mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-29 15:43:59 +08:00
dee4a0be69
Commits6a1c0680cf
and9356b535fc
, 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>
710 lines
24 KiB
C
710 lines
24 KiB
C
#ifndef _LINUX_TTY_H
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#define _LINUX_TTY_H
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#include <linux/fs.h>
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#include <linux/major.h>
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#include <linux/termios.h>
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#include <linux/workqueue.h>
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#include <linux/tty_driver.h>
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#include <linux/tty_ldisc.h>
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#include <linux/mutex.h>
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#include <linux/tty_flags.h>
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#include <uapi/linux/tty.h>
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#include <linux/rwsem.h>
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#include <linux/llist.h>
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/*
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* (Note: the *_driver.minor_start values 1, 64, 128, 192 are
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* hardcoded at present.)
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*/
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#define NR_UNIX98_PTY_DEFAULT 4096 /* Default maximum for Unix98 ptys */
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#define NR_UNIX98_PTY_RESERVE 1024 /* Default reserve for main devpts */
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#define NR_UNIX98_PTY_MAX (1 << MINORBITS) /* Absolute limit */
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/*
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* This character is the same as _POSIX_VDISABLE: it cannot be used as
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* a c_cc[] character, but indicates that a particular special character
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* isn't in use (eg VINTR has no character etc)
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*/
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#define __DISABLED_CHAR '\0'
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struct tty_buffer {
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union {
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struct tty_buffer *next;
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struct llist_node free;
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};
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int used;
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int size;
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int commit;
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int read;
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/* Data points here */
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unsigned long data[0];
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};
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static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
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{
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return ((unsigned char *)b->data) + ofs;
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}
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static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
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{
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return (char *)char_buf_ptr(b, ofs) + b->size;
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}
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struct tty_bufhead {
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struct tty_buffer *head; /* Queue head */
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struct work_struct work;
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struct mutex lock;
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atomic_t priority;
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struct tty_buffer sentinel;
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struct llist_head free; /* Free queue head */
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atomic_t memory_used; /* In-use buffers excluding free list */
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struct tty_buffer *tail; /* Active buffer */
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};
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/*
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* When a break, frame error, or parity error happens, these codes are
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* stuffed into the flags buffer.
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*/
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#define TTY_NORMAL 0
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#define TTY_BREAK 1
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#define TTY_FRAME 2
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#define TTY_PARITY 3
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#define TTY_OVERRUN 4
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#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
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#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
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#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
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#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
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#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
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#define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
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#define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
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#define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
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#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
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#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
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#define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
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#define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
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#define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
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#define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
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#define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
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#define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
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#define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
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#define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
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#define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
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#define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
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#define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
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#define I_IGNBRK(tty) _I_FLAG((tty), IGNBRK)
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#define I_BRKINT(tty) _I_FLAG((tty), BRKINT)
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#define I_IGNPAR(tty) _I_FLAG((tty), IGNPAR)
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#define I_PARMRK(tty) _I_FLAG((tty), PARMRK)
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#define I_INPCK(tty) _I_FLAG((tty), INPCK)
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#define I_ISTRIP(tty) _I_FLAG((tty), ISTRIP)
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#define I_INLCR(tty) _I_FLAG((tty), INLCR)
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#define I_IGNCR(tty) _I_FLAG((tty), IGNCR)
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#define I_ICRNL(tty) _I_FLAG((tty), ICRNL)
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#define I_IUCLC(tty) _I_FLAG((tty), IUCLC)
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#define I_IXON(tty) _I_FLAG((tty), IXON)
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#define I_IXANY(tty) _I_FLAG((tty), IXANY)
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#define I_IXOFF(tty) _I_FLAG((tty), IXOFF)
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#define I_IMAXBEL(tty) _I_FLAG((tty), IMAXBEL)
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#define I_IUTF8(tty) _I_FLAG((tty), IUTF8)
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#define O_OPOST(tty) _O_FLAG((tty), OPOST)
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#define O_OLCUC(tty) _O_FLAG((tty), OLCUC)
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#define O_ONLCR(tty) _O_FLAG((tty), ONLCR)
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#define O_OCRNL(tty) _O_FLAG((tty), OCRNL)
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#define O_ONOCR(tty) _O_FLAG((tty), ONOCR)
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#define O_ONLRET(tty) _O_FLAG((tty), ONLRET)
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#define O_OFILL(tty) _O_FLAG((tty), OFILL)
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#define O_OFDEL(tty) _O_FLAG((tty), OFDEL)
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#define O_NLDLY(tty) _O_FLAG((tty), NLDLY)
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#define O_CRDLY(tty) _O_FLAG((tty), CRDLY)
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#define O_TABDLY(tty) _O_FLAG((tty), TABDLY)
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#define O_BSDLY(tty) _O_FLAG((tty), BSDLY)
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#define O_VTDLY(tty) _O_FLAG((tty), VTDLY)
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#define O_FFDLY(tty) _O_FLAG((tty), FFDLY)
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#define C_BAUD(tty) _C_FLAG((tty), CBAUD)
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#define C_CSIZE(tty) _C_FLAG((tty), CSIZE)
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#define C_CSTOPB(tty) _C_FLAG((tty), CSTOPB)
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#define C_CREAD(tty) _C_FLAG((tty), CREAD)
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#define C_PARENB(tty) _C_FLAG((tty), PARENB)
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#define C_PARODD(tty) _C_FLAG((tty), PARODD)
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#define C_HUPCL(tty) _C_FLAG((tty), HUPCL)
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#define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL)
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#define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD)
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#define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS)
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#define L_ISIG(tty) _L_FLAG((tty), ISIG)
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#define L_ICANON(tty) _L_FLAG((tty), ICANON)
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#define L_XCASE(tty) _L_FLAG((tty), XCASE)
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#define L_ECHO(tty) _L_FLAG((tty), ECHO)
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#define L_ECHOE(tty) _L_FLAG((tty), ECHOE)
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#define L_ECHOK(tty) _L_FLAG((tty), ECHOK)
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#define L_ECHONL(tty) _L_FLAG((tty), ECHONL)
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#define L_NOFLSH(tty) _L_FLAG((tty), NOFLSH)
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#define L_TOSTOP(tty) _L_FLAG((tty), TOSTOP)
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#define L_ECHOCTL(tty) _L_FLAG((tty), ECHOCTL)
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#define L_ECHOPRT(tty) _L_FLAG((tty), ECHOPRT)
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#define L_ECHOKE(tty) _L_FLAG((tty), ECHOKE)
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#define L_FLUSHO(tty) _L_FLAG((tty), FLUSHO)
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#define L_PENDIN(tty) _L_FLAG((tty), PENDIN)
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#define L_IEXTEN(tty) _L_FLAG((tty), IEXTEN)
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#define L_EXTPROC(tty) _L_FLAG((tty), EXTPROC)
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struct device;
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struct signal_struct;
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/*
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* Port level information. Each device keeps its own port level information
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* so provide a common structure for those ports wanting to use common support
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* routines.
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*
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* The tty port has a different lifetime to the tty so must be kept apart.
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* In addition be careful as tty -> port mappings are valid for the life
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* of the tty object but in many cases port -> tty mappings are valid only
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* until a hangup so don't use the wrong path.
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*/
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struct tty_port;
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struct tty_port_operations {
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/* Return 1 if the carrier is raised */
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int (*carrier_raised)(struct tty_port *port);
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/* Control the DTR line */
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void (*dtr_rts)(struct tty_port *port, int raise);
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/* Called when the last close completes or a hangup finishes
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IFF the port was initialized. Do not use to free resources. Called
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under the port mutex to serialize against activate/shutdowns */
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void (*shutdown)(struct tty_port *port);
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void (*drop)(struct tty_port *port);
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/* Called under the port mutex from tty_port_open, serialized using
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the port mutex */
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/* FIXME: long term getting the tty argument *out* of this would be
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good for consoles */
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int (*activate)(struct tty_port *port, struct tty_struct *tty);
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/* Called on the final put of a port */
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void (*destruct)(struct tty_port *port);
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};
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struct tty_port {
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struct tty_bufhead buf; /* Locked internally */
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struct tty_struct *tty; /* Back pointer */
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struct tty_struct *itty; /* internal back ptr */
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const struct tty_port_operations *ops; /* Port operations */
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spinlock_t lock; /* Lock protecting tty field */
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int blocked_open; /* Waiting to open */
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int count; /* Usage count */
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wait_queue_head_t open_wait; /* Open waiters */
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wait_queue_head_t close_wait; /* Close waiters */
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wait_queue_head_t delta_msr_wait; /* Modem status change */
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unsigned long flags; /* TTY flags ASY_*/
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unsigned char console:1, /* port is a console */
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low_latency:1; /* direct buffer flush */
|
|
struct mutex mutex; /* Locking */
|
|
struct mutex buf_mutex; /* Buffer alloc lock */
|
|
unsigned char *xmit_buf; /* Optional buffer */
|
|
unsigned int close_delay; /* Close port delay */
|
|
unsigned int closing_wait; /* Delay for output */
|
|
int drain_delay; /* Set to zero if no pure time
|
|
based drain is needed else
|
|
set to size of fifo */
|
|
struct kref kref; /* Ref counter */
|
|
};
|
|
|
|
/*
|
|
* Where all of the state associated with a tty is kept while the tty
|
|
* is open. Since the termios state should be kept even if the tty
|
|
* has been closed --- for things like the baud rate, etc --- it is
|
|
* not stored here, but rather a pointer to the real state is stored
|
|
* here. Possible the winsize structure should have the same
|
|
* treatment, but (1) the default 80x24 is usually right and (2) it's
|
|
* most often used by a windowing system, which will set the correct
|
|
* size each time the window is created or resized anyway.
|
|
* - TYT, 9/14/92
|
|
*/
|
|
|
|
struct tty_operations;
|
|
|
|
struct tty_struct {
|
|
int magic;
|
|
struct kref kref;
|
|
struct device *dev;
|
|
struct tty_driver *driver;
|
|
const struct tty_operations *ops;
|
|
int index;
|
|
|
|
/* Protects ldisc changes: Lock tty not pty */
|
|
struct ld_semaphore ldisc_sem;
|
|
struct tty_ldisc *ldisc;
|
|
|
|
struct mutex atomic_write_lock;
|
|
struct mutex legacy_mutex;
|
|
struct mutex throttle_mutex;
|
|
struct rw_semaphore termios_rwsem;
|
|
struct mutex winsize_mutex;
|
|
spinlock_t ctrl_lock;
|
|
/* Termios values are protected by the termios rwsem */
|
|
struct ktermios termios, termios_locked;
|
|
struct termiox *termiox; /* May be NULL for unsupported */
|
|
char name[64];
|
|
struct pid *pgrp; /* Protected by ctrl lock */
|
|
struct pid *session;
|
|
unsigned long flags;
|
|
int count;
|
|
struct winsize winsize; /* winsize_mutex */
|
|
unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1;
|
|
unsigned char ctrl_status; /* ctrl_lock */
|
|
unsigned int receive_room; /* Bytes free for queue */
|
|
int flow_change;
|
|
|
|
struct tty_struct *link;
|
|
struct fasync_struct *fasync;
|
|
int alt_speed; /* For magic substitution of 38400 bps */
|
|
wait_queue_head_t write_wait;
|
|
wait_queue_head_t read_wait;
|
|
struct work_struct hangup_work;
|
|
void *disc_data;
|
|
void *driver_data;
|
|
struct list_head tty_files;
|
|
|
|
#define N_TTY_BUF_SIZE 4096
|
|
|
|
unsigned char closing:1;
|
|
unsigned char *write_buf;
|
|
int write_cnt;
|
|
/* If the tty has a pending do_SAK, queue it here - akpm */
|
|
struct work_struct SAK_work;
|
|
struct tty_port *port;
|
|
};
|
|
|
|
/* Each of a tty's open files has private_data pointing to tty_file_private */
|
|
struct tty_file_private {
|
|
struct tty_struct *tty;
|
|
struct file *file;
|
|
struct list_head list;
|
|
};
|
|
|
|
/* tty magic number */
|
|
#define TTY_MAGIC 0x5401
|
|
|
|
/*
|
|
* These bits are used in the flags field of the tty structure.
|
|
*
|
|
* So that interrupts won't be able to mess up the queues,
|
|
* copy_to_cooked must be atomic with respect to itself, as must
|
|
* tty->write. Thus, you must use the inline functions set_bit() and
|
|
* clear_bit() to make things atomic.
|
|
*/
|
|
#define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */
|
|
#define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */
|
|
#define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */
|
|
#define TTY_EXCLUSIVE 3 /* Exclusive open mode */
|
|
#define TTY_DEBUG 4 /* Debugging */
|
|
#define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */
|
|
#define TTY_CLOSING 7 /* ->close() in progress */
|
|
#define TTY_LDISC_OPEN 11 /* Line discipline is open */
|
|
#define TTY_PTY_LOCK 16 /* pty private */
|
|
#define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */
|
|
#define TTY_HUPPED 18 /* Post driver->hangup() */
|
|
#define TTY_HUPPING 21 /* ->hangup() in progress */
|
|
#define TTY_LDISC_HALTED 22 /* Line discipline is halted */
|
|
|
|
#define TTY_WRITE_FLUSH(tty) tty_write_flush((tty))
|
|
|
|
/* Values for tty->flow_change */
|
|
#define TTY_THROTTLE_SAFE 1
|
|
#define TTY_UNTHROTTLE_SAFE 2
|
|
|
|
static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
|
|
{
|
|
tty->flow_change = val;
|
|
}
|
|
|
|
static inline void tty_set_flow_change(struct tty_struct *tty, int val)
|
|
{
|
|
tty->flow_change = val;
|
|
smp_mb();
|
|
}
|
|
|
|
#ifdef CONFIG_TTY
|
|
extern void console_init(void);
|
|
extern void tty_kref_put(struct tty_struct *tty);
|
|
extern struct pid *tty_get_pgrp(struct tty_struct *tty);
|
|
extern void tty_vhangup_self(void);
|
|
extern void disassociate_ctty(int priv);
|
|
extern dev_t tty_devnum(struct tty_struct *tty);
|
|
extern void proc_clear_tty(struct task_struct *p);
|
|
extern struct tty_struct *get_current_tty(void);
|
|
/* tty_io.c */
|
|
extern int __init tty_init(void);
|
|
#else
|
|
static inline void console_init(void)
|
|
{ }
|
|
static inline void tty_kref_put(struct tty_struct *tty)
|
|
{ }
|
|
static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
|
|
{ return NULL; }
|
|
static inline void tty_vhangup_self(void)
|
|
{ }
|
|
static inline void disassociate_ctty(int priv)
|
|
{ }
|
|
static inline dev_t tty_devnum(struct tty_struct *tty)
|
|
{ return 0; }
|
|
static inline void proc_clear_tty(struct task_struct *p)
|
|
{ }
|
|
static inline struct tty_struct *get_current_tty(void)
|
|
{ return NULL; }
|
|
/* tty_io.c */
|
|
static inline int __init tty_init(void)
|
|
{ return 0; }
|
|
#endif
|
|
|
|
extern void tty_write_flush(struct tty_struct *);
|
|
|
|
extern struct ktermios tty_std_termios;
|
|
|
|
extern int vcs_init(void);
|
|
|
|
extern struct class *tty_class;
|
|
|
|
/**
|
|
* tty_kref_get - get a tty reference
|
|
* @tty: tty device
|
|
*
|
|
* Return a new reference to a tty object. The caller must hold
|
|
* sufficient locks/counts to ensure that their existing reference cannot
|
|
* go away
|
|
*/
|
|
|
|
static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
|
|
{
|
|
if (tty)
|
|
kref_get(&tty->kref);
|
|
return tty;
|
|
}
|
|
|
|
extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
|
|
const char *routine);
|
|
extern char *tty_name(struct tty_struct *tty, char *buf);
|
|
extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
|
|
extern int tty_check_change(struct tty_struct *tty);
|
|
extern void stop_tty(struct tty_struct *tty);
|
|
extern void start_tty(struct tty_struct *tty);
|
|
extern int tty_register_driver(struct tty_driver *driver);
|
|
extern int tty_unregister_driver(struct tty_driver *driver);
|
|
extern struct device *tty_register_device(struct tty_driver *driver,
|
|
unsigned index, struct device *dev);
|
|
extern struct device *tty_register_device_attr(struct tty_driver *driver,
|
|
unsigned index, struct device *device,
|
|
void *drvdata,
|
|
const struct attribute_group **attr_grp);
|
|
extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
|
|
extern int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
|
|
int buflen);
|
|
extern void tty_write_message(struct tty_struct *tty, char *msg);
|
|
extern int tty_put_char(struct tty_struct *tty, unsigned char c);
|
|
extern int tty_chars_in_buffer(struct tty_struct *tty);
|
|
extern int tty_write_room(struct tty_struct *tty);
|
|
extern void tty_driver_flush_buffer(struct tty_struct *tty);
|
|
extern void tty_throttle(struct tty_struct *tty);
|
|
extern void tty_unthrottle(struct tty_struct *tty);
|
|
extern int tty_throttle_safe(struct tty_struct *tty);
|
|
extern int tty_unthrottle_safe(struct tty_struct *tty);
|
|
extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
|
|
extern void tty_driver_remove_tty(struct tty_driver *driver,
|
|
struct tty_struct *tty);
|
|
extern void tty_free_termios(struct tty_struct *tty);
|
|
extern int is_current_pgrp_orphaned(void);
|
|
extern int is_ignored(int sig);
|
|
extern int tty_signal(int sig, struct tty_struct *tty);
|
|
extern void tty_hangup(struct tty_struct *tty);
|
|
extern void tty_vhangup(struct tty_struct *tty);
|
|
extern void tty_vhangup_locked(struct tty_struct *tty);
|
|
extern void tty_unhangup(struct file *filp);
|
|
extern int tty_hung_up_p(struct file *filp);
|
|
extern void do_SAK(struct tty_struct *tty);
|
|
extern void __do_SAK(struct tty_struct *tty);
|
|
extern void no_tty(void);
|
|
extern void tty_flush_to_ldisc(struct tty_struct *tty);
|
|
extern void tty_buffer_free_all(struct tty_port *port);
|
|
extern void tty_buffer_flush(struct tty_struct *tty);
|
|
extern void tty_buffer_init(struct tty_port *port);
|
|
extern speed_t tty_termios_baud_rate(struct ktermios *termios);
|
|
extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
|
|
extern void tty_termios_encode_baud_rate(struct ktermios *termios,
|
|
speed_t ibaud, speed_t obaud);
|
|
extern void tty_encode_baud_rate(struct tty_struct *tty,
|
|
speed_t ibaud, speed_t obaud);
|
|
|
|
/**
|
|
* tty_get_baud_rate - get tty bit rates
|
|
* @tty: tty to query
|
|
*
|
|
* Returns the baud rate as an integer for this terminal. The
|
|
* termios lock must be held by the caller and the terminal bit
|
|
* flags may be updated.
|
|
*
|
|
* Locking: none
|
|
*/
|
|
static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
|
|
{
|
|
return tty_termios_baud_rate(&tty->termios);
|
|
}
|
|
|
|
extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
|
|
extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
|
|
extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
|
|
|
|
extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
|
|
extern void tty_ldisc_deref(struct tty_ldisc *);
|
|
extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
|
|
extern void tty_ldisc_hangup(struct tty_struct *tty);
|
|
extern const struct file_operations tty_ldiscs_proc_fops;
|
|
|
|
extern void tty_wakeup(struct tty_struct *tty);
|
|
extern void tty_ldisc_flush(struct tty_struct *tty);
|
|
|
|
extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
|
|
extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
|
|
unsigned int cmd, unsigned long arg);
|
|
extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
|
|
extern void tty_default_fops(struct file_operations *fops);
|
|
extern struct tty_struct *alloc_tty_struct(void);
|
|
extern int tty_alloc_file(struct file *file);
|
|
extern void tty_add_file(struct tty_struct *tty, struct file *file);
|
|
extern void tty_free_file(struct file *file);
|
|
extern void free_tty_struct(struct tty_struct *tty);
|
|
extern void initialize_tty_struct(struct tty_struct *tty,
|
|
struct tty_driver *driver, int idx);
|
|
extern void deinitialize_tty_struct(struct tty_struct *tty);
|
|
extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
|
|
extern int tty_release(struct inode *inode, struct file *filp);
|
|
extern int tty_init_termios(struct tty_struct *tty);
|
|
extern int tty_standard_install(struct tty_driver *driver,
|
|
struct tty_struct *tty);
|
|
|
|
extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
|
|
extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
|
|
|
|
extern struct mutex tty_mutex;
|
|
extern spinlock_t tty_files_lock;
|
|
|
|
extern void tty_write_unlock(struct tty_struct *tty);
|
|
extern int tty_write_lock(struct tty_struct *tty, int ndelay);
|
|
#define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock))
|
|
|
|
extern void tty_port_init(struct tty_port *port);
|
|
extern void tty_port_link_device(struct tty_port *port,
|
|
struct tty_driver *driver, unsigned index);
|
|
extern struct device *tty_port_register_device(struct tty_port *port,
|
|
struct tty_driver *driver, unsigned index,
|
|
struct device *device);
|
|
extern struct device *tty_port_register_device_attr(struct tty_port *port,
|
|
struct tty_driver *driver, unsigned index,
|
|
struct device *device, void *drvdata,
|
|
const struct attribute_group **attr_grp);
|
|
extern int tty_port_alloc_xmit_buf(struct tty_port *port);
|
|
extern void tty_port_free_xmit_buf(struct tty_port *port);
|
|
extern void tty_port_destroy(struct tty_port *port);
|
|
extern void tty_port_put(struct tty_port *port);
|
|
|
|
static inline struct tty_port *tty_port_get(struct tty_port *port)
|
|
{
|
|
if (port)
|
|
kref_get(&port->kref);
|
|
return port;
|
|
}
|
|
|
|
/* If the cts flow control is enabled, return true. */
|
|
static inline bool tty_port_cts_enabled(struct tty_port *port)
|
|
{
|
|
return port->flags & ASYNC_CTS_FLOW;
|
|
}
|
|
|
|
extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
|
|
extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
|
|
extern int tty_port_carrier_raised(struct tty_port *port);
|
|
extern void tty_port_raise_dtr_rts(struct tty_port *port);
|
|
extern void tty_port_lower_dtr_rts(struct tty_port *port);
|
|
extern void tty_port_hangup(struct tty_port *port);
|
|
extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
|
|
extern void tty_port_tty_wakeup(struct tty_port *port);
|
|
extern int tty_port_block_til_ready(struct tty_port *port,
|
|
struct tty_struct *tty, struct file *filp);
|
|
extern int tty_port_close_start(struct tty_port *port,
|
|
struct tty_struct *tty, struct file *filp);
|
|
extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
|
|
extern void tty_port_close(struct tty_port *port,
|
|
struct tty_struct *tty, struct file *filp);
|
|
extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
|
|
struct tty_struct *tty);
|
|
extern int tty_port_open(struct tty_port *port,
|
|
struct tty_struct *tty, struct file *filp);
|
|
static inline int tty_port_users(struct tty_port *port)
|
|
{
|
|
return port->count + port->blocked_open;
|
|
}
|
|
|
|
extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
|
|
extern int tty_unregister_ldisc(int disc);
|
|
extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
|
|
extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
|
|
extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
|
|
extern void tty_ldisc_init(struct tty_struct *tty);
|
|
extern void tty_ldisc_deinit(struct tty_struct *tty);
|
|
extern void tty_ldisc_begin(void);
|
|
|
|
static inline int tty_ldisc_receive_buf(struct tty_ldisc *ld, unsigned char *p,
|
|
char *f, int count)
|
|
{
|
|
if (ld->ops->receive_buf2)
|
|
count = ld->ops->receive_buf2(ld->tty, p, f, count);
|
|
else {
|
|
count = min_t(int, count, ld->tty->receive_room);
|
|
if (count)
|
|
ld->ops->receive_buf(ld->tty, p, f, count);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
|
|
/* n_tty.c */
|
|
extern struct tty_ldisc_ops tty_ldisc_N_TTY;
|
|
extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
|
|
|
|
/* tty_audit.c */
|
|
#ifdef CONFIG_AUDIT
|
|
extern void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
|
|
size_t size, unsigned icanon);
|
|
extern void tty_audit_exit(void);
|
|
extern void tty_audit_fork(struct signal_struct *sig);
|
|
extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
|
|
extern void tty_audit_push(struct tty_struct *tty);
|
|
extern int tty_audit_push_current(void);
|
|
#else
|
|
static inline void tty_audit_add_data(struct tty_struct *tty,
|
|
unsigned char *data, size_t size, unsigned icanon)
|
|
{
|
|
}
|
|
static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
|
|
{
|
|
}
|
|
static inline void tty_audit_exit(void)
|
|
{
|
|
}
|
|
static inline void tty_audit_fork(struct signal_struct *sig)
|
|
{
|
|
}
|
|
static inline void tty_audit_push(struct tty_struct *tty)
|
|
{
|
|
}
|
|
static inline int tty_audit_push_current(void)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/* tty_ioctl.c */
|
|
extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
|
|
unsigned int cmd, unsigned long arg);
|
|
extern long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
|
|
unsigned int cmd, unsigned long arg);
|
|
|
|
/* serial.c */
|
|
|
|
extern void serial_console_init(void);
|
|
|
|
/* pcxx.c */
|
|
|
|
extern int pcxe_open(struct tty_struct *tty, struct file *filp);
|
|
|
|
/* vt.c */
|
|
|
|
extern int vt_ioctl(struct tty_struct *tty,
|
|
unsigned int cmd, unsigned long arg);
|
|
|
|
extern long vt_compat_ioctl(struct tty_struct *tty,
|
|
unsigned int cmd, unsigned long arg);
|
|
|
|
/* tty_mutex.c */
|
|
/* functions for preparation of BKL removal */
|
|
extern void __lockfunc tty_lock(struct tty_struct *tty);
|
|
extern void __lockfunc tty_unlock(struct tty_struct *tty);
|
|
extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
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|
struct tty_struct *tty2);
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|
extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
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|
struct tty_struct *tty2);
|
|
|
|
/*
|
|
* this shall be called only from where BTM is held (like close)
|
|
*
|
|
* We need this to ensure nobody waits for us to finish while we are waiting.
|
|
* Without this we were encountering system stalls.
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|
*
|
|
* This should be indeed removed with BTM removal later.
|
|
*
|
|
* Locking: BTM required. Nobody is allowed to hold port->mutex.
|
|
*/
|
|
static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
|
|
long timeout)
|
|
{
|
|
tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
|
|
tty_wait_until_sent(tty, timeout);
|
|
tty_lock(tty);
|
|
}
|
|
|
|
/*
|
|
* wait_event_interruptible_tty -- wait for a condition with the tty lock held
|
|
*
|
|
* The condition we are waiting for might take a long time to
|
|
* become true, or might depend on another thread taking the
|
|
* BTM. In either case, we need to drop the BTM to guarantee
|
|
* forward progress. This is a leftover from the conversion
|
|
* from the BKL and should eventually get removed as the BTM
|
|
* falls out of use.
|
|
*
|
|
* Do not use in new code.
|
|
*/
|
|
#define wait_event_interruptible_tty(tty, wq, condition) \
|
|
({ \
|
|
int __ret = 0; \
|
|
if (!(condition)) { \
|
|
__wait_event_interruptible_tty(tty, wq, condition, __ret); \
|
|
} \
|
|
__ret; \
|
|
})
|
|
|
|
#define __wait_event_interruptible_tty(tty, wq, condition, ret) \
|
|
do { \
|
|
DEFINE_WAIT(__wait); \
|
|
\
|
|
for (;;) { \
|
|
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
|
|
if (condition) \
|
|
break; \
|
|
if (!signal_pending(current)) { \
|
|
tty_unlock(tty); \
|
|
schedule(); \
|
|
tty_lock(tty); \
|
|
continue; \
|
|
} \
|
|
ret = -ERESTARTSYS; \
|
|
break; \
|
|
} \
|
|
finish_wait(&wq, &__wait); \
|
|
} while (0)
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
extern void proc_tty_register_driver(struct tty_driver *);
|
|
extern void proc_tty_unregister_driver(struct tty_driver *);
|
|
#else
|
|
static inline void proc_tty_register_driver(struct tty_driver *d) {}
|
|
static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
|
|
#endif
|
|
|
|
#endif
|