0x5a0 [] visual_init+0xbc/0x120 [] do_bind_con_driver+0x163/0x320 [] do_take_over_console+0x61/0x70 [] do_fbcon_takeover+0x63/0xc0 [] fbcon_event_notify+0x715/0x820 [] notifier_call_chain+0x5d/0x110 [] __blocking_notifier_call_chain+0x6c/0xc0 [] blocking_notifier_call_chain+0x16/0x20 [] fb_notifier_call_chain+0x1b/0x20 [] register_framebuffer+0x1e2/0x320 [] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [] ? kmemleak_alloc+0x5b/0xc0 [] ? kmem_cache_alloc_trace+0x104/0x290 [] ? drm_fb_helper_single_add_all_connectors+0x81/0xf0 [drm_kms_helper] [] nouveau_fbcon_init+0x105/0x140 [nouveau] [] nouveau_drm_load+0x43f/0x610 [nouveau] [] drm_get_pci_dev+0x17e/0x2a0 [drm] [] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [] ? _raw_spin_unlock_irqrestore+0x42/0x80 [] local_pci_probe+0x4b/0x80 [] pci_device_probe+0x111/0x120 [] driver_probe_device+0x8b/0x3a0 [] __driver_attach+0xab/0xb0 [] ? driver_probe_device+0x3a0/0x3a0 [] bus_for_each_dev+0x5d/0xa0 [] driver_attach+0x1e/0x20 [] bus_add_driver+0x111/0x290 [] ? 0xffffffffa0229fff [] driver_register+0x77/0x170 [] ? 0xffffffffa0229fff [] __pci_register_driver+0x64/0x70 [] drm_pci_init+0x11a/0x130 [drm] [] ? 0xffffffffa0229fff [] ? 0xffffffffa0229fff [] nouveau_drm_init+0x4d/0x1000 [nouveau] [] do_one_initcall+0xea/0x1a0 [] load_module+0x123b/0x1bf0 [] ? ddebug_proc_open+0xb0/0xb0 [] ? trace_hardirqs_on_thunk+0x3a/0x3f [] SyS_init_module+0xd7/0x120 [] system_call_fastpath+0x16/0x1b Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

n_tty: Fix EOF push handling

2013-07-24T00:08:40+00:00

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 Signed-off-by: Greg Kroah-Hartman

tty: Remove private constant from global namespace

2013-07-23T23:47:10+00:00

TTY_BUFFER_PAGE is only used within drivers/tty/tty_buffer.c; relocate to that file scope. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Fix unsafe vt paste_selection()

2013-07-23T23:47:10+00:00

Convert the tty_buffer_flush() exclusion mechanism to a public interface - tty_buffer_lock/unlock_exclusive() - and use the interface to safely write the paste selection to the line discipline. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Use non-atomic state to signal flip buffer flush pending

2013-07-23T23:47:09+00:00

Atomic bit ops are no longer required to indicate a flip buffer flush is pending, as the flush_mutex is sufficient barrier. Remove the unnecessary port .iflags field and localize flip buffer state to struct tty_bufhead. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman