| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Nico Pitre | 3668 | 28.31% | 2 | 0.51% |
| Alan Cox | 2813 | 21.71% | 47 | 11.99% |
| Peter Hurley | 1639 | 12.65% | 61 | 15.56% |
| Al Viro | 1166 | 9.00% | 26 | 6.63% |
| Linus Torvalds (pre-git) | 840 | 6.48% | 80 | 20.41% |
| Okash Khawaja | 484 | 3.74% | 4 | 1.02% |
| Jiri Slaby | 344 | 2.65% | 20 | 5.10% |
| Kay Sievers | 257 | 1.98% | 4 | 1.02% |
| Nicholas Piggin | 158 | 1.22% | 2 | 0.51% |
| Johan Hovold | 113 | 0.87% | 4 | 1.02% |
| Greg Kroah-Hartman | 104 | 0.80% | 14 | 3.57% |
| Paul Fulghum | 96 | 0.74% | 6 | 1.53% |
| Hannes Reinecke | 94 | 0.73% | 2 | 0.51% |
| Eric W. Biedermann | 91 | 0.70% | 9 | 2.30% |
| Peter Zijlstra | 84 | 0.65% | 1 | 0.26% |
| Russell King | 71 | 0.55% | 3 | 0.77% |
| Dmitry Safonov | 70 | 0.54% | 4 | 1.02% |
| Arnd Bergmann | 57 | 0.44% | 6 | 1.53% |
| Masatake YAMATO | 56 | 0.43% | 1 | 0.26% |
| Tomas Hlavacek | 50 | 0.39% | 2 | 0.51% |
| Linus Torvalds | 50 | 0.39% | 9 | 2.30% |
| Sukadev Bhattiprolu | 49 | 0.38% | 3 | 0.77% |
| Richard Watts | 46 | 0.35% | 1 | 0.26% |
| Dmitry Eremin-Solenikov | 42 | 0.32% | 1 | 0.26% |
| Andrew Morton | 40 | 0.31% | 7 | 1.79% |
| Rasmus Villemoes | 33 | 0.25% | 4 | 1.02% |
| Cyrill V. Gorcunov | 32 | 0.25% | 2 | 0.51% |
| Vasiliy Kulikov | 32 | 0.25% | 1 | 0.26% |
| Werner Fink | 31 | 0.24% | 1 | 0.26% |
| Gaurav Kohli | 31 | 0.24% | 1 | 0.26% |
| Leon Yu | 28 | 0.22% | 1 | 0.26% |
| Takashi Iwai | 24 | 0.19% | 1 | 0.26% |
| Tejun Heo | 21 | 0.16% | 1 | 0.26% |
| Ingo Molnar | 17 | 0.13% | 5 | 1.28% |
| Eric Biggers | 17 | 0.13% | 3 | 0.77% |
| Arnaldo Carvalho de Melo | 16 | 0.12% | 1 | 0.26% |
| Jann Horn | 13 | 0.10% | 1 | 0.26% |
| Tetsuo Handa | 12 | 0.09% | 1 | 0.26% |
| Thomas Meyer | 12 | 0.09% | 1 | 0.26% |
| Lin Yi | 11 | 0.08% | 1 | 0.26% |
| Keun-o Park | 11 | 0.08% | 1 | 0.26% |
| Pekka J Enberg | 10 | 0.08% | 1 | 0.26% |
| Brian Gerst | 10 | 0.08% | 2 | 0.51% |
| Alexey Dobriyan | 10 | 0.08% | 1 | 0.26% |
| Jonathan Corbet | 8 | 0.06% | 4 | 1.02% |
| Dipankar Sarma | 7 | 0.05% | 2 | 0.51% |
| Pavel Emelyanov | 6 | 0.05% | 2 | 0.51% |
| Kirill Korotaev | 6 | 0.05% | 1 | 0.26% |
| Vojtech Pavlik | 5 | 0.04% | 1 | 0.26% |
| H. Peter Anvin | 5 | 0.04% | 1 | 0.26% |
| Oleg Nesterov | 5 | 0.04% | 1 | 0.26% |
| Eric Paris | 5 | 0.04% | 1 | 0.26% |
| Cédric Le Goater | 4 | 0.03% | 2 | 0.51% |
| Arjan van de Ven | 4 | 0.03% | 2 | 0.51% |
| Christoph Hellwig | 4 | 0.03% | 1 | 0.26% |
| Rusty Russell | 4 | 0.03% | 1 | 0.26% |
| Heiko Carstens | 3 | 0.02% | 1 | 0.26% |
| David Howells | 3 | 0.02% | 1 | 0.26% |
| Manuel Zerpies | 3 | 0.02% | 1 | 0.26% |
| Miles Chen | 3 | 0.02% | 1 | 0.26% |
| Martin Schwidefsky | 3 | 0.02% | 1 | 0.26% |
| Domen Puncer | 3 | 0.02% | 1 | 0.26% |
| Rob Herring | 3 | 0.02% | 1 | 0.26% |
| Dan Carpenter | 3 | 0.02% | 1 | 0.26% |
| Torben Hohn | 2 | 0.02% | 1 | 0.26% |
| Hansjoerg Lipp | 2 | 0.02% | 1 | 0.26% |
| Adrian Bunk | 2 | 0.02% | 2 | 0.51% |
| Wanlong Gao | 1 | 0.01% | 1 | 0.26% |
| Josh Triplett | 1 | 0.01% | 1 | 0.26% |
| Sudip Mukherjee | 1 | 0.01% | 1 | 0.26% |
| Andi Kleen | 1 | 0.01% | 1 | 0.26% |
| Suzuki K. Poulose | 1 | 0.01% | 1 | 0.26% |
| Thadeu Lima de Souza Cascardo | 1 | 0.01% | 1 | 0.26% |
| Nathael Pajani | 1 | 0.01% | 1 | 0.26% |
| Thomas Koeller | 1 | 0.01% | 1 | 0.26% |
| Davide Libenzi | 1 | 0.01% | 1 | 0.26% |
| Jason Wessel | 1 | 0.01% | 1 | 0.26% |
| Jovi Zhang | 1 | 0.01% | 1 | 0.26% |
| Joe Perches | 1 | 0.01% | 1 | 0.26% |
| Total | 12958 | 392 |
// SPDX-License-Identifier: GPL-2.0 /* * 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/signal.h> #include <linux/sched/task.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/ppp-ioctl.h> #include <linux/proc_fs.h> #include <linux/init.h> #include <linux/module.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/ratelimit.h> #include <linux/compat.h> #include <linux/uaccess.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 #ifdef TTY_DEBUG_HANGUP # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) #else # define tty_debug_hangup(tty, f, args...) do { } while (0) #endif #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, /* .c_line = N_TTY, */ }; 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 */ DEFINE_MUTEX(tty_mutex); 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 __poll_t 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); /** * 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 */ static void free_tty_struct(struct tty_struct *tty) { tty_ldisc_deinit(tty); put_device(tty->dev); kfree(tty->write_buf); tty->magic = 0xDEADDEAD; kfree(tty); } static inline struct tty_struct *file_tty(struct file *file) { return ((struct tty_file_private *)file->private_data)->tty; } int tty_alloc_file(struct file *file) { struct tty_file_private *priv; priv = kmalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; file->private_data = priv; return 0; } /* Associate a new file with the tty structure */ void tty_add_file(struct tty_struct *tty, struct file *file) { struct tty_file_private *priv = file->private_data; priv->tty = tty; priv->file = file; spin_lock(&tty->files_lock); list_add(&priv->list, &tty->tty_files); spin_unlock(&tty->files_lock); } /** * tty_free_file - free file->private_data * * This shall be used only for fail path handling when tty_add_file was not * called yet. */ void tty_free_file(struct file *file) { struct tty_file_private *priv = file->private_data; file->private_data = NULL; kfree(priv); } /* Delete file from its tty */ static void tty_del_file(struct file *file) { struct tty_file_private *priv = file->private_data; struct tty_struct *tty = priv->tty; spin_lock(&tty->files_lock); list_del(&priv->list); spin_unlock(&tty->files_lock); tty_free_file(file); } /** * tty_name - return tty naming * @tty: tty structure * * 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 */ const char *tty_name(const struct tty_struct *tty) { if (!tty) /* Hmm. NULL pointer. That's fun. */ return "NULL tty"; return tty->name; } EXPORT_SYMBOL(tty_name); const char *tty_driver_name(const struct tty_struct *tty) { if (!tty || !tty->driver) return ""; return tty->driver->name; } static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, const char *routine) { #ifdef TTY_PARANOIA_CHECK if (!tty) { pr_warn("(%d:%d): %s: NULL tty\n", imajor(inode), iminor(inode), routine); return 1; } if (tty->magic != TTY_MAGIC) { pr_warn("(%d:%d): %s: bad magic number\n", imajor(inode), iminor(inode), routine); return 1; } #endif return 0; } /* Caller must hold tty_lock */ static int check_tty_count(struct tty_struct *tty, const char *routine) { #ifdef CHECK_TTY_COUNT struct list_head *p; int count = 0, kopen_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_port_kopened(tty->port)) kopen_count++; if (tty->count != (count + kopen_count)) { tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n", routine, tty->count, count, kopen_count); return (count + kopen_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; } /** * tty_dev_name_to_number - return dev_t for device name * @name: user space name of device under /dev * @number: pointer to dev_t that this function will populate * * This function converts device names like ttyS0 or ttyUSB1 into dev_t * like (4, 64) or (188, 1). If no corresponding driver is registered then * the function returns -ENODEV. * * Locking: this acquires tty_mutex to protect the tty_drivers list from * being modified while we are traversing it, and makes sure to * release it before exiting. */ int tty_dev_name_to_number(const char *name, dev_t *number) { struct tty_driver *p; int ret; int index, prefix_length = 0; const char *str; for (str = name; *str && !isdigit(*str); str++) ; if (!*str) return -EINVAL; ret = kstrtoint(str, 10, &index); if (ret) return ret; prefix_length = str - name; mutex_lock(&tty_mutex); list_for_each_entry(p, &tty_drivers, tty_drivers) if (prefix_length == strlen(p->name) && strncmp(name, p->name, prefix_length) == 0) { if (index < p->num) { *number = MKDEV(p->major, p->minor_start + index); goto out; } } /* if here then driver wasn't found */ ret = -ENODEV; out: mutex_unlock(&tty_mutex); return ret; } EXPORT_SYMBOL_GPL(tty_dev_name_to_number); #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 (!len || 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 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 __poll_t hung_up_tty_poll(struct file *filp, poll_table *wait) { return EPOLLIN | EPOLLOUT | EPOLLERR | EPOLLHUP | EPOLLRDNORM | EPOLLWRNORM; } 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 int hung_up_tty_fasync(int fd, struct file *file, int on) { return -ENOTTY; } static void tty_show_fdinfo(struct seq_file *m, struct file *file) { struct tty_struct *tty = file_tty(file); if (tty && tty->ops && tty->ops->show_fdinfo) tty->ops->show_fdinfo(tty, m); } 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, .show_fdinfo = tty_show_fdinfo, }; 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, .fasync = hung_up_tty_fasync, }; static DEFINE_SPINLOCK(redirect_lock); static struct file *redirect; extern void tty_sysctl_init(void); /** * 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, EPOLLOUT); } EXPORT_SYMBOL_GPL(tty_wakeup); /** * __tty_hangup - actual handler for hangup events * @work: tty device * * This can be called by a "kworker" 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_ldiscs_lock from called functions * termios_rwsem resetting termios data * tasklist_lock to walk task list for hangup event * ->siglock to protect ->signal/->sighand */ static void __tty_hangup(struct tty_struct *tty, int exit_session) { struct file *cons_filp = NULL; struct file *filp, *f = NULL; struct tty_file_private *priv; int closecount = 0, n; int refs; if (!tty) return; spin_lock(&redirect_lock); if (redirect && file_tty(redirect) == tty) { f = redirect; redirect = NULL; } spin_unlock(&redirect_lock); tty_lock(tty); if (test_bit(TTY_HUPPED, &tty->flags)) { tty_unlock(tty); return; } /* * Some console devices aren't actually hung up for technical and * historical reasons, which can lead to indefinite interruptible * sleep in n_tty_read(). The following explicitly tells * n_tty_read() to abort readers. */ set_bit(TTY_HUPPING, &tty->flags); /* 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); refs = tty_signal_session_leader(tty, exit_session); /* Account for the p->signal references we killed */ while (refs--) tty_kref_put(tty); tty_ldisc_hangup(tty, cons_filp != NULL); spin_lock_irq(&tty->ctrl_lock); clear_bit(TTY_THROTTLED, &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; spin_unlock_irq(&tty->ctrl_lock); /* * 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, which is now guaranteed. */ set_bit(TTY_HUPPED, &tty->flags); clear_bit(TTY_HUPPING, &tty->flags); tty_unlock(tty); 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, 0); } /** * 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) { tty_debug_hangup(tty, "hangup\n"); 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) { tty_debug_hangup(tty, "vhangup\n"); __tty_hangup(tty, 0); } 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_vhangup_session - hangup session leader exit * @tty: tty to hangup * * The session leader is exiting and hanging up its controlling terminal. * Every process in the foreground process group is signalled SIGHUP. * * We do this synchronously so that when the syscall returns the process * is complete. That guarantee is necessary for security reasons. */ void tty_vhangup_session(struct tty_struct *tty) { tty_debug_hangup(tty, "session hangup\n"); __tty_hangup(tty, 1); } /** * 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 && filp->f_op == &hung_up_tty_fops); } EXPORT_SYMBOL(tty_hung_up_p); /** * stop_tty - propagate flow control * @tty: tty to stop * * Perform flow control to the driver. 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: * flow_lock */ void __stop_tty(struct tty_struct *tty) { if (tty->stopped) return; tty->stopped = 1; if (tty->ops->stop) tty->ops->stop(tty); } void stop_tty(struct tty_struct *tty) { unsigned long flags; spin_lock_irqsave(&tty->flow_lock, flags); __stop_tty(tty); spin_unlock_irqrestore(&tty->flow_lock, flags); } EXPORT_SYMBOL(stop_tty); /** * start_tty - propagate flow control * @tty: tty to start * * Start a tty that has been stopped if at all possible. If this * tty was previous stopped and is now being started, the driver * start method is invoked and the line discipline woken. * * Locking: * flow_lock */ void __start_tty(struct tty_struct *tty) { if (!tty->stopped || tty->flow_stopped) return; tty->stopped = 0; if (tty->ops->start) tty->ops->start(tty); tty_wakeup(tty); } void start_tty(struct tty_struct *tty) { unsigned long flags; spin_lock_irqsave(&tty->flow_lock, flags); __start_tty(tty); spin_unlock_irqrestore(&tty->flow_lock, flags); } EXPORT_SYMBOL(start_tty); static void tty_update_time(struct timespec64 *time) { time64_t sec = ktime_get_real_seconds(); /* * We only care if the two values differ in anything other than the * lower three bits (i.e every 8 seconds). If so, then we can update * the time of the tty device, otherwise it could be construded as a * security leak to let userspace know the exact timing of the tty. */ if ((sec ^ time->tv_sec) & ~7) time->tv_sec = sec; } /** * 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_inode(file); struct tty_struct *tty = file_tty(file); struct tty_ldisc *ld; if (tty_paranoia_check(tty, inode, "tty_read")) return -EIO; if (!tty || tty_io_error(tty)) return -EIO; /* We want to wait for the line discipline to sort out in this situation */ ld = tty_ldisc_ref_wait(tty); if (!ld) return hung_up_tty_read(file, buf, count, ppos); if (ld->ops->read) i = ld->ops->read(tty, file, buf, count); else i = -EIO; tty_ldisc_deref(ld); if (i > 0) tty_update_time(&inode->i_atime); return i; } static void tty_write_unlock(struct tty_struct *tty) { mutex_unlock(&tty->atomic_write_lock); wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); } static 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) { tty_update_time(&file_inode(file)->i_mtime); 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(tty); if (tty->ops->write && tty->count > 0) tty->ops->write(tty, msg, strlen(msg)); tty_unlock(tty); 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 tty_struct *tty = file_tty(file); struct tty_ldisc *ld; ssize_t ret; if (tty_paranoia_check(tty, file_inode(file), "tty_write")) return -EIO; if (!tty || !tty->ops->write || tty_io_error(tty)) return -EIO; /* Short term debug to catch buggy drivers */ if (tty->ops->write_room == NULL) tty_err(tty, "missing write_room method\n"); ld = tty_ldisc_ref_wait(tty); if (!ld) return hung_up_tty_write(file, buf, count, ppos); 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) p = get_file(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); } /** * tty_send_xchar - send priority character * * Send a high priority character to the tty even if stopped * * Locking: none for xchar method, write ordering for write method. */ int tty_send_xchar(struct tty_struct *tty, char ch) { int was_stopped = tty->stopped; if (tty->ops->send_xchar) { down_read(&tty->termios_rwsem); tty->ops->send_xchar(tty, ch); up_read(&tty->termios_rwsem); return 0; } if (tty_write_lock(tty, 0) < 0) return -ERESTARTSYS; down_read(&tty->termios_rwsem); if (was_stopped) start_tty(tty); tty->ops->write(tty, &ch, 1); if (was_stopped) stop_tty(tty); up_read(&tty->termios_rwsem); tty_write_unlock(tty); return 0; } 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 ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) { if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) return sprintf(p, "%s", driver->name); else return 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. If not found, return NULL or ERR_PTR() if the * driver lookup() method returns an error. * * Locking: tty_mutex must be held. If the tty is found, bump the tty kref. */ static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, struct file *file, int idx) { struct tty_struct *tty; if (driver->ops->lookup) if (!file) tty = ERR_PTR(-EIO); else tty = driver->ops->lookup(driver, file, idx); else tty = driver->ttys[idx]; if (!IS_ERR(tty)) tty_kref_get(tty); return tty; } /** * tty_init_termios - helper for termios setup * @tty: the tty to set up * * Initialise the termios structure for this tty. This runs under * the tty_mutex currently so we can be relaxed about ordering. */ void tty_init_termios(struct tty_struct *tty) { struct ktermios *tp; int idx = tty->index; if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) tty->termios = tty->driver->init_termios; else { /* Check for lazy saved data */ tp = tty->driver->termios[idx]; if (tp != NULL) { tty->termios = *tp; tty->termios.c_line = tty->driver->init_termios.c_line; } else tty->termios = tty->driver->init_termios; } /* 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); } EXPORT_SYMBOL_GPL(tty_init_termios); int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) { tty_init_termios(tty); tty_driver_kref_get(driver); tty->count++; driver->ttys[tty->index] = tty; return 0; } EXPORT_SYMBOL_GPL(tty_standard_install); /** * 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) { return driver->ops->install ? driver->ops->install(driver, tty) : tty_standard_install(driver, tty); } /** * 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. * Re-opens on master ptys are not allowed and return -EIO. * * Locking: Caller must hold tty_lock */ static int tty_reopen(struct tty_struct *tty) { struct tty_driver *driver = tty->driver; struct tty_ldisc *ld; int retval = 0; if (driver->type == TTY_DRIVER_TYPE_PTY && driver->subtype == PTY_TYPE_MASTER) return -EIO; if (!tty->count) return -EAGAIN; if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) return -EBUSY; ld = tty_ldisc_ref_wait(tty); if (ld) { tty_ldisc_deref(ld); } else { retval = tty_ldisc_lock(tty, 5 * HZ); if (retval) return retval; if (!tty->ldisc) retval = tty_ldisc_reinit(tty, tty->termios.c_line); tty_ldisc_unlock(tty); } if (retval == 0) tty->count++; return retval; } /** * tty_init_dev - initialise a tty device * @driver: tty driver we are opening a device on * @idx: device index * @ret_tty: returned tty structure * * 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) { struct tty_struct *tty; int retval; /* * 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 * may be retained.) */ if (!try_module_get(driver->owner)) return ERR_PTR(-ENODEV); tty = alloc_tty_struct(driver, idx); if (!tty) { retval = -ENOMEM; goto err_module_put; } tty_lock(tty); retval = tty_driver_install_tty(driver, tty); if (retval < 0) goto err_free_tty; if (!tty->port) tty->port = driver->ports[idx]; if (WARN_RATELIMIT(!tty->port, "%s: %s driver does not set tty->port. This would crash the kernel. Fix the driver!\n", __func__, tty->driver->name)) { retval = -EINVAL; goto err_release_lock; } retval = tty_ldisc_lock(tty, 5 * HZ); if (retval) goto err_release_lock; tty->port->itty = tty; /* * 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 err_release_tty; tty_ldisc_unlock(tty); /* Return the tty locked so that it cannot vanish under the caller */ return tty; err_free_tty: tty_unlock(tty); free_tty_struct(tty); err_module_put: module_put(driver->owner); return ERR_PTR(retval); /* call the tty release_tty routine to clean out this slot */ err_release_tty: tty_ldisc_unlock(tty); tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", retval, idx); err_release_lock: tty_unlock(tty); release_tty(tty, idx); return ERR_PTR(retval); } /** * tty_save_termios() - save tty termios data in driver table * @tty: tty whose termios data to save * * Locking: Caller guarantees serialisation with tty_init_termios(). */ void tty_save_termios(struct tty_struct *tty) { struct ktermios *tp; int idx = tty->index; /* If the port is going to reset then it has no termios to save */ if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) return; /* Stash the termios data */ tp = tty->driver->termios[idx]; if (tp == NULL) { tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); if (tp == NULL) return; tty->driver->termios[idx] = tp; } *tp = tty->termios; } EXPORT_SYMBOL_GPL(tty_save_termios); /** * tty_flush_works - flush all works of a tty/pty pair * @tty: tty device to flush works for (or either end of a pty pair) * * Sync flush all works belonging to @tty (and the 'other' tty). */ static void tty_flush_works(struct tty_struct *tty) { flush_work(&tty->SAK_work); flush_work(&tty->hangup_work); if (tty->link) { flush_work(&tty->link->SAK_work); flush_work(&tty->link->hangup_work); } } /** * 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: * 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; struct module *owner = driver->owner; if (tty->ops->cleanup) tty->ops->cleanup(tty); tty->magic = 0; tty_driver_kref_put(driver); module_put(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); /* 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 * takes the file list lock internally when working on the list * of ttys that the driver keeps. * */ 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); WARN_ON(!mutex_is_locked(&tty_mutex)); if (tty->ops->shutdown) tty->ops->shutdown(tty); tty_save_termios(tty); tty_driver_remove_tty(tty->driver, tty); tty->port->itty = NULL; if (tty->link) tty->link->port->itty = NULL; tty_buffer_cancel_work(tty->port); if (tty->link) tty_buffer_cancel_work(tty->link->port); tty_kref_put(tty->link); tty_kref_put(tty); } /** * tty_release_checks - check a tty before real release * @tty: tty to check * @o_tty: link of @tty (if any) * @idx: index of the tty * * Performs some paranoid checking before true release of the @tty. * This is a no-op unless TTY_PARANOIA_CHECK is defined. */ static int tty_release_checks(struct tty_struct *tty, int idx) { #ifdef TTY_PARANOIA_CHECK if (idx < 0 || idx >= tty->driver->num) { tty_debug(tty, "bad idx %d\n", idx); return -1; } /* not much to check for devpts */ if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) return 0; if (tty != tty->driver->ttys[idx]) { tty_debug(tty, "bad driver table[%d] = %p\n", idx, tty->driver->ttys[idx]); return -1; } if (tty->driver->other) { struct tty_struct *o_tty = tty->link; if (o_tty != tty->driver->other->ttys[idx]) { tty_debug(tty, "bad other table[%d] = %p\n", idx, tty->driver->other->ttys[idx]); return -1; } if (o_tty->link != tty) { tty_debug(tty, "bad link = %p\n", o_tty->link); return -1; } } #endif return 0; } /** * tty_kclose - closes tty opened by tty_kopen * @tty: tty device * * Performs the final steps to release and free a tty device. It is the * same as tty_release_struct except that it also resets TTY_PORT_KOPENED * flag on tty->port. */ void tty_kclose(struct tty_struct *tty) { /* * Ask the line discipline code to release its structures */ tty_ldisc_release(tty); /* Wait for pending work before tty destruction commmences */ tty_flush_works(tty); tty_debug_hangup(tty, "freeing structure\n"); /* * The release_tty function takes care of the details of clearing * the slots and preserving the termios structure. */ mutex_lock(&tty_mutex); tty_port_set_kopened(tty->port, 0); release_tty(tty, tty->index); mutex_unlock(&tty_mutex); } EXPORT_SYMBOL_GPL(tty_kclose); /** * tty_release_struct - release a tty struct * @tty: tty device * @idx: index of the tty * * Performs the final steps to release and free a tty device. It is * roughly the reverse of tty_init_dev. */ void tty_release_struct(struct tty_struct *tty, int idx) { /* * Ask the line discipline code to release its structures */ tty_ldisc_release(tty); /* Wait for pending work before tty destruction commmences */ tty_flush_works(tty); tty_debug_hangup(tty, "freeing structure\n"); /* * The release_tty function takes care of the details of clearing * the slots and preserving the termios structure. */ mutex_lock(&tty_mutex); release_tty(tty, idx); mutex_unlock(&tty_mutex); } EXPORT_SYMBOL_GPL(tty_release_struct); /** * 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 = NULL; int do_sleep, final; int idx; long timeout = 0; int once = 1; if (tty_paranoia_check(tty, inode, __func__)) return 0; tty_lock(tty); check_tty_count(tty, __func__); __tty_fasync(-1, filp, 0); idx = tty->index; if (tty->driver->type == TTY_DRIVER_TYPE_PTY && tty->driver->subtype == PTY_TYPE_MASTER) o_tty = tty->link; if (tty_release_checks(tty, idx)) { tty_unlock(tty); return 0; } tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); if (tty->ops->close) tty->ops->close(tty, filp); /* If tty is pty master, lock the slave pty (stable lock order) */ tty_lock_slave(o_tty); /* * 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 closed, * so we do it now. */ while (1) { do_sleep = 0; if (tty->count <= 1) { if (waitqueue_active(&tty->read_wait)) { wake_up_poll(&tty->read_wait, EPOLLIN); do_sleep++; } if (waitqueue_active(&tty->write_wait)) { wake_up_poll(&tty->write_wait, EPOLLOUT); do_sleep++; } } if (o_tty && o_tty->count <= 1) { if (waitqueue_active(&o_tty->read_wait)) { wake_up_poll(&o_tty->read_wait, EPOLLIN); do_sleep++; } if (waitqueue_active(&o_tty->write_wait)) { wake_up_poll(&o_tty->write_wait, EPOLLOUT); do_sleep++; } } if (!do_sleep) break; if (once) { once = 0; tty_warn(tty, "read/write wait queue active!\n"); } schedule_timeout_killable(timeout); if (timeout < 120 * HZ) timeout = 2 * timeout + 1; else timeout = MAX_SCHEDULE_TIMEOUT; } if (o_tty) { if (--o_tty->count < 0) { tty_warn(tty, "bad slave count (%d)\n", o_tty->count); o_tty->count = 0; } } if (--tty->count < 0) { tty_warn(tty, "bad tty->count (%d)\n", tty->count); 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. * * 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->count) { read_lock(&tasklist_lock); session_clear_tty(tty->session); if (o_tty) session_clear_tty(o_tty->session); read_unlock(&tasklist_lock); } /* check whether both sides are closing ... */ final = !tty->count && !(o_tty && o_tty->count); tty_unlock_slave(o_tty); tty_unlock(tty); /* At this point, the tty->count == 0 should ensure a dead tty cannot be re-opened by a racing opener */ if (!final) return 0; tty_debug_hangup(tty, "final close\n"); tty_release_struct(tty, idx); return 0; } /** * tty_open_current_tty - get locked tty of current task * @device: device number * @filp: file pointer to tty * @return: locked tty of the current task iff @device is /dev/tty * * Performs a re-open of the current task's controlling tty. * * We cannot return driver and index like for the other nodes because * devpts will not work then. It expects inodes to be from devpts FS. */ static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) { struct tty_struct *tty; int retval; if (device != MKDEV(TTYAUX_MAJOR, 0)) return NULL; tty = get_current_tty(); if (!tty) return ERR_PTR(-ENXIO); filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ /* noctty = 1; */ tty_lock(tty); tty_kref_put(tty); /* safe to drop the kref now */ retval = tty_reopen(tty); if (retval < 0) { tty_unlock(tty); tty = ERR_PTR(retval); } return tty; } /** * tty_lookup_driver - lookup a tty driver for a given device file * @device: device number * @filp: file pointer to tty * @index: index for the device in the @return driver * @return: driver for this inode (with increased refcount) * * If @return is not erroneous, the caller is responsible to decrement the * refcount by tty_driver_kref_put. * * Locking: tty_mutex protects get_tty_driver */ static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, int *index) { struct tty_driver *driver = NULL; switch (device) { #ifdef CONFIG_VT case MKDEV(TTY_MAJOR, 0): { extern struct tty_driver *console_driver; driver = tty_driver_kref_get(console_driver); *index = fg_console; break; } #endif case MKDEV(TTYAUX_MAJOR, 1): { struct tty_driver *console_driver = console_device(index); if (console_driver) { driver = tty_driver_kref_get(console_driver); if (driver && filp) { /* Don't let /dev/console block */ filp->f_flags |= O_NONBLOCK; break; } } if (driver) tty_driver_kref_put(driver); return ERR_PTR(-ENODEV); } default: driver = get_tty_driver(device, index); if (!driver) return ERR_PTR(-ENODEV); break; } return driver; } /** * tty_kopen - open a tty device for kernel * @device: dev_t of device to open * * Opens tty exclusively for kernel. Performs the driver lookup, * makes sure it's not already opened and performs the first-time * tty initialization. * * Returns the locked initialized &tty_struct * * Claims the global tty_mutex to serialize: * - concurrent first-time tty initialization * - concurrent tty driver removal w/ lookup * - concurrent tty removal from driver table */ struct tty_struct *tty_kopen(dev_t device) { struct tty_struct *tty; struct tty_driver *driver; int index = -1; mutex_lock(&tty_mutex); driver = tty_lookup_driver(device, NULL, &index); if (IS_ERR(driver)) { mutex_unlock(&tty_mutex); return ERR_CAST(driver); } /* check whether we're reopening an existing tty */ tty = tty_driver_lookup_tty(driver, NULL, index); if (IS_ERR(tty)) goto out; if (tty) { /* drop kref from tty_driver_lookup_tty() */ tty_kref_put(tty); tty = ERR_PTR(-EBUSY); } else { /* tty_init_dev returns tty with the tty_lock held */ tty = tty_init_dev(driver, index); if (IS_ERR(tty)) goto out; tty_port_set_kopened(tty->port, 1); } out: mutex_unlock(&tty_mutex); tty_driver_kref_put(driver); return tty; } EXPORT_SYMBOL_GPL(tty_kopen); /** * tty_open_by_driver - open a tty device * @device: dev_t of device to open * @filp: file pointer to tty * * Performs the driver lookup, checks for a reopen, or otherwise * performs the first-time tty initialization. * * Returns the locked initialized or re-opened &tty_struct * * Claims the global tty_mutex to serialize: * - concurrent first-time tty initialization * - concurrent tty driver removal w/ lookup * - concurrent tty removal from driver table */ static struct tty_struct *tty_open_by_driver(dev_t device, struct file *filp) { struct tty_struct *tty; struct tty_driver *driver = NULL; int index = -1; int retval; mutex_lock(&tty_mutex); driver = tty_lookup_driver(device, filp, &index); if (IS_ERR(driver)) { mutex_unlock(&tty_mutex); return ERR_CAST(driver); } /* check whether we're reopening an existing tty */ tty = tty_driver_lookup_tty(driver, filp, index); if (IS_ERR(tty)) { mutex_unlock(&tty_mutex); goto out; } if (tty) { if (tty_port_kopened(tty->port)) { tty_kref_put(tty); mutex_unlock(&tty_mutex); tty = ERR_PTR(-EBUSY); goto out; } mutex_unlock(&tty_mutex); retval = tty_lock_interruptible(tty); tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ if (retval) { if (retval == -EINTR) retval = -ERESTARTSYS; tty = ERR_PTR(retval); goto out; } retval = tty_reopen(tty); if (retval < 0) { tty_unlock(tty); tty = ERR_PTR(retval); } } else { /* Returns with the tty_lock held for now */ tty = tty_init_dev(driver, index); mutex_unlock(&tty_mutex); } out: tty_driver_kref_put(driver); return tty; } /** * 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, tty_lookup_driver and tty_init_dev. * tty->count should protect the rest. * ->siglock protects ->signal/->sighand * * Note: the tty_unlock/lock cases without a ref are only safe due to * tty_mutex */ static int tty_open(struct inode *inode, struct file *filp) { struct tty_struct *tty; int noctty, retval; dev_t device = inode->i_rdev; unsigned saved_flags = filp->f_flags; nonseekable_open(inode, filp); retry_open: retval = tty_alloc_file(filp); if (retval) return -ENOMEM; tty = tty_open_current_tty(device, filp); if (!tty) tty = tty_open_by_driver(device, filp); if (IS_ERR(tty)) { tty_free_file(filp); retval = PTR_ERR(tty); if (retval != -EAGAIN || signal_pending(current)) return retval; schedule(); goto retry_open; } tty_add_file(tty, filp); check_tty_count(tty, __func__); tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); if (tty->ops->open) retval = tty->ops->open(tty, filp); else retval = -ENODEV; filp->f_flags = saved_flags; if (retval) { tty_debug_hangup(tty, "open error %d, releasing\n", retval); tty_unlock(tty); /* 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. */ if (tty_hung_up_p(filp)) filp->f_op = &tty_fops; goto retry_open; } clear_bit(TTY_HUPPED, &tty->flags); noctty = (filp->f_flags & O_NOCTTY) || (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || device == MKDEV(TTYAUX_MAJOR, 1) || (tty->driver->type == TTY_DRIVER_TYPE_PTY && tty->driver->subtype == PTY_TYPE_MASTER); if (!noctty) tty_open_proc_set_tty(filp, tty); tty_unlock(tty); 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 __poll_t tty_poll(struct file *filp, poll_table *wait) { struct tty_struct *tty = file_tty(filp); struct tty_ldisc *ld; __poll_t ret = 0; if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) return 0; ld = tty_ldisc_ref_wait(tty); if (!ld) return hung_up_tty_poll(filp, wait); 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, file_inode(filp), "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; spin_lock_irqsave(&tty->ctrl_lock, flags); if (tty->pgrp) { pid = tty->pgrp; type = PIDTYPE_PGID; } else { pid = task_pid(current); type = PIDTYPE_TGID; } get_pid(pid); spin_unlock_irqrestore(&tty->ctrl_lock, flags); __f_setown(filp, pid, type, 0); put_pid(pid); retval = 0; } out: return retval; } static int tty_fasync(int fd, struct file *filp, int on) { struct tty_struct *tty = file_tty(filp); int retval = -ENOTTY; tty_lock(tty); if (!tty_hung_up_p(filp)) retval = __tty_fasync(fd, filp, on); tty_unlock(tty); 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_ldiscs_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); if (!ld) return -EIO; if (ld->ops->receive_buf) 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->winsize_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->winsize_mutex); err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); mutex_unlock(&tty->winsize_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; /* Lock the tty */ mutex_lock(&tty->winsize_mutex); if (!memcmp(ws, &tty->winsize, sizeof(*ws))) goto done; /* Signal the foreground process group */ pgrp = tty_get_pgrp(tty); if (pgrp) kill_pgrp(pgrp, SIGWINCH, 1); put_pid(pgrp); tty->winsize = *ws; done: mutex_unlock(&tty->winsize_mutex); return 0; } EXPORT_SYMBOL(tty_do_resize); /** * 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 dependent. 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 administrator 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; } redirect = get_file(file); spin_unlock(&redirect_lock); return 0; } /** * 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 disc; int ret; if (get_user(disc, p)) return -EFAULT; ret = tty_set_ldisc(tty, disc); return ret; } /** * tiocgetd - get line discipline * @tty: tty device * @p: pointer to user data * * Retrieves the line discipline id directly from the ldisc. * * Locking: waits for ldisc reference (in case the line discipline * is changing or the tty is being hungup) */ static int tiocgetd(struct tty_struct *tty, int __user *p) { struct tty_ldisc *ld; int ret; ld = tty_ldisc_ref_wait(tty); if (!ld) return -EIO; ret = put_user(ld->ops->num, p); tty_ldisc_deref(ld); 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, int __user *p) { int retval = -EINVAL; if (tty->ops->tiocmget) { retval = tty->ops->tiocmget(tty); if (retval >= 0) retval = put_user(retval, p); } return retval; } /** * tty_tiocmset - set modem status * @tty: tty device * @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, 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, 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; } static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *ss) { static DEFINE_RATELIMIT_STATE(depr_flags, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); char comm[TASK_COMM_LEN]; struct serial_struct v; int flags; if (copy_from_user(&v, ss, sizeof(struct serial_struct))) return -EFAULT; flags = v.flags & ASYNC_DEPRECATED; if (flags && __ratelimit(&depr_flags)) pr_warn("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", __func__, get_task_comm(comm, current), flags); if (!tty->ops->set_serial) return -ENOTTY; return tty->ops->set_serial(tty, &v); } static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *ss) { struct serial_struct v; int err; memset(&v, 0, sizeof(struct serial_struct)); if (!tty->ops->get_serial) return -ENOTTY; err = tty->ops->get_serial(tty, &v); if (!err && copy_to_user(ss, &v, sizeof(struct serial_struct))) err = -EFAULT; return err; } /* * if pty, return the slave side (real_tty) * otherwise, return self */ static 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; } /* * 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; if (tty_paranoia_check(tty, file_inode(file), "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 TIOCEXCL: set_bit(TTY_EXCLUSIVE, &tty->flags); return 0; case TIOCNXCL: clear_bit(TTY_EXCLUSIVE, &tty->flags); return 0; case TIOCGEXCL: { int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); return put_user(excl, (int __user *)p); } case TIOCGETD: return tiocgetd(tty, p); case TIOCSETD: return tiocsetd(tty, p); case TIOCVHANGUP: if (!capable(CAP_SYS_ADMIN)) return -EPERM; tty_vhangup(tty); return 0; case TIOCGDEV: { unsigned int ret = new_encode_dev(tty_devnum(real_tty)); return put_user(ret, (unsigned int __user *)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, p); case TIOCMSET: case TIOCMBIC: case TIOCMBIS: return tty_tiocmset(tty, cmd, p); case TIOCGICOUNT: return tty_tiocgicount(tty, p); case TCFLSH: switch (arg) { case TCIFLUSH: case TCIOFLUSH: /* flush tty buffer and allow ldisc to process ioctl */ tty_buffer_flush(tty, NULL); break; } break; case TIOCSSERIAL: return tty_tiocsserial(tty, p); case TIOCGSERIAL: return tty_tiocgserial(tty, p); case TIOCGPTPEER: /* Special because the struct file is needed */ return ptm_open_peer(file, tty, (int)arg); default: retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg); if (retval != -ENOIOCTLCMD) return retval; } if (tty->ops->ioctl) { retval = tty->ops->ioctl(tty, cmd, arg); if (retval != -ENOIOCTLCMD) return retval; } ld = tty_ldisc_ref_wait(tty); if (!ld) return hung_up_tty_ioctl(file, cmd, arg); retval = -EINVAL; if (ld->ops->ioctl) { retval = ld->ops->ioctl(tty, file, cmd, arg); if (retval == -ENOIOCTLCMD) retval = -ENOTTY; } tty_ldisc_deref(ld); return retval; } #ifdef CONFIG_COMPAT struct serial_struct32 { compat_int_t type; compat_int_t line; compat_uint_t port; compat_int_t irq; compat_int_t flags; compat_int_t xmit_fifo_size; compat_int_t custom_divisor; compat_int_t baud_base; unsigned short close_delay; char io_type; char reserved_char[1]; compat_int_t hub6; unsigned short closing_wait; /* time to wait before closing */ unsigned short closing_wait2; /* no longer used... */ compat_uint_t iomem_base; unsigned short iomem_reg_shift; unsigned int port_high; /* compat_ulong_t iomap_base FIXME */ compat_int_t reserved[1]; }; static int compat_tty_tiocsserial(struct tty_struct *tty, struct serial_struct32 __user *ss) { static DEFINE_RATELIMIT_STATE(depr_flags, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); char comm[TASK_COMM_LEN]; struct serial_struct32 v32; struct serial_struct v; int flags; if (copy_from_user(&v32, ss, sizeof(struct serial_struct32))) return -EFAULT; memcpy(&v, &v32, offsetof(struct serial_struct32, iomem_base)); v.iomem_base = compat_ptr(v32.iomem_base); v.iomem_reg_shift = v32.iomem_reg_shift; v.port_high = v32.port_high; v.iomap_base = 0; flags = v.flags & ASYNC_DEPRECATED; if (flags && __ratelimit(&depr_flags)) pr_warn("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", __func__, get_task_comm(comm, current), flags); if (!tty->ops->set_serial) return -ENOTTY; return tty->ops->set_serial(tty, &v); } static int compat_tty_tiocgserial(struct tty_struct *tty, struct serial_struct32 __user *ss) { struct serial_struct32 v32; struct serial_struct v; int err; memset(&v, 0, sizeof(v)); memset(&v32, 0, sizeof(v32)); if (!tty->ops->get_serial) return -ENOTTY; err = tty->ops->get_serial(tty, &v); if (!err) { memcpy(&v32, &v, offsetof(struct serial_struct32, iomem_base)); v32.iomem_base = (unsigned long)v.iomem_base >> 32 ? 0xfffffff : ptr_to_compat(v.iomem_base); v32.iomem_reg_shift = v.iomem_reg_shift; v32.port_high = v.port_high; if (copy_to_user(ss, &v32, sizeof(struct serial_struct32))) err = -EFAULT; } return err; } static long tty_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct tty_struct *tty = file_tty(file); struct tty_ldisc *ld; int retval = -ENOIOCTLCMD; switch (cmd) { case TIOCOUTQ: case TIOCSTI: case TIOCGWINSZ: case TIOCSWINSZ: case TIOCGEXCL: case TIOCGETD: case TIOCSETD: case TIOCGDEV: case TIOCMGET: case TIOCMSET: case TIOCMBIC: case TIOCMBIS: case TIOCGICOUNT: case TIOCGPGRP: case TIOCSPGRP: case TIOCGSID: case TIOCSERGETLSR: case TIOCGRS485: case TIOCSRS485: #ifdef TIOCGETP case TIOCGETP: case TIOCSETP: case TIOCSETN: #endif #ifdef TIOCGETC case TIOCGETC: case TIOCSETC: #endif #ifdef TIOCGLTC case TIOCGLTC: case TIOCSLTC: #endif case TCSETSF: case TCSETSW: case TCSETS: case TCGETS: #ifdef TCGETS2 case TCGETS2: case TCSETSF2: case TCSETSW2: case TCSETS2: #endif case TCGETA: case TCSETAF: case TCSETAW: case TCSETA: case TIOCGLCKTRMIOS: case TIOCSLCKTRMIOS: #ifdef TCGETX case TCGETX: case TCSETX: case TCSETXW: case TCSETXF: #endif case TIOCGSOFTCAR: case TIOCSSOFTCAR: case PPPIOCGCHAN: case PPPIOCGUNIT: return tty_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); case TIOCCONS: case TIOCEXCL: case TIOCNXCL: case TIOCVHANGUP: case TIOCSBRK: case TIOCCBRK: case TCSBRK: case TCSBRKP: case TCFLSH: case TIOCGPTPEER: case TIOCNOTTY: case TIOCSCTTY: case TCXONC: case TIOCMIWAIT: case TIOCSERCONFIG: return tty_ioctl(file, cmd, arg); } if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) return -EINVAL; switch (cmd) { case TIOCSSERIAL: return compat_tty_tiocsserial(tty, compat_ptr(arg)); case TIOCGSERIAL: return compat_tty_tiocgserial(tty, compat_ptr(arg)); } if (tty->ops->compat_ioctl) { retval = tty->ops->compat_ioctl(tty, cmd, arg); if (retval != -ENOIOCTLCMD) return retval; } ld = tty_ldisc_ref_wait(tty); if (!ld) return hung_up_tty_compat_ioctl(file, cmd, arg); if (ld->ops->compat_ioctl) retval = ld->ops->compat_ioctl(tty, file, cmd, arg); if (retval == -ENOIOCTLCMD && ld->ops->ioctl) retval = ld->ops->ioctl(tty, file, (unsigned long)compat_ptr(cmd), arg); tty_ldisc_deref(ld); return retval; } #endif static int this_tty(const void *t, struct file *file, unsigned fd) { if (likely(file->f_op->read != tty_read)) return 0; return file_tty(file) != t ? 0 : fd + 1; } /* * 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; 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) { tty_notice(tty, "SAK: killed process %d (%s): by session\n", task_pid_nr(p), p->comm); group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); } 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) { tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", task_pid_nr(p), p->comm); group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); continue; } task_lock(p); i = iterate_fd(p->files, 0, this_tty, tty); if (i != 0) { tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", task_pid_nr(p), p->comm, i - 1); group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); } 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); /* 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_by_devt(tty_class, devt); } /** * alloc_tty_struct * * This subroutine allocates and initializes a tty structure. * * Locking: none - tty in question is not exposed at this point */ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) { struct tty_struct *tty; tty = kzalloc(sizeof(*tty), GFP_KERNEL); if (!tty) return NULL; kref_init(&tty->kref); tty->magic = TTY_MAGIC; if (tty_ldisc_init(tty)) { kfree(tty); return NULL; } tty->session = NULL; tty->pgrp = NULL; mutex_init(&tty->legacy_mutex); mutex_init(&tty->throttle_mutex); init_rwsem(&tty->termios_rwsem); mutex_init(&tty->winsize_mutex); init_ldsem(&tty->ldisc_sem); init_waitqueue_head(&tty->write_wait); init_waitqueue_head(&tty->read_wait); INIT_WORK(&tty->hangup_work, do_tty_hangup); mutex_init(&tty->atomic_write_lock); spin_lock_init(&tty->ctrl_lock); spin_lock_init(&tty->flow_lock); spin_lock_init(&tty->files_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); return 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; static int tty_cdev_add(struct tty_driver *driver, dev_t dev, unsigned int index, unsigned int count) { int err; /* init here, since reused cdevs cause crashes */ driver->cdevs[index] = cdev_alloc(); if (!driver->cdevs[index]) return -ENOMEM; driver->cdevs[index]->ops = &tty_fops; driver->cdevs[index]->owner = driver->owner; err = cdev_add(driver->cdevs[index], dev, count); if (err) kobject_put(&driver->cdevs[index]->kobj); return err; } /** * 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) { return tty_register_device_attr(driver, index, device, NULL, NULL); } EXPORT_SYMBOL(tty_register_device); static void tty_device_create_release(struct device *dev) { dev_dbg(dev, "releasing...\n"); kfree(dev); } /** * tty_register_device_attr - 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. * @drvdata: Driver data to be set to device. * @attr_grp: Attribute group to be set on device. * * 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_attr(struct tty_driver *driver, unsigned index, struct device *device, void *drvdata, const struct attribute_group **attr_grp) { char name[64]; dev_t devt = MKDEV(driver->major, driver->minor_start) + index; struct ktermios *tp; struct device *dev; int retval; if (index >= driver->num) { pr_err("%s: Attempt to register invalid tty line number (%d)\n", driver->name, 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); dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) return ERR_PTR(-ENOMEM); dev->devt = devt; dev->class = tty_class; dev->parent = device; dev->release = tty_device_create_release; dev_set_name(dev, "%s", name); dev->groups = attr_grp; dev_set_drvdata(dev, drvdata); dev_set_uevent_suppress(dev, 1); retval = device_register(dev); if (retval) goto err_put; if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { /* * Free any saved termios data so that the termios state is * reset when reusing a minor number. */ tp = driver->termios[index]; if (tp) { driver->termios[index] = NULL; kfree(tp); } retval = tty_cdev_add(driver, devt, index, 1); if (retval) goto err_del; } dev_set_uevent_suppress(dev, 0); kobject_uevent(&dev->kobj, KOBJ_ADD); return dev; err_del: device_del(dev); err_put: put_device(dev); return ERR_PTR(retval); } EXPORT_SYMBOL_GPL(tty_register_device_attr); /** * 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); if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { cdev_del(driver->cdevs[index]); driver->cdevs[index] = NULL; } } EXPORT_SYMBOL(tty_unregister_device); /** * __tty_alloc_driver -- allocate tty driver * @lines: count of lines this driver can handle at most * @owner: module which is responsible for this driver * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags * * This should not be called directly, some of the provided macros should be * used instead. Use IS_ERR and friends on @retval. */ struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, unsigned long flags) { struct tty_driver *driver; unsigned int cdevs = 1; int err; if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) return ERR_PTR(-EINVAL); driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); if (!driver) return ERR_PTR(-ENOMEM); kref_init(&driver->kref); driver->magic = TTY_DRIVER_MAGIC; driver->num = lines; driver->owner = owner; driver->flags = flags; if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { driver->ttys = kcalloc(lines, sizeof(*driver->ttys), GFP_KERNEL); driver->termios = kcalloc(lines, sizeof(*driver->termios), GFP_KERNEL); if (!driver->ttys || !driver->termios) { err = -ENOMEM; goto err_free_all; } } if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { driver->ports = kcalloc(lines, sizeof(*driver->ports), GFP_KERNEL); if (!driver->ports) { err = -ENOMEM; goto err_free_all; } cdevs = lines; } driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); if (!driver->cdevs) { err = -ENOMEM; goto err_free_all; } return driver; err_free_all: kfree(driver->ports); kfree(driver->ttys); kfree(driver->termios); kfree(driver->cdevs); kfree(driver); return ERR_PTR(err); } EXPORT_SYMBOL(__tty_alloc_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; if (driver->flags & TTY_DRIVER_INSTALLED) { 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); } proc_tty_unregister_driver(driver); if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) cdev_del(driver->cdevs[0]); } kfree(driver->cdevs); kfree(driver->ports); kfree(driver->termios); kfree(driver->ttys); 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; struct device *d; 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) goto err; if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { error = tty_cdev_add(driver, dev, 0, driver->num); if (error) goto err_unreg_char; } 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_unreg_devs; } } } proc_tty_register_driver(driver); driver->flags |= TTY_DRIVER_INSTALLED; return 0; err_unreg_devs: for (i--; i >= 0; i--) tty_unregister_device(driver, i); mutex_lock(&tty_mutex); list_del(&driver->tty_drivers); mutex_unlock(&tty_mutex); err_unreg_char: unregister_chrdev_region(dev, driver->num); err: 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 tty_default_fops(struct file_operations *fops) { *fops = tty_fops; } static char *tty_devnode(struct device *dev, umode_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; static ssize_t show_cons_active(struct device *dev, struct device_attribute *attr, char *buf) { struct console *cs[16]; int i = 0; struct console *c; ssize_t count = 0; console_lock(); for_each_console(c) { if (!c->device) continue; if (!c->write) continue; if ((c->flags & CON_ENABLED) == 0) continue; cs[i++] = c; if (i >= ARRAY_SIZE(cs)) break; } while (i--) { int index = cs[i]->index; struct tty_driver *drv = cs[i]->device(cs[i], &index); /* don't resolve tty0 as some programs depend on it */ if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) count += tty_line_name(drv, index, buf + count); else count += sprintf(buf + count, "%s%d", cs[i]->name, cs[i]->index); count += sprintf(buf + count, "%c", i ? ' ':'\n'); } console_unlock(); return count; } static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); static struct attribute *cons_dev_attrs[] = { &dev_attr_active.attr, NULL }; ATTRIBUTE_GROUPS(cons_dev); static struct device *consdev; void console_sysfs_notify(void) { if (consdev) sysfs_notify(&consdev->kobj, NULL, "active"); } /* * Ok, now we can initialize the rest of the tty devices and can count * on memory allocations, interrupts etc.. */ int __init tty_init(void) { tty_sysctl_init(); 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"); consdev = device_create_with_groups(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, cons_dev_groups, "console"); if (IS_ERR(consdev)) consdev = NULL; #ifdef CONFIG_VT vty_init(&console_fops); #endif return 0; }
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