// 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/termios_internal.h>#include <linux/fs.h> #include <linux/kbd_kern.h>#include <linux/vt_kern.h>#include <linux/selection.h> #include <linux/kmod.h>#include <linux/nsproxy.h>#include "tty.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 kiocb *, struct iov_iter *);static ssize_t tty_write(struct kiocb *, struct iov_iter *);static __poll_t tty_poll(struct file *, poll_table *);static int tty_open(struct inode *, struct file *);#ifdef CONFIG_COMPATstatic long tty_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);#else#define tty_compat_ioctl NULL#endifstatic 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); kvfree(tty->write_buf); 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_obj(*priv); 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 * @file: to free private_data of * * 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; }#endif return 0;} /* Caller must hold tty_lock */static void check_tty_count(struct tty_struct *tty, const char *routine){#ifdef CHECK_TTY_COUNT struct list_head *p; int count = 0, kopen_count = 0; scoped_guard(spinlock, &tty->files_lock) list_for_each(p, &tty->tty_files) count++; 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); }#endif} /** * get_tty_driver - find device of a tty * @device: 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; guard(mutex)(&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); return 0; } } return -ENODEV;}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; 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); guard(mutex)(&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)) { *line = tty_line; return tty_driver_kref_get(p); } } return NULL;}EXPORT_SYMBOL_GPL(tty_find_polling_driver);#endif static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to){ return 0;} static ssize_t hung_up_tty_write(struct kiocb *iocb, struct iov_iter *from){ 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 = { .read_iter = tty_read, .write_iter = tty_write, .splice_read = copy_splice_read, .splice_write = iter_file_splice_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 = { .read_iter = tty_read, .write_iter = redirected_tty_write, .splice_read = copy_splice_read, .splice_write = iter_file_splice_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 = { .read_iter = hung_up_tty_read, .write_iter = 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; /** * tty_wakeup - request more dataLines 1–500 of 3647. 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// 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/termios_internal.h> #include <linux/fs.h> #include <linux/kbd_kern.h> #include <linux/vt_kern.h> #include <linux/selection.h> #include <linux/kmod.h> #include <linux/nsproxy.h> #include "tty.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 kiocb *, struct iov_iter *); static ssize_t tty_write(struct kiocb *, struct iov_iter *); static __poll_t tty_poll(struct file *, poll_table *); static int tty_open(struct inode *, struct file *); #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); kvfree(tty->write_buf); 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_obj(*priv); 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 * @file: to free private_data of * * 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; } #endif return 0; } /* Caller must hold tty_lock */ static void check_tty_count(struct tty_struct *tty, const char *routine) { #ifdef CHECK_TTY_COUNT struct list_head *p; int count = 0, kopen_count = 0; scoped_guard(spinlock, &tty->files_lock) list_for_each(p, &tty->tty_files) count++; 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); } #endif } /** * get_tty_driver - find device of a tty * @device: 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; guard(mutex)(&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); return 0; } } return -ENODEV; } 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; 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); guard(mutex)(&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)) { *line = tty_line; return tty_driver_kref_get(p); } } return NULL; } EXPORT_SYMBOL_GPL(tty_find_polling_driver); #endif static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to) { return 0; } static ssize_t hung_up_tty_write(struct kiocb *iocb, struct iov_iter *from) { 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 = { .read_iter = tty_read, .write_iter = tty_write, .splice_read = copy_splice_read, .splice_write = iter_file_splice_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 = { .read_iter = tty_read, .write_iter = redirected_tty_write, .splice_read = copy_splice_read, .splice_write = iter_file_splice_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 = { .read_iter = hung_up_tty_read, .write_iter = 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; /** * tty_wakeup - request more data