![Linus Torvalds](/assets/img/avatar_default.png)
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2981 lines
74 KiB
C
2981 lines
74 KiB
C
/*
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* linux/drivers/char/tty_io.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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/*
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* 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
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* or rs-channels. It also implements echoing, cooked mode etc.
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*
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* Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
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*
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* Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
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* tty_struct and tty_queue structures. Previously there was an array
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* of 256 tty_struct's which was statically allocated, and the
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* tty_queue structures were allocated at boot time. Both are now
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* dynamically allocated only when the tty is open.
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*
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* Also restructured routines so that there is more of a separation
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* between the high-level tty routines (tty_io.c and tty_ioctl.c) and
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* the low-level tty routines (serial.c, pty.c, console.c). This
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* makes for cleaner and more compact code. -TYT, 9/17/92
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*
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* Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
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* which can be dynamically activated and de-activated by the line
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* discipline handling modules (like SLIP).
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*
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* NOTE: pay no attention to the line discipline code (yet); its
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* interface is still subject to change in this version...
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* -- TYT, 1/31/92
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*
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* Added functionality to the OPOST tty handling. No delays, but all
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* other bits should be there.
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* -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
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*
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* Rewrote canonical mode and added more termios flags.
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* -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
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*
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* Reorganized FASYNC support so mouse code can share it.
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* -- ctm@ardi.com, 9Sep95
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*
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* New TIOCLINUX variants added.
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* -- mj@k332.feld.cvut.cz, 19-Nov-95
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*
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* Restrict vt switching via ioctl()
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* -- grif@cs.ucr.edu, 5-Dec-95
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*
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* Move console and virtual terminal code to more appropriate files,
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* implement CONFIG_VT and generalize console device interface.
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* -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
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*
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* Rewrote init_dev and release_dev to eliminate races.
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* -- Bill Hawes <whawes@star.net>, June 97
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*
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* Added devfs support.
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* -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
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*
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* Added support for a Unix98-style ptmx device.
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* -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
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*
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* Reduced memory usage for older ARM systems
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* -- Russell King <rmk@arm.linux.org.uk>
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*
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* Move do_SAK() into process context. Less stack use in devfs functions.
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* alloc_tty_struct() always uses kmalloc() -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
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*/
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#include <linux/config.h>
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#include <linux/types.h>
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#include <linux/major.h>
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#include <linux/errno.h>
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#include <linux/signal.h>
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#include <linux/fcntl.h>
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#include <linux/sched.h>
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#include <linux/interrupt.h>
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#include <linux/tty.h>
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#include <linux/tty_driver.h>
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#include <linux/tty_flip.h>
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#include <linux/devpts_fs.h>
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#include <linux/file.h>
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#include <linux/console.h>
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#include <linux/timer.h>
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#include <linux/ctype.h>
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#include <linux/kd.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/poll.h>
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#include <linux/proc_fs.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/smp_lock.h>
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#include <linux/device.h>
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#include <linux/idr.h>
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#include <linux/wait.h>
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#include <linux/bitops.h>
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#include <asm/uaccess.h>
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#include <asm/system.h>
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#include <linux/kbd_kern.h>
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#include <linux/vt_kern.h>
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#include <linux/selection.h>
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#include <linux/devfs_fs_kernel.h>
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#include <linux/kmod.h>
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#undef TTY_DEBUG_HANGUP
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#define TTY_PARANOIA_CHECK 1
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#define CHECK_TTY_COUNT 1
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struct termios tty_std_termios = { /* for the benefit of tty drivers */
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.c_iflag = ICRNL | IXON,
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.c_oflag = OPOST | ONLCR,
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.c_cflag = B38400 | CS8 | CREAD | HUPCL,
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.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
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ECHOCTL | ECHOKE | IEXTEN,
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.c_cc = INIT_C_CC
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};
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EXPORT_SYMBOL(tty_std_termios);
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/* This list gets poked at by procfs and various bits of boot up code. This
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could do with some rationalisation such as pulling the tty proc function
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into this file */
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LIST_HEAD(tty_drivers); /* linked list of tty drivers */
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/* Semaphore to protect creating and releasing a tty. This is shared with
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vt.c for deeply disgusting hack reasons */
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DECLARE_MUTEX(tty_sem);
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#ifdef CONFIG_UNIX98_PTYS
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extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */
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extern int pty_limit; /* Config limit on Unix98 ptys */
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static DEFINE_IDR(allocated_ptys);
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static DECLARE_MUTEX(allocated_ptys_lock);
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static int ptmx_open(struct inode *, struct file *);
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#endif
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extern void disable_early_printk(void);
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static void initialize_tty_struct(struct tty_struct *tty);
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static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
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static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *);
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ssize_t redirected_tty_write(struct file *, const char __user *, size_t, loff_t *);
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static unsigned int tty_poll(struct file *, poll_table *);
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static int tty_open(struct inode *, struct file *);
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static int tty_release(struct inode *, struct file *);
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int tty_ioctl(struct inode * inode, struct file * file,
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unsigned int cmd, unsigned long arg);
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static int tty_fasync(int fd, struct file * filp, int on);
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extern void rs_360_init(void);
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static void release_mem(struct tty_struct *tty, int idx);
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static struct tty_struct *alloc_tty_struct(void)
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{
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struct tty_struct *tty;
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tty = kmalloc(sizeof(struct tty_struct), GFP_KERNEL);
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if (tty)
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memset(tty, 0, sizeof(struct tty_struct));
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return tty;
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}
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static inline void free_tty_struct(struct tty_struct *tty)
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{
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kfree(tty->write_buf);
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kfree(tty);
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}
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#define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
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char *tty_name(struct tty_struct *tty, char *buf)
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{
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if (!tty) /* Hmm. NULL pointer. That's fun. */
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strcpy(buf, "NULL tty");
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else
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strcpy(buf, tty->name);
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return buf;
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}
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EXPORT_SYMBOL(tty_name);
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inline int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
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const char *routine)
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{
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#ifdef TTY_PARANOIA_CHECK
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if (!tty) {
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printk(KERN_WARNING
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"null TTY for (%d:%d) in %s\n",
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imajor(inode), iminor(inode), routine);
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return 1;
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}
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if (tty->magic != TTY_MAGIC) {
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printk(KERN_WARNING
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"bad magic number for tty struct (%d:%d) in %s\n",
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imajor(inode), iminor(inode), routine);
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return 1;
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}
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#endif
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return 0;
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}
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static int check_tty_count(struct tty_struct *tty, const char *routine)
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{
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#ifdef CHECK_TTY_COUNT
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struct list_head *p;
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int count = 0;
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file_list_lock();
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list_for_each(p, &tty->tty_files) {
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count++;
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}
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file_list_unlock();
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if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
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tty->driver->subtype == PTY_TYPE_SLAVE &&
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tty->link && tty->link->count)
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count++;
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if (tty->count != count) {
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printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) "
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"!= #fd's(%d) in %s\n",
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tty->name, tty->count, count, routine);
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return count;
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}
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#endif
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return 0;
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}
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/*
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* This is probably overkill for real world processors but
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* they are not on hot paths so a little discipline won't do
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* any harm.
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*/
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static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
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{
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down(&tty->termios_sem);
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tty->termios->c_line = num;
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up(&tty->termios_sem);
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}
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/*
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* This guards the refcounted line discipline lists. The lock
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* must be taken with irqs off because there are hangup path
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* callers who will do ldisc lookups and cannot sleep.
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*/
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static DEFINE_SPINLOCK(tty_ldisc_lock);
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static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
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static struct tty_ldisc tty_ldiscs[NR_LDISCS]; /* line disc dispatch table */
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int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc)
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{
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unsigned long flags;
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int ret = 0;
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if (disc < N_TTY || disc >= NR_LDISCS)
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return -EINVAL;
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spin_lock_irqsave(&tty_ldisc_lock, flags);
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if (new_ldisc) {
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tty_ldiscs[disc] = *new_ldisc;
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tty_ldiscs[disc].num = disc;
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tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED;
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tty_ldiscs[disc].refcount = 0;
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} else {
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if(tty_ldiscs[disc].refcount)
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ret = -EBUSY;
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else
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tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED;
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}
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spin_unlock_irqrestore(&tty_ldisc_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL(tty_register_ldisc);
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struct tty_ldisc *tty_ldisc_get(int disc)
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{
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unsigned long flags;
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struct tty_ldisc *ld;
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if (disc < N_TTY || disc >= NR_LDISCS)
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return NULL;
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spin_lock_irqsave(&tty_ldisc_lock, flags);
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ld = &tty_ldiscs[disc];
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/* Check the entry is defined */
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if(ld->flags & LDISC_FLAG_DEFINED)
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{
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/* If the module is being unloaded we can't use it */
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if (!try_module_get(ld->owner))
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ld = NULL;
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else /* lock it */
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ld->refcount++;
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}
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else
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ld = NULL;
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spin_unlock_irqrestore(&tty_ldisc_lock, flags);
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return ld;
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}
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EXPORT_SYMBOL_GPL(tty_ldisc_get);
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void tty_ldisc_put(int disc)
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{
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struct tty_ldisc *ld;
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unsigned long flags;
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if (disc < N_TTY || disc >= NR_LDISCS)
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BUG();
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spin_lock_irqsave(&tty_ldisc_lock, flags);
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ld = &tty_ldiscs[disc];
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if(ld->refcount == 0)
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BUG();
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ld->refcount --;
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module_put(ld->owner);
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spin_unlock_irqrestore(&tty_ldisc_lock, flags);
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}
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EXPORT_SYMBOL_GPL(tty_ldisc_put);
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static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
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{
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tty->ldisc = *ld;
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tty->ldisc.refcount = 0;
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}
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/**
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* tty_ldisc_try - internal helper
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* @tty: the tty
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*
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* Make a single attempt to grab and bump the refcount on
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* the tty ldisc. Return 0 on failure or 1 on success. This is
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* used to implement both the waiting and non waiting versions
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* of tty_ldisc_ref
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*/
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static int tty_ldisc_try(struct tty_struct *tty)
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{
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unsigned long flags;
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struct tty_ldisc *ld;
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int ret = 0;
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spin_lock_irqsave(&tty_ldisc_lock, flags);
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ld = &tty->ldisc;
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if(test_bit(TTY_LDISC, &tty->flags))
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{
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ld->refcount++;
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ret = 1;
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}
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spin_unlock_irqrestore(&tty_ldisc_lock, flags);
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return ret;
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}
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/**
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* tty_ldisc_ref_wait - wait for the tty ldisc
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* @tty: tty device
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*
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* Dereference the line discipline for the terminal and take a
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* reference to it. If the line discipline is in flux then
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* wait patiently until it changes.
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*
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* Note: Must not be called from an IRQ/timer context. The caller
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* must also be careful not to hold other locks that will deadlock
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* against a discipline change, such as an existing ldisc reference
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* (which we check for)
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*/
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struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
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{
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/* wait_event is a macro */
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wait_event(tty_ldisc_wait, tty_ldisc_try(tty));
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if(tty->ldisc.refcount == 0)
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printk(KERN_ERR "tty_ldisc_ref_wait\n");
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return &tty->ldisc;
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}
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EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
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/**
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* tty_ldisc_ref - get the tty ldisc
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* @tty: tty device
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*
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* Dereference the line discipline for the terminal and take a
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* reference to it. If the line discipline is in flux then
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* return NULL. Can be called from IRQ and timer functions.
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*/
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struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
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{
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if(tty_ldisc_try(tty))
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return &tty->ldisc;
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return NULL;
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}
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EXPORT_SYMBOL_GPL(tty_ldisc_ref);
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/**
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* tty_ldisc_deref - free a tty ldisc reference
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* @ld: reference to free up
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*
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* Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May
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* be called in IRQ context.
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*/
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void tty_ldisc_deref(struct tty_ldisc *ld)
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{
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unsigned long flags;
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if(ld == NULL)
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BUG();
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spin_lock_irqsave(&tty_ldisc_lock, flags);
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if(ld->refcount == 0)
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printk(KERN_ERR "tty_ldisc_deref: no references.\n");
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else
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ld->refcount--;
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if(ld->refcount == 0)
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wake_up(&tty_ldisc_wait);
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spin_unlock_irqrestore(&tty_ldisc_lock, flags);
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}
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EXPORT_SYMBOL_GPL(tty_ldisc_deref);
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/**
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* tty_ldisc_enable - allow ldisc use
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* @tty: terminal to activate ldisc on
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*
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* Set the TTY_LDISC flag when the line discipline can be called
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* again. Do neccessary wakeups for existing sleepers.
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*
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* Note: nobody should set this bit except via this function. Clearing
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* directly is allowed.
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*/
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static void tty_ldisc_enable(struct tty_struct *tty)
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{
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set_bit(TTY_LDISC, &tty->flags);
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wake_up(&tty_ldisc_wait);
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}
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/**
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* tty_set_ldisc - set line discipline
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* @tty: the terminal to set
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* @ldisc: the line discipline
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*
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* Set the discipline of a tty line. Must be called from a process
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* context.
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*/
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static int tty_set_ldisc(struct tty_struct *tty, int ldisc)
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{
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int retval = 0;
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struct tty_ldisc o_ldisc;
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char buf[64];
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int work;
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unsigned long flags;
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struct tty_ldisc *ld;
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if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS))
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return -EINVAL;
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restart:
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if (tty->ldisc.num == ldisc)
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return 0; /* We are already in the desired discipline */
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ld = tty_ldisc_get(ldisc);
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/* Eduardo Blanco <ejbs@cs.cs.com.uy> */
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/* Cyrus Durgin <cider@speakeasy.org> */
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if (ld == NULL) {
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request_module("tty-ldisc-%d", ldisc);
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ld = tty_ldisc_get(ldisc);
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}
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if (ld == NULL)
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return -EINVAL;
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o_ldisc = tty->ldisc;
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tty_wait_until_sent(tty, 0);
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/*
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* Make sure we don't change while someone holds a
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* reference to the line discipline. The TTY_LDISC bit
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* prevents anyone taking a reference once it is clear.
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* We need the lock to avoid racing reference takers.
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*/
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spin_lock_irqsave(&tty_ldisc_lock, flags);
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if(tty->ldisc.refcount)
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{
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/* Free the new ldisc we grabbed. Must drop the lock
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first. */
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spin_unlock_irqrestore(&tty_ldisc_lock, flags);
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tty_ldisc_put(ldisc);
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/*
|
|
* There are several reasons we may be busy, including
|
|
* random momentary I/O traffic. We must therefore
|
|
* retry. We could distinguish between blocking ops
|
|
* and retries if we made tty_ldisc_wait() smarter. That
|
|
* is up for discussion.
|
|
*/
|
|
if(wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0)
|
|
return -ERESTARTSYS;
|
|
goto restart;
|
|
}
|
|
clear_bit(TTY_LDISC, &tty->flags);
|
|
clear_bit(TTY_DONT_FLIP, &tty->flags);
|
|
spin_unlock_irqrestore(&tty_ldisc_lock, flags);
|
|
|
|
/*
|
|
* From this point on we know nobody has an ldisc
|
|
* usage reference, nor can they obtain one until
|
|
* we say so later on.
|
|
*/
|
|
|
|
work = cancel_delayed_work(&tty->flip.work);
|
|
/*
|
|
* Wait for ->hangup_work and ->flip.work handlers to terminate
|
|
*/
|
|
|
|
flush_scheduled_work();
|
|
/* Shutdown the current discipline. */
|
|
if (tty->ldisc.close)
|
|
(tty->ldisc.close)(tty);
|
|
|
|
/* Now set up the new line discipline. */
|
|
tty_ldisc_assign(tty, ld);
|
|
tty_set_termios_ldisc(tty, ldisc);
|
|
if (tty->ldisc.open)
|
|
retval = (tty->ldisc.open)(tty);
|
|
if (retval < 0) {
|
|
tty_ldisc_put(ldisc);
|
|
/* There is an outstanding reference here so this is safe */
|
|
tty_ldisc_assign(tty, tty_ldisc_get(o_ldisc.num));
|
|
tty_set_termios_ldisc(tty, tty->ldisc.num);
|
|
if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) {
|
|
tty_ldisc_put(o_ldisc.num);
|
|
/* This driver is always present */
|
|
tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
|
|
tty_set_termios_ldisc(tty, N_TTY);
|
|
if (tty->ldisc.open) {
|
|
int r = tty->ldisc.open(tty);
|
|
|
|
if (r < 0)
|
|
panic("Couldn't open N_TTY ldisc for "
|
|
"%s --- error %d.",
|
|
tty_name(tty, buf), r);
|
|
}
|
|
}
|
|
}
|
|
/* At this point we hold a reference to the new ldisc and a
|
|
a reference to the old ldisc. If we ended up flipping back
|
|
to the existing ldisc we have two references to it */
|
|
|
|
if (tty->ldisc.num != o_ldisc.num && tty->driver->set_ldisc)
|
|
tty->driver->set_ldisc(tty);
|
|
|
|
tty_ldisc_put(o_ldisc.num);
|
|
|
|
/*
|
|
* Allow ldisc referencing to occur as soon as the driver
|
|
* ldisc callback completes.
|
|
*/
|
|
|
|
tty_ldisc_enable(tty);
|
|
|
|
/* Restart it in case no characters kick it off. Safe if
|
|
already running */
|
|
if(work)
|
|
schedule_delayed_work(&tty->flip.work, 1);
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* This routine returns a tty driver structure, given a device number
|
|
*/
|
|
static struct tty_driver *get_tty_driver(dev_t device, int *index)
|
|
{
|
|
struct tty_driver *p;
|
|
|
|
list_for_each_entry(p, &tty_drivers, tty_drivers) {
|
|
dev_t base = MKDEV(p->major, p->minor_start);
|
|
if (device < base || device >= base + p->num)
|
|
continue;
|
|
*index = device - base;
|
|
return p;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* If we try to write to, or set the state of, a terminal and we're
|
|
* not in the foreground, send a SIGTTOU. If the signal is blocked or
|
|
* ignored, go ahead and perform the operation. (POSIX 7.2)
|
|
*/
|
|
int tty_check_change(struct tty_struct * tty)
|
|
{
|
|
if (current->signal->tty != tty)
|
|
return 0;
|
|
if (tty->pgrp <= 0) {
|
|
printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n");
|
|
return 0;
|
|
}
|
|
if (process_group(current) == tty->pgrp)
|
|
return 0;
|
|
if (is_ignored(SIGTTOU))
|
|
return 0;
|
|
if (is_orphaned_pgrp(process_group(current)))
|
|
return -EIO;
|
|
(void) kill_pg(process_group(current), SIGTTOU, 1);
|
|
return -ERESTARTSYS;
|
|
}
|
|
|
|
EXPORT_SYMBOL(tty_check_change);
|
|
|
|
static ssize_t hung_up_tty_read(struct file * file, char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t hung_up_tty_write(struct file * file, const char __user * buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return -EIO;
|
|
}
|
|
|
|
/* No kernel lock held - none needed ;) */
|
|
static unsigned int hung_up_tty_poll(struct file * filp, poll_table * wait)
|
|
{
|
|
return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM;
|
|
}
|
|
|
|
static int hung_up_tty_ioctl(struct inode * inode, struct file * file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
|
|
}
|
|
|
|
static struct file_operations tty_fops = {
|
|
.llseek = no_llseek,
|
|
.read = tty_read,
|
|
.write = tty_write,
|
|
.poll = tty_poll,
|
|
.ioctl = tty_ioctl,
|
|
.open = tty_open,
|
|
.release = tty_release,
|
|
.fasync = tty_fasync,
|
|
};
|
|
|
|
#ifdef CONFIG_UNIX98_PTYS
|
|
static struct file_operations ptmx_fops = {
|
|
.llseek = no_llseek,
|
|
.read = tty_read,
|
|
.write = tty_write,
|
|
.poll = tty_poll,
|
|
.ioctl = tty_ioctl,
|
|
.open = ptmx_open,
|
|
.release = tty_release,
|
|
.fasync = tty_fasync,
|
|
};
|
|
#endif
|
|
|
|
static struct file_operations console_fops = {
|
|
.llseek = no_llseek,
|
|
.read = tty_read,
|
|
.write = redirected_tty_write,
|
|
.poll = tty_poll,
|
|
.ioctl = tty_ioctl,
|
|
.open = tty_open,
|
|
.release = tty_release,
|
|
.fasync = tty_fasync,
|
|
};
|
|
|
|
static struct file_operations hung_up_tty_fops = {
|
|
.llseek = no_llseek,
|
|
.read = hung_up_tty_read,
|
|
.write = hung_up_tty_write,
|
|
.poll = hung_up_tty_poll,
|
|
.ioctl = hung_up_tty_ioctl,
|
|
.release = tty_release,
|
|
};
|
|
|
|
static DEFINE_SPINLOCK(redirect_lock);
|
|
static struct file *redirect;
|
|
|
|
/**
|
|
* tty_wakeup - request more data
|
|
* @tty: terminal
|
|
*
|
|
* Internal and external helper for wakeups of tty. This function
|
|
* informs the line discipline if present that the driver is ready
|
|
* to receive more output data.
|
|
*/
|
|
|
|
void tty_wakeup(struct tty_struct *tty)
|
|
{
|
|
struct tty_ldisc *ld;
|
|
|
|
if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
|
|
ld = tty_ldisc_ref(tty);
|
|
if(ld) {
|
|
if(ld->write_wakeup)
|
|
ld->write_wakeup(tty);
|
|
tty_ldisc_deref(ld);
|
|
}
|
|
}
|
|
wake_up_interruptible(&tty->write_wait);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(tty_wakeup);
|
|
|
|
/**
|
|
* tty_ldisc_flush - flush line discipline queue
|
|
* @tty: tty
|
|
*
|
|
* Flush the line discipline queue (if any) for this tty. If there
|
|
* is no line discipline active this is a no-op.
|
|
*/
|
|
|
|
void tty_ldisc_flush(struct tty_struct *tty)
|
|
{
|
|
struct tty_ldisc *ld = tty_ldisc_ref(tty);
|
|
if(ld) {
|
|
if(ld->flush_buffer)
|
|
ld->flush_buffer(tty);
|
|
tty_ldisc_deref(ld);
|
|
}
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(tty_ldisc_flush);
|
|
|
|
/*
|
|
* This can be called by the "eventd" kernel thread. That is process synchronous,
|
|
* but doesn't hold any locks, so we need to make sure we have the appropriate
|
|
* locks for what we're doing..
|
|
*/
|
|
static void do_tty_hangup(void *data)
|
|
{
|
|
struct tty_struct *tty = (struct tty_struct *) data;
|
|
struct file * cons_filp = NULL;
|
|
struct file *filp, *f = NULL;
|
|
struct task_struct *p;
|
|
struct tty_ldisc *ld;
|
|
int closecount = 0, n;
|
|
|
|
if (!tty)
|
|
return;
|
|
|
|
/* inuse_filps is protected by the single kernel lock */
|
|
lock_kernel();
|
|
|
|
spin_lock(&redirect_lock);
|
|
if (redirect && redirect->private_data == tty) {
|
|
f = redirect;
|
|
redirect = NULL;
|
|
}
|
|
spin_unlock(&redirect_lock);
|
|
|
|
check_tty_count(tty, "do_tty_hangup");
|
|
file_list_lock();
|
|
/* This breaks for file handles being sent over AF_UNIX sockets ? */
|
|
list_for_each_entry(filp, &tty->tty_files, f_list) {
|
|
if (filp->f_op->write == redirected_tty_write)
|
|
cons_filp = filp;
|
|
if (filp->f_op->write != tty_write)
|
|
continue;
|
|
closecount++;
|
|
tty_fasync(-1, filp, 0); /* can't block */
|
|
filp->f_op = &hung_up_tty_fops;
|
|
}
|
|
file_list_unlock();
|
|
|
|
/* FIXME! What are the locking issues here? This may me overdoing things..
|
|
* this question is especially important now that we've removed the irqlock. */
|
|
|
|
ld = tty_ldisc_ref(tty);
|
|
if(ld != NULL) /* We may have no line discipline at this point */
|
|
{
|
|
if (ld->flush_buffer)
|
|
ld->flush_buffer(tty);
|
|
if (tty->driver->flush_buffer)
|
|
tty->driver->flush_buffer(tty);
|
|
if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
|
|
ld->write_wakeup)
|
|
ld->write_wakeup(tty);
|
|
if (ld->hangup)
|
|
ld->hangup(tty);
|
|
}
|
|
|
|
/* FIXME: Once we trust the LDISC code better we can wait here for
|
|
ldisc completion and fix the driver call race */
|
|
|
|
wake_up_interruptible(&tty->write_wait);
|
|
wake_up_interruptible(&tty->read_wait);
|
|
|
|
/*
|
|
* Shutdown the current line discipline, and reset it to
|
|
* N_TTY.
|
|
*/
|
|
if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
|
|
{
|
|
down(&tty->termios_sem);
|
|
*tty->termios = tty->driver->init_termios;
|
|
up(&tty->termios_sem);
|
|
}
|
|
|
|
/* Defer ldisc switch */
|
|
/* tty_deferred_ldisc_switch(N_TTY);
|
|
|
|
This should get done automatically when the port closes and
|
|
tty_release is called */
|
|
|
|
read_lock(&tasklist_lock);
|
|
if (tty->session > 0) {
|
|
do_each_task_pid(tty->session, PIDTYPE_SID, p) {
|
|
if (p->signal->tty == tty)
|
|
p->signal->tty = NULL;
|
|
if (!p->signal->leader)
|
|
continue;
|
|
send_group_sig_info(SIGHUP, SEND_SIG_PRIV, p);
|
|
send_group_sig_info(SIGCONT, SEND_SIG_PRIV, p);
|
|
if (tty->pgrp > 0)
|
|
p->signal->tty_old_pgrp = tty->pgrp;
|
|
} while_each_task_pid(tty->session, PIDTYPE_SID, p);
|
|
}
|
|
read_unlock(&tasklist_lock);
|
|
|
|
tty->flags = 0;
|
|
tty->session = 0;
|
|
tty->pgrp = -1;
|
|
tty->ctrl_status = 0;
|
|
/*
|
|
* If one of the devices matches a console pointer, we
|
|
* cannot just call hangup() because that will cause
|
|
* tty->count and state->count to go out of sync.
|
|
* So we just call close() the right number of times.
|
|
*/
|
|
if (cons_filp) {
|
|
if (tty->driver->close)
|
|
for (n = 0; n < closecount; n++)
|
|
tty->driver->close(tty, cons_filp);
|
|
} else if (tty->driver->hangup)
|
|
(tty->driver->hangup)(tty);
|
|
|
|
/* We don't want to have driver/ldisc interactions beyond
|
|
the ones we did here. The driver layer expects no
|
|
calls after ->hangup() from the ldisc side. However we
|
|
can't yet guarantee all that */
|
|
|
|
set_bit(TTY_HUPPED, &tty->flags);
|
|
if (ld) {
|
|
tty_ldisc_enable(tty);
|
|
tty_ldisc_deref(ld);
|
|
}
|
|
unlock_kernel();
|
|
if (f)
|
|
fput(f);
|
|
}
|
|
|
|
void tty_hangup(struct tty_struct * tty)
|
|
{
|
|
#ifdef TTY_DEBUG_HANGUP
|
|
char buf[64];
|
|
|
|
printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf));
|
|
#endif
|
|
schedule_work(&tty->hangup_work);
|
|
}
|
|
|
|
EXPORT_SYMBOL(tty_hangup);
|
|
|
|
void tty_vhangup(struct tty_struct * tty)
|
|
{
|
|
#ifdef TTY_DEBUG_HANGUP
|
|
char buf[64];
|
|
|
|
printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf));
|
|
#endif
|
|
do_tty_hangup((void *) tty);
|
|
}
|
|
EXPORT_SYMBOL(tty_vhangup);
|
|
|
|
int tty_hung_up_p(struct file * filp)
|
|
{
|
|
return (filp->f_op == &hung_up_tty_fops);
|
|
}
|
|
|
|
EXPORT_SYMBOL(tty_hung_up_p);
|
|
|
|
/*
|
|
* This function is typically called only by the session leader, when
|
|
* it wants to disassociate itself from its controlling tty.
|
|
*
|
|
* It performs the following functions:
|
|
* (1) Sends a SIGHUP and SIGCONT to the foreground process group
|
|
* (2) Clears the tty from being controlling the session
|
|
* (3) Clears the controlling tty for all processes in the
|
|
* session group.
|
|
*
|
|
* The argument on_exit is set to 1 if called when a process is
|
|
* exiting; it is 0 if called by the ioctl TIOCNOTTY.
|
|
*/
|
|
void disassociate_ctty(int on_exit)
|
|
{
|
|
struct tty_struct *tty;
|
|
struct task_struct *p;
|
|
int tty_pgrp = -1;
|
|
|
|
lock_kernel();
|
|
|
|
down(&tty_sem);
|
|
tty = current->signal->tty;
|
|
if (tty) {
|
|
tty_pgrp = tty->pgrp;
|
|
up(&tty_sem);
|
|
if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
|
|
tty_vhangup(tty);
|
|
} else {
|
|
if (current->signal->tty_old_pgrp) {
|
|
kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit);
|
|
kill_pg(current->signal->tty_old_pgrp, SIGCONT, on_exit);
|
|
}
|
|
up(&tty_sem);
|
|
unlock_kernel();
|
|
return;
|
|
}
|
|
if (tty_pgrp > 0) {
|
|
kill_pg(tty_pgrp, SIGHUP, on_exit);
|
|
if (!on_exit)
|
|
kill_pg(tty_pgrp, SIGCONT, on_exit);
|
|
}
|
|
|
|
/* Must lock changes to tty_old_pgrp */
|
|
down(&tty_sem);
|
|
current->signal->tty_old_pgrp = 0;
|
|
tty->session = 0;
|
|
tty->pgrp = -1;
|
|
|
|
/* Now clear signal->tty under the lock */
|
|
read_lock(&tasklist_lock);
|
|
do_each_task_pid(current->signal->session, PIDTYPE_SID, p) {
|
|
p->signal->tty = NULL;
|
|
} while_each_task_pid(current->signal->session, PIDTYPE_SID, p);
|
|
read_unlock(&tasklist_lock);
|
|
up(&tty_sem);
|
|
unlock_kernel();
|
|
}
|
|
|
|
void stop_tty(struct tty_struct *tty)
|
|
{
|
|
if (tty->stopped)
|
|
return;
|
|
tty->stopped = 1;
|
|
if (tty->link && tty->link->packet) {
|
|
tty->ctrl_status &= ~TIOCPKT_START;
|
|
tty->ctrl_status |= TIOCPKT_STOP;
|
|
wake_up_interruptible(&tty->link->read_wait);
|
|
}
|
|
if (tty->driver->stop)
|
|
(tty->driver->stop)(tty);
|
|
}
|
|
|
|
EXPORT_SYMBOL(stop_tty);
|
|
|
|
void start_tty(struct tty_struct *tty)
|
|
{
|
|
if (!tty->stopped || tty->flow_stopped)
|
|
return;
|
|
tty->stopped = 0;
|
|
if (tty->link && tty->link->packet) {
|
|
tty->ctrl_status &= ~TIOCPKT_STOP;
|
|
tty->ctrl_status |= TIOCPKT_START;
|
|
wake_up_interruptible(&tty->link->read_wait);
|
|
}
|
|
if (tty->driver->start)
|
|
(tty->driver->start)(tty);
|
|
|
|
/* If we have a running line discipline it may need kicking */
|
|
tty_wakeup(tty);
|
|
wake_up_interruptible(&tty->write_wait);
|
|
}
|
|
|
|
EXPORT_SYMBOL(start_tty);
|
|
|
|
static ssize_t tty_read(struct file * file, char __user * buf, size_t count,
|
|
loff_t *ppos)
|
|
{
|
|
int i;
|
|
struct tty_struct * tty;
|
|
struct inode *inode;
|
|
struct tty_ldisc *ld;
|
|
|
|
tty = (struct tty_struct *)file->private_data;
|
|
inode = file->f_dentry->d_inode;
|
|
if (tty_paranoia_check(tty, inode, "tty_read"))
|
|
return -EIO;
|
|
if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
|
|
return -EIO;
|
|
|
|
/* We want to wait for the line discipline to sort out in this
|
|
situation */
|
|
ld = tty_ldisc_ref_wait(tty);
|
|
lock_kernel();
|
|
if (ld->read)
|
|
i = (ld->read)(tty,file,buf,count);
|
|
else
|
|
i = -EIO;
|
|
tty_ldisc_deref(ld);
|
|
unlock_kernel();
|
|
if (i > 0)
|
|
inode->i_atime = current_fs_time(inode->i_sb);
|
|
return i;
|
|
}
|
|
|
|
/*
|
|
* Split writes up in sane blocksizes to avoid
|
|
* denial-of-service type attacks
|
|
*/
|
|
static inline ssize_t do_tty_write(
|
|
ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t),
|
|
struct tty_struct *tty,
|
|
struct file *file,
|
|
const char __user *buf,
|
|
size_t count)
|
|
{
|
|
ssize_t ret = 0, written = 0;
|
|
unsigned int chunk;
|
|
|
|
if (down_interruptible(&tty->atomic_write)) {
|
|
return -ERESTARTSYS;
|
|
}
|
|
|
|
/*
|
|
* We chunk up writes into a temporary buffer. This
|
|
* simplifies low-level drivers immensely, since they
|
|
* don't have locking issues and user mode accesses.
|
|
*
|
|
* But if TTY_NO_WRITE_SPLIT is set, we should use a
|
|
* big chunk-size..
|
|
*
|
|
* The default chunk-size is 2kB, because the NTTY
|
|
* layer has problems with bigger chunks. It will
|
|
* claim to be able to handle more characters than
|
|
* it actually does.
|
|
*/
|
|
chunk = 2048;
|
|
if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags))
|
|
chunk = 65536;
|
|
if (count < chunk)
|
|
chunk = count;
|
|
|
|
/* write_buf/write_cnt is protected by the atomic_write semaphore */
|
|
if (tty->write_cnt < chunk) {
|
|
unsigned char *buf;
|
|
|
|
if (chunk < 1024)
|
|
chunk = 1024;
|
|
|
|
buf = kmalloc(chunk, GFP_KERNEL);
|
|
if (!buf) {
|
|
up(&tty->atomic_write);
|
|
return -ENOMEM;
|
|
}
|
|
kfree(tty->write_buf);
|
|
tty->write_cnt = chunk;
|
|
tty->write_buf = buf;
|
|
}
|
|
|
|
/* Do the write .. */
|
|
for (;;) {
|
|
size_t size = count;
|
|
if (size > chunk)
|
|
size = chunk;
|
|
ret = -EFAULT;
|
|
if (copy_from_user(tty->write_buf, buf, size))
|
|
break;
|
|
lock_kernel();
|
|
ret = write(tty, file, tty->write_buf, size);
|
|
unlock_kernel();
|
|
if (ret <= 0)
|
|
break;
|
|
written += ret;
|
|
buf += ret;
|
|
count -= ret;
|
|
if (!count)
|
|
break;
|
|
ret = -ERESTARTSYS;
|
|
if (signal_pending(current))
|
|
break;
|
|
cond_resched();
|
|
}
|
|
if (written) {
|
|
struct inode *inode = file->f_dentry->d_inode;
|
|
inode->i_mtime = current_fs_time(inode->i_sb);
|
|
ret = written;
|
|
}
|
|
up(&tty->atomic_write);
|
|
return ret;
|
|
}
|
|
|
|
|
|
static ssize_t tty_write(struct file * file, const char __user * buf, size_t count,
|
|
loff_t *ppos)
|
|
{
|
|
struct tty_struct * tty;
|
|
struct inode *inode = file->f_dentry->d_inode;
|
|
ssize_t ret;
|
|
struct tty_ldisc *ld;
|
|
|
|
tty = (struct tty_struct *)file->private_data;
|
|
if (tty_paranoia_check(tty, inode, "tty_write"))
|
|
return -EIO;
|
|
if (!tty || !tty->driver->write || (test_bit(TTY_IO_ERROR, &tty->flags)))
|
|
return -EIO;
|
|
|
|
ld = tty_ldisc_ref_wait(tty);
|
|
if (!ld->write)
|
|
ret = -EIO;
|
|
else
|
|
ret = do_tty_write(ld->write, tty, file, buf, count);
|
|
tty_ldisc_deref(ld);
|
|
return ret;
|
|
}
|
|
|
|
ssize_t redirected_tty_write(struct file * file, const char __user * buf, size_t count,
|
|
loff_t *ppos)
|
|
{
|
|
struct file *p = NULL;
|
|
|
|
spin_lock(&redirect_lock);
|
|
if (redirect) {
|
|
get_file(redirect);
|
|
p = redirect;
|
|
}
|
|
spin_unlock(&redirect_lock);
|
|
|
|
if (p) {
|
|
ssize_t res;
|
|
res = vfs_write(p, buf, count, &p->f_pos);
|
|
fput(p);
|
|
return res;
|
|
}
|
|
|
|
return tty_write(file, buf, count, ppos);
|
|
}
|
|
|
|
static char ptychar[] = "pqrstuvwxyzabcde";
|
|
|
|
static inline void pty_line_name(struct tty_driver *driver, int index, char *p)
|
|
{
|
|
int i = index + driver->name_base;
|
|
/* ->name is initialized to "ttyp", but "tty" is expected */
|
|
sprintf(p, "%s%c%x",
|
|
driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name,
|
|
ptychar[i >> 4 & 0xf], i & 0xf);
|
|
}
|
|
|
|
static inline void tty_line_name(struct tty_driver *driver, int index, char *p)
|
|
{
|
|
sprintf(p, "%s%d", driver->name, index + driver->name_base);
|
|
}
|
|
|
|
/*
|
|
* WSH 06/09/97: Rewritten to remove races and properly clean up after a
|
|
* failed open. The new code protects the open with a semaphore, so it's
|
|
* really quite straightforward. The semaphore locking can probably be
|
|
* relaxed for the (most common) case of reopening a tty.
|
|
*/
|
|
static int init_dev(struct tty_driver *driver, int idx,
|
|
struct tty_struct **ret_tty)
|
|
{
|
|
struct tty_struct *tty, *o_tty;
|
|
struct termios *tp, **tp_loc, *o_tp, **o_tp_loc;
|
|
struct termios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc;
|
|
int retval=0;
|
|
|
|
/* check whether we're reopening an existing tty */
|
|
if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
|
|
tty = devpts_get_tty(idx);
|
|
if (tty && driver->subtype == PTY_TYPE_MASTER)
|
|
tty = tty->link;
|
|
} else {
|
|
tty = driver->ttys[idx];
|
|
}
|
|
if (tty) goto fast_track;
|
|
|
|
/*
|
|
* First time open is complex, especially for PTY devices.
|
|
* This code guarantees that either everything succeeds and the
|
|
* TTY is ready for operation, or else the table slots are vacated
|
|
* and the allocated memory released. (Except that the termios
|
|
* and locked termios may be retained.)
|
|
*/
|
|
|
|
if (!try_module_get(driver->owner)) {
|
|
retval = -ENODEV;
|
|
goto end_init;
|
|
}
|
|
|
|
o_tty = NULL;
|
|
tp = o_tp = NULL;
|
|
ltp = o_ltp = NULL;
|
|
|
|
tty = alloc_tty_struct();
|
|
if(!tty)
|
|
goto fail_no_mem;
|
|
initialize_tty_struct(tty);
|
|
tty->driver = driver;
|
|
tty->index = idx;
|
|
tty_line_name(driver, idx, tty->name);
|
|
|
|
if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
|
|
tp_loc = &tty->termios;
|
|
ltp_loc = &tty->termios_locked;
|
|
} else {
|
|
tp_loc = &driver->termios[idx];
|
|
ltp_loc = &driver->termios_locked[idx];
|
|
}
|
|
|
|
if (!*tp_loc) {
|
|
tp = (struct termios *) kmalloc(sizeof(struct termios),
|
|
GFP_KERNEL);
|
|
if (!tp)
|
|
goto free_mem_out;
|
|
*tp = driver->init_termios;
|
|
}
|
|
|
|
if (!*ltp_loc) {
|
|
ltp = (struct termios *) kmalloc(sizeof(struct termios),
|
|
GFP_KERNEL);
|
|
if (!ltp)
|
|
goto free_mem_out;
|
|
memset(ltp, 0, sizeof(struct termios));
|
|
}
|
|
|
|
if (driver->type == TTY_DRIVER_TYPE_PTY) {
|
|
o_tty = alloc_tty_struct();
|
|
if (!o_tty)
|
|
goto free_mem_out;
|
|
initialize_tty_struct(o_tty);
|
|
o_tty->driver = driver->other;
|
|
o_tty->index = idx;
|
|
tty_line_name(driver->other, idx, o_tty->name);
|
|
|
|
if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
|
|
o_tp_loc = &o_tty->termios;
|
|
o_ltp_loc = &o_tty->termios_locked;
|
|
} else {
|
|
o_tp_loc = &driver->other->termios[idx];
|
|
o_ltp_loc = &driver->other->termios_locked[idx];
|
|
}
|
|
|
|
if (!*o_tp_loc) {
|
|
o_tp = (struct termios *)
|
|
kmalloc(sizeof(struct termios), GFP_KERNEL);
|
|
if (!o_tp)
|
|
goto free_mem_out;
|
|
*o_tp = driver->other->init_termios;
|
|
}
|
|
|
|
if (!*o_ltp_loc) {
|
|
o_ltp = (struct termios *)
|
|
kmalloc(sizeof(struct termios), GFP_KERNEL);
|
|
if (!o_ltp)
|
|
goto free_mem_out;
|
|
memset(o_ltp, 0, sizeof(struct termios));
|
|
}
|
|
|
|
/*
|
|
* Everything allocated ... set up the o_tty structure.
|
|
*/
|
|
if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) {
|
|
driver->other->ttys[idx] = o_tty;
|
|
}
|
|
if (!*o_tp_loc)
|
|
*o_tp_loc = o_tp;
|
|
if (!*o_ltp_loc)
|
|
*o_ltp_loc = o_ltp;
|
|
o_tty->termios = *o_tp_loc;
|
|
o_tty->termios_locked = *o_ltp_loc;
|
|
driver->other->refcount++;
|
|
if (driver->subtype == PTY_TYPE_MASTER)
|
|
o_tty->count++;
|
|
|
|
/* Establish the links in both directions */
|
|
tty->link = o_tty;
|
|
o_tty->link = tty;
|
|
}
|
|
|
|
/*
|
|
* All structures have been allocated, so now we install them.
|
|
* Failures after this point use release_mem to clean up, so
|
|
* there's no need to null out the local pointers.
|
|
*/
|
|
if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
|
|
driver->ttys[idx] = tty;
|
|
}
|
|
|
|
if (!*tp_loc)
|
|
*tp_loc = tp;
|
|
if (!*ltp_loc)
|
|
*ltp_loc = ltp;
|
|
tty->termios = *tp_loc;
|
|
tty->termios_locked = *ltp_loc;
|
|
driver->refcount++;
|
|
tty->count++;
|
|
|
|
/*
|
|
* Structures all installed ... call the ldisc open routines.
|
|
* If we fail here just call release_mem to clean up. No need
|
|
* to decrement the use counts, as release_mem doesn't care.
|
|
*/
|
|
|
|
if (tty->ldisc.open) {
|
|
retval = (tty->ldisc.open)(tty);
|
|
if (retval)
|
|
goto release_mem_out;
|
|
}
|
|
if (o_tty && o_tty->ldisc.open) {
|
|
retval = (o_tty->ldisc.open)(o_tty);
|
|
if (retval) {
|
|
if (tty->ldisc.close)
|
|
(tty->ldisc.close)(tty);
|
|
goto release_mem_out;
|
|
}
|
|
tty_ldisc_enable(o_tty);
|
|
}
|
|
tty_ldisc_enable(tty);
|
|
goto success;
|
|
|
|
/*
|
|
* This fast open can be used if the tty is already open.
|
|
* No memory is allocated, and the only failures are from
|
|
* attempting to open a closing tty or attempting multiple
|
|
* opens on a pty master.
|
|
*/
|
|
fast_track:
|
|
if (test_bit(TTY_CLOSING, &tty->flags)) {
|
|
retval = -EIO;
|
|
goto end_init;
|
|
}
|
|
if (driver->type == TTY_DRIVER_TYPE_PTY &&
|
|
driver->subtype == PTY_TYPE_MASTER) {
|
|
/*
|
|
* special case for PTY masters: only one open permitted,
|
|
* and the slave side open count is incremented as well.
|
|
*/
|
|
if (tty->count) {
|
|
retval = -EIO;
|
|
goto end_init;
|
|
}
|
|
tty->link->count++;
|
|
}
|
|
tty->count++;
|
|
tty->driver = driver; /* N.B. why do this every time?? */
|
|
|
|
/* FIXME */
|
|
if(!test_bit(TTY_LDISC, &tty->flags))
|
|
printk(KERN_ERR "init_dev but no ldisc\n");
|
|
success:
|
|
*ret_tty = tty;
|
|
|
|
/* All paths come through here to release the semaphore */
|
|
end_init:
|
|
return retval;
|
|
|
|
/* Release locally allocated memory ... nothing placed in slots */
|
|
free_mem_out:
|
|
if (o_tp)
|
|
kfree(o_tp);
|
|
if (o_tty)
|
|
free_tty_struct(o_tty);
|
|
if (ltp)
|
|
kfree(ltp);
|
|
if (tp)
|
|
kfree(tp);
|
|
free_tty_struct(tty);
|
|
|
|
fail_no_mem:
|
|
module_put(driver->owner);
|
|
retval = -ENOMEM;
|
|
goto end_init;
|
|
|
|
/* call the tty release_mem routine to clean out this slot */
|
|
release_mem_out:
|
|
printk(KERN_INFO "init_dev: ldisc open failed, "
|
|
"clearing slot %d\n", idx);
|
|
release_mem(tty, idx);
|
|
goto end_init;
|
|
}
|
|
|
|
/*
|
|
* Releases memory associated with a tty structure, and clears out the
|
|
* driver table slots.
|
|
*/
|
|
static void release_mem(struct tty_struct *tty, int idx)
|
|
{
|
|
struct tty_struct *o_tty;
|
|
struct termios *tp;
|
|
int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM;
|
|
|
|
if ((o_tty = tty->link) != NULL) {
|
|
if (!devpts)
|
|
o_tty->driver->ttys[idx] = NULL;
|
|
if (o_tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
|
|
tp = o_tty->termios;
|
|
if (!devpts)
|
|
o_tty->driver->termios[idx] = NULL;
|
|
kfree(tp);
|
|
|
|
tp = o_tty->termios_locked;
|
|
if (!devpts)
|
|
o_tty->driver->termios_locked[idx] = NULL;
|
|
kfree(tp);
|
|
}
|
|
o_tty->magic = 0;
|
|
o_tty->driver->refcount--;
|
|
file_list_lock();
|
|
list_del_init(&o_tty->tty_files);
|
|
file_list_unlock();
|
|
free_tty_struct(o_tty);
|
|
}
|
|
|
|
if (!devpts)
|
|
tty->driver->ttys[idx] = NULL;
|
|
if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
|
|
tp = tty->termios;
|
|
if (!devpts)
|
|
tty->driver->termios[idx] = NULL;
|
|
kfree(tp);
|
|
|
|
tp = tty->termios_locked;
|
|
if (!devpts)
|
|
tty->driver->termios_locked[idx] = NULL;
|
|
kfree(tp);
|
|
}
|
|
|
|
tty->magic = 0;
|
|
tty->driver->refcount--;
|
|
file_list_lock();
|
|
list_del_init(&tty->tty_files);
|
|
file_list_unlock();
|
|
module_put(tty->driver->owner);
|
|
free_tty_struct(tty);
|
|
}
|
|
|
|
/*
|
|
* Even releasing the tty structures is a tricky business.. We have
|
|
* to be very careful that the structures are all released at the
|
|
* same time, as interrupts might otherwise get the wrong pointers.
|
|
*
|
|
* WSH 09/09/97: rewritten to avoid some nasty race conditions that could
|
|
* lead to double frees or releasing memory still in use.
|
|
*/
|
|
static void release_dev(struct file * filp)
|
|
{
|
|
struct tty_struct *tty, *o_tty;
|
|
int pty_master, tty_closing, o_tty_closing, do_sleep;
|
|
int devpts_master, devpts;
|
|
int idx;
|
|
char buf[64];
|
|
unsigned long flags;
|
|
|
|
tty = (struct tty_struct *)filp->private_data;
|
|
if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "release_dev"))
|
|
return;
|
|
|
|
check_tty_count(tty, "release_dev");
|
|
|
|
tty_fasync(-1, filp, 0);
|
|
|
|
idx = tty->index;
|
|
pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
|
|
tty->driver->subtype == PTY_TYPE_MASTER);
|
|
devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0;
|
|
devpts_master = pty_master && devpts;
|
|
o_tty = tty->link;
|
|
|
|
#ifdef TTY_PARANOIA_CHECK
|
|
if (idx < 0 || idx >= tty->driver->num) {
|
|
printk(KERN_DEBUG "release_dev: bad idx when trying to "
|
|
"free (%s)\n", tty->name);
|
|
return;
|
|
}
|
|
if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
|
|
if (tty != tty->driver->ttys[idx]) {
|
|
printk(KERN_DEBUG "release_dev: driver.table[%d] not tty "
|
|
"for (%s)\n", idx, tty->name);
|
|
return;
|
|
}
|
|
if (tty->termios != tty->driver->termios[idx]) {
|
|
printk(KERN_DEBUG "release_dev: driver.termios[%d] not termios "
|
|
"for (%s)\n",
|
|
idx, tty->name);
|
|
return;
|
|
}
|
|
if (tty->termios_locked != tty->driver->termios_locked[idx]) {
|
|
printk(KERN_DEBUG "release_dev: driver.termios_locked[%d] not "
|
|
"termios_locked for (%s)\n",
|
|
idx, tty->name);
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifdef TTY_DEBUG_HANGUP
|
|
printk(KERN_DEBUG "release_dev of %s (tty count=%d)...",
|
|
tty_name(tty, buf), tty->count);
|
|
#endif
|
|
|
|
#ifdef TTY_PARANOIA_CHECK
|
|
if (tty->driver->other &&
|
|
!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
|
|
if (o_tty != tty->driver->other->ttys[idx]) {
|
|
printk(KERN_DEBUG "release_dev: other->table[%d] "
|
|
"not o_tty for (%s)\n",
|
|
idx, tty->name);
|
|
return;
|
|
}
|
|
if (o_tty->termios != tty->driver->other->termios[idx]) {
|
|
printk(KERN_DEBUG "release_dev: other->termios[%d] "
|
|
"not o_termios for (%s)\n",
|
|
idx, tty->name);
|
|
return;
|
|
}
|
|
if (o_tty->termios_locked !=
|
|
tty->driver->other->termios_locked[idx]) {
|
|
printk(KERN_DEBUG "release_dev: other->termios_locked["
|
|
"%d] not o_termios_locked for (%s)\n",
|
|
idx, tty->name);
|
|
return;
|
|
}
|
|
if (o_tty->link != tty) {
|
|
printk(KERN_DEBUG "release_dev: bad pty pointers\n");
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
if (tty->driver->close)
|
|
tty->driver->close(tty, filp);
|
|
|
|
/*
|
|
* Sanity check: if tty->count is going to zero, there shouldn't be
|
|
* any waiters on tty->read_wait or tty->write_wait. We test the
|
|
* wait queues and kick everyone out _before_ actually starting to
|
|
* close. This ensures that we won't block while releasing the tty
|
|
* structure.
|
|
*
|
|
* The test for the o_tty closing is necessary, since the master and
|
|
* slave sides may close in any order. If the slave side closes out
|
|
* first, its count will be one, since the master side holds an open.
|
|
* Thus this test wouldn't be triggered at the time the slave closes,
|
|
* so we do it now.
|
|
*
|
|
* Note that it's possible for the tty to be opened again while we're
|
|
* flushing out waiters. By recalculating the closing flags before
|
|
* each iteration we avoid any problems.
|
|
*/
|
|
while (1) {
|
|
/* Guard against races with tty->count changes elsewhere and
|
|
opens on /dev/tty */
|
|
|
|
down(&tty_sem);
|
|
tty_closing = tty->count <= 1;
|
|
o_tty_closing = o_tty &&
|
|
(o_tty->count <= (pty_master ? 1 : 0));
|
|
up(&tty_sem);
|
|
do_sleep = 0;
|
|
|
|
if (tty_closing) {
|
|
if (waitqueue_active(&tty->read_wait)) {
|
|
wake_up(&tty->read_wait);
|
|
do_sleep++;
|
|
}
|
|
if (waitqueue_active(&tty->write_wait)) {
|
|
wake_up(&tty->write_wait);
|
|
do_sleep++;
|
|
}
|
|
}
|
|
if (o_tty_closing) {
|
|
if (waitqueue_active(&o_tty->read_wait)) {
|
|
wake_up(&o_tty->read_wait);
|
|
do_sleep++;
|
|
}
|
|
if (waitqueue_active(&o_tty->write_wait)) {
|
|
wake_up(&o_tty->write_wait);
|
|
do_sleep++;
|
|
}
|
|
}
|
|
if (!do_sleep)
|
|
break;
|
|
|
|
printk(KERN_WARNING "release_dev: %s: read/write wait queue "
|
|
"active!\n", tty_name(tty, buf));
|
|
schedule();
|
|
}
|
|
|
|
/*
|
|
* The closing flags are now consistent with the open counts on
|
|
* both sides, and we've completed the last operation that could
|
|
* block, so it's safe to proceed with closing.
|
|
*/
|
|
|
|
down(&tty_sem);
|
|
if (pty_master) {
|
|
if (--o_tty->count < 0) {
|
|
printk(KERN_WARNING "release_dev: bad pty slave count "
|
|
"(%d) for %s\n",
|
|
o_tty->count, tty_name(o_tty, buf));
|
|
o_tty->count = 0;
|
|
}
|
|
}
|
|
if (--tty->count < 0) {
|
|
printk(KERN_WARNING "release_dev: bad tty->count (%d) for %s\n",
|
|
tty->count, tty_name(tty, buf));
|
|
tty->count = 0;
|
|
}
|
|
up(&tty_sem);
|
|
|
|
/*
|
|
* We've decremented tty->count, so we need to remove this file
|
|
* descriptor off the tty->tty_files list; this serves two
|
|
* purposes:
|
|
* - check_tty_count sees the correct number of file descriptors
|
|
* associated with this tty.
|
|
* - do_tty_hangup no longer sees this file descriptor as
|
|
* something that needs to be handled for hangups.
|
|
*/
|
|
file_kill(filp);
|
|
filp->private_data = NULL;
|
|
|
|
/*
|
|
* Perform some housekeeping before deciding whether to return.
|
|
*
|
|
* Set the TTY_CLOSING flag if this was the last open. In the
|
|
* case of a pty we may have to wait around for the other side
|
|
* to close, and TTY_CLOSING makes sure we can't be reopened.
|
|
*/
|
|
if(tty_closing)
|
|
set_bit(TTY_CLOSING, &tty->flags);
|
|
if(o_tty_closing)
|
|
set_bit(TTY_CLOSING, &o_tty->flags);
|
|
|
|
/*
|
|
* If _either_ side is closing, make sure there aren't any
|
|
* processes that still think tty or o_tty is their controlling
|
|
* tty.
|
|
*/
|
|
if (tty_closing || o_tty_closing) {
|
|
struct task_struct *p;
|
|
|
|
read_lock(&tasklist_lock);
|
|
do_each_task_pid(tty->session, PIDTYPE_SID, p) {
|
|
p->signal->tty = NULL;
|
|
} while_each_task_pid(tty->session, PIDTYPE_SID, p);
|
|
if (o_tty)
|
|
do_each_task_pid(o_tty->session, PIDTYPE_SID, p) {
|
|
p->signal->tty = NULL;
|
|
} while_each_task_pid(o_tty->session, PIDTYPE_SID, p);
|
|
read_unlock(&tasklist_lock);
|
|
}
|
|
|
|
/* check whether both sides are closing ... */
|
|
if (!tty_closing || (o_tty && !o_tty_closing))
|
|
return;
|
|
|
|
#ifdef TTY_DEBUG_HANGUP
|
|
printk(KERN_DEBUG "freeing tty structure...");
|
|
#endif
|
|
/*
|
|
* Prevent flush_to_ldisc() from rescheduling the work for later. Then
|
|
* kill any delayed work. As this is the final close it does not
|
|
* race with the set_ldisc code path.
|
|
*/
|
|
clear_bit(TTY_LDISC, &tty->flags);
|
|
clear_bit(TTY_DONT_FLIP, &tty->flags);
|
|
cancel_delayed_work(&tty->flip.work);
|
|
|
|
/*
|
|
* Wait for ->hangup_work and ->flip.work handlers to terminate
|
|
*/
|
|
|
|
flush_scheduled_work();
|
|
|
|
/*
|
|
* Wait for any short term users (we know they are just driver
|
|
* side waiters as the file is closing so user count on the file
|
|
* side is zero.
|
|
*/
|
|
spin_lock_irqsave(&tty_ldisc_lock, flags);
|
|
while(tty->ldisc.refcount)
|
|
{
|
|
spin_unlock_irqrestore(&tty_ldisc_lock, flags);
|
|
wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0);
|
|
spin_lock_irqsave(&tty_ldisc_lock, flags);
|
|
}
|
|
spin_unlock_irqrestore(&tty_ldisc_lock, flags);
|
|
/*
|
|
* Shutdown the current line discipline, and reset it to N_TTY.
|
|
* N.B. why reset ldisc when we're releasing the memory??
|
|
*
|
|
* FIXME: this MUST get fixed for the new reflocking
|
|
*/
|
|
if (tty->ldisc.close)
|
|
(tty->ldisc.close)(tty);
|
|
tty_ldisc_put(tty->ldisc.num);
|
|
|
|
/*
|
|
* Switch the line discipline back
|
|
*/
|
|
tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
|
|
tty_set_termios_ldisc(tty,N_TTY);
|
|
if (o_tty) {
|
|
/* FIXME: could o_tty be in setldisc here ? */
|
|
clear_bit(TTY_LDISC, &o_tty->flags);
|
|
if (o_tty->ldisc.close)
|
|
(o_tty->ldisc.close)(o_tty);
|
|
tty_ldisc_put(o_tty->ldisc.num);
|
|
tty_ldisc_assign(o_tty, tty_ldisc_get(N_TTY));
|
|
tty_set_termios_ldisc(o_tty,N_TTY);
|
|
}
|
|
/*
|
|
* The release_mem function takes care of the details of clearing
|
|
* the slots and preserving the termios structure.
|
|
*/
|
|
release_mem(tty, idx);
|
|
|
|
#ifdef CONFIG_UNIX98_PTYS
|
|
/* Make this pty number available for reallocation */
|
|
if (devpts) {
|
|
down(&allocated_ptys_lock);
|
|
idr_remove(&allocated_ptys, idx);
|
|
up(&allocated_ptys_lock);
|
|
}
|
|
#endif
|
|
|
|
}
|
|
|
|
/*
|
|
* tty_open and tty_release keep up the tty count that contains the
|
|
* number of opens done on a tty. We cannot use the inode-count, as
|
|
* different inodes might point to the same tty.
|
|
*
|
|
* Open-counting is needed for pty masters, as well as for keeping
|
|
* track of serial lines: DTR is dropped when the last close happens.
|
|
* (This is not done solely through tty->count, now. - Ted 1/27/92)
|
|
*
|
|
* The termios state of a pty is reset on first open so that
|
|
* settings don't persist across reuse.
|
|
*/
|
|
static int tty_open(struct inode * inode, struct file * filp)
|
|
{
|
|
struct tty_struct *tty;
|
|
int noctty, retval;
|
|
struct tty_driver *driver;
|
|
int index;
|
|
dev_t device = inode->i_rdev;
|
|
unsigned short saved_flags = filp->f_flags;
|
|
|
|
nonseekable_open(inode, filp);
|
|
|
|
retry_open:
|
|
noctty = filp->f_flags & O_NOCTTY;
|
|
index = -1;
|
|
retval = 0;
|
|
|
|
down(&tty_sem);
|
|
|
|
if (device == MKDEV(TTYAUX_MAJOR,0)) {
|
|
if (!current->signal->tty) {
|
|
up(&tty_sem);
|
|
return -ENXIO;
|
|
}
|
|
driver = current->signal->tty->driver;
|
|
index = current->signal->tty->index;
|
|
filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
|
|
/* noctty = 1; */
|
|
goto got_driver;
|
|
}
|
|
#ifdef CONFIG_VT
|
|
if (device == MKDEV(TTY_MAJOR,0)) {
|
|
extern struct tty_driver *console_driver;
|
|
driver = console_driver;
|
|
index = fg_console;
|
|
noctty = 1;
|
|
goto got_driver;
|
|
}
|
|
#endif
|
|
if (device == MKDEV(TTYAUX_MAJOR,1)) {
|
|
driver = console_device(&index);
|
|
if (driver) {
|
|
/* Don't let /dev/console block */
|
|
filp->f_flags |= O_NONBLOCK;
|
|
noctty = 1;
|
|
goto got_driver;
|
|
}
|
|
up(&tty_sem);
|
|
return -ENODEV;
|
|
}
|
|
|
|
driver = get_tty_driver(device, &index);
|
|
if (!driver) {
|
|
up(&tty_sem);
|
|
return -ENODEV;
|
|
}
|
|
got_driver:
|
|
retval = init_dev(driver, index, &tty);
|
|
up(&tty_sem);
|
|
if (retval)
|
|
return retval;
|
|
|
|
filp->private_data = tty;
|
|
file_move(filp, &tty->tty_files);
|
|
check_tty_count(tty, "tty_open");
|
|
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
|
|
tty->driver->subtype == PTY_TYPE_MASTER)
|
|
noctty = 1;
|
|
#ifdef TTY_DEBUG_HANGUP
|
|
printk(KERN_DEBUG "opening %s...", tty->name);
|
|
#endif
|
|
if (!retval) {
|
|
if (tty->driver->open)
|
|
retval = tty->driver->open(tty, filp);
|
|
else
|
|
retval = -ENODEV;
|
|
}
|
|
filp->f_flags = saved_flags;
|
|
|
|
if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN))
|
|
retval = -EBUSY;
|
|
|
|
if (retval) {
|
|
#ifdef TTY_DEBUG_HANGUP
|
|
printk(KERN_DEBUG "error %d in opening %s...", retval,
|
|
tty->name);
|
|
#endif
|
|
release_dev(filp);
|
|
if (retval != -ERESTARTSYS)
|
|
return retval;
|
|
if (signal_pending(current))
|
|
return retval;
|
|
schedule();
|
|
/*
|
|
* Need to reset f_op in case a hangup happened.
|
|
*/
|
|
if (filp->f_op == &hung_up_tty_fops)
|
|
filp->f_op = &tty_fops;
|
|
goto retry_open;
|
|
}
|
|
if (!noctty &&
|
|
current->signal->leader &&
|
|
!current->signal->tty &&
|
|
tty->session == 0) {
|
|
task_lock(current);
|
|
current->signal->tty = tty;
|
|
task_unlock(current);
|
|
current->signal->tty_old_pgrp = 0;
|
|
tty->session = current->signal->session;
|
|
tty->pgrp = process_group(current);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_UNIX98_PTYS
|
|
static int ptmx_open(struct inode * inode, struct file * filp)
|
|
{
|
|
struct tty_struct *tty;
|
|
int retval;
|
|
int index;
|
|
int idr_ret;
|
|
|
|
nonseekable_open(inode, filp);
|
|
|
|
/* find a device that is not in use. */
|
|
down(&allocated_ptys_lock);
|
|
if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) {
|
|
up(&allocated_ptys_lock);
|
|
return -ENOMEM;
|
|
}
|
|
idr_ret = idr_get_new(&allocated_ptys, NULL, &index);
|
|
if (idr_ret < 0) {
|
|
up(&allocated_ptys_lock);
|
|
if (idr_ret == -EAGAIN)
|
|
return -ENOMEM;
|
|
return -EIO;
|
|
}
|
|
if (index >= pty_limit) {
|
|
idr_remove(&allocated_ptys, index);
|
|
up(&allocated_ptys_lock);
|
|
return -EIO;
|
|
}
|
|
up(&allocated_ptys_lock);
|
|
|
|
down(&tty_sem);
|
|
retval = init_dev(ptm_driver, index, &tty);
|
|
up(&tty_sem);
|
|
|
|
if (retval)
|
|
goto out;
|
|
|
|
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
|
|
filp->private_data = tty;
|
|
file_move(filp, &tty->tty_files);
|
|
|
|
retval = -ENOMEM;
|
|
if (devpts_pty_new(tty->link))
|
|
goto out1;
|
|
|
|
check_tty_count(tty, "tty_open");
|
|
retval = ptm_driver->open(tty, filp);
|
|
if (!retval)
|
|
return 0;
|
|
out1:
|
|
release_dev(filp);
|
|
out:
|
|
down(&allocated_ptys_lock);
|
|
idr_remove(&allocated_ptys, index);
|
|
up(&allocated_ptys_lock);
|
|
return retval;
|
|
}
|
|
#endif
|
|
|
|
static int tty_release(struct inode * inode, struct file * filp)
|
|
{
|
|
lock_kernel();
|
|
release_dev(filp);
|
|
unlock_kernel();
|
|
return 0;
|
|
}
|
|
|
|
/* No kernel lock held - fine */
|
|
static unsigned int tty_poll(struct file * filp, poll_table * wait)
|
|
{
|
|
struct tty_struct * tty;
|
|
struct tty_ldisc *ld;
|
|
int ret = 0;
|
|
|
|
tty = (struct tty_struct *)filp->private_data;
|
|
if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_poll"))
|
|
return 0;
|
|
|
|
ld = tty_ldisc_ref_wait(tty);
|
|
if (ld->poll)
|
|
ret = (ld->poll)(tty, filp, wait);
|
|
tty_ldisc_deref(ld);
|
|
return ret;
|
|
}
|
|
|
|
static int tty_fasync(int fd, struct file * filp, int on)
|
|
{
|
|
struct tty_struct * tty;
|
|
int retval;
|
|
|
|
tty = (struct tty_struct *)filp->private_data;
|
|
if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_fasync"))
|
|
return 0;
|
|
|
|
retval = fasync_helper(fd, filp, on, &tty->fasync);
|
|
if (retval <= 0)
|
|
return retval;
|
|
|
|
if (on) {
|
|
if (!waitqueue_active(&tty->read_wait))
|
|
tty->minimum_to_wake = 1;
|
|
retval = f_setown(filp, (-tty->pgrp) ? : current->pid, 0);
|
|
if (retval)
|
|
return retval;
|
|
} else {
|
|
if (!tty->fasync && !waitqueue_active(&tty->read_wait))
|
|
tty->minimum_to_wake = N_TTY_BUF_SIZE;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int tiocsti(struct tty_struct *tty, char __user *p)
|
|
{
|
|
char ch, mbz = 0;
|
|
struct tty_ldisc *ld;
|
|
|
|
if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
if (get_user(ch, p))
|
|
return -EFAULT;
|
|
ld = tty_ldisc_ref_wait(tty);
|
|
ld->receive_buf(tty, &ch, &mbz, 1);
|
|
tty_ldisc_deref(ld);
|
|
return 0;
|
|
}
|
|
|
|
static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg)
|
|
{
|
|
if (copy_to_user(arg, &tty->winsize, sizeof(*arg)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty,
|
|
struct winsize __user * arg)
|
|
{
|
|
struct winsize tmp_ws;
|
|
|
|
if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
|
|
return -EFAULT;
|
|
if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg)))
|
|
return 0;
|
|
#ifdef CONFIG_VT
|
|
if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) {
|
|
int rc;
|
|
|
|
acquire_console_sem();
|
|
rc = vc_resize(tty->driver_data, tmp_ws.ws_col, tmp_ws.ws_row);
|
|
release_console_sem();
|
|
if (rc)
|
|
return -ENXIO;
|
|
}
|
|
#endif
|
|
if (tty->pgrp > 0)
|
|
kill_pg(tty->pgrp, SIGWINCH, 1);
|
|
if ((real_tty->pgrp != tty->pgrp) && (real_tty->pgrp > 0))
|
|
kill_pg(real_tty->pgrp, SIGWINCH, 1);
|
|
tty->winsize = tmp_ws;
|
|
real_tty->winsize = tmp_ws;
|
|
return 0;
|
|
}
|
|
|
|
static int tioccons(struct file *file)
|
|
{
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
if (file->f_op->write == redirected_tty_write) {
|
|
struct file *f;
|
|
spin_lock(&redirect_lock);
|
|
f = redirect;
|
|
redirect = NULL;
|
|
spin_unlock(&redirect_lock);
|
|
if (f)
|
|
fput(f);
|
|
return 0;
|
|
}
|
|
spin_lock(&redirect_lock);
|
|
if (redirect) {
|
|
spin_unlock(&redirect_lock);
|
|
return -EBUSY;
|
|
}
|
|
get_file(file);
|
|
redirect = file;
|
|
spin_unlock(&redirect_lock);
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int fionbio(struct file *file, int __user *p)
|
|
{
|
|
int nonblock;
|
|
|
|
if (get_user(nonblock, p))
|
|
return -EFAULT;
|
|
|
|
if (nonblock)
|
|
file->f_flags |= O_NONBLOCK;
|
|
else
|
|
file->f_flags &= ~O_NONBLOCK;
|
|
return 0;
|
|
}
|
|
|
|
static int tiocsctty(struct tty_struct *tty, int arg)
|
|
{
|
|
task_t *p;
|
|
|
|
if (current->signal->leader &&
|
|
(current->signal->session == tty->session))
|
|
return 0;
|
|
/*
|
|
* The process must be a session leader and
|
|
* not have a controlling tty already.
|
|
*/
|
|
if (!current->signal->leader || current->signal->tty)
|
|
return -EPERM;
|
|
if (tty->session > 0) {
|
|
/*
|
|
* This tty is already the controlling
|
|
* tty for another session group!
|
|
*/
|
|
if ((arg == 1) && capable(CAP_SYS_ADMIN)) {
|
|
/*
|
|
* Steal it away
|
|
*/
|
|
|
|
read_lock(&tasklist_lock);
|
|
do_each_task_pid(tty->session, PIDTYPE_SID, p) {
|
|
p->signal->tty = NULL;
|
|
} while_each_task_pid(tty->session, PIDTYPE_SID, p);
|
|
read_unlock(&tasklist_lock);
|
|
} else
|
|
return -EPERM;
|
|
}
|
|
task_lock(current);
|
|
current->signal->tty = tty;
|
|
task_unlock(current);
|
|
current->signal->tty_old_pgrp = 0;
|
|
tty->session = current->signal->session;
|
|
tty->pgrp = process_group(current);
|
|
return 0;
|
|
}
|
|
|
|
static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
|
|
{
|
|
/*
|
|
* (tty == real_tty) is a cheap way of
|
|
* testing if the tty is NOT a master pty.
|
|
*/
|
|
if (tty == real_tty && current->signal->tty != real_tty)
|
|
return -ENOTTY;
|
|
return put_user(real_tty->pgrp, p);
|
|
}
|
|
|
|
static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
|
|
{
|
|
pid_t pgrp;
|
|
int retval = tty_check_change(real_tty);
|
|
|
|
if (retval == -EIO)
|
|
return -ENOTTY;
|
|
if (retval)
|
|
return retval;
|
|
if (!current->signal->tty ||
|
|
(current->signal->tty != real_tty) ||
|
|
(real_tty->session != current->signal->session))
|
|
return -ENOTTY;
|
|
if (get_user(pgrp, p))
|
|
return -EFAULT;
|
|
if (pgrp < 0)
|
|
return -EINVAL;
|
|
if (session_of_pgrp(pgrp) != current->signal->session)
|
|
return -EPERM;
|
|
real_tty->pgrp = pgrp;
|
|
return 0;
|
|
}
|
|
|
|
static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
|
|
{
|
|
/*
|
|
* (tty == real_tty) is a cheap way of
|
|
* testing if the tty is NOT a master pty.
|
|
*/
|
|
if (tty == real_tty && current->signal->tty != real_tty)
|
|
return -ENOTTY;
|
|
if (real_tty->session <= 0)
|
|
return -ENOTTY;
|
|
return put_user(real_tty->session, p);
|
|
}
|
|
|
|
static int tiocsetd(struct tty_struct *tty, int __user *p)
|
|
{
|
|
int ldisc;
|
|
|
|
if (get_user(ldisc, p))
|
|
return -EFAULT;
|
|
return tty_set_ldisc(tty, ldisc);
|
|
}
|
|
|
|
static int send_break(struct tty_struct *tty, int duration)
|
|
{
|
|
tty->driver->break_ctl(tty, -1);
|
|
if (!signal_pending(current)) {
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
schedule_timeout(duration);
|
|
}
|
|
tty->driver->break_ctl(tty, 0);
|
|
if (signal_pending(current))
|
|
return -EINTR;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p)
|
|
{
|
|
int retval = -EINVAL;
|
|
|
|
if (tty->driver->tiocmget) {
|
|
retval = tty->driver->tiocmget(tty, file);
|
|
|
|
if (retval >= 0)
|
|
retval = put_user(retval, p);
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
static int
|
|
tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd,
|
|
unsigned __user *p)
|
|
{
|
|
int retval = -EINVAL;
|
|
|
|
if (tty->driver->tiocmset) {
|
|
unsigned int set, clear, val;
|
|
|
|
retval = get_user(val, p);
|
|
if (retval)
|
|
return retval;
|
|
|
|
set = clear = 0;
|
|
switch (cmd) {
|
|
case TIOCMBIS:
|
|
set = val;
|
|
break;
|
|
case TIOCMBIC:
|
|
clear = val;
|
|
break;
|
|
case TIOCMSET:
|
|
set = val;
|
|
clear = ~val;
|
|
break;
|
|
}
|
|
|
|
set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
|
|
clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
|
|
|
|
retval = tty->driver->tiocmset(tty, file, set, clear);
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Split this up, as gcc can choke on it otherwise..
|
|
*/
|
|
int tty_ioctl(struct inode * inode, struct file * file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct tty_struct *tty, *real_tty;
|
|
void __user *p = (void __user *)arg;
|
|
int retval;
|
|
struct tty_ldisc *ld;
|
|
|
|
tty = (struct tty_struct *)file->private_data;
|
|
if (tty_paranoia_check(tty, inode, "tty_ioctl"))
|
|
return -EINVAL;
|
|
|
|
real_tty = tty;
|
|
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
|
|
tty->driver->subtype == PTY_TYPE_MASTER)
|
|
real_tty = tty->link;
|
|
|
|
/*
|
|
* Break handling by driver
|
|
*/
|
|
if (!tty->driver->break_ctl) {
|
|
switch(cmd) {
|
|
case TIOCSBRK:
|
|
case TIOCCBRK:
|
|
if (tty->driver->ioctl)
|
|
return tty->driver->ioctl(tty, file, cmd, arg);
|
|
return -EINVAL;
|
|
|
|
/* These two ioctl's always return success; even if */
|
|
/* the driver doesn't support them. */
|
|
case TCSBRK:
|
|
case TCSBRKP:
|
|
if (!tty->driver->ioctl)
|
|
return 0;
|
|
retval = tty->driver->ioctl(tty, file, cmd, arg);
|
|
if (retval == -ENOIOCTLCMD)
|
|
retval = 0;
|
|
return retval;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Factor out some common prep work
|
|
*/
|
|
switch (cmd) {
|
|
case TIOCSETD:
|
|
case TIOCSBRK:
|
|
case TIOCCBRK:
|
|
case TCSBRK:
|
|
case TCSBRKP:
|
|
retval = tty_check_change(tty);
|
|
if (retval)
|
|
return retval;
|
|
if (cmd != TIOCCBRK) {
|
|
tty_wait_until_sent(tty, 0);
|
|
if (signal_pending(current))
|
|
return -EINTR;
|
|
}
|
|
break;
|
|
}
|
|
|
|
switch (cmd) {
|
|
case TIOCSTI:
|
|
return tiocsti(tty, p);
|
|
case TIOCGWINSZ:
|
|
return tiocgwinsz(tty, p);
|
|
case TIOCSWINSZ:
|
|
return tiocswinsz(tty, real_tty, p);
|
|
case TIOCCONS:
|
|
return real_tty!=tty ? -EINVAL : tioccons(file);
|
|
case FIONBIO:
|
|
return fionbio(file, p);
|
|
case TIOCEXCL:
|
|
set_bit(TTY_EXCLUSIVE, &tty->flags);
|
|
return 0;
|
|
case TIOCNXCL:
|
|
clear_bit(TTY_EXCLUSIVE, &tty->flags);
|
|
return 0;
|
|
case TIOCNOTTY:
|
|
if (current->signal->tty != tty)
|
|
return -ENOTTY;
|
|
if (current->signal->leader)
|
|
disassociate_ctty(0);
|
|
task_lock(current);
|
|
current->signal->tty = NULL;
|
|
task_unlock(current);
|
|
return 0;
|
|
case TIOCSCTTY:
|
|
return tiocsctty(tty, arg);
|
|
case TIOCGPGRP:
|
|
return tiocgpgrp(tty, real_tty, p);
|
|
case TIOCSPGRP:
|
|
return tiocspgrp(tty, real_tty, p);
|
|
case TIOCGSID:
|
|
return tiocgsid(tty, real_tty, p);
|
|
case TIOCGETD:
|
|
/* FIXME: check this is ok */
|
|
return put_user(tty->ldisc.num, (int __user *)p);
|
|
case TIOCSETD:
|
|
return tiocsetd(tty, p);
|
|
#ifdef CONFIG_VT
|
|
case TIOCLINUX:
|
|
return tioclinux(tty, arg);
|
|
#endif
|
|
/*
|
|
* Break handling
|
|
*/
|
|
case TIOCSBRK: /* Turn break on, unconditionally */
|
|
tty->driver->break_ctl(tty, -1);
|
|
return 0;
|
|
|
|
case TIOCCBRK: /* Turn break off, unconditionally */
|
|
tty->driver->break_ctl(tty, 0);
|
|
return 0;
|
|
case TCSBRK: /* SVID version: non-zero arg --> no break */
|
|
/*
|
|
* XXX is the above comment correct, or the
|
|
* code below correct? Is this ioctl used at
|
|
* all by anyone?
|
|
*/
|
|
if (!arg)
|
|
return send_break(tty, HZ/4);
|
|
return 0;
|
|
case TCSBRKP: /* support for POSIX tcsendbreak() */
|
|
return send_break(tty, arg ? arg*(HZ/10) : HZ/4);
|
|
|
|
case TIOCMGET:
|
|
return tty_tiocmget(tty, file, p);
|
|
|
|
case TIOCMSET:
|
|
case TIOCMBIC:
|
|
case TIOCMBIS:
|
|
return tty_tiocmset(tty, file, cmd, p);
|
|
}
|
|
if (tty->driver->ioctl) {
|
|
retval = (tty->driver->ioctl)(tty, file, cmd, arg);
|
|
if (retval != -ENOIOCTLCMD)
|
|
return retval;
|
|
}
|
|
ld = tty_ldisc_ref_wait(tty);
|
|
retval = -EINVAL;
|
|
if (ld->ioctl) {
|
|
retval = ld->ioctl(tty, file, cmd, arg);
|
|
if (retval == -ENOIOCTLCMD)
|
|
retval = -EINVAL;
|
|
}
|
|
tty_ldisc_deref(ld);
|
|
return retval;
|
|
}
|
|
|
|
|
|
/*
|
|
* This implements the "Secure Attention Key" --- the idea is to
|
|
* prevent trojan horses by killing all processes associated with this
|
|
* tty when the user hits the "Secure Attention Key". Required for
|
|
* super-paranoid applications --- see the Orange Book for more details.
|
|
*
|
|
* This code could be nicer; ideally it should send a HUP, wait a few
|
|
* seconds, then send a INT, and then a KILL signal. But you then
|
|
* have to coordinate with the init process, since all processes associated
|
|
* with the current tty must be dead before the new getty is allowed
|
|
* to spawn.
|
|
*
|
|
* Now, if it would be correct ;-/ The current code has a nasty hole -
|
|
* it doesn't catch files in flight. We may send the descriptor to ourselves
|
|
* via AF_UNIX socket, close it and later fetch from socket. FIXME.
|
|
*
|
|
* Nasty bug: do_SAK is being called in interrupt context. This can
|
|
* deadlock. We punt it up to process context. AKPM - 16Mar2001
|
|
*/
|
|
static void __do_SAK(void *arg)
|
|
{
|
|
#ifdef TTY_SOFT_SAK
|
|
tty_hangup(tty);
|
|
#else
|
|
struct tty_struct *tty = arg;
|
|
struct task_struct *p;
|
|
int session;
|
|
int i;
|
|
struct file *filp;
|
|
struct tty_ldisc *disc;
|
|
|
|
if (!tty)
|
|
return;
|
|
session = tty->session;
|
|
|
|
/* We don't want an ldisc switch during this */
|
|
disc = tty_ldisc_ref(tty);
|
|
if (disc && disc->flush_buffer)
|
|
disc->flush_buffer(tty);
|
|
tty_ldisc_deref(disc);
|
|
|
|
if (tty->driver->flush_buffer)
|
|
tty->driver->flush_buffer(tty);
|
|
|
|
read_lock(&tasklist_lock);
|
|
do_each_task_pid(session, PIDTYPE_SID, p) {
|
|
if (p->signal->tty == tty || session > 0) {
|
|
printk(KERN_NOTICE "SAK: killed process %d"
|
|
" (%s): p->signal->session==tty->session\n",
|
|
p->pid, p->comm);
|
|
send_sig(SIGKILL, p, 1);
|
|
continue;
|
|
}
|
|
task_lock(p);
|
|
if (p->files) {
|
|
spin_lock(&p->files->file_lock);
|
|
for (i=0; i < p->files->max_fds; i++) {
|
|
filp = fcheck_files(p->files, i);
|
|
if (!filp)
|
|
continue;
|
|
if (filp->f_op->read == tty_read &&
|
|
filp->private_data == tty) {
|
|
printk(KERN_NOTICE "SAK: killed process %d"
|
|
" (%s): fd#%d opened to the tty\n",
|
|
p->pid, p->comm, i);
|
|
send_sig(SIGKILL, p, 1);
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock(&p->files->file_lock);
|
|
}
|
|
task_unlock(p);
|
|
} while_each_task_pid(session, PIDTYPE_SID, p);
|
|
read_unlock(&tasklist_lock);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* The tq handling here is a little racy - tty->SAK_work may already be queued.
|
|
* Fortunately we don't need to worry, because if ->SAK_work is already queued,
|
|
* the values which we write to it will be identical to the values which it
|
|
* already has. --akpm
|
|
*/
|
|
void do_SAK(struct tty_struct *tty)
|
|
{
|
|
if (!tty)
|
|
return;
|
|
PREPARE_WORK(&tty->SAK_work, __do_SAK, tty);
|
|
schedule_work(&tty->SAK_work);
|
|
}
|
|
|
|
EXPORT_SYMBOL(do_SAK);
|
|
|
|
/*
|
|
* This routine is called out of the software interrupt to flush data
|
|
* from the flip buffer to the line discipline.
|
|
*/
|
|
|
|
static void flush_to_ldisc(void *private_)
|
|
{
|
|
struct tty_struct *tty = (struct tty_struct *) private_;
|
|
unsigned char *cp;
|
|
char *fp;
|
|
int count;
|
|
unsigned long flags;
|
|
struct tty_ldisc *disc;
|
|
|
|
disc = tty_ldisc_ref(tty);
|
|
if (disc == NULL) /* !TTY_LDISC */
|
|
return;
|
|
|
|
if (test_bit(TTY_DONT_FLIP, &tty->flags)) {
|
|
/*
|
|
* Do it after the next timer tick:
|
|
*/
|
|
schedule_delayed_work(&tty->flip.work, 1);
|
|
goto out;
|
|
}
|
|
spin_lock_irqsave(&tty->read_lock, flags);
|
|
if (tty->flip.buf_num) {
|
|
cp = tty->flip.char_buf + TTY_FLIPBUF_SIZE;
|
|
fp = tty->flip.flag_buf + TTY_FLIPBUF_SIZE;
|
|
tty->flip.buf_num = 0;
|
|
tty->flip.char_buf_ptr = tty->flip.char_buf;
|
|
tty->flip.flag_buf_ptr = tty->flip.flag_buf;
|
|
} else {
|
|
cp = tty->flip.char_buf;
|
|
fp = tty->flip.flag_buf;
|
|
tty->flip.buf_num = 1;
|
|
tty->flip.char_buf_ptr = tty->flip.char_buf + TTY_FLIPBUF_SIZE;
|
|
tty->flip.flag_buf_ptr = tty->flip.flag_buf + TTY_FLIPBUF_SIZE;
|
|
}
|
|
count = tty->flip.count;
|
|
tty->flip.count = 0;
|
|
spin_unlock_irqrestore(&tty->read_lock, flags);
|
|
|
|
disc->receive_buf(tty, cp, fp, count);
|
|
out:
|
|
tty_ldisc_deref(disc);
|
|
}
|
|
|
|
/*
|
|
* Routine which returns the baud rate of the tty
|
|
*
|
|
* Note that the baud_table needs to be kept in sync with the
|
|
* include/asm/termbits.h file.
|
|
*/
|
|
static int baud_table[] = {
|
|
0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
|
|
9600, 19200, 38400, 57600, 115200, 230400, 460800,
|
|
#ifdef __sparc__
|
|
76800, 153600, 307200, 614400, 921600
|
|
#else
|
|
500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
|
|
2500000, 3000000, 3500000, 4000000
|
|
#endif
|
|
};
|
|
|
|
static int n_baud_table = ARRAY_SIZE(baud_table);
|
|
|
|
/**
|
|
* tty_termios_baud_rate
|
|
* @termios: termios structure
|
|
*
|
|
* Convert termios baud rate data into a speed. This should be called
|
|
* with the termios lock held if this termios is a terminal termios
|
|
* structure. May change the termios data.
|
|
*/
|
|
|
|
int tty_termios_baud_rate(struct termios *termios)
|
|
{
|
|
unsigned int cbaud;
|
|
|
|
cbaud = termios->c_cflag & CBAUD;
|
|
|
|
if (cbaud & CBAUDEX) {
|
|
cbaud &= ~CBAUDEX;
|
|
|
|
if (cbaud < 1 || cbaud + 15 > n_baud_table)
|
|
termios->c_cflag &= ~CBAUDEX;
|
|
else
|
|
cbaud += 15;
|
|
}
|
|
return baud_table[cbaud];
|
|
}
|
|
|
|
EXPORT_SYMBOL(tty_termios_baud_rate);
|
|
|
|
/**
|
|
* tty_get_baud_rate - get tty bit rates
|
|
* @tty: tty to query
|
|
*
|
|
* Returns the baud rate as an integer for this terminal. The
|
|
* termios lock must be held by the caller and the terminal bit
|
|
* flags may be updated.
|
|
*/
|
|
|
|
int tty_get_baud_rate(struct tty_struct *tty)
|
|
{
|
|
int baud = tty_termios_baud_rate(tty->termios);
|
|
|
|
if (baud == 38400 && tty->alt_speed) {
|
|
if (!tty->warned) {
|
|
printk(KERN_WARNING "Use of setserial/setrocket to "
|
|
"set SPD_* flags is deprecated\n");
|
|
tty->warned = 1;
|
|
}
|
|
baud = tty->alt_speed;
|
|
}
|
|
|
|
return baud;
|
|
}
|
|
|
|
EXPORT_SYMBOL(tty_get_baud_rate);
|
|
|
|
/**
|
|
* tty_flip_buffer_push - terminal
|
|
* @tty: tty to push
|
|
*
|
|
* Queue a push of the terminal flip buffers to the line discipline. This
|
|
* function must not be called from IRQ context if tty->low_latency is set.
|
|
*
|
|
* In the event of the queue being busy for flipping the work will be
|
|
* held off and retried later.
|
|
*/
|
|
|
|
void tty_flip_buffer_push(struct tty_struct *tty)
|
|
{
|
|
if (tty->low_latency)
|
|
flush_to_ldisc((void *) tty);
|
|
else
|
|
schedule_delayed_work(&tty->flip.work, 1);
|
|
}
|
|
|
|
EXPORT_SYMBOL(tty_flip_buffer_push);
|
|
|
|
/*
|
|
* This subroutine initializes a tty structure.
|
|
*/
|
|
static void initialize_tty_struct(struct tty_struct *tty)
|
|
{
|
|
memset(tty, 0, sizeof(struct tty_struct));
|
|
tty->magic = TTY_MAGIC;
|
|
tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
|
|
tty->pgrp = -1;
|
|
tty->overrun_time = jiffies;
|
|
tty->flip.char_buf_ptr = tty->flip.char_buf;
|
|
tty->flip.flag_buf_ptr = tty->flip.flag_buf;
|
|
INIT_WORK(&tty->flip.work, flush_to_ldisc, tty);
|
|
init_MUTEX(&tty->flip.pty_sem);
|
|
init_MUTEX(&tty->termios_sem);
|
|
init_waitqueue_head(&tty->write_wait);
|
|
init_waitqueue_head(&tty->read_wait);
|
|
INIT_WORK(&tty->hangup_work, do_tty_hangup, tty);
|
|
sema_init(&tty->atomic_read, 1);
|
|
sema_init(&tty->atomic_write, 1);
|
|
spin_lock_init(&tty->read_lock);
|
|
INIT_LIST_HEAD(&tty->tty_files);
|
|
INIT_WORK(&tty->SAK_work, NULL, NULL);
|
|
}
|
|
|
|
/*
|
|
* The default put_char routine if the driver did not define one.
|
|
*/
|
|
static void tty_default_put_char(struct tty_struct *tty, unsigned char ch)
|
|
{
|
|
tty->driver->write(tty, &ch, 1);
|
|
}
|
|
|
|
static struct class_simple *tty_class;
|
|
|
|
/**
|
|
* tty_register_device - register a tty device
|
|
* @driver: the tty driver that describes the tty device
|
|
* @index: the index in the tty driver for this tty device
|
|
* @device: a struct device that is associated with this tty device.
|
|
* This field is optional, if there is no known struct device for this
|
|
* tty device it can be set to NULL safely.
|
|
*
|
|
* This call is required to be made to register an individual tty device if
|
|
* the tty driver's flags have the TTY_DRIVER_NO_DEVFS bit set. If that
|
|
* bit is not set, this function should not be called.
|
|
*/
|
|
void tty_register_device(struct tty_driver *driver, unsigned index,
|
|
struct device *device)
|
|
{
|
|
char name[64];
|
|
dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
|
|
|
|
if (index >= driver->num) {
|
|
printk(KERN_ERR "Attempt to register invalid tty line number "
|
|
" (%d).\n", index);
|
|
return;
|
|
}
|
|
|
|
devfs_mk_cdev(dev, S_IFCHR | S_IRUSR | S_IWUSR,
|
|
"%s%d", driver->devfs_name, index + driver->name_base);
|
|
|
|
if (driver->type == TTY_DRIVER_TYPE_PTY)
|
|
pty_line_name(driver, index, name);
|
|
else
|
|
tty_line_name(driver, index, name);
|
|
class_simple_device_add(tty_class, dev, device, name);
|
|
}
|
|
|
|
/**
|
|
* tty_unregister_device - unregister a tty device
|
|
* @driver: the tty driver that describes the tty device
|
|
* @index: the index in the tty driver for this tty device
|
|
*
|
|
* If a tty device is registered with a call to tty_register_device() then
|
|
* this function must be made when the tty device is gone.
|
|
*/
|
|
void tty_unregister_device(struct tty_driver *driver, unsigned index)
|
|
{
|
|
devfs_remove("%s%d", driver->devfs_name, index + driver->name_base);
|
|
class_simple_device_remove(MKDEV(driver->major, driver->minor_start) + index);
|
|
}
|
|
|
|
EXPORT_SYMBOL(tty_register_device);
|
|
EXPORT_SYMBOL(tty_unregister_device);
|
|
|
|
struct tty_driver *alloc_tty_driver(int lines)
|
|
{
|
|
struct tty_driver *driver;
|
|
|
|
driver = kmalloc(sizeof(struct tty_driver), GFP_KERNEL);
|
|
if (driver) {
|
|
memset(driver, 0, sizeof(struct tty_driver));
|
|
driver->magic = TTY_DRIVER_MAGIC;
|
|
driver->num = lines;
|
|
/* later we'll move allocation of tables here */
|
|
}
|
|
return driver;
|
|
}
|
|
|
|
void put_tty_driver(struct tty_driver *driver)
|
|
{
|
|
kfree(driver);
|
|
}
|
|
|
|
void tty_set_operations(struct tty_driver *driver, struct tty_operations *op)
|
|
{
|
|
driver->open = op->open;
|
|
driver->close = op->close;
|
|
driver->write = op->write;
|
|
driver->put_char = op->put_char;
|
|
driver->flush_chars = op->flush_chars;
|
|
driver->write_room = op->write_room;
|
|
driver->chars_in_buffer = op->chars_in_buffer;
|
|
driver->ioctl = op->ioctl;
|
|
driver->set_termios = op->set_termios;
|
|
driver->throttle = op->throttle;
|
|
driver->unthrottle = op->unthrottle;
|
|
driver->stop = op->stop;
|
|
driver->start = op->start;
|
|
driver->hangup = op->hangup;
|
|
driver->break_ctl = op->break_ctl;
|
|
driver->flush_buffer = op->flush_buffer;
|
|
driver->set_ldisc = op->set_ldisc;
|
|
driver->wait_until_sent = op->wait_until_sent;
|
|
driver->send_xchar = op->send_xchar;
|
|
driver->read_proc = op->read_proc;
|
|
driver->write_proc = op->write_proc;
|
|
driver->tiocmget = op->tiocmget;
|
|
driver->tiocmset = op->tiocmset;
|
|
}
|
|
|
|
|
|
EXPORT_SYMBOL(alloc_tty_driver);
|
|
EXPORT_SYMBOL(put_tty_driver);
|
|
EXPORT_SYMBOL(tty_set_operations);
|
|
|
|
/*
|
|
* Called by a tty driver to register itself.
|
|
*/
|
|
int tty_register_driver(struct tty_driver *driver)
|
|
{
|
|
int error;
|
|
int i;
|
|
dev_t dev;
|
|
void **p = NULL;
|
|
|
|
if (driver->flags & TTY_DRIVER_INSTALLED)
|
|
return 0;
|
|
|
|
if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
|
|
p = kmalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL);
|
|
if (!p)
|
|
return -ENOMEM;
|
|
memset(p, 0, driver->num * 3 * sizeof(void *));
|
|
}
|
|
|
|
if (!driver->major) {
|
|
error = alloc_chrdev_region(&dev, driver->minor_start, driver->num,
|
|
(char*)driver->name);
|
|
if (!error) {
|
|
driver->major = MAJOR(dev);
|
|
driver->minor_start = MINOR(dev);
|
|
}
|
|
} else {
|
|
dev = MKDEV(driver->major, driver->minor_start);
|
|
error = register_chrdev_region(dev, driver->num,
|
|
(char*)driver->name);
|
|
}
|
|
if (error < 0) {
|
|
kfree(p);
|
|
return error;
|
|
}
|
|
|
|
if (p) {
|
|
driver->ttys = (struct tty_struct **)p;
|
|
driver->termios = (struct termios **)(p + driver->num);
|
|
driver->termios_locked = (struct termios **)(p + driver->num * 2);
|
|
} else {
|
|
driver->ttys = NULL;
|
|
driver->termios = NULL;
|
|
driver->termios_locked = NULL;
|
|
}
|
|
|
|
cdev_init(&driver->cdev, &tty_fops);
|
|
driver->cdev.owner = driver->owner;
|
|
error = cdev_add(&driver->cdev, dev, driver->num);
|
|
if (error) {
|
|
cdev_del(&driver->cdev);
|
|
unregister_chrdev_region(dev, driver->num);
|
|
driver->ttys = NULL;
|
|
driver->termios = driver->termios_locked = NULL;
|
|
kfree(p);
|
|
return error;
|
|
}
|
|
|
|
if (!driver->put_char)
|
|
driver->put_char = tty_default_put_char;
|
|
|
|
list_add(&driver->tty_drivers, &tty_drivers);
|
|
|
|
if ( !(driver->flags & TTY_DRIVER_NO_DEVFS) ) {
|
|
for(i = 0; i < driver->num; i++)
|
|
tty_register_device(driver, i, NULL);
|
|
}
|
|
proc_tty_register_driver(driver);
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(tty_register_driver);
|
|
|
|
/*
|
|
* Called by a tty driver to unregister itself.
|
|
*/
|
|
int tty_unregister_driver(struct tty_driver *driver)
|
|
{
|
|
int i;
|
|
struct termios *tp;
|
|
void *p;
|
|
|
|
if (driver->refcount)
|
|
return -EBUSY;
|
|
|
|
unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
|
|
driver->num);
|
|
|
|
list_del(&driver->tty_drivers);
|
|
|
|
/*
|
|
* Free the termios and termios_locked structures because
|
|
* we don't want to get memory leaks when modular tty
|
|
* drivers are removed from the kernel.
|
|
*/
|
|
for (i = 0; i < driver->num; i++) {
|
|
tp = driver->termios[i];
|
|
if (tp) {
|
|
driver->termios[i] = NULL;
|
|
kfree(tp);
|
|
}
|
|
tp = driver->termios_locked[i];
|
|
if (tp) {
|
|
driver->termios_locked[i] = NULL;
|
|
kfree(tp);
|
|
}
|
|
if (!(driver->flags & TTY_DRIVER_NO_DEVFS))
|
|
tty_unregister_device(driver, i);
|
|
}
|
|
p = driver->ttys;
|
|
proc_tty_unregister_driver(driver);
|
|
driver->ttys = NULL;
|
|
driver->termios = driver->termios_locked = NULL;
|
|
kfree(p);
|
|
cdev_del(&driver->cdev);
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(tty_unregister_driver);
|
|
|
|
|
|
/*
|
|
* Initialize the console device. This is called *early*, so
|
|
* we can't necessarily depend on lots of kernel help here.
|
|
* Just do some early initializations, and do the complex setup
|
|
* later.
|
|
*/
|
|
void __init console_init(void)
|
|
{
|
|
initcall_t *call;
|
|
|
|
/* Setup the default TTY line discipline. */
|
|
(void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
|
|
|
|
/*
|
|
* set up the console device so that later boot sequences can
|
|
* inform about problems etc..
|
|
*/
|
|
#ifdef CONFIG_EARLY_PRINTK
|
|
disable_early_printk();
|
|
#endif
|
|
#ifdef CONFIG_SERIAL_68360
|
|
/* This is not a console initcall. I know not what it's doing here.
|
|
So I haven't moved it. dwmw2 */
|
|
rs_360_init();
|
|
#endif
|
|
call = __con_initcall_start;
|
|
while (call < __con_initcall_end) {
|
|
(*call)();
|
|
call++;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_VT
|
|
extern int vty_init(void);
|
|
#endif
|
|
|
|
static int __init tty_class_init(void)
|
|
{
|
|
tty_class = class_simple_create(THIS_MODULE, "tty");
|
|
if (IS_ERR(tty_class))
|
|
return PTR_ERR(tty_class);
|
|
return 0;
|
|
}
|
|
|
|
postcore_initcall(tty_class_init);
|
|
|
|
/* 3/2004 jmc: why do these devices exist? */
|
|
|
|
static struct cdev tty_cdev, console_cdev;
|
|
#ifdef CONFIG_UNIX98_PTYS
|
|
static struct cdev ptmx_cdev;
|
|
#endif
|
|
#ifdef CONFIG_VT
|
|
static struct cdev vc0_cdev;
|
|
#endif
|
|
|
|
/*
|
|
* Ok, now we can initialize the rest of the tty devices and can count
|
|
* on memory allocations, interrupts etc..
|
|
*/
|
|
static int __init tty_init(void)
|
|
{
|
|
cdev_init(&tty_cdev, &tty_fops);
|
|
if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
|
|
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
|
|
panic("Couldn't register /dev/tty driver\n");
|
|
devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 0), S_IFCHR|S_IRUGO|S_IWUGO, "tty");
|
|
class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
|
|
|
|
cdev_init(&console_cdev, &console_fops);
|
|
if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
|
|
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
|
|
panic("Couldn't register /dev/console driver\n");
|
|
devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 1), S_IFCHR|S_IRUSR|S_IWUSR, "console");
|
|
class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 1), NULL, "console");
|
|
|
|
#ifdef CONFIG_UNIX98_PTYS
|
|
cdev_init(&ptmx_cdev, &ptmx_fops);
|
|
if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
|
|
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
|
|
panic("Couldn't register /dev/ptmx driver\n");
|
|
devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 2), S_IFCHR|S_IRUGO|S_IWUGO, "ptmx");
|
|
class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
|
|
#endif
|
|
|
|
#ifdef CONFIG_VT
|
|
cdev_init(&vc0_cdev, &console_fops);
|
|
if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
|
|
register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
|
|
panic("Couldn't register /dev/tty0 driver\n");
|
|
devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR, "vc/0");
|
|
class_simple_device_add(tty_class, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
|
|
|
|
vty_init();
|
|
#endif
|
|
return 0;
|
|
}
|
|
module_init(tty_init);
|