diff options
Diffstat (limited to 'drivers/char/tty_io.c')
| -rw-r--r-- | drivers/char/tty_io.c | 3263 |
1 files changed, 0 insertions, 3263 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c deleted file mode 100644 index c05c5af5aa0..00000000000 --- a/drivers/char/tty_io.c +++ /dev/null @@ -1,3263 +0,0 @@ -/* - * linux/drivers/char/tty_io.c - * - * Copyright (C) 1991, 1992 Linus Torvalds - */ - -/* - * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles - * or rs-channels. It also implements echoing, cooked mode etc. - * - * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. - * - * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the - * tty_struct and tty_queue structures. Previously there was an array - * of 256 tty_struct's which was statically allocated, and the - * tty_queue structures were allocated at boot time. Both are now - * dynamically allocated only when the tty is open. - * - * Also restructured routines so that there is more of a separation - * between the high-level tty routines (tty_io.c and tty_ioctl.c) and - * the low-level tty routines (serial.c, pty.c, console.c). This - * makes for cleaner and more compact code. -TYT, 9/17/92 - * - * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines - * which can be dynamically activated and de-activated by the line - * discipline handling modules (like SLIP). - * - * NOTE: pay no attention to the line discipline code (yet); its - * interface is still subject to change in this version... - * -- TYT, 1/31/92 - * - * Added functionality to the OPOST tty handling. No delays, but all - * other bits should be there. - * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. - * - * Rewrote canonical mode and added more termios flags. - * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 - * - * Reorganized FASYNC support so mouse code can share it. - * -- ctm@ardi.com, 9Sep95 - * - * New TIOCLINUX variants added. - * -- mj@k332.feld.cvut.cz, 19-Nov-95 - * - * Restrict vt switching via ioctl() - * -- grif@cs.ucr.edu, 5-Dec-95 - * - * Move console and virtual terminal code to more appropriate files, - * implement CONFIG_VT and generalize console device interface. - * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 - * - * Rewrote tty_init_dev and tty_release_dev to eliminate races. - * -- Bill Hawes <whawes@star.net>, June 97 - * - * Added devfs support. - * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 - * - * Added support for a Unix98-style ptmx device. - * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 - * - * Reduced memory usage for older ARM systems - * -- Russell King <rmk@arm.linux.org.uk> - * - * Move do_SAK() into process context. Less stack use in devfs functions. - * alloc_tty_struct() always uses kmalloc() - * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 - */ - -#include <linux/types.h> -#include <linux/major.h> -#include <linux/errno.h> -#include <linux/signal.h> -#include <linux/fcntl.h> -#include <linux/sched.h> -#include <linux/interrupt.h> -#include <linux/tty.h> -#include <linux/tty_driver.h> -#include <linux/tty_flip.h> -#include <linux/devpts_fs.h> -#include <linux/file.h> -#include <linux/fdtable.h> -#include <linux/console.h> -#include <linux/timer.h> -#include <linux/ctype.h> -#include <linux/kd.h> -#include <linux/mm.h> -#include <linux/string.h> -#include <linux/slab.h> -#include <linux/poll.h> -#include <linux/proc_fs.h> -#include <linux/init.h> -#include <linux/module.h> -#include <linux/smp_lock.h> -#include <linux/device.h> -#include <linux/wait.h> -#include <linux/bitops.h> -#include <linux/delay.h> -#include <linux/seq_file.h> -#include <linux/serial.h> - -#include <linux/uaccess.h> -#include <asm/system.h> - -#include <linux/kbd_kern.h> -#include <linux/vt_kern.h> -#include <linux/selection.h> - -#include <linux/kmod.h> -#include <linux/nsproxy.h> - -#undef TTY_DEBUG_HANGUP - -#define TTY_PARANOIA_CHECK 1 -#define CHECK_TTY_COUNT 1 - -struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ - .c_iflag = ICRNL | IXON, - .c_oflag = OPOST | ONLCR, - .c_cflag = B38400 | CS8 | CREAD | HUPCL, - .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | - ECHOCTL | ECHOKE | IEXTEN, - .c_cc = INIT_C_CC, - .c_ispeed = 38400, - .c_ospeed = 38400 -}; - -EXPORT_SYMBOL(tty_std_termios); - -/* This list gets poked at by procfs and various bits of boot up code. This - could do with some rationalisation such as pulling the tty proc function - into this file */ - -LIST_HEAD(tty_drivers); /* linked list of tty drivers */ - -/* Mutex to protect creating and releasing a tty. This is shared with - vt.c for deeply disgusting hack reasons */ -DEFINE_MUTEX(tty_mutex); -EXPORT_SYMBOL(tty_mutex); - -/* Spinlock to protect the tty->tty_files list */ -DEFINE_SPINLOCK(tty_files_lock); - -static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); -static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); -ssize_t redirected_tty_write(struct file *, const char __user *, - size_t, loff_t *); -static unsigned int tty_poll(struct file *, poll_table *); -static int tty_open(struct inode *, struct file *); -long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); -#ifdef CONFIG_COMPAT -static long tty_compat_ioctl(struct file *file, unsigned int cmd, - unsigned long arg); -#else -#define tty_compat_ioctl NULL -#endif -static int __tty_fasync(int fd, struct file *filp, int on); -static int tty_fasync(int fd, struct file *filp, int on); -static void release_tty(struct tty_struct *tty, int idx); -static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); -static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); - -/** - * alloc_tty_struct - allocate a tty object - * - * Return a new empty tty structure. The data fields have not - * been initialized in any way but has been zeroed - * - * Locking: none - */ - -struct tty_struct *alloc_tty_struct(void) -{ - return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); -} - -/** - * free_tty_struct - free a disused tty - * @tty: tty struct to free - * - * Free the write buffers, tty queue and tty memory itself. - * - * Locking: none. Must be called after tty is definitely unused - */ - -void free_tty_struct(struct tty_struct *tty) -{ - if (tty->dev) - put_device(tty->dev); - kfree(tty->write_buf); - tty_buffer_free_all(tty); - kfree(tty); -} - -static inline struct tty_struct *file_tty(struct file *file) -{ - return ((struct tty_file_private *)file->private_data)->tty; -} - -/* Associate a new file with the tty structure */ -int tty_add_file(struct tty_struct *tty, struct file *file) -{ - struct tty_file_private *priv; - - priv = kmalloc(sizeof(*priv), GFP_KERNEL); - if (!priv) - return -ENOMEM; - - priv->tty = tty; - priv->file = file; - file->private_data = priv; - - spin_lock(&tty_files_lock); - list_add(&priv->list, &tty->tty_files); - spin_unlock(&tty_files_lock); - - return 0; -} - -/* Delete file from its tty */ -void tty_del_file(struct file *file) -{ - struct tty_file_private *priv = file->private_data; - - spin_lock(&tty_files_lock); - list_del(&priv->list); - spin_unlock(&tty_files_lock); - file->private_data = NULL; - kfree(priv); -} - - -#define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) - -/** - * tty_name - return tty naming - * @tty: tty structure - * @buf: buffer for output - * - * Convert a tty structure into a name. The name reflects the kernel - * naming policy and if udev is in use may not reflect user space - * - * Locking: none - */ - -char *tty_name(struct tty_struct *tty, char *buf) -{ - if (!tty) /* Hmm. NULL pointer. That's fun. */ - strcpy(buf, "NULL tty"); - else - strcpy(buf, tty->name); - return buf; -} - -EXPORT_SYMBOL(tty_name); - -int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, - const char *routine) -{ -#ifdef TTY_PARANOIA_CHECK - if (!tty) { - printk(KERN_WARNING - "null TTY for (%d:%d) in %s\n", - imajor(inode), iminor(inode), routine); - return 1; - } - if (tty->magic != TTY_MAGIC) { - printk(KERN_WARNING - "bad magic number for tty struct (%d:%d) in %s\n", - imajor(inode), iminor(inode), routine); - return 1; - } -#endif - return 0; -} - -static int check_tty_count(struct tty_struct *tty, const char *routine) -{ -#ifdef CHECK_TTY_COUNT - struct list_head *p; - int count = 0; - - spin_lock(&tty_files_lock); - list_for_each(p, &tty->tty_files) { - count++; - } - spin_unlock(&tty_files_lock); - if (tty->driver->type == TTY_DRIVER_TYPE_PTY && - tty->driver->subtype == PTY_TYPE_SLAVE && - tty->link && tty->link->count) - count++; - if (tty->count != count) { - printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " - "!= #fd's(%d) in %s\n", - tty->name, tty->count, count, routine); - return count; - } -#endif - return 0; -} - -/** - * get_tty_driver - find device of a tty - * @dev_t: device identifier - * @index: returns the index of the tty - * - * This routine returns a tty driver structure, given a device number - * and also passes back the index number. - * - * Locking: caller must hold tty_mutex - */ - -static struct tty_driver *get_tty_driver(dev_t device, int *index) -{ - struct tty_driver *p; - - list_for_each_entry(p, &tty_drivers, tty_drivers) { - dev_t base = MKDEV(p->major, p->minor_start); - if (device < base || device >= base + p->num) - continue; - *index = device - base; - return tty_driver_kref_get(p); - } - return NULL; -} - -#ifdef CONFIG_CONSOLE_POLL - -/** - * tty_find_polling_driver - find device of a polled tty - * @name: name string to match - * @line: pointer to resulting tty line nr - * - * This routine returns a tty driver structure, given a name - * and the condition that the tty driver is capable of polled - * operation. - */ -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, *stp; - - 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) { - if (strncmp(name, p->name, len) != 0) - continue; - stp = str; - if (*stp == ',') - stp++; - if (*stp == '\0') - stp = NULL; - - if (tty_line >= 0 && tty_line < p->num && p->ops && - p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { - res = tty_driver_kref_get(p); - *line = tty_line; - break; - } - } - mutex_unlock(&tty_mutex); - - return res; -} -EXPORT_SYMBOL_GPL(tty_find_polling_driver); -#endif - -/** - * tty_check_change - check for POSIX terminal changes - * @tty: tty to check - * - * If we try to write to, or set the state of, a terminal and we're - * not in the foreground, send a SIGTTOU. If the signal is blocked or - * ignored, go ahead and perform the operation. (POSIX 7.2) - * - * Locking: ctrl_lock - */ - -int tty_check_change(struct tty_struct *tty) -{ - unsigned long flags; - int ret = 0; - - if (current->signal->tty != tty) - return 0; - - spin_lock_irqsave(&tty->ctrl_lock, flags); - - if (!tty->pgrp) { - printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); - goto out_unlock; - } - if (task_pgrp(current) == tty->pgrp) - goto out_unlock; - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - if (is_ignored(SIGTTOU)) - goto out; - if (is_current_pgrp_orphaned()) { - ret = -EIO; - goto out; - } - kill_pgrp(task_pgrp(current), SIGTTOU, 1); - set_thread_flag(TIF_SIGPENDING); - ret = -ERESTARTSYS; -out: - return ret; -out_unlock: - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - return ret; -} - -EXPORT_SYMBOL(tty_check_change); - -static ssize_t hung_up_tty_read(struct file *file, char __user *buf, - size_t count, loff_t *ppos) -{ - return 0; -} - -static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, - size_t count, loff_t *ppos) -{ - return -EIO; -} - -/* No kernel lock held - none needed ;) */ -static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) -{ - return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; -} - -static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) -{ - return cmd == TIOCSPGRP ? -ENOTTY : -EIO; -} - -static long hung_up_tty_compat_ioctl(struct file *file, - unsigned int cmd, unsigned long arg) -{ - return cmd == TIOCSPGRP ? -ENOTTY : -EIO; -} - -static const struct file_operations tty_fops = { - .llseek = no_llseek, - .read = tty_read, - .write = tty_write, - .poll = tty_poll, - .unlocked_ioctl = tty_ioctl, - .compat_ioctl = tty_compat_ioctl, - .open = tty_open, - .release = tty_release, - .fasync = tty_fasync, -}; - -static const struct file_operations console_fops = { - .llseek = no_llseek, - .read = tty_read, - .write = redirected_tty_write, - .poll = tty_poll, - .unlocked_ioctl = tty_ioctl, - .compat_ioctl = tty_compat_ioctl, - .open = tty_open, - .release = tty_release, - .fasync = tty_fasync, -}; - -static const struct file_operations hung_up_tty_fops = { - .llseek = no_llseek, - .read = hung_up_tty_read, - .write = hung_up_tty_write, - .poll = hung_up_tty_poll, - .unlocked_ioctl = hung_up_tty_ioctl, - .compat_ioctl = hung_up_tty_compat_ioctl, - .release = tty_release, -}; - -static DEFINE_SPINLOCK(redirect_lock); -static struct file *redirect; - -/** - * tty_wakeup - request more data - * @tty: terminal - * - * Internal and external helper for wakeups of tty. This function - * informs the line discipline if present that the driver is ready - * to receive more output data. - */ - -void tty_wakeup(struct tty_struct *tty) -{ - struct tty_ldisc *ld; - - if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { - ld = tty_ldisc_ref(tty); - if (ld) { - if (ld->ops->write_wakeup) - ld->ops->write_wakeup(tty); - tty_ldisc_deref(ld); - } - } - wake_up_interruptible_poll(&tty->write_wait, POLLOUT); -} - -EXPORT_SYMBOL_GPL(tty_wakeup); - -/** - * __tty_hangup - actual handler for hangup events - * @work: tty device - * - * This can be called by the "eventd" kernel thread. That is process - * synchronous but doesn't hold any locks, so we need to make sure we - * have the appropriate locks for what we're doing. - * - * The hangup event clears any pending redirections onto the hung up - * device. It ensures future writes will error and it does the needed - * line discipline hangup and signal delivery. The tty object itself - * remains intact. - * - * Locking: - * BTM - * redirect lock for undoing redirection - * file list lock for manipulating list of ttys - * tty_ldisc_lock from called functions - * termios_mutex resetting termios data - * tasklist_lock to walk task list for hangup event - * ->siglock to protect ->signal/->sighand - */ -void __tty_hangup(struct tty_struct *tty) -{ - struct file *cons_filp = NULL; - struct file *filp, *f = NULL; - struct task_struct *p; - struct tty_file_private *priv; - int closecount = 0, n; - unsigned long flags; - int refs = 0; - - if (!tty) - return; - - - spin_lock(&redirect_lock); - if (redirect && file_tty(redirect) == tty) { - f = redirect; - redirect = NULL; - } - spin_unlock(&redirect_lock); - - tty_lock(); - - /* inuse_filps is protected by the single tty lock, - this really needs to change if we want to flush the - workqueue with the lock held */ - check_tty_count(tty, "tty_hangup"); - - spin_lock(&tty_files_lock); - /* This breaks for file handles being sent over AF_UNIX sockets ? */ - list_for_each_entry(priv, &tty->tty_files, list) { - filp = priv->file; - if (filp->f_op->write == redirected_tty_write) - cons_filp = filp; - if (filp->f_op->write != tty_write) - continue; - closecount++; - __tty_fasync(-1, filp, 0); /* can't block */ - filp->f_op = &hung_up_tty_fops; - } - spin_unlock(&tty_files_lock); - - tty_ldisc_hangup(tty); - - read_lock(&tasklist_lock); - if (tty->session) { - do_each_pid_task(tty->session, PIDTYPE_SID, p) { - spin_lock_irq(&p->sighand->siglock); - if (p->signal->tty == tty) { - p->signal->tty = NULL; - /* We defer the dereferences outside fo - the tasklist lock */ - refs++; - } - if (!p->signal->leader) { - spin_unlock_irq(&p->sighand->siglock); - continue; - } - __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); - __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); - put_pid(p->signal->tty_old_pgrp); /* A noop */ - spin_lock_irqsave(&tty->ctrl_lock, flags); - if (tty->pgrp) - p->signal->tty_old_pgrp = get_pid(tty->pgrp); - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - spin_unlock_irq(&p->sighand->siglock); - } while_each_pid_task(tty->session, PIDTYPE_SID, p); - } - read_unlock(&tasklist_lock); - - spin_lock_irqsave(&tty->ctrl_lock, flags); - clear_bit(TTY_THROTTLED, &tty->flags); - clear_bit(TTY_PUSH, &tty->flags); - clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); - put_pid(tty->session); - put_pid(tty->pgrp); - tty->session = NULL; - tty->pgrp = NULL; - tty->ctrl_status = 0; - set_bit(TTY_HUPPED, &tty->flags); - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - - /* Account for the p->signal references we killed */ - while (refs--) - tty_kref_put(tty); - - /* - * If one of the devices matches a console pointer, we - * cannot just call hangup() because that will cause - * tty->count and state->count to go out of sync. - * So we just call close() the right number of times. - */ - if (cons_filp) { - if (tty->ops->close) - for (n = 0; n < closecount; n++) - tty->ops->close(tty, cons_filp); - } else if (tty->ops->hangup) - (tty->ops->hangup)(tty); - /* - * We don't want to have driver/ldisc interactions beyond - * the ones we did here. The driver layer expects no - * calls after ->hangup() from the ldisc side. However we - * can't yet guarantee all that. - */ - set_bit(TTY_HUPPED, &tty->flags); - tty_ldisc_enable(tty); - - tty_unlock(); - - if (f) - fput(f); -} - -static void do_tty_hangup(struct work_struct *work) -{ - struct tty_struct *tty = - container_of(work, struct tty_struct, hangup_work); - - __tty_hangup(tty); -} - -/** - * tty_hangup - trigger a hangup event - * @tty: tty to hangup - * - * A carrier loss (virtual or otherwise) has occurred on this like - * schedule a hangup sequence to run after this event. - */ - -void tty_hangup(struct tty_struct *tty) -{ -#ifdef TTY_DEBUG_HANGUP - char buf[64]; - printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); -#endif - schedule_work(&tty->hangup_work); -} - -EXPORT_SYMBOL(tty_hangup); - -/** - * tty_vhangup - process vhangup - * @tty: tty to hangup - * - * The user has asked via system call for the terminal to be hung up. - * We do this synchronously so that when the syscall returns the process - * is complete. That guarantee is necessary for security reasons. - */ - -void tty_vhangup(struct tty_struct *tty) -{ -#ifdef TTY_DEBUG_HANGUP - char buf[64]; - - printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); -#endif - __tty_hangup(tty); -} - -EXPORT_SYMBOL(tty_vhangup); - - -/** - * tty_vhangup_self - process vhangup for own ctty - * - * Perform a vhangup on the current controlling tty - */ - -void tty_vhangup_self(void) -{ - struct tty_struct *tty; - - tty = get_current_tty(); - if (tty) { - tty_vhangup(tty); - tty_kref_put(tty); - } -} - -/** - * tty_hung_up_p - was tty hung up - * @filp: file pointer of tty - * - * Return true if the tty has been subject to a vhangup or a carrier - * loss - */ - -int tty_hung_up_p(struct file *filp) -{ - return (filp->f_op == &hung_up_tty_fops); -} - -EXPORT_SYMBOL(tty_hung_up_p); - -static void session_clear_tty(struct pid *session) -{ - struct task_struct *p; - do_each_pid_task(session, PIDTYPE_SID, p) { - proc_clear_tty(p); - } while_each_pid_task(session, PIDTYPE_SID, p); -} - -/** - * disassociate_ctty - disconnect controlling tty - * @on_exit: true if exiting so need to "hang up" the session - * - * This function is typically called only by the session leader, when - * it wants to disassociate itself from its controlling tty. - * - * It performs the following functions: - * (1) Sends a SIGHUP and SIGCONT to the foreground process group - * (2) Clears the tty from being controlling the session - * (3) Clears the controlling tty for all processes in the - * session group. - * - * The argument on_exit is set to 1 if called when a process is - * exiting; it is 0 if called by the ioctl TIOCNOTTY. - * - * Locking: - * BTM is taken for hysterical raisins, and held when - * called from no_tty(). - * tty_mutex is taken to protect tty - * ->siglock is taken to protect ->signal/->sighand - * tasklist_lock is taken to walk process list for sessions - * ->siglock is taken to protect ->signal/->sighand - */ - -void disassociate_ctty(int on_exit) -{ - struct tty_struct *tty; - struct pid *tty_pgrp = NULL; - - if (!current->signal->leader) - return; - - tty = get_current_tty(); - if (tty) { - tty_pgrp = get_pid(tty->pgrp); - if (on_exit) { - if (tty->driver->type != TTY_DRIVER_TYPE_PTY) - tty_vhangup(tty); - } - tty_kref_put(tty); - } else if (on_exit) { - struct pid *old_pgrp; - spin_lock_irq(¤t->sighand->siglock); - old_pgrp = current->signal->tty_old_pgrp; - current->signal->tty_old_pgrp = NULL; - spin_unlock_irq(¤t->sighand->siglock); - if (old_pgrp) { - kill_pgrp(old_pgrp, SIGHUP, on_exit); - kill_pgrp(old_pgrp, SIGCONT, on_exit); - put_pid(old_pgrp); - } - return; - } - if (tty_pgrp) { - kill_pgrp(tty_pgrp, SIGHUP, on_exit); - if (!on_exit) - kill_pgrp(tty_pgrp, SIGCONT, on_exit); - put_pid(tty_pgrp); - } - - spin_lock_irq(¤t->sighand->siglock); - put_pid(current->signal->tty_old_pgrp); - current->signal->tty_old_pgrp = NULL; - spin_unlock_irq(¤t->sighand->siglock); - - tty = get_current_tty(); - if (tty) { - unsigned long flags; - spin_lock_irqsave(&tty->ctrl_lock, flags); - put_pid(tty->session); - put_pid(tty->pgrp); - tty->session = NULL; - tty->pgrp = NULL; - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - tty_kref_put(tty); - } else { -#ifdef TTY_DEBUG_HANGUP - printk(KERN_DEBUG "error attempted to write to tty [0x%p]" - " = NULL", tty); -#endif - } - - /* Now clear signal->tty under the lock */ - read_lock(&tasklist_lock); - session_clear_tty(task_session(current)); - read_unlock(&tasklist_lock); -} - -/** - * - * no_tty - Ensure the current process does not have a controlling tty - */ -void no_tty(void) -{ - struct task_struct *tsk = current; - tty_lock(); - disassociate_ctty(0); - tty_unlock(); - proc_clear_tty(tsk); -} - - -/** - * stop_tty - propagate flow control - * @tty: tty to stop - * - * Perform flow control to the driver. For PTY/TTY pairs we - * must also propagate the TIOCKPKT status. May be called - * on an already stopped device and will not re-call the driver - * method. - * - * This functionality is used by both the line disciplines for - * halting incoming flow and by the driver. It may therefore be - * called from any context, may be under the tty atomic_write_lock - * but not always. - * - * Locking: - * Uses the tty control lock internally - */ - -void stop_tty(struct tty_struct *tty) -{ - unsigned long flags; - spin_lock_irqsave(&tty->ctrl_lock, flags); - if (tty->stopped) { - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - return; - } - tty->stopped = 1; - if (tty->link && tty->link->packet) { - tty->ctrl_status &= ~TIOCPKT_START; - tty->ctrl_status |= TIOCPKT_STOP; - wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); - } - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - if (tty->ops->stop) - (tty->ops->stop)(tty); -} - -EXPORT_SYMBOL(stop_tty); - -/** - * start_tty - propagate flow control - * @tty: tty to start - * - * Start a tty that has been stopped if at all possible. Perform - * any necessary wakeups and propagate the TIOCPKT status. If this - * is the tty was previous stopped and is being started then the - * driver start method is invoked and the line discipline woken. - * - * Locking: - * ctrl_lock - */ - -void start_tty(struct tty_struct *tty) -{ - unsigned long flags; - spin_lock_irqsave(&tty->ctrl_lock, flags); - if (!tty->stopped || tty->flow_stopped) { - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - return; - } - tty->stopped = 0; - if (tty->link && tty->link->packet) { - tty->ctrl_status &= ~TIOCPKT_STOP; - tty->ctrl_status |= TIOCPKT_START; - wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); - } - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - if (tty->ops->start) - (tty->ops->start)(tty); - /* If we have a running line discipline it may need kicking */ - tty_wakeup(tty); -} - -EXPORT_SYMBOL(start_tty); - -/** - * tty_read - read method for tty device files - * @file: pointer to tty file - * @buf: user buffer - * @count: size of user buffer - * @ppos: unused - * - * Perform the read system call function on this terminal device. Checks - * for hung up devices before calling the line discipline method. - * - * Locking: - * Locks the line discipline internally while needed. Multiple - * read calls may be outstanding in parallel. - */ - -static ssize_t tty_read(struct file *file, char __user *buf, size_t count, - loff_t *ppos) -{ - int i; - struct inode *inode = file->f_path.dentry->d_inode; - struct tty_struct *tty = file_tty(file); - struct tty_ldisc *ld; - - if (tty_paranoia_check(tty, inode, "tty_read")) - return -EIO; - if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) - return -EIO; - - /* We want to wait for the line discipline to sort out in this - situation */ - ld = tty_ldisc_ref_wait(tty); - if (ld->ops->read) - i = (ld->ops->read)(tty, file, buf, count); - else - i = -EIO; - tty_ldisc_deref(ld); - if (i > 0) - inode->i_atime = current_fs_time(inode->i_sb); - return i; -} - -void tty_write_unlock(struct tty_struct *tty) -{ - mutex_unlock(&tty->atomic_write_lock); - wake_up_interruptible_poll(&tty->write_wait, POLLOUT); -} - -int tty_write_lock(struct tty_struct *tty, int ndelay) -{ - if (!mutex_trylock(&tty->atomic_write_lock)) { - if (ndelay) - return -EAGAIN; - if (mutex_lock_interruptible(&tty->atomic_write_lock)) - return -ERESTARTSYS; - } - return 0; -} - -/* - * Split writes up in sane blocksizes to avoid - * denial-of-service type attacks - */ -static inline ssize_t do_tty_write( - ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), - struct tty_struct *tty, - struct file *file, - const char __user *buf, - size_t count) -{ - ssize_t ret, written = 0; - unsigned int chunk; - - ret = tty_write_lock(tty, file->f_flags & O_NDELAY); - if (ret < 0) - return ret; - - /* - * We chunk up writes into a temporary buffer. This - * simplifies low-level drivers immensely, since they - * don't have locking issues and user mode accesses. - * - * But if TTY_NO_WRITE_SPLIT is set, we should use a - * big chunk-size.. - * - * The default chunk-size is 2kB, because the NTTY - * layer has problems with bigger chunks. It will - * claim to be able to handle more characters than - * it actually does. - * - * FIXME: This can probably go away now except that 64K chunks - * are too likely to fail unless switched to vmalloc... - */ - chunk = 2048; - if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) - chunk = 65536; - if (count < chunk) - chunk = count; - - /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ - if (tty->write_cnt < chunk) { - unsigned char *buf_chunk; - - if (chunk < 1024) - chunk = 1024; - - buf_chunk = kmalloc(chunk, GFP_KERNEL); - if (!buf_chunk) { - ret = -ENOMEM; - goto out; - } - kfree(tty->write_buf); - tty->write_cnt = chunk; - tty->write_buf = buf_chunk; - } - - /* Do the write .. */ - for (;;) { - size_t size = count; - if (size > chunk) - size = chunk; - ret = -EFAULT; - if (copy_from_user(tty->write_buf, buf, size)) - break; - ret = write(tty, file, tty->write_buf, size); - if (ret <= 0) - break; - written += ret; - buf += ret; - count -= ret; - if (!count) - break; - ret = -ERESTARTSYS; - if (signal_pending(current)) - break; - cond_resched(); - } - if (written) { - struct inode *inode = file->f_path.dentry->d_inode; - inode->i_mtime = current_fs_time(inode->i_sb); - ret = written; - } -out: - tty_write_unlock(tty); - return ret; -} - -/** - * tty_write_message - write a message to a certain tty, not just the console. - * @tty: the destination tty_struct - * @msg: the message to write - * - * This is used for messages that need to be redirected to a specific tty. - * We don't put it into the syslog queue right now maybe in the future if - * really needed. - * - * We must still hold the BTM and test the CLOSING flag for the moment. - */ - -void tty_write_message(struct tty_struct *tty, char *msg) -{ - if (tty) { - mutex_lock(&tty->atomic_write_lock); - tty_lock(); - if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { - tty_unlock(); - tty->ops->write(tty, msg, strlen(msg)); - } else - tty_unlock(); - tty_write_unlock(tty); - } - return; -} - - -/** - * tty_write - write method for tty device file - * @file: tty file pointer - * @buf: user data to write - * @count: bytes to write - * @ppos: unused - * - * Write data to a tty device via the line discipline. - * - * Locking: - * Locks the line discipline as required - * Writes to the tty driver are serialized by the atomic_write_lock - * and are then processed in chunks to the device. The line discipline - * write method will not be invoked in parallel for each device. - */ - -static ssize_t tty_write(struct file *file, const char __user *buf, - size_t count, loff_t *ppos) -{ - struct inode *inode = file->f_path.dentry->d_inode; - struct tty_struct *tty = file_tty(file); - struct tty_ldisc *ld; - ssize_t ret; - - if (tty_paranoia_check(tty, inode, "tty_write")) - return -EIO; - if (!tty || !tty->ops->write || - (test_bit(TTY_IO_ERROR, &tty->flags))) - return -EIO; - /* Short term debug to catch buggy drivers */ - if (tty->ops->write_room == NULL) - printk(KERN_ERR "tty driver %s lacks a write_room method.\n", - tty->driver->name); - ld = tty_ldisc_ref_wait(tty); - if (!ld->ops->write) - ret = -EIO; - else - ret = do_tty_write(ld->ops->write, tty, file, buf, count); - tty_ldisc_deref(ld); - return ret; -} - -ssize_t redirected_tty_write(struct file *file, const char __user *buf, - size_t count, loff_t *ppos) -{ - struct file *p = NULL; - - spin_lock(&redirect_lock); - if (redirect) { - get_file(redirect); - p = redirect; - } - spin_unlock(&redirect_lock); - - if (p) { - ssize_t res; - res = vfs_write(p, buf, count, &p->f_pos); - fput(p); - return res; - } - return tty_write(file, buf, count, ppos); -} - -static char ptychar[] = "pqrstuvwxyzabcde"; - -/** - * pty_line_name - generate name for a pty - * @driver: the tty driver in use - * @index: the minor number - * @p: output buffer of at least 6 bytes - * - * Generate a name from a driver reference and write it to the output - * buffer. - * - * Locking: None - */ -static void pty_line_name(struct tty_driver *driver, int index, char *p) -{ - int i = index + driver->name_base; - /* ->name is initialized to "ttyp", but "tty" is expected */ - sprintf(p, "%s%c%x", - driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, - ptychar[i >> 4 & 0xf], i & 0xf); -} - -/** - * tty_line_name - generate name for a tty - * @driver: the tty driver in use - * @index: the minor number - * @p: output buffer of at least 7 bytes - * - * Generate a name from a driver reference and write it to the output - * buffer. - * - * Locking: None - */ -static void tty_line_name(struct tty_driver *driver, int index, char *p) -{ - sprintf(p, "%s%d", driver->name, index + driver->name_base); -} - -/** - * tty_driver_lookup_tty() - find an existing tty, if any - * @driver: the driver for the tty - * @idx: the minor number - * - * Return the tty, if found or ERR_PTR() otherwise. - * - * Locking: tty_mutex must be held. If tty is found, the mutex must - * be held until the 'fast-open' is also done. Will change once we - * have refcounting in the driver and per driver locking - */ -static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, - struct inode *inode, int idx) -{ - struct tty_struct *tty; - - if (driver->ops->lookup) - return driver->ops->lookup(driver, inode, idx); - - tty = driver->ttys[idx]; - return tty; -} - -/** - * tty_init_termios - helper for termios setup - * @tty: the tty to set up - * - * Initialise the termios structures for this tty. Thus runs under - * the tty_mutex currently so we can be relaxed about ordering. - */ - -int tty_init_termios(struct tty_struct *tty) -{ - struct ktermios *tp; - int idx = tty->index; - - tp = tty->driver->termios[idx]; - if (tp == NULL) { - tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); - if (tp == NULL) - return -ENOMEM; - memcpy(tp, &tty->driver->init_termios, - sizeof(struct ktermios)); - tty->driver->termios[idx] = tp; - } - tty->termios = tp; - tty->termios_locked = tp + 1; - - /* Compatibility until drivers always set this */ - tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); - tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); - return 0; -} -EXPORT_SYMBOL_GPL(tty_init_termios); - -/** - * tty_driver_install_tty() - install a tty entry in the driver - * @driver: the driver for the tty - * @tty: the tty - * - * Install a tty object into the driver tables. The tty->index field - * will be set by the time this is called. This method is responsible - * for ensuring any need additional structures are allocated and - * configured. - * - * Locking: tty_mutex for now - */ -static int tty_driver_install_tty(struct tty_driver *driver, - struct tty_struct *tty) -{ - int idx = tty->index; - int ret; - - if (driver->ops->install) { - ret = driver->ops->install(driver, tty); - return ret; - } - - if (tty_init_termios(tty) == 0) { - tty_driver_kref_get(driver); - tty->count++; - driver->ttys[idx] = tty; - return 0; - } - return -ENOMEM; -} - -/** - * tty_driver_remove_tty() - remove a tty from the driver tables - * @driver: the driver for the tty - * @idx: the minor number - * - * Remvoe a tty object from the driver tables. The tty->index field - * will be set by the time this is called. - * - * Locking: tty_mutex for now - */ -static void tty_driver_remove_tty(struct tty_driver *driver, - struct tty_struct *tty) -{ - if (driver->ops->remove) - driver->ops->remove(driver, tty); - else - driver->ttys[tty->index] = NULL; -} - -/* - * tty_reopen() - fast re-open of an open tty - * @tty - the tty to open - * - * Return 0 on success, -errno on error. - * - * Locking: tty_mutex must be held from the time the tty was found - * till this open completes. - */ -static int tty_reopen(struct tty_struct *tty) -{ - struct tty_driver *driver = tty->driver; - - if (test_bit(TTY_CLOSING, &tty->flags)) - return -EIO; - - if (driver->type == TTY_DRIVER_TYPE_PTY && - driver->subtype == PTY_TYPE_MASTER) { - /* - * special case for PTY masters: only one open permitted, - * and the slave side open count is incremented as well. - */ - if (tty->count) - return -EIO; - - tty->link->count++; - } - tty->count++; - tty->driver = driver; /* N.B. why do this every time?? */ - - mutex_lock(&tty->ldisc_mutex); - WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); - mutex_unlock(&tty->ldisc_mutex); - - return 0; -} - -/** - * tty_init_dev - initialise a tty device - * @driver: tty driver we are opening a device on - * @idx: device index - * @ret_tty: returned tty structure - * @first_ok: ok to open a new device (used by ptmx) - * - * Prepare a tty device. This may not be a "new" clean device but - * could also be an active device. The pty drivers require special - * handling because of this. - * - * Locking: - * The function is called under the tty_mutex, which - * protects us from the tty struct or driver itself going away. - * - * On exit the tty device has the line discipline attached and - * a reference count of 1. If a pair was created for pty/tty use - * and the other was a pty master then it too has a reference count of 1. - * - * WSH 06/09/97: Rewritten to remove races and properly clean up after a - * failed open. The new code protects the open with a mutex, so it's - * really quite straightforward. The mutex locking can probably be - * relaxed for the (most common) case of reopening a tty. - */ - -struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, - int first_ok) -{ - struct tty_struct *tty; - int retval; - - /* Check if pty master is being opened multiple times */ - if (driver->subtype == PTY_TYPE_MASTER && - (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) { - return ERR_PTR(-EIO); - } - - /* - * First time open is complex, especially for PTY devices. - * This code guarantees that either everything succeeds and the - * TTY is ready for operation, or else the table slots are vacated - * and the allocated memory released. (Except that the termios - * and locked termios may be retained.) - */ - - if (!try_module_get(driver->owner)) - return ERR_PTR(-ENODEV); - - tty = alloc_tty_struct(); - if (!tty) - goto fail_no_mem; - initialize_tty_struct(tty, driver, idx); - - retval = tty_driver_install_tty(driver, tty); - if (retval < 0) { - free_tty_struct(tty); - module_put(driver->owner); - return ERR_PTR(retval); - } - - /* - * Structures all installed ... call the ldisc open routines. - * If we fail here just call release_tty to clean up. No need - * to decrement the use counts, as release_tty doesn't care. - */ - retval = tty_ldisc_setup(tty, tty->link); - if (retval) - goto release_mem_out; - return tty; - -fail_no_mem: - module_put(driver->owner); - return ERR_PTR(-ENOMEM); - - /* call the tty release_tty routine to clean out this slot */ -release_mem_out: - if (printk_ratelimit()) - printk(KERN_INFO "tty_init_dev: ldisc open failed, " - "clearing slot %d\n", idx); - release_tty(tty, idx); - return ERR_PTR(retval); -} - -void tty_free_termios(struct tty_struct *tty) -{ - struct ktermios *tp; - int idx = tty->index; - /* Kill this flag and push into drivers for locking etc */ - if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { - /* FIXME: Locking on ->termios array */ - tp = tty->termios; - tty->driver->termios[idx] = NULL; - kfree(tp); - } -} -EXPORT_SYMBOL(tty_free_termios); - -void tty_shutdown(struct tty_struct *tty) -{ - tty_driver_remove_tty(tty->driver, tty); - tty_free_termios(tty); -} -EXPORT_SYMBOL(tty_shutdown); - -/** - * release_one_tty - release tty structure memory - * @kref: kref of tty we are obliterating - * - * Releases memory associated with a tty structure, and clears out the - * driver table slots. This function is called when a device is no longer - * in use. It also gets called when setup of a device fails. - * - * Locking: - * tty_mutex - sometimes only - * takes the file list lock internally when working on the list - * of ttys that the driver keeps. - * - * This method gets called from a work queue so that the driver private - * cleanup ops can sleep (needed for USB at least) - */ -static void release_one_tty(struct work_struct *work) -{ - struct tty_struct *tty = - container_of(work, struct tty_struct, hangup_work); - struct tty_driver *driver = tty->driver; - - if (tty->ops->cleanup) - tty->ops->cleanup(tty); - - tty->magic = 0; - tty_driver_kref_put(driver); - module_put(driver->owner); - - spin_lock(&tty_files_lock); - list_del_init(&tty->tty_files); - spin_unlock(&tty_files_lock); - - put_pid(tty->pgrp); - put_pid(tty->session); - free_tty_struct(tty); -} - -static void queue_release_one_tty(struct kref *kref) -{ - struct tty_struct *tty = container_of(kref, struct tty_struct, kref); - - if (tty->ops->shutdown) - tty->ops->shutdown(tty); - else - tty_shutdown(tty); - - /* The hangup queue is now free so we can reuse it rather than - waste a chunk of memory for each port */ - INIT_WORK(&tty->hangup_work, release_one_tty); - schedule_work(&tty->hangup_work); -} - -/** - * tty_kref_put - release a tty kref - * @tty: tty device - * - * Release a reference to a tty device and if need be let the kref - * layer destruct the object for us - */ - -void tty_kref_put(struct tty_struct *tty) -{ - if (tty) - kref_put(&tty->kref, queue_release_one_tty); -} -EXPORT_SYMBOL(tty_kref_put); - -/** - * release_tty - release tty structure memory - * - * Release both @tty and a possible linked partner (think pty pair), - * and decrement the refcount of the backing module. - * - * Locking: - * tty_mutex - sometimes only - * takes the file list lock internally when working on the list - * of ttys that the driver keeps. - * FIXME: should we require tty_mutex is held here ?? - * - */ -static void release_tty(struct tty_struct *tty, int idx) -{ - /* This should always be true but check for the moment */ - WARN_ON(tty->index != idx); - - if (tty->link) - tty_kref_put(tty->link); - tty_kref_put(tty); -} - -/** - * tty_release - vfs callback for close - * @inode: inode of tty - * @filp: file pointer for handle to tty - * - * Called the last time each file handle is closed that references - * this tty. There may however be several such references. - * - * Locking: - * Takes bkl. See tty_release_dev - * - * Even releasing the tty structures is a tricky business.. We have - * to be very careful that the structures are all released at the - * same time, as interrupts might otherwise get the wrong pointers. - * - * WSH 09/09/97: rewritten to avoid some nasty race conditions that could - * lead to double frees or releasing memory still in use. - */ - -int tty_release(struct inode *inode, struct file *filp) -{ - struct tty_struct *tty = file_tty(filp); - struct tty_struct *o_tty; - int pty_master, tty_closing, o_tty_closing, do_sleep; - int devpts; - int idx; - char buf[64]; - - if (tty_paranoia_check(tty, inode, "tty_release_dev")) - return 0; - - tty_lock(); - check_tty_count(tty, "tty_release_dev"); - - __tty_fasync(-1, filp, 0); - - idx = tty->index; - pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && - tty->driver->subtype == PTY_TYPE_MASTER); - devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; - o_tty = tty->link; - -#ifdef TTY_PARANOIA_CHECK - if (idx < 0 || idx >= tty->driver->num) { - printk(KERN_DEBUG "tty_release_dev: bad idx when trying to " - "free (%s)\n", tty->name); - tty_unlock(); - return 0; - } - if (!devpts) { - if (tty != tty->driver->ttys[idx]) { - tty_unlock(); - printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty " - "for (%s)\n", idx, tty->name); - return 0; - } - if (tty->termios != tty->driver->termios[idx]) { - tty_unlock(); - printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios " - "for (%s)\n", - idx, tty->name); - return 0; - } - } -#endif - -#ifdef TTY_DEBUG_HANGUP - printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...", - tty_name(tty, buf), tty->count); -#endif - -#ifdef TTY_PARANOIA_CHECK - if (tty->driver->other && - !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { - if (o_tty != tty->driver->other->ttys[idx]) { - tty_unlock(); - printk(KERN_DEBUG "tty_release_dev: other->table[%d] " - "not o_tty for (%s)\n", - idx, tty->name); - return 0 ; - } - if (o_tty->termios != tty->driver->other->termios[idx]) { - tty_unlock(); - printk(KERN_DEBUG "tty_release_dev: other->termios[%d] " - "not o_termios for (%s)\n", - idx, tty->name); - return 0; - } - if (o_tty->link != tty) { - tty_unlock(); - printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n"); - return 0; - } - } -#endif - if (tty->ops->close) - tty->ops->close(tty, filp); - - tty_unlock(); - /* - * Sanity check: if tty->count is going to zero, there shouldn't be - * any waiters on tty->read_wait or tty->write_wait. We test the - * wait queues and kick everyone out _before_ actually starting to - * close. This ensures that we won't block while releasing the tty - * structure. - * - * The test for the o_tty closing is necessary, since the master and - * slave sides may close in any order. If the slave side closes out - * first, its count will be one, since the master side holds an open. - * Thus this test wouldn't be triggered at the time the slave closes, - * so we do it now. - * - * Note that it's possible for the tty to be opened again while we're - * flushing out waiters. By recalculating the closing flags before - * each iteration we avoid any problems. - */ - while (1) { - /* Guard against races with tty->count changes elsewhere and - opens on /dev/tty */ - - mutex_lock(&tty_mutex); - tty_lock(); - tty_closing = tty->count <= 1; - o_tty_closing = o_tty && - (o_tty->count <= (pty_master ? 1 : 0)); - do_sleep = 0; - - if (tty_closing) { - if (waitqueue_active(&tty->read_wait)) { - wake_up_poll(&tty->read_wait, POLLIN); - do_sleep++; - } - if (waitqueue_active(&tty->write_wait)) { - wake_up_poll(&tty->write_wait, POLLOUT); - do_sleep++; - } - } - if (o_tty_closing) { - if (waitqueue_active(&o_tty->read_wait)) { - wake_up_poll(&o_tty->read_wait, POLLIN); - do_sleep++; - } - if (waitqueue_active(&o_tty->write_wait)) { - wake_up_poll(&o_tty->write_wait, POLLOUT); - do_sleep++; - } - } - if (!do_sleep) - break; - - printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue " - "active!\n", tty_name(tty, buf)); - tty_unlock(); - mutex_unlock(&tty_mutex); - schedule(); - } - - /* - * The closing flags are now consistent with the open counts on - * both sides, and we've completed the last operation that could - * block, so it's safe to proceed with closing. - */ - if (pty_master) { - if (--o_tty->count < 0) { - printk(KERN_WARNING "tty_release_dev: bad pty slave count " - "(%d) for %s\n", - o_tty->count, tty_name(o_tty, buf)); - o_tty->count = 0; - } - } - if (--tty->count < 0) { - printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n", - tty->count, tty_name(tty, buf)); - tty->count = 0; - } - - /* - * We've decremented tty->count, so we need to remove this file - * descriptor off the tty->tty_files list; this serves two - * purposes: - * - check_tty_count sees the correct number of file descriptors - * associated with this tty. - * - do_tty_hangup no longer sees this file descriptor as - * something that needs to be handled for hangups. - */ - tty_del_file(filp); - - /* - * Perform some housekeeping before deciding whether to return. - * - * Set the TTY_CLOSING flag if this was the last open. In the - * case of a pty we may have to wait around for the other side - * to close, and TTY_CLOSING makes sure we can't be reopened. - */ - if (tty_closing) - set_bit(TTY_CLOSING, &tty->flags); - if (o_tty_closing) - set_bit(TTY_CLOSING, &o_tty->flags); - - /* - * If _either_ side is closing, make sure there aren't any - * processes that still think tty or o_tty is their controlling - * tty. - */ - if (tty_closing || o_tty_closing) { - read_lock(&tasklist_lock); - session_clear_tty(tty->session); - if (o_tty) - session_clear_tty(o_tty->session); - read_unlock(&tasklist_lock); - } - - mutex_unlock(&tty_mutex); - - /* check whether both sides are closing ... */ - if (!tty_closing || (o_tty && !o_tty_closing)) { - tty_unlock(); - return 0; - } - -#ifdef TTY_DEBUG_HANGUP - printk(KERN_DEBUG "freeing tty structure..."); -#endif - /* - * Ask the line discipline code to release its structures - */ - tty_ldisc_release(tty, o_tty); - /* - * The release_tty function takes care of the details of clearing - * the slots and preserving the termios structure. - */ - release_tty(tty, idx); - - /* Make this pty number available for reallocation */ - if (devpts) - devpts_kill_index(inode, idx); - tty_unlock(); - return 0; -} - -/** - * tty_open - open a tty device - * @inode: inode of device file - * @filp: file pointer to tty - * - * tty_open and tty_release keep up the tty count that contains the - * number of opens done on a tty. We cannot use the inode-count, as - * different inodes might point to the same tty. - * - * Open-counting is needed for pty masters, as well as for keeping - * track of serial lines: DTR is dropped when the last close happens. - * (This is not done solely through tty->count, now. - Ted 1/27/92) - * - * The termios state of a pty is reset on first open so that - * settings don't persist across reuse. - * - * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work. - * tty->count should protect the rest. - * ->siglock protects ->signal/->sighand - */ - -static int tty_open(struct inode *inode, struct file *filp) -{ - struct tty_struct *tty = NULL; - int noctty, retval; - struct tty_driver *driver; - int index; - dev_t device = inode->i_rdev; - unsigned saved_flags = filp->f_flags; - - nonseekable_open(inode, filp); - -retry_open: - noctty = filp->f_flags & O_NOCTTY; - index = -1; - retval = 0; - - mutex_lock(&tty_mutex); - tty_lock(); - - if (device == MKDEV(TTYAUX_MAJOR, 0)) { - tty = get_current_tty(); - if (!tty) { - tty_unlock(); - mutex_unlock(&tty_mutex); - return -ENXIO; - } - driver = tty_driver_kref_get(tty->driver); - index = tty->index; - filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ - /* noctty = 1; */ - /* FIXME: Should we take a driver reference ? */ - tty_kref_put(tty); - goto got_driver; - } -#ifdef CONFIG_VT - if (device == MKDEV(TTY_MAJOR, 0)) { - extern struct tty_driver *console_driver; - driver = tty_driver_kref_get(console_driver); - index = fg_console; - noctty = 1; - goto got_driver; - } -#endif - if (device == MKDEV(TTYAUX_MAJOR, 1)) { - struct tty_driver *console_driver = console_device(&index); - if (console_driver) { - driver = tty_driver_kref_get(console_driver); - if (driver) { - /* Don't let /dev/console block */ - filp->f_flags |= O_NONBLOCK; - noctty = 1; - goto got_driver; - } - } - tty_unlock(); - mutex_unlock(&tty_mutex); - return -ENODEV; - } - - driver = get_tty_driver(device, &index); - if (!driver) { - tty_unlock(); - mutex_unlock(&tty_mutex); - return -ENODEV; - } -got_driver: - if (!tty) { - /* check whether we're reopening an existing tty */ - tty = tty_driver_lookup_tty(driver, inode, index); - - if (IS_ERR(tty)) { - tty_unlock(); - mutex_unlock(&tty_mutex); - return PTR_ERR(tty); - } - } - - if (tty) { - retval = tty_reopen(tty); - if (retval) - tty = ERR_PTR(retval); - } else - tty = tty_init_dev(driver, index, 0); - - mutex_unlock(&tty_mutex); - tty_driver_kref_put(driver); - if (IS_ERR(tty)) { - tty_unlock(); - return PTR_ERR(tty); - } - - retval = tty_add_file(tty, filp); - if (retval) { - tty_unlock(); - return retval; - } - - check_tty_count(tty, "tty_open"); - if (tty->driver->type == TTY_DRIVER_TYPE_PTY && - tty->driver->subtype == PTY_TYPE_MASTER) - noctty = 1; -#ifdef TTY_DEBUG_HANGUP - printk(KERN_DEBUG "opening %s...", tty->name); -#endif - if (!retval) { - if (tty->ops->open) - retval = tty->ops->open(tty, filp); - else - retval = -ENODEV; - } - filp->f_flags = saved_flags; - - if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && - !capable(CAP_SYS_ADMIN)) - retval = -EBUSY; - - if (retval) { -#ifdef TTY_DEBUG_HANGUP - printk(KERN_DEBUG "error %d in opening %s...", retval, - tty->name); -#endif - tty_unlock(); /* need to call tty_release without BTM */ - tty_release(inode, filp); - if (retval != -ERESTARTSYS) - return retval; - - if (signal_pending(current)) - return retval; - - schedule(); - /* - * Need to reset f_op in case a hangup happened. - */ - tty_lock(); - if (filp->f_op == &hung_up_tty_fops) - filp->f_op = &tty_fops; - tty_unlock(); - goto retry_open; - } - tty_unlock(); - - - mutex_lock(&tty_mutex); - tty_lock(); - spin_lock_irq(¤t->sighand->siglock); - if (!noctty && - current->signal->leader && - !current->signal->tty && - tty->session == NULL) - __proc_set_tty(current, tty); - spin_unlock_irq(¤t->sighand->siglock); - tty_unlock(); - mutex_unlock(&tty_mutex); - return 0; -} - - - -/** - * tty_poll - check tty status - * @filp: file being polled - * @wait: poll wait structures to update - * - * Call the line discipline polling method to obtain the poll - * status of the device. - * - * Locking: locks called line discipline but ldisc poll method - * may be re-entered freely by other callers. - */ - -static unsigned int tty_poll(struct file *filp, poll_table *wait) -{ - struct tty_struct *tty = file_tty(filp); - struct tty_ldisc *ld; - int ret = 0; - - if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) - return 0; - - ld = tty_ldisc_ref_wait(tty); - if (ld->ops->poll) - ret = (ld->ops->poll)(tty, filp, wait); - tty_ldisc_deref(ld); - return ret; -} - -static int __tty_fasync(int fd, struct file *filp, int on) -{ - struct tty_struct *tty = file_tty(filp); - unsigned long flags; - int retval = 0; - - if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) - goto out; - - retval = fasync_helper(fd, filp, on, &tty->fasync); - if (retval <= 0) - goto out; - - if (on) { - enum pid_type type; - struct pid *pid; - if (!waitqueue_active(&tty->read_wait)) - tty->minimum_to_wake = 1; - spin_lock_irqsave(&tty->ctrl_lock, flags); - if (tty->pgrp) { - pid = tty->pgrp; - type = PIDTYPE_PGID; - } else { - pid = task_pid(current); - type = PIDTYPE_PID; - } - get_pid(pid); - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - retval = __f_setown(filp, pid, type, 0); - put_pid(pid); - if (retval) - goto out; - } else { - if (!tty->fasync && !waitqueue_active(&tty->read_wait)) - tty->minimum_to_wake = N_TTY_BUF_SIZE; - } - retval = 0; -out: - return retval; -} - -static int tty_fasync(int fd, struct file *filp, int on) -{ - int retval; - tty_lock(); - retval = __tty_fasync(fd, filp, on); - tty_unlock(); - return retval; -} - -/** - * tiocsti - fake input character - * @tty: tty to fake input into - * @p: pointer to character - * - * Fake input to a tty device. Does the necessary locking and - * input management. - * - * FIXME: does not honour flow control ?? - * - * Locking: - * Called functions take tty_ldisc_lock - * current->signal->tty check is safe without locks - * - * FIXME: may race normal receive processing - */ - -static int tiocsti(struct tty_struct *tty, char __user *p) -{ - char ch, mbz = 0; - struct tty_ldisc *ld; - - if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) - return -EPERM; - if (get_user(ch, p)) - return -EFAULT; - tty_audit_tiocsti(tty, ch); - ld = tty_ldisc_ref_wait(tty); - ld->ops->receive_buf(tty, &ch, &mbz, 1); - tty_ldisc_deref(ld); - return 0; -} - -/** - * tiocgwinsz - implement window query ioctl - * @tty; tty - * @arg: user buffer for result - * - * Copies the kernel idea of the window size into the user buffer. - * - * Locking: tty->termios_mutex is taken to ensure the winsize data - * is consistent. - */ - -static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) -{ - int err; - - mutex_lock(&tty->termios_mutex); - err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); - mutex_unlock(&tty->termios_mutex); - - return err ? -EFAULT: 0; -} - -/** - * tty_do_resize - resize event - * @tty: tty being resized - * @rows: rows (character) - * @cols: cols (character) - * - * Update the termios variables and send the necessary signals to - * peform a terminal resize correctly - */ - -int tty_do_resize(struct tty_struct *tty, struct winsize *ws) -{ - struct pid *pgrp; - unsigned long flags; - - /* Lock the tty */ - mutex_lock(&tty->termios_mutex); - if (!memcmp(ws, &tty->winsize, sizeof(*ws))) - goto done; - /* 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); - pgrp = get_pid(tty->pgrp); - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - - if (pgrp) - kill_pgrp(pgrp, SIGWINCH, 1); - put_pid(pgrp); - - tty->winsize = *ws; -done: - mutex_unlock(&tty->termios_mutex); - return 0; -} - -/** - * tiocswinsz - implement window size set ioctl - * @tty; tty side of 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 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, &tmp_ws); - else - return tty_do_resize(tty, &tmp_ws); -} - -/** - * tioccons - allow admin to move logical console - * @file: the file to become console - * - * Allow the adminstrator to move the redirected console device - * - * Locking: uses redirect_lock to guard the redirect information - */ - -static int tioccons(struct file *file) -{ - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - if (file->f_op->write == redirected_tty_write) { - struct file *f; - spin_lock(&redirect_lock); - f = redirect; - redirect = NULL; - spin_unlock(&redirect_lock); - if (f) - fput(f); - return 0; - } - spin_lock(&redirect_lock); - if (redirect) { - spin_unlock(&redirect_lock); - return -EBUSY; - } - get_file(file); - redirect = file; - spin_unlock(&redirect_lock); - return 0; -} - -/** - * fionbio - non blocking ioctl - * @file: file to set blocking value - * @p: user parameter - * - * Historical tty interfaces had a blocking control ioctl before - * the generic functionality existed. This piece of history is preserved - * in the expected tty API of posix OS's. - * - * Locking: none, the open file handle ensures it won't go away. - */ - -static int fionbio(struct file *file, int __user *p) -{ - int nonblock; - - if (get_user(nonblock, p)) - return -EFAULT; - - spin_lock(&file->f_lock); - if (nonblock) - file->f_flags |= O_NONBLOCK; - else - file->f_flags &= ~O_NONBLOCK; - spin_unlock(&file->f_lock); - return 0; -} - -/** - * tiocsctty - set controlling tty - * @tty: tty structure - * @arg: user argument - * - * This ioctl is used to manage job control. It permits a session - * leader to set this tty as the controlling tty for the session. - * - * Locking: - * Takes tty_mutex() to protect tty instance - * Takes tasklist_lock internally to walk sessions - * Takes ->siglock() when updating signal->tty - */ - -static int tiocsctty(struct tty_struct *tty, int arg) -{ - int ret = 0; - if (current->signal->leader && (task_session(current) == tty->session)) - return ret; - - mutex_lock(&tty_mutex); - /* - * The process must be a session leader and - * not have a controlling tty already. - */ - if (!current->signal->leader || current->signal->tty) { - ret = -EPERM; - goto unlock; - } - - if (tty->session) { - /* - * This tty is already the controlling - * tty for another session group! - */ - if (arg == 1 && capable(CAP_SYS_ADMIN)) { - /* - * Steal it away - */ - read_lock(&tasklist_lock); - session_clear_tty(tty->session); - read_unlock(&tasklist_lock); - } else { - ret = -EPERM; - goto unlock; - } - } - proc_set_tty(current, tty); -unlock: - mutex_unlock(&tty_mutex); - return ret; -} - -/** - * tty_get_pgrp - return a ref counted pgrp pid - * @tty: tty to read - * - * Returns a refcounted instance of the pid struct for the process - * group controlling the tty. - */ - -struct pid *tty_get_pgrp(struct tty_struct *tty) -{ - unsigned long flags; - struct pid *pgrp; - - spin_lock_irqsave(&tty->ctrl_lock, flags); - pgrp = get_pid(tty->pgrp); - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - - return pgrp; -} -EXPORT_SYMBOL_GPL(tty_get_pgrp); - -/** - * tiocgpgrp - get process group - * @tty: tty passed by user - * @real_tty: tty side of the tty pased by the user if a pty else the tty - * @p: returned pid - * - * Obtain the process group of the tty. If there is no process group - * return an error. - * - * Locking: none. Reference to current->signal->tty is safe. - */ - -static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) -{ - struct pid *pid; - int ret; - /* - * (tty == real_tty) is a cheap way of - * testing if the tty is NOT a master pty. - */ - if (tty == real_tty && current->signal->tty != real_tty) - return -ENOTTY; - pid = tty_get_pgrp(real_tty); - ret = put_user(pid_vnr(pid), p); - put_pid(pid); - return ret; -} - -/** - * tiocspgrp - attempt to set process group - * @tty: tty passed by user - * @real_tty: tty side device matching tty passed by user - * @p: pid pointer - * - * Set the process group of the tty to the session passed. Only - * permitted where the tty session is our session. - * - * Locking: RCU, ctrl lock - */ - -static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) -{ - struct pid *pgrp; - pid_t pgrp_nr; - int retval = tty_check_change(real_tty); - unsigned long flags; - - if (retval == -EIO) - return -ENOTTY; - if (retval) - return retval; - if (!current->signal->tty || - (current->signal->tty != real_tty) || - (real_tty->session != task_session(current))) - return -ENOTTY; - if (get_user(pgrp_nr, p)) - return -EFAULT; - if (pgrp_nr < 0) - return -EINVAL; - rcu_read_lock(); - pgrp = find_vpid(pgrp_nr); - retval = -ESRCH; - if (!pgrp) - goto out_unlock; - retval = -EPERM; - if (session_of_pgrp(pgrp) != task_session(current)) - goto out_unlock; - retval = 0; - spin_lock_irqsave(&tty->ctrl_lock, flags); - put_pid(real_tty->pgrp); - real_tty->pgrp = get_pid(pgrp); - spin_unlock_irqrestore(&tty->ctrl_lock, flags); -out_unlock: - rcu_read_unlock(); - return retval; -} - -/** - * tiocgsid - get session id - * @tty: tty passed by user - * @real_tty: tty side of the tty pased by the user if a pty else the tty - * @p: pointer to returned session id - * - * Obtain the session id of the tty. If there is no session - * return an error. - * - * Locking: none. Reference to current->signal->tty is safe. - */ - -static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) -{ - /* - * (tty == real_tty) is a cheap way of - * testing if the tty is NOT a master pty. - */ - if (tty == real_tty && current->signal->tty != real_tty) - return -ENOTTY; - if (!real_tty->session) - return -ENOTTY; - return put_user(pid_vnr(real_tty->session), p); -} - -/** - * tiocsetd - set line discipline - * @tty: tty device - * @p: pointer to user data - * - * Set the line discipline according to user request. - * - * Locking: see tty_set_ldisc, this function is just a helper - */ - -static int tiocsetd(struct tty_struct *tty, int __user *p) -{ - int ldisc; - int ret; - - if (get_user(ldisc, p)) - return -EFAULT; - - ret = tty_set_ldisc(tty, ldisc); - - return ret; -} - -/** - * send_break - performed time break - * @tty: device to break on - * @duration: timeout in mS - * - * Perform a timed break on hardware that lacks its own driver level - * timed break functionality. - * - * Locking: - * atomic_write_lock serializes - * - */ - -static int send_break(struct tty_struct *tty, unsigned int duration) -{ - 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; -} - -/** - * tty_tiocmget - get modem status - * @tty: tty device - * @file: user file pointer - * @p: pointer to result - * - * Obtain the modem status bits from the tty driver if the feature - * is supported. Return -EINVAL if it is not available. - * - * Locking: none (up to the driver) - */ - -static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) -{ - int retval = -EINVAL; - - if (tty->ops->tiocmget) { - retval = tty->ops->tiocmget(tty, file); - - if (retval >= 0) - retval = put_user(retval, p); - } - return retval; -} - -/** - * tty_tiocmset - set modem status - * @tty: tty device - * @file: user file pointer - * @cmd: command - clear bits, set bits or set all - * @p: pointer to desired bits - * - * Set the modem status bits from the tty driver if the feature - * is supported. Return -EINVAL if it is not available. - * - * Locking: none (up to the driver) - */ - -static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, - unsigned __user *p) -{ - int retval; - unsigned int set, clear, val; - - if (tty->ops->tiocmset == NULL) - return -EINVAL; - - 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; - } - 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); -} - -static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) -{ - int retval = -EINVAL; - struct serial_icounter_struct icount; - memset(&icount, 0, sizeof(icount)); - if (tty->ops->get_icount) - retval = tty->ops->get_icount(tty, &icount); - if (retval != 0) - return retval; - if (copy_to_user(arg, &icount, sizeof(icount))) - return -EFAULT; - return 0; -} - -struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) -{ - if (tty->driver->type == TTY_DRIVER_TYPE_PTY && - tty->driver->subtype == PTY_TYPE_MASTER) - tty = tty->link; - return tty; -} -EXPORT_SYMBOL(tty_pair_get_tty); - -struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) -{ - if (tty->driver->type == TTY_DRIVER_TYPE_PTY && - tty->driver->subtype == PTY_TYPE_MASTER) - return tty; - return tty->link; -} -EXPORT_SYMBOL(tty_pair_get_pty); - -/* - * Split this up, as gcc can choke on it otherwise.. - */ -long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) -{ - struct tty_struct *tty = file_tty(file); - struct tty_struct *real_tty; - void __user *p = (void __user *)arg; - int retval; - struct tty_ldisc *ld; - struct inode *inode = file->f_dentry->d_inode; - - if (tty_paranoia_check(tty, inode, "tty_ioctl")) - return -EINVAL; - - real_tty = tty_pair_get_tty(tty); - - /* - * Factor out some common prep work - */ - switch (cmd) { - case TIOCSETD: - case TIOCSBRK: - case TIOCCBRK: - case TCSBRK: - case TCSBRKP: - retval = tty_check_change(tty); - if (retval) - return retval; - if (cmd != TIOCCBRK) { - tty_wait_until_sent(tty, 0); - if (signal_pending(current)) - return -EINTR; - } - break; - } - - /* - * Now do the stuff. - */ - switch (cmd) { - case TIOCSTI: - return tiocsti(tty, p); - case TIOCGWINSZ: - return tiocgwinsz(real_tty, p); - case TIOCSWINSZ: - return tiocswinsz(real_tty, p); - case TIOCCONS: - return real_tty != tty ? -EINVAL : tioccons(file); - case FIONBIO: - return fionbio(file, p); - case TIOCEXCL: - set_bit(TTY_EXCLUSIVE, &tty->flags); - return 0; - case TIOCNXCL: - clear_bit(TTY_EXCLUSIVE, &tty->flags); - return 0; - case TIOCNOTTY: - if (current->signal->tty != tty) - return -ENOTTY; - no_tty(); - return 0; - case TIOCSCTTY: - return tiocsctty(tty, arg); - case TIOCGPGRP: - return tiocgpgrp(tty, real_tty, p); - case TIOCSPGRP: - return tiocspgrp(tty, real_tty, p); - case TIOCGSID: - return tiocgsid(tty, real_tty, p); - case TIOCGETD: - return put_user(tty->ldisc->ops->num, (int __user *)p); - case TIOCSETD: - return tiocsetd(tty, p); - /* - * Break handling - */ - case TIOCSBRK: /* Turn break on, unconditionally */ - if (tty->ops->break_ctl) - return tty->ops->break_ctl(tty, -1); - return 0; - case TIOCCBRK: /* Turn break off, unconditionally */ - if (tty->ops->break_ctl) - 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 - * to be sent (performed above) but don't send break. - * This is used by the tcdrain() termios function. - */ - if (!arg) - return send_break(tty, 250); - return 0; - case TCSBRKP: /* support for POSIX tcsendbreak() */ - return send_break(tty, arg ? arg*100 : 250); - - case TIOCMGET: - return tty_tiocmget(tty, file, p); - case TIOCMSET: - case TIOCMBIC: - case TIOCMBIS: - return tty_tiocmset(tty, file, cmd, p); - case TIOCGICOUNT: - retval = tty_tiocgicount(tty, p); - /* For the moment allow fall through to the old method */ - if (retval != -EINVAL) - return retval; - break; - case TCFLSH: - switch (arg) { - case TCIFLUSH: - case TCIOFLUSH: - /* flush tty buffer and allow ldisc to process ioctl */ - tty_buffer_flush(tty); - break; - } - break; - } - if (tty->ops->ioctl) { - retval = (tty->ops->ioctl)(tty, file, cmd, arg); - if (retval != -ENOIOCTLCMD) - return retval; - } - ld = tty_ldisc_ref_wait(tty); - retval = -EINVAL; - if (ld->ops->ioctl) { - retval = ld->ops->ioctl(tty, file, cmd, arg); - if (retval == -ENOIOCTLCMD) - retval = -EINVAL; - } - tty_ldisc_deref(ld); - return retval; -} - -#ifdef CONFIG_COMPAT -static long tty_compat_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) -{ - struct inode *inode = file->f_dentry->d_inode; - struct tty_struct *tty = file_tty(file); - struct tty_ldisc *ld; - int retval = -ENOIOCTLCMD; - - if (tty_paranoia_check(tty, inode, "tty_ioctl")) - return -EINVAL; - - if (tty->ops->compat_ioctl) { - retval = (tty->ops->compat_ioctl)(tty, file, cmd, arg); - if (retval != -ENOIOCTLCMD) - return retval; - } - - ld = tty_ldisc_ref_wait(tty); - if (ld->ops->compat_ioctl) - retval = ld->ops->compat_ioctl(tty, file, cmd, arg); - tty_ldisc_deref(ld); - - return retval; -} -#endif - -/* - * This implements the "Secure Attention Key" --- the idea is to - * prevent trojan horses by killing all processes associated with this - * tty when the user hits the "Secure Attention Key". Required for - * super-paranoid applications --- see the Orange Book for more details. - * - * This code could be nicer; ideally it should send a HUP, wait a few - * seconds, then send a INT, and then a KILL signal. But you then - * have to coordinate with the init process, since all processes associated - * with the current tty must be dead before the new getty is allowed - * to spawn. - * - * Now, if it would be correct ;-/ The current code has a nasty hole - - * it doesn't catch files in flight. We may send the descriptor to ourselves - * via AF_UNIX socket, close it and later fetch from socket. FIXME. - * - * Nasty bug: do_SAK is being called in interrupt context. This can - * deadlock. We punt it up to process context. AKPM - 16Mar2001 - */ -void __do_SAK(struct tty_struct *tty) -{ -#ifdef TTY_SOFT_SAK - tty_hangup(tty); -#else - struct task_struct *g, *p; - struct pid *session; - int i; - struct file *filp; - struct fdtable *fdt; - - if (!tty) - return; - session = tty->session; - - tty_ldisc_flush(tty); - - tty_driver_flush_buffer(tty); - - read_lock(&tasklist_lock); - /* Kill the entire session */ - do_each_pid_task(session, PIDTYPE_SID, p) { - printk(KERN_NOTICE "SAK: killed process %d" - " (%s): task_session(p)==tty->session\n", - task_pid_nr(p), p->comm); - send_sig(SIGKILL, p, 1); - } while_each_pid_task(session, PIDTYPE_SID, p); - /* Now kill any processes that happen to have the - * tty open. - */ - do_each_thread(g, p) { - if (p->signal->tty == tty) { - printk(KERN_NOTICE "SAK: killed process %d" - " (%s): task_session(p)==tty->session\n", - task_pid_nr(p), p->comm); - send_sig(SIGKILL, p, 1); - continue; - } - task_lock(p); - if (p->files) { - /* - * We don't take a ref to the file, so we must - * hold ->file_lock instead. - */ - spin_lock(&p->files->file_lock); - fdt = files_fdtable(p->files); - for (i = 0; i < fdt->max_fds; i++) { - filp = fcheck_files(p->files, i); - if (!filp) - continue; - if (filp->f_op->read == tty_read && - file_tty(filp) == tty) { - printk(KERN_NOTICE "SAK: killed process %d" - " (%s): fd#%d opened to the tty\n", - task_pid_nr(p), p->comm, i); - force_sig(SIGKILL, p); - break; - } - } - spin_unlock(&p->files->file_lock); - } - task_unlock(p); - } while_each_thread(g, p); - read_unlock(&tasklist_lock); -#endif -} - -static void do_SAK_work(struct work_struct *work) -{ - struct tty_struct *tty = - container_of(work, struct tty_struct, SAK_work); - __do_SAK(tty); -} - -/* - * The tq handling here is a little racy - tty->SAK_work may already be queued. - * Fortunately we don't need to worry, because if ->SAK_work is already queued, - * the values which we write to it will be identical to the values which it - * already has. --akpm - */ -void do_SAK(struct tty_struct *tty) -{ - if (!tty) - return; - schedule_work(&tty->SAK_work); -} - -EXPORT_SYMBOL(do_SAK); - -static int dev_match_devt(struct device *dev, void *data) -{ - dev_t *devt = data; - return dev->devt == *devt; -} - -/* Must put_device() after it's unused! */ -static struct device *tty_get_device(struct tty_struct *tty) -{ - dev_t devt = tty_devnum(tty); - return class_find_device(tty_class, NULL, &devt, dev_match_devt); -} - - -/** - * initialize_tty_struct - * @tty: tty to initialize - * - * This subroutine initializes a tty structure that has been newly - * allocated. - * - * Locking: none - tty in question must not be exposed at this point - */ - -void initialize_tty_struct(struct tty_struct *tty, - struct tty_driver *driver, int idx) -{ - memset(tty, 0, sizeof(struct tty_struct)); - kref_init(&tty->kref); - tty->magic = TTY_MAGIC; - tty_ldisc_init(tty); - tty->session = NULL; - tty->pgrp = NULL; - tty->overrun_time = jiffies; - tty->buf.head = tty->buf.tail = NULL; - tty_buffer_init(tty); - mutex_init(&tty->termios_mutex); - mutex_init(&tty->ldisc_mutex); - init_waitqueue_head(&tty->write_wait); - init_waitqueue_head(&tty->read_wait); - INIT_WORK(&tty->hangup_work, do_tty_hangup); - mutex_init(&tty->atomic_read_lock); - mutex_init(&tty->atomic_write_lock); - mutex_init(&tty->output_lock); - mutex_init(&tty->echo_lock); - spin_lock_init(&tty->read_lock); - spin_lock_init(&tty->ctrl_lock); - INIT_LIST_HEAD(&tty->tty_files); - INIT_WORK(&tty->SAK_work, do_SAK_work); - - tty->driver = driver; - tty->ops = driver->ops; - tty->index = idx; - tty_line_name(driver, idx, tty->name); - tty->dev = tty_get_device(tty); -} - -/** - * tty_put_char - write one character to a tty - * @tty: tty - * @ch: character - * - * Write one byte to the tty using the provided put_char method - * if present. Returns the number of characters successfully output. - * - * Note: the specific put_char operation in the driver layer may go - * away soon. Don't call it directly, use this method - */ - -int tty_put_char(struct tty_struct *tty, unsigned char ch) -{ - if (tty->ops->put_char) - return tty->ops->put_char(tty, ch); - return tty->ops->write(tty, &ch, 1); -} -EXPORT_SYMBOL_GPL(tty_put_char); - -struct class *tty_class; - -/** - * tty_register_device - register a tty device - * @driver: the tty driver that describes the tty device - * @index: the index in the tty driver for this tty device - * @device: a struct device that is associated with this tty device. - * This field is optional, if there is no known struct device - * for this tty device it can be set to NULL safely. - * - * Returns a pointer to the struct device for this tty device - * (or ERR_PTR(-EFOO) on error). - * - * This call is required to be made to register an individual tty device - * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If - * that bit is not set, this function should not be called by a tty - * driver. - * - * Locking: ?? - */ - -struct device *tty_register_device(struct tty_driver *driver, unsigned index, - struct device *device) -{ - char name[64]; - dev_t dev = MKDEV(driver->major, driver->minor_start) + index; - - if (index >= driver->num) { - printk(KERN_ERR "Attempt to register invalid tty line number " - " (%d).\n", index); - return ERR_PTR(-EINVAL); - } - - if (driver->type == TTY_DRIVER_TYPE_PTY) - pty_line_name(driver, index, name); - else - tty_line_name(driver, index, name); - - return device_create(tty_class, device, dev, NULL, name); -} -EXPORT_SYMBOL(tty_register_device); - -/** - * tty_unregister_device - unregister a tty device - * @driver: the tty driver that describes the tty device - * @index: the index in the tty driver for this tty device - * - * If a tty device is registered with a call to tty_register_device() then - * this function must be called when the tty device is gone. - * - * Locking: ?? - */ - -void tty_unregister_device(struct tty_driver *driver, unsigned index) -{ - device_destroy(tty_class, - MKDEV(driver->major, driver->minor_start) + index); -} -EXPORT_SYMBOL(tty_unregister_device); - -struct tty_driver *alloc_tty_driver(int lines) -{ - struct tty_driver *driver; - - driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); - if (driver) { - kref_init(&driver->kref); - driver->magic = TTY_DRIVER_MAGIC; - driver->num = lines; - /* later we'll move allocation of tables here */ - } - return driver; -} -EXPORT_SYMBOL(alloc_tty_driver); - -static void destruct_tty_driver(struct kref *kref) -{ - struct tty_driver *driver = container_of(kref, struct tty_driver, kref); - int i; - struct ktermios *tp; - void *p; - - if (driver->flags & TTY_DRIVER_INSTALLED) { - /* - * Free the termios and termios_locked structures because - * we don't want to get memory leaks when modular tty - * drivers are removed from the kernel. - */ - for (i = 0; i < driver->num; i++) { - tp = driver->termios[i]; - if (tp) { - driver->termios[i] = NULL; - kfree(tp); - } - if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) - tty_unregister_device(driver, i); - } - p = driver->ttys; - proc_tty_unregister_driver(driver); - driver->ttys = NULL; - driver->termios = NULL; - kfree(p); - cdev_del(&driver->cdev); - } - kfree(driver); -} - -void tty_driver_kref_put(struct tty_driver *driver) -{ - kref_put(&driver->kref, destruct_tty_driver); -} -EXPORT_SYMBOL(tty_driver_kref_put); - -void tty_set_operations(struct tty_driver *driver, - const struct tty_operations *op) -{ - driver->ops = op; -}; -EXPORT_SYMBOL(tty_set_operations); - -void put_tty_driver(struct tty_driver *d) -{ - tty_driver_kref_put(d); -} -EXPORT_SYMBOL(put_tty_driver); - -/* - * Called by a tty driver to register itself. - */ -int tty_register_driver(struct tty_driver *driver) -{ - int error; - int i; - dev_t dev; - void **p = NULL; - struct device *d; - - if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { - p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL); - if (!p) - return -ENOMEM; - } - - if (!driver->major) { - error = alloc_chrdev_region(&dev, driver->minor_start, - driver->num, driver->name); - if (!error) { - driver->major = MAJOR(dev); - driver->minor_start = MINOR(dev); - } - } else { - dev = MKDEV(driver->major, driver->minor_start); - error = register_chrdev_region(dev, driver->num, driver->name); - } - if (error < 0) { - kfree(p); - return error; - } - - if (p) { - driver->ttys = (struct tty_struct **)p; - driver->termios = (struct ktermios **)(p + driver->num); - } else { - driver->ttys = NULL; - driver->termios = NULL; - } - - cdev_init(&driver->cdev, &tty_fops); - driver->cdev.owner = driver->owner; - error = cdev_add(&driver->cdev, dev, driver->num); - if (error) { - unregister_chrdev_region(dev, driver->num); - driver->ttys = NULL; - driver->termios = NULL; - kfree(p); - return error; - } - - mutex_lock(&tty_mutex); - list_add(&driver->tty_drivers, &tty_drivers); - mutex_unlock(&tty_mutex); - - if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { - for (i = 0; i < driver->num; i++) { - d = tty_register_device(driver, i, NULL); - if (IS_ERR(d)) { - error = PTR_ERR(d); - goto err; - } - } - } - proc_tty_register_driver(driver); - driver->flags |= TTY_DRIVER_INSTALLED; - return 0; - -err: - for (i--; i >= 0; i--) - tty_unregister_device(driver, i); - - mutex_lock(&tty_mutex); - list_del(&driver->tty_drivers); - mutex_unlock(&tty_mutex); - - unregister_chrdev_region(dev, driver->num); - driver->ttys = NULL; - driver->termios = NULL; - kfree(p); - return error; -} - -EXPORT_SYMBOL(tty_register_driver); - -/* - * Called by a tty driver to unregister itself. - */ -int tty_unregister_driver(struct tty_driver *driver) -{ -#if 0 - /* FIXME */ - if (driver->refcount) - return -EBUSY; -#endif - unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), - driver->num); - mutex_lock(&tty_mutex); - list_del(&driver->tty_drivers); - mutex_unlock(&tty_mutex); - return 0; -} - -EXPORT_SYMBOL(tty_unregister_driver); - -dev_t tty_devnum(struct tty_struct *tty) -{ - return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; -} -EXPORT_SYMBOL(tty_devnum); - -void proc_clear_tty(struct task_struct *p) -{ - unsigned long flags; - struct tty_struct *tty; - spin_lock_irqsave(&p->sighand->siglock, flags); - tty = p->signal->tty; - p->signal->tty = NULL; - spin_unlock_irqrestore(&p->sighand->siglock, flags); - tty_kref_put(tty); -} - -/* Called under the sighand lock */ - -static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) -{ - if (tty) { - unsigned long flags; - /* We should not have a session or pgrp to put here but.... */ - spin_lock_irqsave(&tty->ctrl_lock, flags); - put_pid(tty->session); - put_pid(tty->pgrp); - tty->pgrp = get_pid(task_pgrp(tsk)); - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - tty->session = get_pid(task_session(tsk)); - if (tsk->signal->tty) { - printk(KERN_DEBUG "tty not NULL!!\n"); - tty_kref_put(tsk->signal->tty); - } - } - put_pid(tsk->signal->tty_old_pgrp); - tsk->signal->tty = tty_kref_get(tty); - tsk->signal->tty_old_pgrp = NULL; -} - -static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) -{ - spin_lock_irq(&tsk->sighand->siglock); - __proc_set_tty(tsk, tty); - spin_unlock_irq(&tsk->sighand->siglock); -} - -struct tty_struct *get_current_tty(void) -{ - struct tty_struct *tty; - unsigned long flags; - - spin_lock_irqsave(¤t->sighand->siglock, flags); - tty = tty_kref_get(current->signal->tty); - spin_unlock_irqrestore(¤t->sighand->siglock, flags); - return tty; -} -EXPORT_SYMBOL_GPL(get_current_tty); - -void tty_default_fops(struct file_operations *fops) -{ - *fops = tty_fops; -} - -/* - * Initialize the console device. This is called *early*, so - * we can't necessarily depend on lots of kernel help here. - * Just do some early initializations, and do the complex setup - * later. - */ -void __init console_init(void) -{ - initcall_t *call; - - /* Setup the default TTY line discipline. */ - tty_ldisc_begin(); - - /* - * set up the console device so that later boot sequences can - * inform about problems etc.. - */ - call = __con_initcall_start; - while (call < __con_initcall_end) { - (*call)(); - call++; - } -} - -static char *tty_devnode(struct device *dev, mode_t *mode) -{ - if (!mode) - return NULL; - if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || - dev->devt == MKDEV(TTYAUX_MAJOR, 2)) - *mode = 0666; - return NULL; -} - -static int __init tty_class_init(void) -{ - tty_class = class_create(THIS_MODULE, "tty"); - if (IS_ERR(tty_class)) - return PTR_ERR(tty_class); - tty_class->devnode = tty_devnode; - return 0; -} - -postcore_initcall(tty_class_init); - -/* 3/2004 jmc: why do these devices exist? */ - -static struct cdev tty_cdev, console_cdev; - -/* - * Ok, now we can initialize the rest of the tty devices and can count - * on memory allocations, interrupts etc.. - */ -int __init tty_init(void) -{ - cdev_init(&tty_cdev, &tty_fops); - 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), 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), NULL, - "console"); - -#ifdef CONFIG_VT - vty_init(&console_fops); -#endif - return 0; -} - |