diff options
Diffstat (limited to 'drivers/char/tty_io.c')
| -rw-r--r-- | drivers/char/tty_io.c | 2980 |
1 files changed, 2980 insertions, 0 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c new file mode 100644 index 000000000000..06e5a3f1836d --- /dev/null +++ b/drivers/char/tty_io.c @@ -0,0 +1,2980 @@ +/* + * 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 init_dev and 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/config.h> +#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/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/idr.h> +#include <linux/wait.h> +#include <linux/bitops.h> + +#include <asm/uaccess.h> +#include <asm/system.h> + +#include <linux/kbd_kern.h> +#include <linux/vt_kern.h> +#include <linux/selection.h> +#include <linux/devfs_fs_kernel.h> + +#include <linux/kmod.h> + +#undef TTY_DEBUG_HANGUP + +#define TTY_PARANOIA_CHECK 1 +#define CHECK_TTY_COUNT 1 + +struct termios 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 +}; + +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 */ + +/* Semaphore to protect creating and releasing a tty. This is shared with + vt.c for deeply disgusting hack reasons */ +DECLARE_MUTEX(tty_sem); + +#ifdef CONFIG_UNIX98_PTYS +extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */ +extern int pty_limit; /* Config limit on Unix98 ptys */ +static DEFINE_IDR(allocated_ptys); +static DECLARE_MUTEX(allocated_ptys_lock); +static int ptmx_open(struct inode *, struct file *); +#endif + +extern void disable_early_printk(void); + +static void initialize_tty_struct(struct tty_struct *tty); + +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 *); +static int tty_release(struct inode *, struct file *); +int tty_ioctl(struct inode * inode, struct file * file, + unsigned int cmd, unsigned long arg); +static int tty_fasync(int fd, struct file * filp, int on); +extern void rs_360_init(void); +static void release_mem(struct tty_struct *tty, int idx); + + +static struct tty_struct *alloc_tty_struct(void) +{ + struct tty_struct *tty; + + tty = kmalloc(sizeof(struct tty_struct), GFP_KERNEL); + if (tty) + memset(tty, 0, sizeof(struct tty_struct)); + return tty; +} + +static inline void free_tty_struct(struct tty_struct *tty) +{ + kfree(tty->write_buf); + kfree(tty); +} + +#define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) + +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); + +inline 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; + + file_list_lock(); + list_for_each(p, &tty->tty_files) { + count++; + } + file_list_unlock(); + 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; +} + +/* + * This is probably overkill for real world processors but + * they are not on hot paths so a little discipline won't do + * any harm. + */ + +static void tty_set_termios_ldisc(struct tty_struct *tty, int num) +{ + down(&tty->termios_sem); + tty->termios->c_line = num; + up(&tty->termios_sem); +} + +/* + * 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); +static struct tty_ldisc tty_ldiscs[NR_LDISCS]; /* line disc dispatch table */ + +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); + if (new_ldisc) { + tty_ldiscs[disc] = *new_ldisc; + tty_ldiscs[disc].num = disc; + tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED; + tty_ldiscs[disc].refcount = 0; + } else { + 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_register_ldisc); + +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); + +void tty_ldisc_put(int disc) +{ + struct tty_ldisc *ld; + unsigned long flags; + + if (disc < N_TTY || disc >= NR_LDISCS) + BUG(); + + spin_lock_irqsave(&tty_ldisc_lock, flags); + ld = &tty_ldiscs[disc]; + if(ld->refcount == 0) + BUG(); + ld->refcount --; + module_put(ld->owner); + spin_unlock_irqrestore(&tty_ldisc_lock, flags); +} + +EXPORT_SYMBOL_GPL(tty_ldisc_put); + +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 + */ + +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) + */ + +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. + */ + +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. + */ + +void tty_ldisc_deref(struct tty_ldisc *ld) +{ + unsigned long flags; + + if(ld == NULL) + BUG(); + + 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 neccessary 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. + */ + +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; + + if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS)) + return -EINVAL; + +restart: + + if (tty->ldisc.num == ldisc) + return 0; /* We are already in the desired discipline */ + + 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; + + o_ldisc = tty->ldisc; + + tty_wait_until_sent(tty, 0); + + /* + * 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) + { + /* 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; + } + clear_bit(TTY_LDISC, &tty->flags); + clear_bit(TTY_DONT_FLIP, &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->flip.work); + /* + * Wait for ->hangup_work and ->flip.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->driver->set_ldisc) + tty->driver->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); + + /* Restart it in case no characters kick it off. Safe if + already running */ + if(work) + schedule_delayed_work(&tty->flip.work, 1); + return retval; +} + +/* + * This routine returns a tty driver structure, given a device number + */ +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 p; + } + return NULL; +} + +/* + * 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) + */ +int tty_check_change(struct tty_struct * tty) +{ + if (current->signal->tty != tty) + return 0; + if (tty->pgrp <= 0) { + printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n"); + return 0; + } + if (process_group(current) == tty->pgrp) + return 0; + if (is_ignored(SIGTTOU)) + return 0; + if (is_orphaned_pgrp(process_group(current))) + return -EIO; + (void) kill_pg(process_group(current), SIGTTOU, 1); + return -ERESTARTSYS; +} + +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 int hung_up_tty_ioctl(struct inode * inode, struct file * file, + unsigned int cmd, unsigned long arg) +{ + return cmd == TIOCSPGRP ? -ENOTTY : -EIO; +} + +static struct file_operations tty_fops = { + .llseek = no_llseek, + .read = tty_read, + .write = tty_write, + .poll = tty_poll, + .ioctl = tty_ioctl, + .open = tty_open, + .release = tty_release, + .fasync = tty_fasync, +}; + +#ifdef CONFIG_UNIX98_PTYS +static struct file_operations ptmx_fops = { + .llseek = no_llseek, + .read = tty_read, + .write = tty_write, + .poll = tty_poll, + .ioctl = tty_ioctl, + .open = ptmx_open, + .release = tty_release, + .fasync = tty_fasync, +}; +#endif + +static struct file_operations console_fops = { + .llseek = no_llseek, + .read = tty_read, + .write = redirected_tty_write, + .poll = tty_poll, + .ioctl = tty_ioctl, + .open = tty_open, + .release = tty_release, + .fasync = tty_fasync, +}; + +static 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, + .ioctl = hung_up_tty_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->write_wakeup) + ld->write_wakeup(tty); + tty_ldisc_deref(ld); + } + } + wake_up_interruptible(&tty->write_wait); +} + +EXPORT_SYMBOL_GPL(tty_wakeup); + +/** + * tty_ldisc_flush - flush line discipline queue + * @tty: tty + * + * Flush the line discipline queue (if any) for this tty. If there + * is no line discipline active this is a no-op. + */ + +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); + tty_ldisc_deref(ld); + } +} + +EXPORT_SYMBOL_GPL(tty_ldisc_flush); + +/* + * 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.. + */ +static void do_tty_hangup(void *data) +{ + struct tty_struct *tty = (struct tty_struct *) data; + struct file * cons_filp = NULL; + struct file *filp, *f = NULL; + struct task_struct *p; + struct tty_ldisc *ld; + int closecount = 0, n; + + if (!tty) + return; + + /* inuse_filps is protected by the single kernel lock */ + lock_kernel(); + + spin_lock(&redirect_lock); + if (redirect && redirect->private_data == tty) { + f = redirect; + redirect = NULL; + } + spin_unlock(&redirect_lock); + + check_tty_count(tty, "do_tty_hangup"); + file_list_lock(); + /* This breaks for file handles being sent over AF_UNIX sockets ? */ + list_for_each_entry(filp, &tty->tty_files, f_list) { + 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; + } + file_list_unlock(); + + /* FIXME! What are the locking issues here? This may me overdoing things.. + * this question is especially important now that we've removed the irqlock. */ + + 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 (tty->driver->flush_buffer) + 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); + } + + /* FIXME: Once we trust the LDISC code better we can wait here for + ldisc completion and fix the driver call race */ + + wake_up_interruptible(&tty->write_wait); + wake_up_interruptible(&tty->read_wait); + + /* + * Shutdown the current line discipline, and reset it to + * N_TTY. + */ + if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) + { + down(&tty->termios_sem); + *tty->termios = tty->driver->init_termios; + up(&tty->termios_sem); + } + + /* Defer ldisc switch */ + /* tty_deferred_ldisc_switch(N_TTY); + + This should get done automatically when the port closes and + tty_release is called */ + + read_lock(&tasklist_lock); + if (tty->session > 0) { + do_each_task_pid(tty->session, PIDTYPE_SID, p) { + if (p->signal->tty == tty) + p->signal->tty = NULL; + if (!p->signal->leader) + continue; + send_group_sig_info(SIGHUP, SEND_SIG_PRIV, p); + send_group_sig_info(SIGCONT, SEND_SIG_PRIV, p); + if (tty->pgrp > 0) + p->signal->tty_old_pgrp = tty->pgrp; + } while_each_task_pid(tty->session, PIDTYPE_SID, p); + } + read_unlock(&tasklist_lock); + + tty->flags = 0; + tty->session = 0; + tty->pgrp = -1; + tty->ctrl_status = 0; + /* + * 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->driver->close) + for (n = 0; n < closecount; n++) + tty->driver->close(tty, cons_filp); + } else if (tty->driver->hangup) + (tty->driver->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); + if (ld) { + tty_ldisc_enable(tty); + tty_ldisc_deref(ld); + } + unlock_kernel(); + if (f) + fput(f); +} + +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); + +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 + do_tty_hangup((void *) tty); +} +EXPORT_SYMBOL(tty_vhangup); + +int tty_hung_up_p(struct file * filp) +{ + return (filp->f_op == &hung_up_tty_fops); +} + +EXPORT_SYMBOL(tty_hung_up_p); + +/* + * 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. + */ +void disassociate_ctty(int on_exit) +{ + struct tty_struct *tty; + struct task_struct *p; + int tty_pgrp = -1; + + lock_kernel(); + + down(&tty_sem); + tty = current->signal->tty; + if (tty) { + tty_pgrp = tty->pgrp; + up(&tty_sem); + if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) + tty_vhangup(tty); + } else { + if (current->signal->tty_old_pgrp) { + kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit); + kill_pg(current->signal->tty_old_pgrp, SIGCONT, on_exit); + } + up(&tty_sem); + unlock_kernel(); + return; + } + if (tty_pgrp > 0) { + kill_pg(tty_pgrp, SIGHUP, on_exit); + if (!on_exit) + kill_pg(tty_pgrp, SIGCONT, on_exit); + } + + /* Must lock changes to tty_old_pgrp */ + down(&tty_sem); + current->signal->tty_old_pgrp = 0; + tty->session = 0; + tty->pgrp = -1; + + /* Now clear signal->tty under the lock */ + read_lock(&tasklist_lock); + do_each_task_pid(current->signal->session, PIDTYPE_SID, p) { + p->signal->tty = NULL; + } while_each_task_pid(current->signal->session, PIDTYPE_SID, p); + read_unlock(&tasklist_lock); + up(&tty_sem); + unlock_kernel(); +} + +void stop_tty(struct tty_struct *tty) +{ + if (tty->stopped) + return; + tty->stopped = 1; + if (tty->link && tty->link->packet) { + tty->ctrl_status &= ~TIOCPKT_START; + tty->ctrl_status |= TIOCPKT_STOP; + wake_up_interruptible(&tty->link->read_wait); + } + if (tty->driver->stop) + (tty->driver->stop)(tty); +} + +EXPORT_SYMBOL(stop_tty); + +void start_tty(struct tty_struct *tty) +{ + if (!tty->stopped || tty->flow_stopped) + return; + tty->stopped = 0; + if (tty->link && tty->link->packet) { + tty->ctrl_status &= ~TIOCPKT_STOP; + tty->ctrl_status |= TIOCPKT_START; + wake_up_interruptible(&tty->link->read_wait); + } + if (tty->driver->start) + (tty->driver->start)(tty); + + /* If we have a running line discipline it may need kicking */ + tty_wakeup(tty); + wake_up_interruptible(&tty->write_wait); +} + +EXPORT_SYMBOL(start_tty); + +static ssize_t tty_read(struct file * file, char __user * buf, size_t count, + loff_t *ppos) +{ + int i; + struct tty_struct * tty; + struct inode *inode; + struct tty_ldisc *ld; + + tty = (struct tty_struct *)file->private_data; + inode = file->f_dentry->d_inode; + 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); + lock_kernel(); + if (ld->read) + i = (ld->read)(tty,file,buf,count); + else + i = -EIO; + tty_ldisc_deref(ld); + unlock_kernel(); + if (i > 0) + inode->i_atime = current_fs_time(inode->i_sb); + return i; +} + +/* + * 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 = 0, written = 0; + unsigned int chunk; + + if (down_interruptible(&tty->atomic_write)) { + return -ERESTARTSYS; + } + + /* + * 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. + */ + 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 semaphore */ + if (tty->write_cnt < chunk) { + unsigned char *buf; + + if (chunk < 1024) + chunk = 1024; + + buf = kmalloc(chunk, GFP_KERNEL); + if (!buf) { + up(&tty->atomic_write); + return -ENOMEM; + } + kfree(tty->write_buf); + tty->write_cnt = chunk; + tty->write_buf = buf; + } + + /* 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; + lock_kernel(); + ret = write(tty, file, tty->write_buf, size); + unlock_kernel(); + 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_dentry->d_inode; + inode->i_mtime = current_fs_time(inode->i_sb); + ret = written; + } + up(&tty->atomic_write); + return ret; +} + + +static ssize_t tty_write(struct file * file, const char __user * buf, size_t count, + loff_t *ppos) +{ + struct tty_struct * tty; + struct inode *inode = file->f_dentry->d_inode; + ssize_t ret; + struct tty_ldisc *ld; + + tty = (struct tty_struct *)file->private_data; + if (tty_paranoia_check(tty, inode, "tty_write")) + return -EIO; + if (!tty || !tty->driver->write || (test_bit(TTY_IO_ERROR, &tty->flags))) + return -EIO; + + ld = tty_ldisc_ref_wait(tty); + if (!ld->write) + ret = -EIO; + else + ret = do_tty_write(ld->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"; + +static inline 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); +} + +static inline void tty_line_name(struct tty_driver *driver, int index, char *p) +{ + sprintf(p, "%s%d", driver->name, index + driver->name_base); +} + +/* + * WSH 06/09/97: Rewritten to remove races and properly clean up after a + * failed open. The new code protects the open with a semaphore, so it's + * really quite straightforward. The semaphore locking can probably be + * relaxed for the (most common) case of reopening a tty. + */ +static int init_dev(struct tty_driver *driver, int idx, + struct tty_struct **ret_tty) +{ + struct tty_struct *tty, *o_tty; + struct termios *tp, **tp_loc, *o_tp, **o_tp_loc; + struct termios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; + int retval=0; + + /* check whether we're reopening an existing tty */ + if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { + tty = devpts_get_tty(idx); + if (tty && driver->subtype == PTY_TYPE_MASTER) + tty = tty->link; + } else { + tty = driver->ttys[idx]; + } + if (tty) goto fast_track; + + /* + * 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)) { + retval = -ENODEV; + goto end_init; + } + + o_tty = NULL; + tp = o_tp = NULL; + ltp = o_ltp = NULL; + + tty = alloc_tty_struct(); + if(!tty) + goto fail_no_mem; + initialize_tty_struct(tty); + tty->driver = driver; + tty->index = idx; + tty_line_name(driver, idx, tty->name); + + if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { + tp_loc = &tty->termios; + ltp_loc = &tty->termios_locked; + } else { + tp_loc = &driver->termios[idx]; + ltp_loc = &driver->termios_locked[idx]; + } + + if (!*tp_loc) { + tp = (struct termios *) kmalloc(sizeof(struct termios), + GFP_KERNEL); + if (!tp) + goto free_mem_out; + *tp = driver->init_termios; + } + + if (!*ltp_loc) { + ltp = (struct termios *) kmalloc(sizeof(struct termios), + GFP_KERNEL); + if (!ltp) + goto free_mem_out; + memset(ltp, 0, sizeof(struct termios)); + } + + if (driver->type == TTY_DRIVER_TYPE_PTY) { + o_tty = alloc_tty_struct(); + if (!o_tty) + goto free_mem_out; + initialize_tty_struct(o_tty); + o_tty->driver = driver->other; + o_tty->index = idx; + tty_line_name(driver->other, idx, o_tty->name); + + if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { + o_tp_loc = &o_tty->termios; + o_ltp_loc = &o_tty->termios_locked; + } else { + o_tp_loc = &driver->other->termios[idx]; + o_ltp_loc = &driver->other->termios_locked[idx]; + } + + if (!*o_tp_loc) { + o_tp = (struct termios *) + kmalloc(sizeof(struct termios), GFP_KERNEL); + if (!o_tp) + goto free_mem_out; + *o_tp = driver->other->init_termios; + } + + if (!*o_ltp_loc) { + o_ltp = (struct termios *) + kmalloc(sizeof(struct termios), GFP_KERNEL); + if (!o_ltp) + goto free_mem_out; + memset(o_ltp, 0, sizeof(struct termios)); + } + + /* + * Everything allocated ... set up the o_tty structure. + */ + if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) { + driver->other->ttys[idx] = o_tty; + } + if (!*o_tp_loc) + *o_tp_loc = o_tp; + if (!*o_ltp_loc) + *o_ltp_loc = o_ltp; + o_tty->termios = *o_tp_loc; + o_tty->termios_locked = *o_ltp_loc; + driver->other->refcount++; + if (driver->subtype == PTY_TYPE_MASTER) + o_tty->count++; + + /* Establish the links in both directions */ + tty->link = o_tty; + o_tty->link = tty; + } + + /* + * All structures have been allocated, so now we install them. + * Failures after this point use release_mem to clean up, so + * there's no need to null out the local pointers. + */ + if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { + driver->ttys[idx] = tty; + } + + if (!*tp_loc) + *tp_loc = tp; + if (!*ltp_loc) + *ltp_loc = ltp; + tty->termios = *tp_loc; + tty->termios_locked = *ltp_loc; + driver->refcount++; + tty->count++; + + /* + * Structures all installed ... call the ldisc open routines. + * If we fail here just call release_mem to clean up. No need + * to decrement the use counts, as release_mem 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; + + /* + * This fast open can be used if the tty is already open. + * No memory is allocated, and the only failures are from + * attempting to open a closing tty or attempting multiple + * opens on a pty master. + */ +fast_track: + if (test_bit(TTY_CLOSING, &tty->flags)) { + retval = -EIO; + goto end_init; + } + 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) { + retval = -EIO; + goto end_init; + } + tty->link->count++; + } + tty->count++; + tty->driver = driver; /* N.B. why do this every time?? */ + + /* FIXME */ + if(!test_bit(TTY_LDISC, &tty->flags)) + printk(KERN_ERR "init_dev but no ldisc\n"); +success: + *ret_tty = tty; + + /* All paths come through here to release the semaphore */ +end_init: + return retval; + + /* Release locally allocated memory ... nothing placed in slots */ +free_mem_out: + if (o_tp) + kfree(o_tp); + if (o_tty) + free_tty_struct(o_tty); + if (ltp) + kfree(ltp); + if (tp) + kfree(tp); + free_tty_struct(tty); + +fail_no_mem: + module_put(driver->owner); + retval = -ENOMEM; + goto end_init; + + /* call the tty release_mem routine to clean out this slot */ +release_mem_out: + printk(KERN_INFO "init_dev: ldisc open failed, " + "clearing slot %d\n", idx); + release_mem(tty, idx); + goto end_init; +} + +/* + * Releases memory associated with a tty structure, and clears out the + * driver table slots. + */ +static void release_mem(struct tty_struct *tty, int idx) +{ + struct tty_struct *o_tty; + struct termios *tp; + int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM; + + if ((o_tty = tty->link) != NULL) { + if (!devpts) + o_tty->driver->ttys[idx] = NULL; + if (o_tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { + tp = o_tty->termios; + if (!devpts) + o_tty->driver->termios[idx] = NULL; + kfree(tp); + + tp = o_tty->termios_locked; + if (!devpts) + o_tty->driver->termios_locked[idx] = NULL; + kfree(tp); + } + o_tty->magic = 0; + o_tty->driver->refcount--; + file_list_lock(); + list_del_init(&o_tty->tty_files); + file_list_unlock(); + free_tty_struct(o_tty); + } + + if (!devpts) + tty->driver->ttys[idx] = NULL; + if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { + tp = tty->termios; + if (!devpts) + tty->driver->termios[idx] = NULL; + kfree(tp); + + tp = tty->termios_locked; + if (!devpts) + tty->driver->termios_locked[idx] = NULL; + kfree(tp); + } + + tty->magic = 0; + tty->driver->refcount--; + file_list_lock(); + list_del_init(&tty->tty_files); + file_list_unlock(); + module_put(tty->driver->owner); + free_tty_struct(tty); +} + +/* + * 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. + */ +static void release_dev(struct file * filp) +{ + struct tty_struct *tty, *o_tty; + int pty_master, tty_closing, o_tty_closing, do_sleep; + int devpts_master, devpts; + int idx; + char buf[64]; + unsigned long flags; + + tty = (struct tty_struct *)filp->private_data; + if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "release_dev")) + return; + + check_tty_count(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; + devpts_master = pty_master && devpts; + o_tty = tty->link; + +#ifdef TTY_PARANOIA_CHECK + if (idx < 0 || idx >= tty->driver->num) { + printk(KERN_DEBUG "release_dev: bad idx when trying to " + "free (%s)\n", tty->name); + return; + } + if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { + if (tty != tty->driver->ttys[idx]) { + printk(KERN_DEBUG "release_dev: driver.table[%d] not tty " + "for (%s)\n", idx, tty->name); + return; + } + if (tty->termios != tty->driver->termios[idx]) { + printk(KERN_DEBUG "release_dev: driver.termios[%d] not termios " + "for (%s)\n", + idx, tty->name); + return; + } + if (tty->termios_locked != tty->driver->termios_locked[idx]) { + printk(KERN_DEBUG "release_dev: driver.termios_locked[%d] not " + "termios_locked for (%s)\n", + idx, tty->name); + return; + } + } +#endif + +#ifdef TTY_DEBUG_HANGUP + printk(KERN_DEBUG "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]) { + printk(KERN_DEBUG "release_dev: other->table[%d] " + "not o_tty for (%s)\n", + idx, tty->name); + return; + } + if (o_tty->termios != tty->driver->other->termios[idx]) { + printk(KERN_DEBUG "release_dev: other->termios[%d] " + "not o_termios for (%s)\n", + idx, tty->name); + return; + } + if (o_tty->termios_locked != + tty->driver->other->termios_locked[idx]) { + printk(KERN_DEBUG "release_dev: other->termios_locked[" + "%d] not o_termios_locked for (%s)\n", + idx, tty->name); + return; + } + if (o_tty->link != tty) { + printk(KERN_DEBUG "release_dev: bad pty pointers\n"); + return; + } + } +#endif + if (tty->driver->close) + tty->driver->close(tty, filp); + + /* + * 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 */ + + down(&tty_sem); + tty_closing = tty->count <= 1; + o_tty_closing = o_tty && + (o_tty->count <= (pty_master ? 1 : 0)); + up(&tty_sem); + do_sleep = 0; + + if (tty_closing) { + if (waitqueue_active(&tty->read_wait)) { + wake_up(&tty->read_wait); + do_sleep++; + } + if (waitqueue_active(&tty->write_wait)) { + wake_up(&tty->write_wait); + do_sleep++; + } + } + if (o_tty_closing) { + if (waitqueue_active(&o_tty->read_wait)) { + wake_up(&o_tty->read_wait); + do_sleep++; + } + if (waitqueue_active(&o_tty->write_wait)) { + wake_up(&o_tty->write_wait); + do_sleep++; + } + } + if (!do_sleep) + break; + + printk(KERN_WARNING "release_dev: %s: read/write wait queue " + "active!\n", tty_name(tty, buf)); + 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. + */ + + down(&tty_sem); + if (pty_master) { + if (--o_tty->count < 0) { + printk(KERN_WARNING "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 "release_dev: bad tty->count (%d) for %s\n", + tty->count, tty_name(tty, buf)); + tty->count = 0; + } + up(&tty_sem); + + /* + * 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. + */ + file_kill(filp); + filp->private_data = NULL; + + /* + * 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) { + struct task_struct *p; + + read_lock(&tasklist_lock); + do_each_task_pid(tty->session, PIDTYPE_SID, p) { + p->signal->tty = NULL; + } while_each_task_pid(tty->session, PIDTYPE_SID, p); + if (o_tty) + do_each_task_pid(o_tty->session, PIDTYPE_SID, p) { + p->signal->tty = NULL; + } while_each_task_pid(o_tty->session, PIDTYPE_SID, p); + read_unlock(&tasklist_lock); + } + + /* check whether both sides are closing ... */ + if (!tty_closing || (o_tty && !o_tty_closing)) + return; + +#ifdef TTY_DEBUG_HANGUP + 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); + clear_bit(TTY_DONT_FLIP, &tty->flags); + cancel_delayed_work(&tty->flip.work); + + /* + * Wait for ->hangup_work and ->flip.work handlers to terminate + */ + + 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); + } + /* + * The release_mem function takes care of the details of clearing + * the slots and preserving the termios structure. + */ + release_mem(tty, idx); + +#ifdef CONFIG_UNIX98_PTYS + /* Make this pty number available for reallocation */ + if (devpts) { + down(&allocated_ptys_lock); + idr_remove(&allocated_ptys, idx); + up(&allocated_ptys_lock); + } +#endif + +} + +/* + * 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. + */ +static int tty_open(struct inode * inode, struct file * filp) +{ + struct tty_struct *tty; + int noctty, retval; + struct tty_driver *driver; + int index; + dev_t device = inode->i_rdev; + unsigned short saved_flags = filp->f_flags; + + nonseekable_open(inode, filp); + +retry_open: + noctty = filp->f_flags & O_NOCTTY; + index = -1; + retval = 0; + + down(&tty_sem); + + if (device == MKDEV(TTYAUX_MAJOR,0)) { + if (!current->signal->tty) { + up(&tty_sem); + return -ENXIO; + } + driver = current->signal->tty->driver; + index = current->signal->tty->index; + filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ + /* noctty = 1; */ + goto got_driver; + } +#ifdef CONFIG_VT + if (device == MKDEV(TTY_MAJOR,0)) { + extern struct tty_driver *console_driver; + driver = console_driver; + index = fg_console; + noctty = 1; + goto got_driver; + } +#endif + if (device == MKDEV(TTYAUX_MAJOR,1)) { + driver = console_device(&index); + if (driver) { + /* Don't let /dev/console block */ + filp->f_flags |= O_NONBLOCK; + noctty = 1; + goto got_driver; + } + up(&tty_sem); + return -ENODEV; + } + + driver = get_tty_driver(device, &index); + if (!driver) { + up(&tty_sem); + return -ENODEV; + } +got_driver: + retval = init_dev(driver, index, &tty); + up(&tty_sem); + if (retval) + return retval; + + filp->private_data = tty; + file_move(filp, &tty->tty_files); + 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->driver->open) + retval = tty->driver->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 + release_dev(filp); + if (retval != -ERESTARTSYS) + return retval; + if (signal_pending(current)) + return retval; + schedule(); + /* + * Need to reset f_op in case a hangup happened. + */ + if (filp->f_op == &hung_up_tty_fops) + filp->f_op = &tty_fops; + goto retry_open; + } + if (!noctty && + current->signal->leader && + !current->signal->tty && + tty->session == 0) { + task_lock(current); + current->signal->tty = tty; + task_unlock(current); + current->signal->tty_old_pgrp = 0; + tty->session = current->signal->session; + tty->pgrp = process_group(current); + } + return 0; +} + +#ifdef CONFIG_UNIX98_PTYS +static int ptmx_open(struct inode * inode, struct file * filp) +{ + struct tty_struct *tty; + int retval; + int index; + int idr_ret; + + nonseekable_open(inode, filp); + + /* find a device that is not in use. */ + down(&allocated_ptys_lock); + if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) { + up(&allocated_ptys_lock); + return -ENOMEM; + } + idr_ret = idr_get_new(&allocated_ptys, NULL, &index); + if (idr_ret < 0) { + up(&allocated_ptys_lock); + if (idr_ret == -EAGAIN) + return -ENOMEM; + return -EIO; + } + if (index >= pty_limit) { + idr_remove(&allocated_ptys, index); + up(&allocated_ptys_lock); + return -EIO; + } + up(&allocated_ptys_lock); + + down(&tty_sem); + retval = init_dev(ptm_driver, index, &tty); + up(&tty_sem); + + if (retval) + goto out; + + set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ + filp->private_data = tty; + file_move(filp, &tty->tty_files); + + retval = -ENOMEM; + if (devpts_pty_new(tty->link)) + goto out1; + + check_tty_count(tty, "tty_open"); + retval = ptm_driver->open(tty, filp); + if (!retval) + return 0; +out1: + release_dev(filp); +out: + down(&allocated_ptys_lock); + idr_remove(&allocated_ptys, index); + up(&allocated_ptys_lock); + return retval; +} +#endif + +static int tty_release(struct inode * inode, struct file * filp) +{ + lock_kernel(); + release_dev(filp); + unlock_kernel(); + return 0; +} + +/* No kernel lock held - fine */ +static unsigned int tty_poll(struct file * filp, poll_table * wait) +{ + struct tty_struct * tty; + struct tty_ldisc *ld; + int ret = 0; + + tty = (struct tty_struct *)filp->private_data; + if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_poll")) + return 0; + + ld = tty_ldisc_ref_wait(tty); + if (ld->poll) + ret = (ld->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; + int retval; + + tty = (struct tty_struct *)filp->private_data; + if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_fasync")) + return 0; + + retval = fasync_helper(fd, filp, on, &tty->fasync); + if (retval <= 0) + return retval; + + if (on) { + if (!waitqueue_active(&tty->read_wait)) + tty->minimum_to_wake = 1; + retval = f_setown(filp, (-tty->pgrp) ? : current->pid, 0); + if (retval) + return retval; + } else { + if (!tty->fasync && !waitqueue_active(&tty->read_wait)) + tty->minimum_to_wake = N_TTY_BUF_SIZE; + } + return 0; +} + +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; + ld = tty_ldisc_ref_wait(tty); + ld->receive_buf(tty, &ch, &mbz, 1); + tty_ldisc_deref(ld); + return 0; +} + +static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg) +{ + if (copy_to_user(arg, &tty->winsize, sizeof(*arg))) + return -EFAULT; + return 0; +} + +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 (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg))) + return 0; +#ifdef CONFIG_VT + if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) { + int rc; + + acquire_console_sem(); + rc = vc_resize(tty->driver_data, tmp_ws.ws_col, tmp_ws.ws_row); + release_console_sem(); + if (rc) + return -ENXIO; + } +#endif + if (tty->pgrp > 0) + kill_pg(tty->pgrp, SIGWINCH, 1); + if ((real_tty->pgrp != tty->pgrp) && (real_tty->pgrp > 0)) + kill_pg(real_tty->pgrp, SIGWINCH, 1); + tty->winsize = tmp_ws; + real_tty->winsize = tmp_ws; + return 0; +} + +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; +} + + +static int fionbio(struct file *file, int __user *p) +{ + int nonblock; + + if (get_user(nonblock, p)) + return -EFAULT; + + if (nonblock) + file->f_flags |= O_NONBLOCK; + else + file->f_flags &= ~O_NONBLOCK; + return 0; +} + +static int tiocsctty(struct tty_struct *tty, int arg) +{ + task_t *p; + + if (current->signal->leader && + (current->signal->session == tty->session)) + return 0; + /* + * The process must be a session leader and + * not have a controlling tty already. + */ + if (!current->signal->leader || current->signal->tty) + return -EPERM; + if (tty->session > 0) { + /* + * 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); + do_each_task_pid(tty->session, PIDTYPE_SID, p) { + p->signal->tty = NULL; + } while_each_task_pid(tty->session, PIDTYPE_SID, p); + read_unlock(&tasklist_lock); + } else + return -EPERM; + } + task_lock(current); + current->signal->tty = tty; + task_unlock(current); + current->signal->tty_old_pgrp = 0; + tty->session = current->signal->session; + tty->pgrp = process_group(current); + return 0; +} + +static int tiocgpgrp(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; + return put_user(real_tty->pgrp, p); +} + +static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) +{ + pid_t pgrp; + int retval = tty_check_change(real_tty); + + if (retval == -EIO) + return -ENOTTY; + if (retval) + return retval; + if (!current->signal->tty || + (current->signal->tty != real_tty) || + (real_tty->session != current->signal->session)) + return -ENOTTY; + if (get_user(pgrp, p)) + return -EFAULT; + if (pgrp < 0) + return -EINVAL; + if (session_of_pgrp(pgrp) != current->signal->session) + return -EPERM; + real_tty->pgrp = pgrp; + return 0; +} + +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 <= 0) + return -ENOTTY; + return put_user(real_tty->session, p); +} + +static int tiocsetd(struct tty_struct *tty, int __user *p) +{ + int ldisc; + + if (get_user(ldisc, p)) + return -EFAULT; + return tty_set_ldisc(tty, ldisc); +} + +static int send_break(struct tty_struct *tty, int duration) +{ + tty->driver->break_ctl(tty, -1); + if (!signal_pending(current)) { + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(duration); + } + tty->driver->break_ctl(tty, 0); + if (signal_pending(current)) + return -EINTR; + return 0; +} + +static int +tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) +{ + int retval = -EINVAL; + + if (tty->driver->tiocmget) { + retval = tty->driver->tiocmget(tty, file); + + if (retval >= 0) + retval = put_user(retval, p); + } + return retval; +} + +static int +tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, + unsigned __user *p) +{ + int retval = -EINVAL; + + if (tty->driver->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; + } + + set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; + clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; + + retval = tty->driver->tiocmset(tty, file, set, clear); + } + return retval; +} + +/* + * Split this up, as gcc can choke on it otherwise.. + */ +int tty_ioctl(struct inode * inode, struct file * file, + unsigned int cmd, unsigned long arg) +{ + struct tty_struct *tty, *real_tty; + void __user *p = (void __user *)arg; + int retval; + struct tty_ldisc *ld; + + tty = (struct tty_struct *)file->private_data; + if (tty_paranoia_check(tty, inode, "tty_ioctl")) + return -EINVAL; + + real_tty = tty; + if (tty->driver->type == TTY_DRIVER_TYPE_PTY && + tty->driver->subtype == PTY_TYPE_MASTER) + real_tty = tty->link; + + /* + * Break handling by driver + */ + if (!tty->driver->break_ctl) { + switch(cmd) { + case TIOCSBRK: + case TIOCCBRK: + if (tty->driver->ioctl) + return tty->driver->ioctl(tty, file, cmd, arg); + return -EINVAL; + + /* These two ioctl's always return success; even if */ + /* the driver doesn't support them. */ + case TCSBRK: + case TCSBRKP: + if (!tty->driver->ioctl) + return 0; + retval = tty->driver->ioctl(tty, file, cmd, arg); + if (retval == -ENOIOCTLCMD) + retval = 0; + return retval; + } + } + + /* + * 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; + } + + switch (cmd) { + case TIOCSTI: + return tiocsti(tty, p); + case TIOCGWINSZ: + return tiocgwinsz(tty, p); + case TIOCSWINSZ: + return tiocswinsz(tty, 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; + if (current->signal->leader) + disassociate_ctty(0); + task_lock(current); + current->signal->tty = NULL; + task_unlock(current); + 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: + /* FIXME: check this is ok */ + return put_user(tty->ldisc.num, (int __user *)p); + case TIOCSETD: + return tiocsetd(tty, p); +#ifdef CONFIG_VT + case TIOCLINUX: + return tioclinux(tty, arg); +#endif + /* + * Break handling + */ + case TIOCSBRK: /* Turn break on, unconditionally */ + tty->driver->break_ctl(tty, -1); + return 0; + + case TIOCCBRK: /* Turn break off, unconditionally */ + tty->driver->break_ctl(tty, 0); + return 0; + case TCSBRK: /* SVID version: non-zero arg --> no break */ + /* + * XXX is the above comment correct, or the + * code below correct? Is this ioctl used at + * all by anyone? + */ + if (!arg) + return send_break(tty, HZ/4); + return 0; + case TCSBRKP: /* support for POSIX tcsendbreak() */ + return send_break(tty, arg ? arg*(HZ/10) : HZ/4); + + case TIOCMGET: + return tty_tiocmget(tty, file, p); + + case TIOCMSET: + case TIOCMBIC: + case TIOCMBIS: + return tty_tiocmset(tty, file, cmd, p); + } + if (tty->driver->ioctl) { + retval = (tty->driver->ioctl)(tty, file, cmd, arg); + if (retval != -ENOIOCTLCMD) + return retval; + } + ld = tty_ldisc_ref_wait(tty); + retval = -EINVAL; + if (ld->ioctl) { + retval = ld->ioctl(tty, file, cmd, arg); + if (retval == -ENOIOCTLCMD) + retval = -EINVAL; + } + tty_ldisc_deref(ld); + return retval; +} + + +/* + * 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 + */ +static void __do_SAK(void *arg) +{ +#ifdef TTY_SOFT_SAK + tty_hangup(tty); +#else + struct tty_struct *tty = arg; + struct task_struct *p; + int session; + int i; + struct file *filp; + struct tty_ldisc *disc; + + if (!tty) + return; + session = tty->session; + + /* We don't want an ldisc switch during this */ + disc = tty_ldisc_ref(tty); + if (disc && disc->flush_buffer) + disc->flush_buffer(tty); + tty_ldisc_deref(disc); + + if (tty->driver->flush_buffer) + tty->driver->flush_buffer(tty); + + read_lock(&tasklist_lock); + do_each_task_pid(session, PIDTYPE_SID, p) { + if (p->signal->tty == tty || session > 0) { + printk(KERN_NOTICE "SAK: killed process %d" + " (%s): p->signal->session==tty->session\n", + p->pid, p->comm); + send_sig(SIGKILL, p, 1); + continue; + } + task_lock(p); + if (p->files) { + spin_lock(&p->files->file_lock); + for (i=0; i < p->files->max_fds; i++) { + filp = fcheck_files(p->files, i); + if (!filp) + continue; + if (filp->f_op->read == tty_read && + filp->private_data == tty) { + printk(KERN_NOTICE "SAK: killed process %d" + " (%s): fd#%d opened to the tty\n", + p->pid, p->comm, i); + send_sig(SIGKILL, p, 1); + break; + } + } + spin_unlock(&p->files->file_lock); + } + task_unlock(p); + } while_each_task_pid(session, PIDTYPE_SID, p); + read_unlock(&tasklist_lock); +#endif +} + +/* + * 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; + PREPARE_WORK(&tty->SAK_work, __do_SAK, tty); + schedule_work(&tty->SAK_work); +} + +EXPORT_SYMBOL(do_SAK); + +/* + * This routine is called out of the software interrupt to flush data + * from the flip buffer to the line discipline. + */ + +static void flush_to_ldisc(void *private_) +{ + struct tty_struct *tty = (struct tty_struct *) private_; + unsigned char *cp; + char *fp; + int count; + unsigned long flags; + struct tty_ldisc *disc; + + disc = tty_ldisc_ref(tty); + if (disc == NULL) /* !TTY_LDISC */ + return; + + if (test_bit(TTY_DONT_FLIP, &tty->flags)) { + /* + * Do it after the next timer tick: + */ + schedule_delayed_work(&tty->flip.work, 1); + goto out; + } + spin_lock_irqsave(&tty->read_lock, flags); + if (tty->flip.buf_num) { + cp = tty->flip.char_buf + TTY_FLIPBUF_SIZE; + fp = tty->flip.flag_buf + TTY_FLIPBUF_SIZE; + tty->flip.buf_num = 0; + tty->flip.char_buf_ptr = tty->flip.char_buf; + tty->flip.flag_buf_ptr = tty->flip.flag_buf; + } else { + cp = tty->flip.char_buf; + fp = tty->flip.flag_buf; + tty->flip.buf_num = 1; + tty->flip.char_buf_ptr = tty->flip.char_buf + TTY_FLIPBUF_SIZE; + tty->flip.flag_buf_ptr = tty->flip.flag_buf + TTY_FLIPBUF_SIZE; + } + count = tty->flip.count; + tty->flip.count = 0; + spin_unlock_irqrestore(&tty->read_lock, flags); + + disc->receive_buf(tty, cp, fp, count); +out: + tty_ldisc_deref(disc); +} + +/* + * Routine which returns the baud rate of the tty + * + * Note that the baud_table needs to be kept in sync with the + * include/asm/termbits.h file. + */ +static int baud_table[] = { + 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, + 9600, 19200, 38400, 57600, 115200, 230400, 460800, +#ifdef __sparc__ + 76800, 153600, 307200, 614400, 921600 +#else + 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000, + 2500000, 3000000, 3500000, 4000000 +#endif +}; + +static int n_baud_table = ARRAY_SIZE(baud_table); + +/** + * tty_termios_baud_rate + * @termios: termios structure + * + * Convert termios baud rate data into a speed. This should be called + * with the termios lock held if this termios is a terminal termios + * structure. May change the termios data. + */ + +int tty_termios_baud_rate(struct termios *termios) +{ + unsigned int cbaud; + + cbaud = termios->c_cflag & CBAUD; + + if (cbaud & CBAUDEX) { + cbaud &= ~CBAUDEX; + + if (cbaud < 1 || cbaud + 15 > n_baud_table) + termios->c_cflag &= ~CBAUDEX; + else + cbaud += 15; + } + return baud_table[cbaud]; +} + +EXPORT_SYMBOL(tty_termios_baud_rate); + +/** + * tty_get_baud_rate - get tty bit rates + * @tty: tty to query + * + * Returns the baud rate as an integer for this terminal. The + * termios lock must be held by the caller and the terminal bit + * flags may be updated. + */ + +int tty_get_baud_rate(struct tty_struct *tty) +{ + int baud = tty_termios_baud_rate(tty->termios); + + if (baud == 38400 && tty->alt_speed) { + if (!tty->warned) { + printk(KERN_WARNING "Use of setserial/setrocket to " + "set SPD_* flags is deprecated\n"); + tty->warned = 1; + } + baud = tty->alt_speed; + } + + return baud; +} + +EXPORT_SYMBOL(tty_get_baud_rate); + +/** + * tty_flip_buffer_push - terminal + * @tty: tty to push + * + * Queue a push of the terminal flip buffers to the line discipline. This + * function must not be called from IRQ context if tty->low_latency is set. + * + * In the event of the queue being busy for flipping the work will be + * held off and retried later. + */ + +void tty_flip_buffer_push(struct tty_struct *tty) +{ + if (tty->low_latency) + flush_to_ldisc((void *) tty); + else + schedule_delayed_work(&tty->flip.work, 1); +} + +EXPORT_SYMBOL(tty_flip_buffer_push); + +/* + * This subroutine initializes a tty structure. + */ +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->pgrp = -1; + tty->overrun_time = jiffies; + tty->flip.char_buf_ptr = tty->flip.char_buf; + tty->flip.flag_buf_ptr = tty->flip.flag_buf; + INIT_WORK(&tty->flip.work, flush_to_ldisc, tty); + init_MUTEX(&tty->flip.pty_sem); + init_MUTEX(&tty->termios_sem); + init_waitqueue_head(&tty->write_wait); + init_waitqueue_head(&tty->read_wait); + INIT_WORK(&tty->hangup_work, do_tty_hangup, tty); + sema_init(&tty->atomic_read, 1); + sema_init(&tty->atomic_write, 1); + spin_lock_init(&tty->read_lock); + INIT_LIST_HEAD(&tty->tty_files); + INIT_WORK(&tty->SAK_work, NULL, NULL); +} + +/* + * The default put_char routine if the driver did not define one. + */ +static void tty_default_put_char(struct tty_struct *tty, unsigned char ch) +{ + tty->driver->write(tty, &ch, 1); +} + +static struct class_simple *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. + * + * This call is required to be made to register an individual tty device if + * the tty driver's flags have the TTY_DRIVER_NO_DEVFS bit set. If that + * bit is not set, this function should not be called. + */ +void 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; + } + + devfs_mk_cdev(dev, S_IFCHR | S_IRUSR | S_IWUSR, + "%s%d", driver->devfs_name, index + driver->name_base); + + if (driver->type == TTY_DRIVER_TYPE_PTY) + pty_line_name(driver, index, name); + else + tty_line_name(driver, index, name); + class_simple_device_add(tty_class, dev, device, name); +} + +/** + * 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 made when the tty device is gone. + */ +void tty_unregister_device(struct tty_driver *driver, unsigned index) +{ + devfs_remove("%s%d", driver->devfs_name, index + driver->name_base); + class_simple_device_remove(MKDEV(driver->major, driver->minor_start) + index); +} + +EXPORT_SYMBOL(tty_register_device); +EXPORT_SYMBOL(tty_unregister_device); + +struct tty_driver *alloc_tty_driver(int lines) +{ + struct tty_driver *driver; + + driver = kmalloc(sizeof(struct tty_driver), GFP_KERNEL); + if (driver) { + memset(driver, 0, sizeof(struct tty_driver)); + driver->magic = TTY_DRIVER_MAGIC; + driver->num = lines; + /* later we'll move allocation of tables here */ + } + return driver; +} + +void put_tty_driver(struct tty_driver *driver) +{ + kfree(driver); +} + +void tty_set_operations(struct tty_driver *driver, struct tty_operations *op) +{ + driver->open = op->open; + driver->close = op->close; + driver->write = op->write; + driver->put_char = op->put_char; + driver->flush_chars = op->flush_chars; + driver->write_room = op->write_room; + driver->chars_in_buffer = op->chars_in_buffer; + driver->ioctl = op->ioctl; + driver->set_termios = op->set_termios; + driver->throttle = op->throttle; + driver->unthrottle = op->unthrottle; + driver->stop = op->stop; + driver->start = op->start; + driver->hangup = op->hangup; + driver->break_ctl = op->break_ctl; + driver->flush_buffer = op->flush_buffer; + driver->set_ldisc = op->set_ldisc; + driver->wait_until_sent = op->wait_until_sent; + driver->send_xchar = op->send_xchar; + driver->read_proc = op->read_proc; + driver->write_proc = op->write_proc; + driver->tiocmget = op->tiocmget; + driver->tiocmset = op->tiocmset; +} + + +EXPORT_SYMBOL(alloc_tty_driver); +EXPORT_SYMBOL(put_tty_driver); +EXPORT_SYMBOL(tty_set_operations); + +/* + * 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; + + if (driver->flags & TTY_DRIVER_INSTALLED) + return 0; + + if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { + p = kmalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL); + if (!p) + return -ENOMEM; + memset(p, 0, driver->num * 3 * sizeof(void *)); + } + + if (!driver->major) { + error = alloc_chrdev_region(&dev, driver->minor_start, driver->num, + (char*)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, + (char*)driver->name); + } + if (error < 0) { + kfree(p); + return error; + } + + if (p) { + driver->ttys = (struct tty_struct **)p; + driver->termios = (struct termios **)(p + driver->num); + driver->termios_locked = (struct termios **)(p + driver->num * 2); + } else { + driver->ttys = NULL; + driver->termios = NULL; + driver->termios_locked = NULL; + } + + cdev_init(&driver->cdev, &tty_fops); + driver->cdev.owner = driver->owner; + error = cdev_add(&driver->cdev, dev, driver->num); + if (error) { + cdev_del(&driver->cdev); + unregister_chrdev_region(dev, driver->num); + driver->ttys = NULL; + driver->termios = driver->termios_locked = NULL; + kfree(p); + return error; + } + + if (!driver->put_char) + driver->put_char = tty_default_put_char; + + list_add(&driver->tty_drivers, &tty_drivers); + + if ( !(driver->flags & TTY_DRIVER_NO_DEVFS) ) { + for(i = 0; i < driver->num; i++) + tty_register_device(driver, i, NULL); + } + proc_tty_register_driver(driver); + return 0; +} + +EXPORT_SYMBOL(tty_register_driver); + +/* + * Called by a tty driver to unregister itself. + */ +int tty_unregister_driver(struct tty_driver *driver) +{ + int i; + struct termios *tp; + void *p; + + if (driver->refcount) + return -EBUSY; + + unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), + driver->num); + + list_del(&driver->tty_drivers); + + /* + * 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); + } + tp = driver->termios_locked[i]; + if (tp) { + driver->termios_locked[i] = NULL; + kfree(tp); + } + if (!(driver->flags & TTY_DRIVER_NO_DEVFS)) + tty_unregister_device(driver, i); + } + p = driver->ttys; + proc_tty_unregister_driver(driver); + driver->ttys = NULL; + driver->termios = driver->termios_locked = NULL; + kfree(p); + cdev_del(&driver->cdev); + return 0; +} + +EXPORT_SYMBOL(tty_unregister_driver); + + +/* + * 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. */ + (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY); + + /* + * set up the console device so that later boot sequences can + * inform about problems etc.. + */ +#ifdef CONFIG_EARLY_PRINTK + disable_early_printk(); +#endif +#ifdef CONFIG_SERIAL_68360 + /* This is not a console initcall. I know not what it's doing here. + So I haven't moved it. dwmw2 */ + rs_360_init(); +#endif + call = __con_initcall_start; + while (call < __con_initcall_end) { + (*call)(); + call++; + } +} + +#ifdef CONFIG_VT +extern int vty_init(void); +#endif + +static int __init tty_class_init(void) +{ + tty_class = class_simple_create(THIS_MODULE, "tty"); + if (IS_ERR(tty_class)) + return PTR_ERR(tty_class); + return 0; +} + +postcore_initcall(tty_class_init); + +/* 3/2004 jmc: why do these devices exist? */ + +static struct cdev tty_cdev, console_cdev; +#ifdef CONFIG_UNIX98_PTYS +static struct cdev ptmx_cdev; +#endif +#ifdef CONFIG_VT +static struct cdev vc0_cdev; +#endif + +/* + * Ok, now we can initialize the rest of the tty devices and can count + * on memory allocations, interrupts etc.. + */ +static 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"); + devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 0), S_IFCHR|S_IRUGO|S_IWUGO, "tty"); + class_simple_device_add(tty_class, 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"); + devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 1), S_IFCHR|S_IRUSR|S_IWUSR, "console"); + class_simple_device_add(tty_class, 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"); + devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 2), S_IFCHR|S_IRUGO|S_IWUGO, "ptmx"); + class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); +#endif + +#ifdef CONFIG_VT + cdev_init(&vc0_cdev, &console_fops); + 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"); + devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR, "vc/0"); + class_simple_device_add(tty_class, MKDEV(TTY_MAJOR, 0), NULL, "tty0"); + + vty_init(); +#endif + return 0; +} +module_init(tty_init); |