diff options
Diffstat (limited to 'drivers/char/tty_io.c')
| -rw-r--r-- | drivers/char/tty_io.c | 872 |
1 files changed, 184 insertions, 688 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 047a17339f83..e4dce8709541 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -95,8 +95,9 @@ #include <linux/wait.h> #include <linux/bitops.h> #include <linux/delay.h> +#include <linux/seq_file.h> -#include <asm/uaccess.h> +#include <linux/uaccess.h> #include <asm/system.h> #include <linux/kbd_kern.h> @@ -655,478 +656,6 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags); /** - * tty_set_termios_ldisc - set ldisc field - * @tty: tty structure - * @num: line discipline number - * - * This is probably overkill for real world processors but - * they are not on hot paths so a little discipline won't do - * any harm. - * - * Locking: takes termios_mutex - */ - -static void tty_set_termios_ldisc(struct tty_struct *tty, int num) -{ - mutex_lock(&tty->termios_mutex); - tty->termios->c_line = num; - mutex_unlock(&tty->termios_mutex); -} - -/* - * This guards the refcounted line discipline lists. The lock - * must be taken with irqs off because there are hangup path - * callers who will do ldisc lookups and cannot sleep. - */ - -static DEFINE_SPINLOCK(tty_ldisc_lock); -static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait); -/* Line disc dispatch table */ -static struct tty_ldisc tty_ldiscs[NR_LDISCS]; - -/** - * tty_register_ldisc - install a line discipline - * @disc: ldisc number - * @new_ldisc: pointer to the ldisc object - * - * Installs a new line discipline into the kernel. The discipline - * is set up as unreferenced and then made available to the kernel - * from this point onwards. - * - * Locking: - * takes tty_ldisc_lock to guard against ldisc races - */ - -int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc) -{ - unsigned long flags; - int ret = 0; - - if (disc < N_TTY || disc >= NR_LDISCS) - return -EINVAL; - - spin_lock_irqsave(&tty_ldisc_lock, flags); - tty_ldiscs[disc] = *new_ldisc; - tty_ldiscs[disc].num = disc; - tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED; - tty_ldiscs[disc].refcount = 0; - spin_unlock_irqrestore(&tty_ldisc_lock, flags); - - return ret; -} -EXPORT_SYMBOL(tty_register_ldisc); - -/** - * tty_unregister_ldisc - unload a line discipline - * @disc: ldisc number - * @new_ldisc: pointer to the ldisc object - * - * Remove a line discipline from the kernel providing it is not - * currently in use. - * - * Locking: - * takes tty_ldisc_lock to guard against ldisc races - */ - -int tty_unregister_ldisc(int disc) -{ - unsigned long flags; - int ret = 0; - - if (disc < N_TTY || disc >= NR_LDISCS) - return -EINVAL; - - spin_lock_irqsave(&tty_ldisc_lock, flags); - if (tty_ldiscs[disc].refcount) - ret = -EBUSY; - else - tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED; - spin_unlock_irqrestore(&tty_ldisc_lock, flags); - - return ret; -} -EXPORT_SYMBOL(tty_unregister_ldisc); - -/** - * tty_ldisc_get - take a reference to an ldisc - * @disc: ldisc number - * - * Takes a reference to a line discipline. Deals with refcounts and - * module locking counts. Returns NULL if the discipline is not available. - * Returns a pointer to the discipline and bumps the ref count if it is - * available - * - * Locking: - * takes tty_ldisc_lock to guard against ldisc races - */ - -struct tty_ldisc *tty_ldisc_get(int disc) -{ - unsigned long flags; - struct tty_ldisc *ld; - - if (disc < N_TTY || disc >= NR_LDISCS) - return NULL; - - spin_lock_irqsave(&tty_ldisc_lock, flags); - - ld = &tty_ldiscs[disc]; - /* Check the entry is defined */ - if (ld->flags & LDISC_FLAG_DEFINED) { - /* If the module is being unloaded we can't use it */ - if (!try_module_get(ld->owner)) - ld = NULL; - else /* lock it */ - ld->refcount++; - } else - ld = NULL; - spin_unlock_irqrestore(&tty_ldisc_lock, flags); - return ld; -} - -EXPORT_SYMBOL_GPL(tty_ldisc_get); - -/** - * tty_ldisc_put - drop ldisc reference - * @disc: ldisc number - * - * Drop a reference to a line discipline. Manage refcounts and - * module usage counts - * - * Locking: - * takes tty_ldisc_lock to guard against ldisc races - */ - -void tty_ldisc_put(int disc) -{ - struct tty_ldisc *ld; - unsigned long flags; - - BUG_ON(disc < N_TTY || disc >= NR_LDISCS); - - spin_lock_irqsave(&tty_ldisc_lock, flags); - ld = &tty_ldiscs[disc]; - BUG_ON(ld->refcount == 0); - ld->refcount--; - module_put(ld->owner); - spin_unlock_irqrestore(&tty_ldisc_lock, flags); -} - -EXPORT_SYMBOL_GPL(tty_ldisc_put); - -/** - * tty_ldisc_assign - set ldisc on a tty - * @tty: tty to assign - * @ld: line discipline - * - * Install an instance of a line discipline into a tty structure. The - * ldisc must have a reference count above zero to ensure it remains/ - * The tty instance refcount starts at zero. - * - * Locking: - * Caller must hold references - */ - -static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld) -{ - tty->ldisc = *ld; - tty->ldisc.refcount = 0; -} - -/** - * tty_ldisc_try - internal helper - * @tty: the tty - * - * Make a single attempt to grab and bump the refcount on - * the tty ldisc. Return 0 on failure or 1 on success. This is - * used to implement both the waiting and non waiting versions - * of tty_ldisc_ref - * - * Locking: takes tty_ldisc_lock - */ - -static int tty_ldisc_try(struct tty_struct *tty) -{ - unsigned long flags; - struct tty_ldisc *ld; - int ret = 0; - - spin_lock_irqsave(&tty_ldisc_lock, flags); - ld = &tty->ldisc; - if (test_bit(TTY_LDISC, &tty->flags)) { - ld->refcount++; - ret = 1; - } - spin_unlock_irqrestore(&tty_ldisc_lock, flags); - return ret; -} - -/** - * tty_ldisc_ref_wait - wait for the tty ldisc - * @tty: tty device - * - * Dereference the line discipline for the terminal and take a - * reference to it. If the line discipline is in flux then - * wait patiently until it changes. - * - * Note: Must not be called from an IRQ/timer context. The caller - * must also be careful not to hold other locks that will deadlock - * against a discipline change, such as an existing ldisc reference - * (which we check for) - * - * Locking: call functions take tty_ldisc_lock - */ - -struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty) -{ - /* wait_event is a macro */ - wait_event(tty_ldisc_wait, tty_ldisc_try(tty)); - if (tty->ldisc.refcount == 0) - printk(KERN_ERR "tty_ldisc_ref_wait\n"); - return &tty->ldisc; -} - -EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait); - -/** - * tty_ldisc_ref - get the tty ldisc - * @tty: tty device - * - * Dereference the line discipline for the terminal and take a - * reference to it. If the line discipline is in flux then - * return NULL. Can be called from IRQ and timer functions. - * - * Locking: called functions take tty_ldisc_lock - */ - -struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty) -{ - if (tty_ldisc_try(tty)) - return &tty->ldisc; - return NULL; -} - -EXPORT_SYMBOL_GPL(tty_ldisc_ref); - -/** - * tty_ldisc_deref - free a tty ldisc reference - * @ld: reference to free up - * - * Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May - * be called in IRQ context. - * - * Locking: takes tty_ldisc_lock - */ - -void tty_ldisc_deref(struct tty_ldisc *ld) -{ - unsigned long flags; - - BUG_ON(ld == NULL); - - spin_lock_irqsave(&tty_ldisc_lock, flags); - if (ld->refcount == 0) - printk(KERN_ERR "tty_ldisc_deref: no references.\n"); - else - ld->refcount--; - if (ld->refcount == 0) - wake_up(&tty_ldisc_wait); - spin_unlock_irqrestore(&tty_ldisc_lock, flags); -} - -EXPORT_SYMBOL_GPL(tty_ldisc_deref); - -/** - * tty_ldisc_enable - allow ldisc use - * @tty: terminal to activate ldisc on - * - * Set the TTY_LDISC flag when the line discipline can be called - * again. Do necessary wakeups for existing sleepers. - * - * Note: nobody should set this bit except via this function. Clearing - * directly is allowed. - */ - -static void tty_ldisc_enable(struct tty_struct *tty) -{ - set_bit(TTY_LDISC, &tty->flags); - wake_up(&tty_ldisc_wait); -} - -/** - * tty_set_ldisc - set line discipline - * @tty: the terminal to set - * @ldisc: the line discipline - * - * Set the discipline of a tty line. Must be called from a process - * context. - * - * Locking: takes tty_ldisc_lock. - * called functions take termios_mutex - */ - -static int tty_set_ldisc(struct tty_struct *tty, int ldisc) -{ - int retval = 0; - struct tty_ldisc o_ldisc; - char buf[64]; - int work; - unsigned long flags; - struct tty_ldisc *ld; - struct tty_struct *o_tty; - - if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS)) - return -EINVAL; - -restart: - - ld = tty_ldisc_get(ldisc); - /* Eduardo Blanco <ejbs@cs.cs.com.uy> */ - /* Cyrus Durgin <cider@speakeasy.org> */ - if (ld == NULL) { - request_module("tty-ldisc-%d", ldisc); - ld = tty_ldisc_get(ldisc); - } - if (ld == NULL) - return -EINVAL; - - /* - * Problem: What do we do if this blocks ? - */ - - tty_wait_until_sent(tty, 0); - - if (tty->ldisc.num == ldisc) { - tty_ldisc_put(ldisc); - return 0; - } - - /* - * No more input please, we are switching. The new ldisc - * will update this value in the ldisc open function - */ - - tty->receive_room = 0; - - o_ldisc = tty->ldisc; - o_tty = tty->link; - - /* - * Make sure we don't change while someone holds a - * reference to the line discipline. The TTY_LDISC bit - * prevents anyone taking a reference once it is clear. - * We need the lock to avoid racing reference takers. - */ - - spin_lock_irqsave(&tty_ldisc_lock, flags); - if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) { - if (tty->ldisc.refcount) { - /* Free the new ldisc we grabbed. Must drop the lock - first. */ - spin_unlock_irqrestore(&tty_ldisc_lock, flags); - tty_ldisc_put(ldisc); - /* - * There are several reasons we may be busy, including - * random momentary I/O traffic. We must therefore - * retry. We could distinguish between blocking ops - * and retries if we made tty_ldisc_wait() smarter. - * That is up for discussion. - */ - if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0) - return -ERESTARTSYS; - goto restart; - } - if (o_tty && o_tty->ldisc.refcount) { - spin_unlock_irqrestore(&tty_ldisc_lock, flags); - tty_ldisc_put(ldisc); - if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0) - return -ERESTARTSYS; - goto restart; - } - } - /* - * If the TTY_LDISC bit is set, then we are racing against - * another ldisc change - */ - if (!test_bit(TTY_LDISC, &tty->flags)) { - spin_unlock_irqrestore(&tty_ldisc_lock, flags); - tty_ldisc_put(ldisc); - ld = tty_ldisc_ref_wait(tty); - tty_ldisc_deref(ld); - goto restart; - } - - clear_bit(TTY_LDISC, &tty->flags); - if (o_tty) - clear_bit(TTY_LDISC, &o_tty->flags); - spin_unlock_irqrestore(&tty_ldisc_lock, flags); - - /* - * From this point on we know nobody has an ldisc - * usage reference, nor can they obtain one until - * we say so later on. - */ - - work = cancel_delayed_work(&tty->buf.work); - /* - * Wait for ->hangup_work and ->buf.work handlers to terminate - */ - flush_scheduled_work(); - /* Shutdown the current discipline. */ - if (tty->ldisc.close) - (tty->ldisc.close)(tty); - - /* Now set up the new line discipline. */ - tty_ldisc_assign(tty, ld); - tty_set_termios_ldisc(tty, ldisc); - if (tty->ldisc.open) - retval = (tty->ldisc.open)(tty); - if (retval < 0) { - tty_ldisc_put(ldisc); - /* There is an outstanding reference here so this is safe */ - tty_ldisc_assign(tty, tty_ldisc_get(o_ldisc.num)); - tty_set_termios_ldisc(tty, tty->ldisc.num); - if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) { - tty_ldisc_put(o_ldisc.num); - /* This driver is always present */ - tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); - tty_set_termios_ldisc(tty, N_TTY); - if (tty->ldisc.open) { - int r = tty->ldisc.open(tty); - - if (r < 0) - panic("Couldn't open N_TTY ldisc for " - "%s --- error %d.", - tty_name(tty, buf), r); - } - } - } - /* At this point we hold a reference to the new ldisc and a - a reference to the old ldisc. If we ended up flipping back - to the existing ldisc we have two references to it */ - - if (tty->ldisc.num != o_ldisc.num && tty->ops->set_ldisc) - tty->ops->set_ldisc(tty); - - tty_ldisc_put(o_ldisc.num); - - /* - * Allow ldisc referencing to occur as soon as the driver - * ldisc callback completes. - */ - - tty_ldisc_enable(tty); - if (o_tty) - tty_ldisc_enable(o_tty); - - /* Restart it in case no characters kick it off. Safe if - already running */ - if (work) - schedule_delayed_work(&tty->buf.work, 1); - return retval; -} - -/** * get_tty_driver - find device of a tty * @dev_t: device identifier * @index: returns the index of the tty @@ -1166,13 +695,23 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line) { struct tty_driver *p, *res = NULL; int tty_line = 0; + int len; char *str; + for (str = name; *str; str++) + if ((*str >= '0' && *str <= '9') || *str == ',') + break; + if (!*str) + return NULL; + + len = str - name; + tty_line = simple_strtoul(str, &str, 10); + mutex_lock(&tty_mutex); /* Search through the tty devices to look for a match */ list_for_each_entry(p, &tty_drivers, tty_drivers) { - str = name + strlen(p->name); - tty_line = simple_strtoul(str, &str, 10); + if (strncmp(name, p->name, len) != 0) + continue; if (*str == ',') str++; if (*str == '\0') @@ -1335,8 +874,8 @@ void tty_wakeup(struct tty_struct *tty) if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { ld = tty_ldisc_ref(tty); if (ld) { - if (ld->write_wakeup) - ld->write_wakeup(tty); + if (ld->ops->write_wakeup) + ld->ops->write_wakeup(tty); tty_ldisc_deref(ld); } } @@ -1357,8 +896,8 @@ void tty_ldisc_flush(struct tty_struct *tty) { struct tty_ldisc *ld = tty_ldisc_ref(tty); if (ld) { - if (ld->flush_buffer) - ld->flush_buffer(tty); + if (ld->ops->flush_buffer) + ld->ops->flush_buffer(tty); tty_ldisc_deref(ld); } tty_buffer_flush(tty); @@ -1449,14 +988,14 @@ static void do_tty_hangup(struct work_struct *work) ld = tty_ldisc_ref(tty); if (ld != NULL) { /* We may have no line discipline at this point */ - if (ld->flush_buffer) - ld->flush_buffer(tty); + if (ld->ops->flush_buffer) + ld->ops->flush_buffer(tty); tty_driver_flush_buffer(tty); if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) && - ld->write_wakeup) - ld->write_wakeup(tty); - if (ld->hangup) - ld->hangup(tty); + ld->ops->write_wakeup) + ld->ops->write_wakeup(tty); + if (ld->ops->hangup) + ld->ops->hangup(tty); } /* * FIXME: Once we trust the LDISC code better we can wait here for @@ -1590,19 +1129,6 @@ int tty_hung_up_p(struct file *filp) EXPORT_SYMBOL(tty_hung_up_p); -/** - * is_tty - checker whether file is a TTY - * @filp: file handle that may be a tty - * - * Check if the file handle is a tty handle. - */ - -int is_tty(struct file *filp) -{ - return filp->f_op->read == tty_read - || filp->f_op->read == hung_up_tty_read; -} - static void session_clear_tty(struct pid *session) { struct task_struct *p; @@ -1645,8 +1171,8 @@ void disassociate_ctty(int on_exit) tty = get_current_tty(); if (tty) { tty_pgrp = get_pid(tty->pgrp); - mutex_unlock(&tty_mutex); lock_kernel(); + mutex_unlock(&tty_mutex); /* XXX: here we race, there is nothing protecting tty */ if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) tty_vhangup(tty); @@ -1825,8 +1351,8 @@ static ssize_t tty_read(struct file *file, char __user *buf, size_t count, /* We want to wait for the line discipline to sort out in this situation */ ld = tty_ldisc_ref_wait(tty); - if (ld->read) - i = (ld->read)(tty, file, buf, count); + if (ld->ops->read) + i = (ld->ops->read)(tty, file, buf, count); else i = -EIO; tty_ldisc_deref(ld); @@ -1978,10 +1504,10 @@ static ssize_t tty_write(struct file *file, const char __user *buf, printk(KERN_ERR "tty driver %s lacks a write_room method.\n", tty->driver->name); ld = tty_ldisc_ref_wait(tty); - if (!ld->write) + if (!ld->ops->write) ret = -EIO; else - ret = do_tty_write(ld->write, tty, file, buf, count); + ret = do_tty_write(ld->ops->write, tty, file, buf, count); tty_ldisc_deref(ld); return ret; } @@ -2007,6 +1533,42 @@ ssize_t redirected_tty_write(struct file *file, const char __user *buf, return tty_write(file, buf, count, ppos); } +void tty_port_init(struct tty_port *port) +{ + memset(port, 0, sizeof(*port)); + init_waitqueue_head(&port->open_wait); + init_waitqueue_head(&port->close_wait); + mutex_init(&port->mutex); + port->close_delay = (50 * HZ) / 100; + port->closing_wait = (3000 * HZ) / 100; +} +EXPORT_SYMBOL(tty_port_init); + +int tty_port_alloc_xmit_buf(struct tty_port *port) +{ + /* We may sleep in get_zeroed_page() */ + mutex_lock(&port->mutex); + if (port->xmit_buf == NULL) + port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); + mutex_unlock(&port->mutex); + if (port->xmit_buf == NULL) + return -ENOMEM; + return 0; +} +EXPORT_SYMBOL(tty_port_alloc_xmit_buf); + +void tty_port_free_xmit_buf(struct tty_port *port) +{ + mutex_lock(&port->mutex); + if (port->xmit_buf != NULL) { + free_page((unsigned long)port->xmit_buf); + port->xmit_buf = NULL; + } + mutex_unlock(&port->mutex); +} +EXPORT_SYMBOL(tty_port_free_xmit_buf); + + static char ptychar[] = "pqrstuvwxyzabcde"; /** @@ -2225,22 +1787,11 @@ static int init_dev(struct tty_driver *driver, int idx, * to decrement the use counts, as release_tty doesn't care. */ - if (tty->ldisc.open) { - retval = (tty->ldisc.open)(tty); - if (retval) - goto release_mem_out; - } - if (o_tty && o_tty->ldisc.open) { - retval = (o_tty->ldisc.open)(o_tty); - if (retval) { - if (tty->ldisc.close) - (tty->ldisc.close)(tty); - goto release_mem_out; - } - tty_ldisc_enable(o_tty); - } - tty_ldisc_enable(tty); - goto success; + retval = tty_ldisc_setup(tty, o_tty); + + if (retval) + goto release_mem_out; + goto success; /* * This fast open can be used if the tty is already open. @@ -2382,7 +1933,6 @@ static void release_dev(struct file *filp) int devpts; int idx; char buf[64]; - unsigned long flags; tty = (struct tty_struct *)filp->private_data; if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, @@ -2584,55 +2134,9 @@ static void release_dev(struct file *filp) printk(KERN_DEBUG "freeing tty structure..."); #endif /* - * Prevent flush_to_ldisc() from rescheduling the work for later. Then - * kill any delayed work. As this is the final close it does not - * race with the set_ldisc code path. - */ - clear_bit(TTY_LDISC, &tty->flags); - cancel_delayed_work(&tty->buf.work); - - /* - * Wait for ->hangup_work and ->buf.work handlers to terminate + * Ask the line discipline code to release its structures */ - - flush_scheduled_work(); - - /* - * Wait for any short term users (we know they are just driver - * side waiters as the file is closing so user count on the file - * side is zero. - */ - spin_lock_irqsave(&tty_ldisc_lock, flags); - while (tty->ldisc.refcount) { - spin_unlock_irqrestore(&tty_ldisc_lock, flags); - wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0); - spin_lock_irqsave(&tty_ldisc_lock, flags); - } - spin_unlock_irqrestore(&tty_ldisc_lock, flags); - /* - * Shutdown the current line discipline, and reset it to N_TTY. - * N.B. why reset ldisc when we're releasing the memory?? - * - * FIXME: this MUST get fixed for the new reflocking - */ - if (tty->ldisc.close) - (tty->ldisc.close)(tty); - tty_ldisc_put(tty->ldisc.num); - - /* - * Switch the line discipline back - */ - tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); - tty_set_termios_ldisc(tty, N_TTY); - if (o_tty) { - /* FIXME: could o_tty be in setldisc here ? */ - clear_bit(TTY_LDISC, &o_tty->flags); - if (o_tty->ldisc.close) - (o_tty->ldisc.close)(o_tty); - tty_ldisc_put(o_tty->ldisc.num); - tty_ldisc_assign(o_tty, tty_ldisc_get(N_TTY)); - tty_set_termios_ldisc(o_tty, N_TTY); - } + tty_ldisc_release(tty, o_tty); /* * The release_tty function takes care of the details of clearing * the slots and preserving the termios structure. @@ -2899,8 +2403,8 @@ static unsigned int tty_poll(struct file *filp, poll_table *wait) return 0; ld = tty_ldisc_ref_wait(tty); - if (ld->poll) - ret = (ld->poll)(tty, filp, wait); + if (ld->ops->poll) + ret = (ld->ops->poll)(tty, filp, wait); tty_ldisc_deref(ld); return ret; } @@ -2974,7 +2478,7 @@ static int tiocsti(struct tty_struct *tty, char __user *p) if (get_user(ch, p)) return -EFAULT; ld = tty_ldisc_ref_wait(tty); - ld->receive_buf(tty, &ch, &mbz, 1); + ld->ops->receive_buf(tty, &ch, &mbz, 1); tty_ldisc_deref(ld); return 0; } @@ -3002,45 +2506,26 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) } /** - * tiocswinsz - implement window size set ioctl - * @tty; tty - * @arg: user buffer for result - * - * Copies the user idea of the window size to the kernel. Traditionally - * this is just advisory information but for the Linux console it - * actually has driver level meaning and triggers a VC resize. + * tty_do_resize - resize event + * @tty: tty being resized + * @real_tty: real tty (not the same as tty if using a pty/tty pair) + * @rows: rows (character) + * @cols: cols (character) * - * Locking: - * Called function use the console_sem is used to ensure we do - * not try and resize the console twice at once. - * The tty->termios_mutex is used to ensure we don't double - * resize and get confused. Lock order - tty->termios_mutex before - * console sem + * Update the termios variables and send the neccessary signals to + * peform a terminal resize correctly */ -static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, - struct winsize __user *arg) +int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, + struct winsize *ws) { - struct winsize tmp_ws; struct pid *pgrp, *rpgrp; unsigned long flags; - if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) - return -EFAULT; - - mutex_lock(&tty->termios_mutex); - if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg))) + /* For a PTY we need to lock the tty side */ + mutex_lock(&real_tty->termios_mutex); + if (!memcmp(ws, &tty->winsize, sizeof(*ws))) goto done; - -#ifdef CONFIG_VT - if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) { - if (vc_lock_resize(tty->driver_data, tmp_ws.ws_col, - tmp_ws.ws_row)) { - mutex_unlock(&tty->termios_mutex); - return -ENXIO; - } - } -#endif /* Get the PID values and reference them so we can avoid holding the tty ctrl lock while sending signals */ spin_lock_irqsave(&tty->ctrl_lock, flags); @@ -3056,14 +2541,42 @@ static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, put_pid(pgrp); put_pid(rpgrp); - tty->winsize = tmp_ws; - real_tty->winsize = tmp_ws; + tty->winsize = *ws; + real_tty->winsize = *ws; done: - mutex_unlock(&tty->termios_mutex); + mutex_unlock(&real_tty->termios_mutex); return 0; } /** + * tiocswinsz - implement window size set ioctl + * @tty; tty + * @arg: user buffer for result + * + * Copies the user idea of the window size to the kernel. Traditionally + * this is just advisory information but for the Linux console it + * actually has driver level meaning and triggers a VC resize. + * + * Locking: + * Driver dependant. The default do_resize method takes the + * tty termios mutex and ctrl_lock. The console takes its own lock + * then calls into the default method. + */ + +static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, + struct winsize __user *arg) +{ + struct winsize tmp_ws; + if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) + return -EFAULT; + + if (tty->ops->resize) + return tty->ops->resize(tty, real_tty, &tmp_ws); + else + return tty_do_resize(tty, real_tty, &tmp_ws); +} + +/** * tioccons - allow admin to move logical console * @file: the file to become console * @@ -3342,16 +2855,29 @@ static int tiocsetd(struct tty_struct *tty, int __user *p) static int send_break(struct tty_struct *tty, unsigned int duration) { - if (tty_write_lock(tty, 0) < 0) - return -EINTR; - tty->ops->break_ctl(tty, -1); - if (!signal_pending(current)) - msleep_interruptible(duration); - tty->ops->break_ctl(tty, 0); - tty_write_unlock(tty); - if (signal_pending(current)) - return -EINTR; - return 0; + int retval; + + if (tty->ops->break_ctl == NULL) + return 0; + + if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) + retval = tty->ops->break_ctl(tty, duration); + else { + /* Do the work ourselves */ + if (tty_write_lock(tty, 0) < 0) + return -EINTR; + retval = tty->ops->break_ctl(tty, -1); + if (retval) + goto out; + if (!signal_pending(current)) + msleep_interruptible(duration); + retval = tty->ops->break_ctl(tty, 0); +out: + tty_write_unlock(tty); + if (signal_pending(current)) + retval = -EINTR; + } + return retval; } /** @@ -3395,35 +2921,31 @@ static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned __user *p) { - int retval = -EINVAL; - - if (tty->ops->tiocmset) { - unsigned int set, clear, val; - - retval = get_user(val, p); - if (retval) - return retval; - - set = clear = 0; - switch (cmd) { - case TIOCMBIS: - set = val; - break; - case TIOCMBIC: - clear = val; - break; - case TIOCMSET: - set = val; - clear = ~val; - break; - } + int retval; + unsigned int set, clear, val; - set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; - clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; + if (tty->ops->tiocmset == NULL) + return -EINVAL; - retval = tty->ops->tiocmset(tty, file, set, clear); + retval = get_user(val, p); + if (retval) + return retval; + set = clear = 0; + switch (cmd) { + case TIOCMBIS: + set = val; + break; + case TIOCMBIC: + clear = val; + break; + case TIOCMSET: + set = val; + clear = ~val; + break; } - return retval; + set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; + clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; + return tty->ops->tiocmset(tty, file, set, clear); } /* @@ -3446,36 +2968,6 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) tty->driver->subtype == PTY_TYPE_MASTER) real_tty = tty->link; - /* - * Break handling by driver - */ - - retval = -EINVAL; - - if (!tty->ops->break_ctl) { - switch (cmd) { - case TIOCSBRK: - case TIOCCBRK: - if (tty->ops->ioctl) - retval = tty->ops->ioctl(tty, file, cmd, arg); - if (retval != -EINVAL && retval != -ENOIOCTLCMD) - printk(KERN_WARNING "tty: driver %s needs updating to use break_ctl\n", tty->driver->name); - return retval; - - /* These two ioctl's always return success; even if */ - /* the driver doesn't support them. */ - case TCSBRK: - case TCSBRKP: - if (!tty->ops->ioctl) - return 0; - retval = tty->ops->ioctl(tty, file, cmd, arg); - if (retval != -EINVAL && retval != -ENOIOCTLCMD) - printk(KERN_WARNING "tty: driver %s needs updating to use break_ctl\n", tty->driver->name); - if (retval == -ENOIOCTLCMD) - retval = 0; - return retval; - } - } /* * Factor out some common prep work @@ -3497,6 +2989,9 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) break; } + /* + * Now do the stuff. + */ switch (cmd) { case TIOCSTI: return tiocsti(tty, p); @@ -3528,7 +3023,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case TIOCGSID: return tiocgsid(tty, real_tty, p); case TIOCGETD: - return put_user(tty->ldisc.num, (int __user *)p); + return put_user(tty->ldisc.ops->num, (int __user *)p); case TIOCSETD: return tiocsetd(tty, p); #ifdef CONFIG_VT @@ -3540,12 +3035,11 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) */ case TIOCSBRK: /* Turn break on, unconditionally */ if (tty->ops->break_ctl) - tty->ops->break_ctl(tty, -1); + return tty->ops->break_ctl(tty, -1); return 0; - case TIOCCBRK: /* Turn break off, unconditionally */ if (tty->ops->break_ctl) - tty->ops->break_ctl(tty, 0); + return tty->ops->break_ctl(tty, 0); return 0; case TCSBRK: /* SVID version: non-zero arg --> no break */ /* non-zero arg means wait for all output data @@ -3581,8 +3075,8 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) } ld = tty_ldisc_ref_wait(tty); retval = -EINVAL; - if (ld->ioctl) { - retval = ld->ioctl(tty, file, cmd, arg); + if (ld->ops->ioctl) { + retval = ld->ops->ioctl(tty, file, cmd, arg); if (retval == -ENOIOCTLCMD) retval = -EINVAL; } @@ -3609,8 +3103,8 @@ static long tty_compat_ioctl(struct file *file, unsigned int cmd, } ld = tty_ldisc_ref_wait(tty); - if (ld->compat_ioctl) - retval = ld->compat_ioctl(tty, file, cmd, arg); + if (ld->ops->compat_ioctl) + retval = ld->ops->compat_ioctl(tty, file, cmd, arg); tty_ldisc_deref(ld); return retval; @@ -3782,7 +3276,8 @@ static void flush_to_ldisc(struct work_struct *work) flag_buf = head->flag_buf_ptr + head->read; head->read += count; spin_unlock_irqrestore(&tty->buf.lock, flags); - disc->receive_buf(tty, char_buf, flag_buf, count); + disc->ops->receive_buf(tty, char_buf, + flag_buf, count); spin_lock_irqsave(&tty->buf.lock, flags); } /* Restore the queue head */ @@ -3845,7 +3340,7 @@ static void initialize_tty_struct(struct tty_struct *tty) { memset(tty, 0, sizeof(struct tty_struct)); tty->magic = TTY_MAGIC; - tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); + tty_ldisc_init(tty); tty->session = NULL; tty->pgrp = NULL; tty->overrun_time = jiffies; @@ -3923,7 +3418,7 @@ struct device *tty_register_device(struct tty_driver *driver, unsigned index, else tty_line_name(driver, index, name); - return device_create(tty_class, device, dev, name); + return device_create_drvdata(tty_class, device, dev, NULL, name); } /** @@ -4104,7 +3599,6 @@ void proc_clear_tty(struct task_struct *p) p->signal->tty = NULL; spin_unlock_irq(&p->sighand->siglock); } -EXPORT_SYMBOL(proc_clear_tty); /* Called under the sighand lock */ @@ -4158,7 +3652,7 @@ void __init console_init(void) initcall_t *call; /* Setup the default TTY line discipline. */ - (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY); + tty_ldisc_begin(); /* * set up the console device so that later boot sequences can @@ -4201,20 +3695,22 @@ static int __init tty_init(void) if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) panic("Couldn't register /dev/tty driver\n"); - device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), "tty"); + device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, + "tty"); cdev_init(&console_cdev, &console_fops); if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) panic("Couldn't register /dev/console driver\n"); - device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), "console"); + device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, + "console"); #ifdef CONFIG_UNIX98_PTYS cdev_init(&ptmx_cdev, &ptmx_fops); if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) panic("Couldn't register /dev/ptmx driver\n"); - device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), "ptmx"); + device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); #endif #ifdef CONFIG_VT @@ -4222,7 +3718,7 @@ static int __init tty_init(void) if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) || register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0) panic("Couldn't register /dev/tty0 driver\n"); - device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), "tty0"); + device_create_drvdata(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0"); vty_init(); #endif |