| /* |
| * linux/drivers/char/tty_io.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| */ |
| |
| /* |
| * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles |
| * or rs-channels. It also implements echoing, cooked mode etc. |
| * |
| * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. |
| * |
| * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the |
| * tty_struct and tty_queue structures. Previously there was an array |
| * of 256 tty_struct's which was statically allocated, and the |
| * tty_queue structures were allocated at boot time. Both are now |
| * dynamically allocated only when the tty is open. |
| * |
| * Also restructured routines so that there is more of a separation |
| * between the high-level tty routines (tty_io.c and tty_ioctl.c) and |
| * the low-level tty routines (serial.c, pty.c, console.c). This |
| * makes for cleaner and more compact code. -TYT, 9/17/92 |
| * |
| * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines |
| * which can be dynamically activated and de-activated by the line |
| * discipline handling modules (like SLIP). |
| * |
| * NOTE: pay no attention to the line discipline code (yet); its |
| * interface is still subject to change in this version... |
| * -- TYT, 1/31/92 |
| * |
| * Added functionality to the OPOST tty handling. No delays, but all |
| * other bits should be there. |
| * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. |
| * |
| * Rewrote canonical mode and added more termios flags. |
| * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 |
| * |
| * Reorganized FASYNC support so mouse code can share it. |
| * -- ctm@ardi.com, 9Sep95 |
| * |
| * New TIOCLINUX variants added. |
| * -- mj@k332.feld.cvut.cz, 19-Nov-95 |
| * |
| * Restrict vt switching via ioctl() |
| * -- grif@cs.ucr.edu, 5-Dec-95 |
| * |
| * Move console and virtual terminal code to more appropriate files, |
| * implement CONFIG_VT and generalize console device interface. |
| * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 |
| * |
| * Rewrote init_dev and release_dev to eliminate races. |
| * -- Bill Hawes <whawes@star.net>, June 97 |
| * |
| * Added devfs support. |
| * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 |
| * |
| * Added support for a Unix98-style ptmx device. |
| * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 |
| * |
| * Reduced memory usage for older ARM systems |
| * -- Russell King <rmk@arm.linux.org.uk> |
| * |
| * Move do_SAK() into process context. Less stack use in devfs functions. |
| * alloc_tty_struct() always uses kmalloc() -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/major.h> |
| #include <linux/errno.h> |
| #include <linux/signal.h> |
| #include <linux/fcntl.h> |
| #include <linux/sched.h> |
| #include <linux/interrupt.h> |
| #include <linux/tty.h> |
| #include <linux/tty_driver.h> |
| #include <linux/tty_flip.h> |
| #include <linux/devpts_fs.h> |
| #include <linux/file.h> |
| #include <linux/console.h> |
| #include <linux/timer.h> |
| #include <linux/ctype.h> |
| #include <linux/kd.h> |
| #include <linux/mm.h> |
| #include <linux/string.h> |
| #include <linux/slab.h> |
| #include <linux/poll.h> |
| #include <linux/proc_fs.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/smp_lock.h> |
| #include <linux/device.h> |
| #include <linux/idr.h> |
| #include <linux/wait.h> |
| #include <linux/bitops.h> |
| #include <linux/delay.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/system.h> |
| |
| #include <linux/kbd_kern.h> |
| #include <linux/vt_kern.h> |
| #include <linux/selection.h> |
| |
| #include <linux/kmod.h> |
| |
| #undef TTY_DEBUG_HANGUP |
| |
| #define TTY_PARANOIA_CHECK 1 |
| #define CHECK_TTY_COUNT 1 |
| |
| struct termios tty_std_termios = { /* for the benefit of tty drivers */ |
| .c_iflag = ICRNL | IXON, |
| .c_oflag = OPOST | ONLCR, |
| .c_cflag = B38400 | CS8 | CREAD | HUPCL, |
| .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | |
| ECHOCTL | ECHOKE | IEXTEN, |
| .c_cc = INIT_C_CC |
| }; |
| |
| EXPORT_SYMBOL(tty_std_termios); |
| |
| /* This list gets poked at by procfs and various bits of boot up code. This |
| could do with some rationalisation such as pulling the tty proc function |
| into this file */ |
| |
| LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
| |
| /* Mutex to protect creating and releasing a tty. This is shared with |
| vt.c for deeply disgusting hack reasons */ |
| DEFINE_MUTEX(tty_mutex); |
| EXPORT_SYMBOL(tty_mutex); |
| |
| #ifdef CONFIG_UNIX98_PTYS |
| extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */ |
| extern int pty_limit; /* Config limit on Unix98 ptys */ |
| static DEFINE_IDR(allocated_ptys); |
| static DECLARE_MUTEX(allocated_ptys_lock); |
| static int ptmx_open(struct inode *, struct file *); |
| #endif |
| |
| extern void disable_early_printk(void); |
| |
| static void initialize_tty_struct(struct tty_struct *tty); |
| |
| static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
| static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); |
| ssize_t redirected_tty_write(struct file *, const char __user *, size_t, loff_t *); |
| static unsigned int tty_poll(struct file *, poll_table *); |
| static int tty_open(struct inode *, struct file *); |
| static int tty_release(struct inode *, struct file *); |
| int tty_ioctl(struct inode * inode, struct file * file, |
| unsigned int cmd, unsigned long arg); |
| static int tty_fasync(int fd, struct file * filp, int on); |
| static void release_mem(struct tty_struct *tty, int idx); |
| |
| /** |
| * alloc_tty_struct - allocate a tty object |
| * |
| * Return a new empty tty structure. The data fields have not |
| * been initialized in any way but has been zeroed |
| * |
| * Locking: none |
| */ |
| |
| static struct tty_struct *alloc_tty_struct(void) |
| { |
| return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); |
| } |
| |
| static void tty_buffer_free_all(struct tty_struct *); |
| |
| /** |
| * free_tty_struct - free a disused tty |
| * @tty: tty struct to free |
| * |
| * Free the write buffers, tty queue and tty memory itself. |
| * |
| * Locking: none. Must be called after tty is definitely unused |
| */ |
| |
| static inline void free_tty_struct(struct tty_struct *tty) |
| { |
| kfree(tty->write_buf); |
| tty_buffer_free_all(tty); |
| kfree(tty); |
| } |
| |
| #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
| |
| /** |
| * tty_name - return tty naming |
| * @tty: tty structure |
| * @buf: buffer for output |
| * |
| * Convert a tty structure into a name. The name reflects the kernel |
| * naming policy and if udev is in use may not reflect user space |
| * |
| * Locking: none |
| */ |
| |
| char *tty_name(struct tty_struct *tty, char *buf) |
| { |
| if (!tty) /* Hmm. NULL pointer. That's fun. */ |
| strcpy(buf, "NULL tty"); |
| else |
| strcpy(buf, tty->name); |
| return buf; |
| } |
| |
| EXPORT_SYMBOL(tty_name); |
| |
| int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
| const char *routine) |
| { |
| #ifdef TTY_PARANOIA_CHECK |
| if (!tty) { |
| printk(KERN_WARNING |
| "null TTY for (%d:%d) in %s\n", |
| imajor(inode), iminor(inode), routine); |
| return 1; |
| } |
| if (tty->magic != TTY_MAGIC) { |
| printk(KERN_WARNING |
| "bad magic number for tty struct (%d:%d) in %s\n", |
| imajor(inode), iminor(inode), routine); |
| return 1; |
| } |
| #endif |
| return 0; |
| } |
| |
| static int check_tty_count(struct tty_struct *tty, const char *routine) |
| { |
| #ifdef CHECK_TTY_COUNT |
| struct list_head *p; |
| int count = 0; |
| |
| file_list_lock(); |
| list_for_each(p, &tty->tty_files) { |
| count++; |
| } |
| file_list_unlock(); |
| if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
| tty->driver->subtype == PTY_TYPE_SLAVE && |
| tty->link && tty->link->count) |
| count++; |
| if (tty->count != count) { |
| printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " |
| "!= #fd's(%d) in %s\n", |
| tty->name, tty->count, count, routine); |
| return count; |
| } |
| #endif |
| return 0; |
| } |
| |
| /* |
| * Tty buffer allocation management |
| */ |
| |
| /** |
| * tty_buffer_free_all - free buffers used by a tty |
| * @tty: tty to free from |
| * |
| * Remove all the buffers pending on a tty whether queued with data |
| * or in the free ring. Must be called when the tty is no longer in use |
| * |
| * Locking: none |
| */ |
| |
| static void tty_buffer_free_all(struct tty_struct *tty) |
| { |
| struct tty_buffer *thead; |
| while((thead = tty->buf.head) != NULL) { |
| tty->buf.head = thead->next; |
| kfree(thead); |
| } |
| while((thead = tty->buf.free) != NULL) { |
| tty->buf.free = thead->next; |
| kfree(thead); |
| } |
| tty->buf.tail = NULL; |
| tty->buf.memory_used = 0; |
| } |
| |
| /** |
| * tty_buffer_init - prepare a tty buffer structure |
| * @tty: tty to initialise |
| * |
| * Set up the initial state of the buffer management for a tty device. |
| * Must be called before the other tty buffer functions are used. |
| * |
| * Locking: none |
| */ |
| |
| static void tty_buffer_init(struct tty_struct *tty) |
| { |
| spin_lock_init(&tty->buf.lock); |
| tty->buf.head = NULL; |
| tty->buf.tail = NULL; |
| tty->buf.free = NULL; |
| tty->buf.memory_used = 0; |
| } |
| |
| /** |
| * tty_buffer_alloc - allocate a tty buffer |
| * @tty: tty device |
| * @size: desired size (characters) |
| * |
| * Allocate a new tty buffer to hold the desired number of characters. |
| * Return NULL if out of memory or the allocation would exceed the |
| * per device queue |
| * |
| * Locking: Caller must hold tty->buf.lock |
| */ |
| |
| static struct tty_buffer *tty_buffer_alloc(struct tty_struct *tty, size_t size) |
| { |
| struct tty_buffer *p; |
| |
| if (tty->buf.memory_used + size > 65536) |
| return NULL; |
| p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC); |
| if(p == NULL) |
| return NULL; |
| p->used = 0; |
| p->size = size; |
| p->next = NULL; |
| p->commit = 0; |
| p->read = 0; |
| p->char_buf_ptr = (char *)(p->data); |
| p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size; |
| tty->buf.memory_used += size; |
| return p; |
| } |
| |
| /** |
| * tty_buffer_free - free a tty buffer |
| * @tty: tty owning the buffer |
| * @b: the buffer to free |
| * |
| * Free a tty buffer, or add it to the free list according to our |
| * internal strategy |
| * |
| * Locking: Caller must hold tty->buf.lock |
| */ |
| |
| static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b) |
| { |
| /* Dumb strategy for now - should keep some stats */ |
| tty->buf.memory_used -= b->size; |
| WARN_ON(tty->buf.memory_used < 0); |
| |
| if(b->size >= 512) |
| kfree(b); |
| else { |
| b->next = tty->buf.free; |
| tty->buf.free = b; |
| } |
| } |
| |
| /** |
| * tty_buffer_find - find a free tty buffer |
| * @tty: tty owning the buffer |
| * @size: characters wanted |
| * |
| * Locate an existing suitable tty buffer or if we are lacking one then |
| * allocate a new one. We round our buffers off in 256 character chunks |
| * to get better allocation behaviour. |
| * |
| * Locking: Caller must hold tty->buf.lock |
| */ |
| |
| static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size) |
| { |
| struct tty_buffer **tbh = &tty->buf.free; |
| while((*tbh) != NULL) { |
| struct tty_buffer *t = *tbh; |
| if(t->size >= size) { |
| *tbh = t->next; |
| t->next = NULL; |
| t->used = 0; |
| t->commit = 0; |
| t->read = 0; |
| tty->buf.memory_used += t->size; |
| return t; |
| } |
| tbh = &((*tbh)->next); |
| } |
| /* Round the buffer size out */ |
| size = (size + 0xFF) & ~ 0xFF; |
| return tty_buffer_alloc(tty, size); |
| /* Should possibly check if this fails for the largest buffer we |
| have queued and recycle that ? */ |
| } |
| |
| /** |
| * tty_buffer_request_room - grow tty buffer if needed |
| * @tty: tty structure |
| * @size: size desired |
| * |
| * Make at least size bytes of linear space available for the tty |
| * buffer. If we fail return the size we managed to find. |
| * |
| * Locking: Takes tty->buf.lock |
| */ |
| int tty_buffer_request_room(struct tty_struct *tty, size_t size) |
| { |
| struct tty_buffer *b, *n; |
| int left; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&tty->buf.lock, flags); |
| |
| /* OPTIMISATION: We could keep a per tty "zero" sized buffer to |
| remove this conditional if its worth it. This would be invisible |
| to the callers */ |
| if ((b = tty->buf.tail) != NULL) |
| left = b->size - b->used; |
| else |
| left = 0; |
| |
| if (left < size) { |
| /* This is the slow path - looking for new buffers to use */ |
| if ((n = tty_buffer_find(tty, size)) != NULL) { |
| if (b != NULL) { |
| b->next = n; |
| b->commit = b->used; |
| } else |
| tty->buf.head = n; |
| tty->buf.tail = n; |
| } else |
| size = left; |
| } |
| |
| spin_unlock_irqrestore(&tty->buf.lock, flags); |
| return size; |
| } |
| EXPORT_SYMBOL_GPL(tty_buffer_request_room); |
| |
| /** |
| * tty_insert_flip_string - Add characters to the tty buffer |
| * @tty: tty structure |
| * @chars: characters |
| * @size: size |
| * |
| * Queue a series of bytes to the tty buffering. All the characters |
| * passed are marked as without error. Returns the number added. |
| * |
| * Locking: Called functions may take tty->buf.lock |
| */ |
| |
| int tty_insert_flip_string(struct tty_struct *tty, const unsigned char *chars, |
| size_t size) |
| { |
| int copied = 0; |
| do { |
| int space = tty_buffer_request_room(tty, size - copied); |
| struct tty_buffer *tb = tty->buf.tail; |
| /* If there is no space then tb may be NULL */ |
| if(unlikely(space == 0)) |
| break; |
| memcpy(tb->char_buf_ptr + tb->used, chars, space); |
| memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space); |
| tb->used += space; |
| copied += space; |
| chars += space; |
| /* There is a small chance that we need to split the data over |
| several buffers. If this is the case we must loop */ |
| } while (unlikely(size > copied)); |
| return copied; |
| } |
| EXPORT_SYMBOL(tty_insert_flip_string); |
| |
| /** |
| * tty_insert_flip_string_flags - Add characters to the tty buffer |
| * @tty: tty structure |
| * @chars: characters |
| * @flags: flag bytes |
| * @size: size |
| * |
| * Queue a series of bytes to the tty buffering. For each character |
| * the flags array indicates the status of the character. Returns the |
| * number added. |
| * |
| * Locking: Called functions may take tty->buf.lock |
| */ |
| |
| int tty_insert_flip_string_flags(struct tty_struct *tty, |
| const unsigned char *chars, const char *flags, size_t size) |
| { |
| int copied = 0; |
| do { |
| int space = tty_buffer_request_room(tty, size - copied); |
| struct tty_buffer *tb = tty->buf.tail; |
| /* If there is no space then tb may be NULL */ |
| if(unlikely(space == 0)) |
| break; |
| memcpy(tb->char_buf_ptr + tb->used, chars, space); |
| memcpy(tb->flag_buf_ptr + tb->used, flags, space); |
| tb->used += space; |
| copied += space; |
| chars += space; |
| flags += space; |
| /* There is a small chance that we need to split the data over |
| several buffers. If this is the case we must loop */ |
| } while (unlikely(size > copied)); |
| return copied; |
| } |
| EXPORT_SYMBOL(tty_insert_flip_string_flags); |
| |
| /** |
| * tty_schedule_flip - push characters to ldisc |
| * @tty: tty to push from |
| * |
| * Takes any pending buffers and transfers their ownership to the |
| * ldisc side of the queue. It then schedules those characters for |
| * processing by the line discipline. |
| * |
| * Locking: Takes tty->buf.lock |
| */ |
| |
| void tty_schedule_flip(struct tty_struct *tty) |
| { |
| unsigned long flags; |
| spin_lock_irqsave(&tty->buf.lock, flags); |
| if (tty->buf.tail != NULL) |
| tty->buf.tail->commit = tty->buf.tail->used; |
| spin_unlock_irqrestore(&tty->buf.lock, flags); |
| schedule_delayed_work(&tty->buf.work, 1); |
| } |
| EXPORT_SYMBOL(tty_schedule_flip); |
| |
| /** |
| * tty_prepare_flip_string - make room for characters |
| * @tty: tty |
| * @chars: return pointer for character write area |
| * @size: desired size |
| * |
| * Prepare a block of space in the buffer for data. Returns the length |
| * available and buffer pointer to the space which is now allocated and |
| * accounted for as ready for normal characters. This is used for drivers |
| * that need their own block copy routines into the buffer. There is no |
| * guarantee the buffer is a DMA target! |
| * |
| * Locking: May call functions taking tty->buf.lock |
| */ |
| |
| int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars, size_t size) |
| { |
| int space = tty_buffer_request_room(tty, size); |
| if (likely(space)) { |
| struct tty_buffer *tb = tty->buf.tail; |
| *chars = tb->char_buf_ptr + tb->used; |
| memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space); |
| tb->used += space; |
| } |
| return space; |
| } |
| |
| EXPORT_SYMBOL_GPL(tty_prepare_flip_string); |
| |
| /** |
| * tty_prepare_flip_string_flags - make room for characters |
| * @tty: tty |
| * @chars: return pointer for character write area |
| * @flags: return pointer for status flag write area |
| * @size: desired size |
| * |
| * Prepare a block of space in the buffer for data. Returns the length |
| * available and buffer pointer to the space which is now allocated and |
| * accounted for as ready for characters. This is used for drivers |
| * that need their own block copy routines into the buffer. There is no |
| * guarantee the buffer is a DMA target! |
| * |
| * Locking: May call functions taking tty->buf.lock |
| */ |
| |
| int tty_prepare_flip_string_flags(struct tty_struct *tty, unsigned char **chars, char **flags, size_t size) |
| { |
| int space = tty_buffer_request_room(tty, size); |
| if (likely(space)) { |
| struct tty_buffer *tb = tty->buf.tail; |
| *chars = tb->char_buf_ptr + tb->used; |
| *flags = tb->flag_buf_ptr + tb->used; |
| tb->used += space; |
| } |
| return space; |
| } |
| |
| EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags); |
| |
| |
| |
| /** |
| * tty_set_termios_ldisc - set ldisc field |
| * @tty: tty structure |
| * @num: line discipline number |
| * |
| * This is probably overkill for real world processors but |
| * they are not on hot paths so a little discipline won't do |
| * any harm. |
| * |
| * Locking: takes termios_mutex |
| */ |
| |
| static void tty_set_termios_ldisc(struct tty_struct *tty, int num) |
| { |
| mutex_lock(&tty->termios_mutex); |
| tty->termios->c_line = num; |
| mutex_unlock(&tty->termios_mutex); |
| } |
| |
| /* |
| * This guards the refcounted line discipline lists. The lock |
| * must be taken with irqs off because there are hangup path |
| * callers who will do ldisc lookups and cannot sleep. |
| */ |
| |
| static DEFINE_SPINLOCK(tty_ldisc_lock); |
| static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait); |
| static struct tty_ldisc tty_ldiscs[NR_LDISCS]; /* line disc dispatch table */ |
| |
| /** |
| * tty_register_ldisc - install a line discipline |
| * @disc: ldisc number |
| * @new_ldisc: pointer to the ldisc object |
| * |
| * Installs a new line discipline into the kernel. The discipline |
| * is set up as unreferenced and then made available to the kernel |
| * from this point onwards. |
| * |
| * Locking: |
| * takes tty_ldisc_lock to guard against ldisc races |
| */ |
| |
| int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc) |
| { |
| unsigned long flags; |
| int ret = 0; |
| |
| if (disc < N_TTY || disc >= NR_LDISCS) |
| return -EINVAL; |
| |
| spin_lock_irqsave(&tty_ldisc_lock, flags); |
| tty_ldiscs[disc] = *new_ldisc; |
| tty_ldiscs[disc].num = disc; |
| tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED; |
| tty_ldiscs[disc].refcount = 0; |
| spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(tty_register_ldisc); |
| |
| /** |
| * tty_unregister_ldisc - unload a line discipline |
| * @disc: ldisc number |
| * @new_ldisc: pointer to the ldisc object |
| * |
| * Remove a line discipline from the kernel providing it is not |
| * currently in use. |
| * |
| * Locking: |
| * takes tty_ldisc_lock to guard against ldisc races |
| */ |
| |
| int tty_unregister_ldisc(int disc) |
| { |
| unsigned long flags; |
| int ret = 0; |
| |
| if (disc < N_TTY || disc >= NR_LDISCS) |
| return -EINVAL; |
| |
| spin_lock_irqsave(&tty_ldisc_lock, flags); |
| if (tty_ldiscs[disc].refcount) |
| ret = -EBUSY; |
| else |
| tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED; |
| spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(tty_unregister_ldisc); |
| |
| /** |
| * tty_ldisc_get - take a reference to an ldisc |
| * @disc: ldisc number |
| * |
| * Takes a reference to a line discipline. Deals with refcounts and |
| * module locking counts. Returns NULL if the discipline is not available. |
| * Returns a pointer to the discipline and bumps the ref count if it is |
| * available |
| * |
| * Locking: |
| * takes tty_ldisc_lock to guard against ldisc races |
| */ |
| |
| struct tty_ldisc *tty_ldisc_get(int disc) |
| { |
| unsigned long flags; |
| struct tty_ldisc *ld; |
| |
| if (disc < N_TTY || disc >= NR_LDISCS) |
| return NULL; |
| |
| spin_lock_irqsave(&tty_ldisc_lock, flags); |
| |
| ld = &tty_ldiscs[disc]; |
| /* Check the entry is defined */ |
| if(ld->flags & LDISC_FLAG_DEFINED) |
| { |
| /* If the module is being unloaded we can't use it */ |
| if (!try_module_get(ld->owner)) |
| ld = NULL; |
| else /* lock it */ |
| ld->refcount++; |
| } |
| else |
| ld = NULL; |
| spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| return ld; |
| } |
| |
| EXPORT_SYMBOL_GPL(tty_ldisc_get); |
| |
| /** |
| * tty_ldisc_put - drop ldisc reference |
| * @disc: ldisc number |
| * |
| * Drop a reference to a line discipline. Manage refcounts and |
| * module usage counts |
| * |
| * Locking: |
| * takes tty_ldisc_lock to guard against ldisc races |
| */ |
| |
| void tty_ldisc_put(int disc) |
| { |
| struct tty_ldisc *ld; |
| unsigned long flags; |
| |
| BUG_ON(disc < N_TTY || disc >= NR_LDISCS); |
| |
| spin_lock_irqsave(&tty_ldisc_lock, flags); |
| ld = &tty_ldiscs[disc]; |
| BUG_ON(ld->refcount == 0); |
| ld->refcount--; |
| module_put(ld->owner); |
| spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| } |
| |
| EXPORT_SYMBOL_GPL(tty_ldisc_put); |
| |
| /** |
| * tty_ldisc_assign - set ldisc on a tty |
| * @tty: tty to assign |
| * @ld: line discipline |
| * |
| * Install an instance of a line discipline into a tty structure. The |
| * ldisc must have a reference count above zero to ensure it remains/ |
| * The tty instance refcount starts at zero. |
| * |
| * Locking: |
| * Caller must hold references |
| */ |
| |
| static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld) |
| { |
| tty->ldisc = *ld; |
| tty->ldisc.refcount = 0; |
| } |
| |
| /** |
| * tty_ldisc_try - internal helper |
| * @tty: the tty |
| * |
| * Make a single attempt to grab and bump the refcount on |
| * the tty ldisc. Return 0 on failure or 1 on success. This is |
| * used to implement both the waiting and non waiting versions |
| * of tty_ldisc_ref |
| * |
| * Locking: takes tty_ldisc_lock |
| */ |
| |
| static int tty_ldisc_try(struct tty_struct *tty) |
| { |
| unsigned long flags; |
| struct tty_ldisc *ld; |
| int ret = 0; |
| |
| spin_lock_irqsave(&tty_ldisc_lock, flags); |
| ld = &tty->ldisc; |
| if(test_bit(TTY_LDISC, &tty->flags)) |
| { |
| ld->refcount++; |
| ret = 1; |
| } |
| spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| return ret; |
| } |
| |
| /** |
| * tty_ldisc_ref_wait - wait for the tty ldisc |
| * @tty: tty device |
| * |
| * Dereference the line discipline for the terminal and take a |
| * reference to it. If the line discipline is in flux then |
| * wait patiently until it changes. |
| * |
| * Note: Must not be called from an IRQ/timer context. The caller |
| * must also be careful not to hold other locks that will deadlock |
| * against a discipline change, such as an existing ldisc reference |
| * (which we check for) |
| * |
| * Locking: call functions take tty_ldisc_lock |
| */ |
| |
| struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty) |
| { |
| /* wait_event is a macro */ |
| wait_event(tty_ldisc_wait, tty_ldisc_try(tty)); |
| if(tty->ldisc.refcount == 0) |
| printk(KERN_ERR "tty_ldisc_ref_wait\n"); |
| return &tty->ldisc; |
| } |
| |
| EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait); |
| |
| /** |
| * tty_ldisc_ref - get the tty ldisc |
| * @tty: tty device |
| * |
| * Dereference the line discipline for the terminal and take a |
| * reference to it. If the line discipline is in flux then |
| * return NULL. Can be called from IRQ and timer functions. |
| * |
| * Locking: called functions take tty_ldisc_lock |
| */ |
| |
| struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty) |
| { |
| if(tty_ldisc_try(tty)) |
| return &tty->ldisc; |
| return NULL; |
| } |
| |
| EXPORT_SYMBOL_GPL(tty_ldisc_ref); |
| |
| /** |
| * tty_ldisc_deref - free a tty ldisc reference |
| * @ld: reference to free up |
| * |
| * Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May |
| * be called in IRQ context. |
| * |
| * Locking: takes tty_ldisc_lock |
| */ |
| |
| void tty_ldisc_deref(struct tty_ldisc *ld) |
| { |
| unsigned long flags; |
| |
| BUG_ON(ld == NULL); |
| |
| spin_lock_irqsave(&tty_ldisc_lock, flags); |
| if(ld->refcount == 0) |
| printk(KERN_ERR "tty_ldisc_deref: no references.\n"); |
| else |
| ld->refcount--; |
| if(ld->refcount == 0) |
| wake_up(&tty_ldisc_wait); |
| spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| } |
| |
| EXPORT_SYMBOL_GPL(tty_ldisc_deref); |
| |
| /** |
| * tty_ldisc_enable - allow ldisc use |
| * @tty: terminal to activate ldisc on |
| * |
| * Set the TTY_LDISC flag when the line discipline can be called |
| * again. Do neccessary wakeups for existing sleepers. |
| * |
| * Note: nobody should set this bit except via this function. Clearing |
| * directly is allowed. |
| */ |
| |
| static void tty_ldisc_enable(struct tty_struct *tty) |
| { |
| set_bit(TTY_LDISC, &tty->flags); |
| wake_up(&tty_ldisc_wait); |
| } |
| |
| /** |
| * tty_set_ldisc - set line discipline |
| * @tty: the terminal to set |
| * @ldisc: the line discipline |
| * |
| * Set the discipline of a tty line. Must be called from a process |
| * context. |
| * |
| * Locking: takes tty_ldisc_lock. |
| * called functions take termios_mutex |
| */ |
| |
| static int tty_set_ldisc(struct tty_struct *tty, int ldisc) |
| { |
| int retval = 0; |
| struct tty_ldisc o_ldisc; |
| char buf[64]; |
| int work; |
| unsigned long flags; |
| struct tty_ldisc *ld; |
| struct tty_struct *o_tty; |
| |
| if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS)) |
| return -EINVAL; |
| |
| restart: |
| |
| ld = tty_ldisc_get(ldisc); |
| /* Eduardo Blanco <ejbs@cs.cs.com.uy> */ |
| /* Cyrus Durgin <cider@speakeasy.org> */ |
| if (ld == NULL) { |
| request_module("tty-ldisc-%d", ldisc); |
| ld = tty_ldisc_get(ldisc); |
| } |
| if (ld == NULL) |
| return -EINVAL; |
| |
| /* |
| * No more input please, we are switching. The new ldisc |
| * will update this value in the ldisc open function |
| */ |
| |
| tty->receive_room = 0; |
| |
| /* |
| * Problem: What do we do if this blocks ? |
| */ |
| |
| tty_wait_until_sent(tty, 0); |
| |
| if (tty->ldisc.num == ldisc) { |
| tty_ldisc_put(ldisc); |
| return 0; |
| } |
| |
| o_ldisc = tty->ldisc; |
| o_tty = tty->link; |
| |
| /* |
| * Make sure we don't change while someone holds a |
| * reference to the line discipline. The TTY_LDISC bit |
| * prevents anyone taking a reference once it is clear. |
| * We need the lock to avoid racing reference takers. |
| */ |
| |
| spin_lock_irqsave(&tty_ldisc_lock, flags); |
| if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) { |
| if(tty->ldisc.refcount) { |
| /* Free the new ldisc we grabbed. Must drop the lock |
| first. */ |
| spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| tty_ldisc_put(ldisc); |
| /* |
| * There are several reasons we may be busy, including |
| * random momentary I/O traffic. We must therefore |
| * retry. We could distinguish between blocking ops |
| * and retries if we made tty_ldisc_wait() smarter. That |
| * is up for discussion. |
| */ |
| if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0) |
| return -ERESTARTSYS; |
| goto restart; |
| } |
| if(o_tty && o_tty->ldisc.refcount) { |
| spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| tty_ldisc_put(ldisc); |
| if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0) |
| return -ERESTARTSYS; |
| goto restart; |
| } |
| } |
| |
| /* if the TTY_LDISC bit is set, then we are racing against another ldisc change */ |
| |
| if (!test_bit(TTY_LDISC, &tty->flags)) { |
| spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| tty_ldisc_put(ldisc); |
| ld = tty_ldisc_ref_wait(tty); |
| tty_ldisc_deref(ld); |
| goto restart; |
| } |
| |
| clear_bit(TTY_LDISC, &tty->flags); |
| if (o_tty) |
| clear_bit(TTY_LDISC, &o_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->buf.work); |
| /* |
| * Wait for ->hangup_work and ->buf.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); |
| if (o_tty) |
| tty_ldisc_enable(o_tty); |
| |
| /* Restart it in case no characters kick it off. Safe if |
| already running */ |
| if (work) |
| schedule_delayed_work(&tty->buf.work, 1); |
| return retval; |
| } |
| |
| /** |
| * get_tty_driver - find device of a tty |
| * @dev_t: device identifier |
| * @index: returns the index of the tty |
| * |
| * This routine returns a tty driver structure, given a device number |
| * and also passes back the index number. |
| * |
| * Locking: caller must hold tty_mutex |
| */ |
| |
| static struct tty_driver *get_tty_driver(dev_t device, int *index) |
| { |
| struct tty_driver *p; |
| |
| list_for_each_entry(p, &tty_drivers, tty_drivers) { |
| dev_t base = MKDEV(p->major, p->minor_start); |
| if (device < base || device >= base + p->num) |
| continue; |
| *index = device - base; |
| return p; |
| } |
| return NULL; |
| } |
| |
| /** |
| * tty_check_change - check for POSIX terminal changes |
| * @tty: tty to check |
| * |
| * If we try to write to, or set the state of, a terminal and we're |
| * not in the foreground, send a SIGTTOU. If the signal is blocked or |
| * ignored, go ahead and perform the operation. (POSIX 7.2) |
| * |
| * Locking: none |
| */ |
| |
| 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 const 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 const 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 const 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 const struct file_operations hung_up_tty_fops = { |
| .llseek = no_llseek, |
| .read = hung_up_tty_read, |
| .write = hung_up_tty_write, |
| .poll = hung_up_tty_poll, |
| .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); |
| |
| /** |
| * do_tty_hangup - actual handler for hangup events |
| * @work: tty device |
| * |
| * This can be called by the "eventd" kernel thread. That is process |
| * synchronous but doesn't hold any locks, so we need to make sure we |
| * have the appropriate locks for what we're doing. |
| * |
| * The hangup event clears any pending redirections onto the hung up |
| * device. It ensures future writes will error and it does the needed |
| * line discipline hangup and signal delivery. The tty object itself |
| * remains intact. |
| * |
| * Locking: |
| * BKL |
| * redirect lock for undoing redirection |
| * file list lock for manipulating list of ttys |
| * tty_ldisc_lock from called functions |
| * termios_mutex resetting termios data |
| * tasklist_lock to walk task list for hangup event |
| * ->siglock to protect ->signal/->sighand |
| */ |
| static void do_tty_hangup(struct work_struct *work) |
| { |
| struct tty_struct *tty = |
| container_of(work, struct tty_struct, hangup_work); |
| 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_u.fu_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) |
| { |
| mutex_lock(&tty->termios_mutex); |
| *tty->termios = tty->driver->init_termios; |
| mutex_unlock(&tty->termios_mutex); |
| } |
| |
| /* 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) { |
| spin_lock_irq(&p->sighand->siglock); |
| if (p->signal->tty == tty) |
| p->signal->tty = NULL; |
| if (!p->signal->leader) { |
| spin_unlock_irq(&p->sighand->siglock); |
| continue; |
| } |
| __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); |
| __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); |
| if (tty->pgrp > 0) |
| p->signal->tty_old_pgrp = tty->pgrp; |
| spin_unlock_irq(&p->sighand->siglock); |
| } 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); |
| } |
| |
| /** |
| * tty_hangup - trigger a hangup event |
| * @tty: tty to hangup |
| * |
| * A carrier loss (virtual or otherwise) has occurred on this like |
| * schedule a hangup sequence to run after this event. |
| */ |
| |
| void tty_hangup(struct tty_struct * tty) |
| { |
| #ifdef TTY_DEBUG_HANGUP |
| char buf[64]; |
| |
| printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
| #endif |
| schedule_work(&tty->hangup_work); |
| } |
| |
| EXPORT_SYMBOL(tty_hangup); |
| |
| /** |
| * tty_vhangup - process vhangup |
| * @tty: tty to hangup |
| * |
| * The user has asked via system call for the terminal to be hung up. |
| * We do this synchronously so that when the syscall returns the process |
| * is complete. That guarantee is neccessary for security reasons. |
| */ |
| |
| void tty_vhangup(struct tty_struct * tty) |
| { |
| #ifdef TTY_DEBUG_HANGUP |
| char buf[64]; |
| |
| printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); |
| #endif |
| do_tty_hangup(&tty->hangup_work); |
| } |
| EXPORT_SYMBOL(tty_vhangup); |
| |
| /** |
| * tty_hung_up_p - was tty hung up |
| * @filp: file pointer of tty |
| * |
| * Return true if the tty has been subject to a vhangup or a carrier |
| * loss |
| */ |
| |
| int tty_hung_up_p(struct file * filp) |
| { |
| return (filp->f_op == &hung_up_tty_fops); |
| } |
| |
| EXPORT_SYMBOL(tty_hung_up_p); |
| |
| static void session_clear_tty(pid_t session) |
| { |
| struct task_struct *p; |
| do_each_task_pid(session, PIDTYPE_SID, p) { |
| proc_clear_tty(p); |
| } while_each_task_pid(session, PIDTYPE_SID, p); |
| } |
| |
| /** |
| * disassociate_ctty - disconnect controlling tty |
| * @on_exit: true if exiting so need to "hang up" the session |
| * |
| * This function is typically called only by the session leader, when |
| * it wants to disassociate itself from its controlling tty. |
| * |
| * It performs the following functions: |
| * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
| * (2) Clears the tty from being controlling the session |
| * (3) Clears the controlling tty for all processes in the |
| * session group. |
| * |
| * The argument on_exit is set to 1 if called when a process is |
| * exiting; it is 0 if called by the ioctl TIOCNOTTY. |
| * |
| * Locking: |
| * BKL is taken for hysterical raisins |
| * tty_mutex is taken to protect tty |
| * ->siglock is taken to protect ->signal/->sighand |
| * tasklist_lock is taken to walk process list for sessions |
| * ->siglock is taken to protect ->signal/->sighand |
| */ |
| |
| void disassociate_ctty(int on_exit) |
| { |
| struct tty_struct *tty; |
| int tty_pgrp = -1; |
| int session; |
| |
| lock_kernel(); |
| |
| mutex_lock(&tty_mutex); |
| tty = get_current_tty(); |
| if (tty) { |
| tty_pgrp = tty->pgrp; |
| mutex_unlock(&tty_mutex); |
| /* XXX: here we race, there is nothing protecting tty */ |
| if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) |
| tty_vhangup(tty); |
| } else { |
| pid_t old_pgrp = current->signal->tty_old_pgrp; |
| if (old_pgrp) { |
| kill_pg(old_pgrp, SIGHUP, on_exit); |
| kill_pg(old_pgrp, SIGCONT, on_exit); |
| } |
| mutex_unlock(&tty_mutex); |
| unlock_kernel(); |
| return; |
| } |
| if (tty_pgrp > 0) { |
| kill_pg(tty_pgrp, SIGHUP, on_exit); |
| if (!on_exit) |
| kill_pg(tty_pgrp, SIGCONT, on_exit); |
| } |
| |
| spin_lock_irq(¤t->sighand->siglock); |
| current->signal->tty_old_pgrp = 0; |
| session = current->signal->session; |
| spin_unlock_irq(¤t->sighand->siglock); |
| |
| mutex_lock(&tty_mutex); |
| /* It is possible that do_tty_hangup has free'd this tty */ |
| tty = get_current_tty(); |
| if (tty) { |
| tty->session = 0; |
| tty->pgrp = 0; |
| } else { |
| #ifdef TTY_DEBUG_HANGUP |
| printk(KERN_DEBUG "error attempted to write to tty [0x%p]" |
| " = NULL", tty); |
| #endif |
| } |
| mutex_unlock(&tty_mutex); |
| |
| /* Now clear signal->tty under the lock */ |
| read_lock(&tasklist_lock); |
| session_clear_tty(session); |
| read_unlock(&tasklist_lock); |
| unlock_kernel(); |
| } |
| |
| |
| /** |
| * stop_tty - propogate flow control |
| * @tty: tty to stop |
| * |
| * Perform flow control to the driver. For PTY/TTY pairs we |
| * must also propogate the TIOCKPKT status. May be called |
| * on an already stopped device and will not re-call the driver |
| * method. |
| * |
| * This functionality is used by both the line disciplines for |
| * halting incoming flow and by the driver. It may therefore be |
| * called from any context, may be under the tty atomic_write_lock |
| * but not always. |
| * |
| * Locking: |
| * Broken. Relies on BKL which is unsafe here. |
| */ |
| |
| 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); |
| |
| /** |
| * start_tty - propogate flow control |
| * @tty: tty to start |
| * |
| * Start a tty that has been stopped if at all possible. Perform |
| * any neccessary wakeups and propogate the TIOCPKT status. If this |
| * is the tty was previous stopped and is being started then the |
| * driver start method is invoked and the line discipline woken. |
| * |
| * Locking: |
| * Broken. Relies on BKL which is unsafe here. |
| */ |
| |
| 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); |
| |
| /** |
| * tty_read - read method for tty device files |
| * @file: pointer to tty file |
| * @buf: user buffer |
| * @count: size of user buffer |
| * @ppos: unused |
| * |
| * Perform the read system call function on this terminal device. Checks |
| * for hung up devices before calling the line discipline method. |
| * |
| * Locking: |
| * Locks the line discipline internally while needed |
| * For historical reasons the line discipline read method is |
| * invoked under the BKL. This will go away in time so do not rely on it |
| * in new code. Multiple read calls may be outstanding in parallel. |
| */ |
| |
| static ssize_t tty_read(struct file * file, char __user * buf, size_t count, |
| loff_t *ppos) |
| { |
| int i; |
| struct 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; |
| |
| /* FIXME: O_NDELAY ... */ |
| if (mutex_lock_interruptible(&tty->atomic_write_lock)) { |
| 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. |
| * |
| * FIXME: This can probably go away now except that 64K chunks |
| * are too likely to fail unless switched to vmalloc... |
| */ |
| chunk = 2048; |
| if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) |
| chunk = 65536; |
| if (count < chunk) |
| chunk = count; |
| |
| /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
| if (tty->write_cnt < chunk) { |
| unsigned char *buf; |
| |
| if (chunk < 1024) |
| chunk = 1024; |
| |
| buf = kmalloc(chunk, GFP_KERNEL); |
| if (!buf) { |
| mutex_unlock(&tty->atomic_write_lock); |
| 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; |
| } |
| mutex_unlock(&tty->atomic_write_lock); |
| return ret; |
| } |
| |
| |
| /** |
| * tty_write - write method for tty device file |
| * @file: tty file pointer |
| * @buf: user data to write |
| * @count: bytes to write |
| * @ppos: unused |
| * |
| * Write data to a tty device via the line discipline. |
| * |
| * Locking: |
| * Locks the line discipline as required |
| * Writes to the tty driver are serialized by the atomic_write_lock |
| * and are then processed in chunks to the device. The line discipline |
| * write method will not be involked in parallel for each device |
| * The line discipline write method is called under the big |
| * kernel lock for historical reasons. New code should not rely on this. |
| */ |
| |
| 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"; |
| |
| /** |
| * pty_line_name - generate name for a pty |
| * @driver: the tty driver in use |
| * @index: the minor number |
| * @p: output buffer of at least 6 bytes |
| * |
| * Generate a name from a driver reference and write it to the output |
| * buffer. |
| * |
| * Locking: None |
| */ |
| static void pty_line_name(struct tty_driver *driver, int index, char *p) |
| { |
| int i = index + driver->name_base; |
| /* ->name is initialized to "ttyp", but "tty" is expected */ |
| sprintf(p, "%s%c%x", |
| driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
| ptychar[i >> 4 & 0xf], i & 0xf); |
| } |
| |
| /** |
| * pty_line_name - generate name for a tty |
| * @driver: the tty driver in use |
| * @index: the minor number |
| * @p: output buffer of at least 7 bytes |
| * |
| * Generate a name from a driver reference and write it to the output |
| * buffer. |
| * |
| * Locking: None |
| */ |
| static void tty_line_name(struct tty_driver *driver, int index, char *p) |
| { |
| sprintf(p, "%s%d", driver->name, index + driver->name_base); |
| } |
| |
| /** |
| * init_dev - initialise a tty device |
| * @driver: tty driver we are opening a device on |
| * @idx: device index |
| * @tty: returned tty structure |
| * |
| * Prepare a tty device. This may not be a "new" clean device but |
| * could also be an active device. The pty drivers require special |
| * handling because of this. |
| * |
| * Locking: |
| * The function is called under the tty_mutex, which |
| * protects us from the tty struct or driver itself going away. |
| * |
| * On exit the tty device has the line discipline attached and |
| * a reference count of 1. If a pair was created for pty/tty use |
| * and the other was a pty master then it too has a reference count of 1. |
| * |
| * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
| * failed open. The new code protects the open with a mutex, so it's |
| * really quite straightforward. The mutex locking can probably be |
| * relaxed for the (most common) case of reopening a tty. |
| */ |
| |
| 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 mutex */ |
| end_init: |
| return retval; |
| |
| /* Release locally allocated memory ... nothing placed in slots */ |
| free_mem_out: |
| kfree(o_tp); |
| if (o_tty) |
| free_tty_struct(o_tty); |
| kfree(ltp); |
| 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: |
| if (printk_ratelimit()) |
| printk(KERN_INFO "init_dev: ldisc open failed, " |
| "clearing slot %d\n", idx); |
| release_mem(tty, idx); |
| goto end_init; |
| } |
| |
| /** |
| * release_mem - release tty structure memory |
| * |
| * Releases memory associated with a tty structure, and clears out the |
| * driver table slots. This function is called when a device is no longer |
| * in use. It also gets called when setup of a device fails. |
| * |
| * Locking: |
| * tty_mutex - sometimes only |
| * takes the file list lock internally when working on the list |
| * of ttys that the driver keeps. |
| * FIXME: should we require tty_mutex is held here ?? |
| */ |
| |
| 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; |
| 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; |
| 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 */ |
| |
| mutex_lock(&tty_mutex); |
| tty_closing = tty->count <= 1; |
| o_tty_closing = o_tty && |
| (o_tty->count <= (pty_master ? 1 : 0)); |
| do_sleep = 0; |
| |
| if (tty_closing) { |
| if (waitqueue_active(&tty->read_wait)) { |
| wake_up(&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)); |
| mutex_unlock(&tty_mutex); |
| schedule(); |
| } |
| |
| /* |
| * The closing flags are now consistent with the open counts on |
| * both sides, and we've completed the last operation that could |
| * block, so it's safe to proceed with closing. |
| */ |
| if (pty_master) { |
| if (--o_tty->count < 0) { |
| printk(KERN_WARNING "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; |
| } |
| |
| /* |
| * 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) { |
| read_lock(&tasklist_lock); |
| session_clear_tty(tty->session); |
| if (o_tty) |
| session_clear_tty(o_tty->session); |
| read_unlock(&tasklist_lock); |
| } |
| |
| mutex_unlock(&tty_mutex); |
| |
| /* check whether both sides are closing ... */ |
| if (!tty_closing || (o_tty && !o_tty_closing)) |
| 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); |
| cancel_delayed_work(&tty->buf.work); |
| |
| /* |
| * Wait for ->hangup_work and ->buf.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 - open a tty device |
| * @inode: inode of device file |
| * @filp: file pointer to tty |
| * |
| * tty_open and tty_release keep up the tty count that contains the |
| * number of opens done on a tty. We cannot use the inode-count, as |
| * different inodes might point to the same tty. |
| * |
| * Open-counting is needed for pty masters, as well as for keeping |
| * track of serial lines: DTR is dropped when the last close happens. |
| * (This is not done solely through tty->count, now. - Ted 1/27/92) |
| * |
| * The termios state of a pty is reset on first open so that |
| * settings don't persist across reuse. |
| * |
| * Locking: tty_mutex protects tty, get_tty_driver and init_dev work. |
| * tty->count should protect the rest. |
| * ->siglock protects ->signal/->sighand |
| */ |
| |
| static int tty_open(struct inode * inode, struct file * filp) |
| { |
| struct tty_struct *tty; |
| 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; |
| |
| mutex_lock(&tty_mutex); |
| |
| if (device == MKDEV(TTYAUX_MAJOR,0)) { |
| tty = get_current_tty(); |
| if (!tty) { |
| mutex_unlock(&tty_mutex); |
| return -ENXIO; |
| } |
| driver = tty->driver; |
| index = 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; |
| } |
| mutex_unlock(&tty_mutex); |
| return -ENODEV; |
| } |
| |
| driver = get_tty_driver(device, &index); |
| if (!driver) { |
| mutex_unlock(&tty_mutex); |
| return -ENODEV; |
| } |
| got_driver: |
| retval = init_dev(driver, index, &tty); |
| mutex_unlock(&tty_mutex); |
| 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; |
| } |
| |
| mutex_lock(&tty_mutex); |
| spin_lock_irq(¤t->sighand->siglock); |
| if (!noctty && |
| current->signal->leader && |
| !current->signal->tty && |
| tty->session == 0) |
| __proc_set_tty(current, tty); |
| spin_unlock_irq(¤t->sighand->siglock); |
| mutex_unlock(&tty_mutex); |
| return 0; |
| } |
| |
| #ifdef CONFIG_UNIX98_PTYS |
| /** |
| * ptmx_open - open a unix 98 pty master |
| * @inode: inode of device file |
| * @filp: file pointer to tty |
| * |
| * Allocate a unix98 pty master device from the ptmx driver. |
| * |
| * Locking: tty_mutex protects theinit_dev work. tty->count should |
| protect the rest. |
| * allocated_ptys_lock handles the list of free pty numbers |
| */ |
| |
| 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); |
| |
| mutex_lock(&tty_mutex); |
| retval = init_dev(ptm_driver, index, &tty); |
| mutex_unlock(&tty_mutex); |
| |
| 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); |
| return retval; |
| out: |
| down(&allocated_ptys_lock); |
| idr_remove(&allocated_ptys, index); |
| up(&allocated_ptys_lock); |
| return retval; |
| } |
| #endif |
| |
| /** |
| * tty_release - vfs callback for close |
| * @inode: inode of tty |
| * @filp: file pointer for handle to tty |
| * |
| * Called the last time each file handle is closed that references |
| * this tty. There may however be several such references. |
| * |
| * Locking: |
| * Takes bkl. See release_dev |
| */ |
| |
| static int tty_release(struct inode * inode, struct file * filp) |
| { |
| lock_kernel(); |
| release_dev(filp); |
| unlock_kernel(); |
| return 0; |
| } |
| |
| /** |
| * tty_poll - check tty status |
| * @filp: file being polled |
| * @wait: poll wait structures to update |
| * |
| * Call the line discipline polling method to obtain the poll |
| * status of the device. |
| * |
| * Locking: locks called line discipline but ldisc poll method |
| * may be re-entered freely by other callers. |
| */ |
| |
| static unsigned int tty_poll(struct file * filp, poll_table * wait) |
| { |
| struct tty_struct * tty; |
| 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; |
| } |
| |
| /** |
| * tiocsti - fake input character |
| * @tty: tty to fake input into |
| * @p: pointer to character |
| * |
| * Fake input to a tty device. Does the neccessary locking and |
| * input management. |
| * |
| * FIXME: does not honour flow control ?? |
| * |
| * Locking: |
| * Called functions take tty_ldisc_lock |
| * current->signal->tty check is safe without locks |
| * |
| * FIXME: may race normal receive processing |
| */ |
| |
| static int tiocsti(struct tty_struct *tty, char __user *p) |
| { |
| char ch, mbz = 0; |
| struct tty_ldisc *ld; |
| |
| if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
| return -EPERM; |
| if (get_user(ch, p)) |
| return -EFAULT; |
| ld = tty_ldisc_ref_wait(tty); |
| ld->receive_buf(tty, &ch, &mbz, 1); |
| tty_ldisc_deref(ld); |
| return 0; |
| } |
| |
| /** |
| * tiocgwinsz - implement window query ioctl |
| * @tty; tty |
| * @arg: user buffer for result |
| * |
| * Copies the kernel idea of the window size into the user buffer. |
| * |
| * Locking: tty->termios_mutex is taken to ensure the winsize data |
| * is consistent. |
| */ |
| |
| static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg) |
| { |
| int err; |
| |
| mutex_lock(&tty->termios_mutex); |
| err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
| mutex_unlock(&tty->termios_mutex); |
| |
| return err ? -EFAULT: 0; |
| } |
| |
| /** |
| * tiocswinsz - implement window size set ioctl |
| * @tty; tty |
| * @arg: user buffer for result |
| * |
| * Copies the user idea of the window size to the kernel. Traditionally |
| * this is just advisory information but for the Linux console it |
| * actually has driver level meaning and triggers a VC resize. |
| * |
| * Locking: |
| * Called function use the console_sem is used to ensure we do |
| * not try and resize the console twice at once. |
| * The tty->termios_mutex is used to ensure we don't double |
| * resize and get confused. Lock order - tty->termios_mutex before |
| * console sem |
| */ |
| |
| 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; |
| |
| mutex_lock(&tty->termios_mutex); |
| if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg))) |
| goto done; |
| |
| #ifdef CONFIG_VT |
| if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) { |
| if (vc_lock_resize(tty->driver_data, tmp_ws.ws_col, |
| tmp_ws.ws_row)) { |
| mutex_unlock(&tty->termios_mutex); |
| 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; |
| done: |
| mutex_unlock(&tty->termios_mutex); |
| return 0; |
| } |
| |
| /** |
| * tioccons - allow admin to move logical console |
| * @file: the file to become console |
| * |
| * Allow the adminstrator to move the redirected console device |
| * |
| * Locking: uses redirect_lock to guard the redirect information |
| */ |
| |
| static int tioccons(struct file *file) |
| { |
| if (!capable(CAP_SYS_ADMIN)) |
| return -EPERM; |
| if (file->f_op->write == redirected_tty_write) { |
| struct file *f; |
| spin_lock(&redirect_lock); |
| f = redirect; |
| redirect = NULL; |
| spin_unlock(&redirect_lock); |
| if (f) |
| fput(f); |
| return 0; |
| } |
| spin_lock(&redirect_lock); |
| if (redirect) { |
| spin_unlock(&redirect_lock); |
| return -EBUSY; |
| } |
| get_file(file); |
| redirect = file; |
| spin_unlock(&redirect_lock); |
| return 0; |
| } |
| |
| /** |
| * fionbio - non blocking ioctl |
| * @file: file to set blocking value |
| * @p: user parameter |
| * |
| * Historical tty interfaces had a blocking control ioctl before |
| * the generic functionality existed. This piece of history is preserved |
| * in the expected tty API of posix OS's. |
| * |
| * Locking: none, the open fle handle ensures it won't go away. |
| */ |
| |
| static int fionbio(struct file *file, int __user *p) |
| { |
| int nonblock; |
| |
| if (get_user(nonblock, p)) |
| return -EFAULT; |
| |
| if (nonblock) |
| file->f_flags |= O_NONBLOCK; |
| else |
| file->f_flags &= ~O_NONBLOCK; |
| return 0; |
| } |
| |
| /** |
| * tiocsctty - set controlling tty |
| * @tty: tty structure |
| * @arg: user argument |
| * |
| * This ioctl is used to manage job control. It permits a session |
| * leader to set this tty as the controlling tty for the session. |
| * |
| * Locking: |
| * Takes tty_mutex() to protect tty instance |
| * Takes tasklist_lock internally to walk sessions |
| * Takes ->siglock() when updating signal->tty |
| */ |
| |
| static int tiocsctty(struct tty_struct *tty, int arg) |
| { |
| int ret = 0; |
| if (current->signal->leader && |
| (current->signal->session == tty->session)) |
| return ret; |
| |
| mutex_lock(&tty_mutex); |
| /* |
| * The process must be a session leader and |
| * not have a controlling tty already. |
| */ |
| if (!current->signal->leader || current->signal->tty) { |
| ret = -EPERM; |
| goto unlock; |
| } |
| |
| if (tty->session > 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); |
| session_clear_tty(tty->session); |
| read_unlock(&tasklist_lock); |
| } else { |
| ret = -EPERM; |
| goto unlock; |
| } |
| } |
| proc_set_tty(current, tty); |
| unlock: |
| mutex_unlock(&tty_mutex); |
| return ret; |
| } |
| |
| /** |
| * tiocgpgrp - get process group |
| * @tty: tty passed by user |
| * @real_tty: tty side of the tty pased by the user if a pty else the tty |
| * @p: returned pid |
| * |
| * Obtain the process group of the tty. If there is no process group |
| * return an error. |
| * |
| * Locking: none. Reference to current->signal->tty is safe. |
| */ |
| |
| static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
| { |
| /* |
| * (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); |
| } |
| |
| /** |
| * tiocspgrp - attempt to set process group |
| * @tty: tty passed by user |
| * @real_tty: tty side device matching tty passed by user |
| * @p: pid pointer |
| * |
| * Set the process group of the tty to the session passed. Only |
| * permitted where the tty session is our session. |
| * |
| * Locking: None |
| */ |
| |
| 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; |
| } |
| |
| /** |
| * tiocgsid - get session id |
| * @tty: tty passed by user |
| * @real_tty: tty side of the tty pased by the user if a pty else the tty |
| * @p: pointer to returned session id |
| * |
| * Obtain the session id of the tty. If there is no session |
| * return an error. |
| * |
| * Locking: none. Reference to current->signal->tty is safe. |
| */ |
| |
| static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
| { |
| /* |
| * (tty == real_tty) is a cheap way of |
| * testing if the tty is NOT a master pty. |
| */ |
| if (tty == real_tty && current->signal->tty != real_tty) |
| return -ENOTTY; |
| if (real_tty->session <= 0) |
| return -ENOTTY; |
| return put_user(real_tty->session, p); |
| } |
| |
| /** |
| * tiocsetd - set line discipline |
| * @tty: tty device |
| * @p: pointer to user data |
| * |
| * Set the line discipline according to user request. |
| * |
| * Locking: see tty_set_ldisc, this function is just a helper |
| */ |
| |
| static int tiocsetd(struct tty_struct *tty, int __user *p) |
| { |
| int ldisc; |
| |
| if (get_user(ldisc, p)) |
| return -EFAULT; |
| return tty_set_ldisc(tty, ldisc); |
| } |
| |
| /** |
| * send_break - performed time break |
| * @tty: device to break on |
| * @duration: timeout in mS |
| * |
| * Perform a timed break on hardware that lacks its own driver level |
| * timed break functionality. |
| * |
| * Locking: |
| * atomic_write_lock serializes |
| * |
| */ |
| |
| static int send_break(struct tty_struct *tty, unsigned int duration) |
| { |
| if (mutex_lock_interruptible(&tty->atomic_write_lock)) |
| return -EINTR; |
| tty->driver->break_ctl(tty, -1); |
| if (!signal_pending(current)) { |
| msleep_interruptible(duration); |
| } |
| tty->driver->break_ctl(tty, 0); |
| mutex_unlock(&tty->atomic_write_lock); |
| if (signal_pending(current)) |
| return -EINTR; |
| return 0; |
| } |
| |
| /** |
| * tiocmget - get modem status |
| * @tty: tty device |
| * @file: user file pointer |
| * @p: pointer to result |
| * |
| * Obtain the modem status bits from the tty driver if the feature |
| * is supported. Return -EINVAL if it is not available. |
| * |
| * Locking: none (up to the driver) |
| */ |
| |
| static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) |
| { |
| int retval = -EINVAL; |
| |
| if (tty->driver->tiocmget) { |
| retval = tty->driver->tiocmget(tty, file); |
| |
| if (retval >= 0) |
| retval = put_user(retval, p); |
| } |
| return retval; |
| } |
| |
| /** |
| * tiocmset - set modem status |
| * @tty: tty device |
| * @file: user file pointer |
| * @cmd: command - clear bits, set bits or set all |
| * @p: pointer to desired bits |
| * |
| * Set the modem status bits from the tty driver if the feature |
| * is supported. Return -EINVAL if it is not available. |
| * |
| * Locking: none (up to the driver) |
| */ |
| |
| static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, |
| unsigned __user *p) |
| { |
| int retval = -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; |
| |
| /* CHECKME: is this safe as one end closes ? */ |
| |
| 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); |
| proc_clear_tty(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 */ |
| /* non-zero arg means wait for all output data |
| * to be sent (performed above) but don't send break. |
| * This is used by the tcdrain() termios function. |
| */ |
| if (!arg) |
| return send_break(tty, 250); |
| return 0; |
| case TCSBRKP: /* support for POSIX tcsendbreak() */ |
| return send_break(tty, arg ? arg*100 : 250); |
| |
| case TIOCMGET: |
| return tty_tiocmget(tty, file, p); |
| |
| case TIOCMSET: |
| case TIOCMBIC: |
| case TIOCMBIS: |
| return tty_tiocmset(tty, file, cmd, p); |
| } |
| 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(struct work_struct *work) |
| { |
| struct tty_struct *tty = |
| container_of(work, struct tty_struct, SAK_work); |
| #ifdef TTY_SOFT_SAK |
| tty_hangup(tty); |
| #else |
| struct task_struct *g, *p; |
| int session; |
| int i; |
| struct file *filp; |
| struct tty_ldisc *disc; |
| struct fdtable *fdt; |
| |
| 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); |
| /* Kill the entire session */ |
| do_each_task_pid(session, PIDTYPE_SID, p) { |
| printk(KERN_NOTICE "SAK: killed process %d" |
| " (%s): p->signal->session==tty->session\n", |
| p->pid, p->comm); |
| send_sig(SIGKILL, p, 1); |
| } while_each_task_pid(session, PIDTYPE_SID, p); |
| /* Now kill any processes that happen to have the |
| * tty open. |
| */ |
| do_each_thread(g, p) { |
| if (p->signal->tty == tty) { |
| printk(KERN_NOTICE "SAK: killed process %d" |
| " (%s): p->signal->session==tty->session\n", |
| p->pid, p->comm); |
| send_sig(SIGKILL, p, 1); |
| continue; |
| } |
| task_lock(p); |
| if (p->files) { |
| /* |
| * We don't take a ref to the file, so we must |
| * hold ->file_lock instead. |
| */ |
| spin_lock(&p->files->file_lock); |
| fdt = files_fdtable(p->files); |
| for (i=0; i < fdt->max_fds; i++) { |
| filp = fcheck_files(p->files, i); |
| if (!filp) |
| continue; |
| if (filp->f_op->read == tty_read && |
| filp->private_data == tty) { |
| printk(KERN_NOTICE "SAK: killed process %d" |
| " (%s): fd#%d opened to the tty\n", |
| p->pid, p->comm, i); |
| force_sig(SIGKILL, p); |
| break; |
| } |
| } |
| spin_unlock(&p->files->file_lock); |
| } |
| task_unlock(p); |
| } while_each_thread(g, p); |
| read_unlock(&tasklist_lock); |
| #endif |
| } |
| |
| /* |
| * 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); |
| schedule_work(&tty->SAK_work); |
| } |
| |
| EXPORT_SYMBOL(do_SAK); |
| |
| /** |
| * flush_to_ldisc |
| * @work: tty structure passed from work queue. |
| * |
| * This routine is called out of the software interrupt to flush data |
| * from the buffer chain to the line discipline. |
| * |
| * Locking: holds tty->buf.lock to guard buffer list. Drops the lock |
| * while invoking the line discipline receive_buf method. The |
| * receive_buf method is single threaded for each tty instance. |
| */ |
| |
| static void flush_to_ldisc(struct work_struct *work) |
| { |
| struct tty_struct *tty = |
| container_of(work, struct tty_struct, buf.work.work); |
| unsigned long flags; |
| struct tty_ldisc *disc; |
| struct tty_buffer *tbuf, *head; |
| char *char_buf; |
| unsigned char *flag_buf; |
| |
| disc = tty_ldisc_ref(tty); |
| if (disc == NULL) /* !TTY_LDISC */ |
| return; |
| |
| spin_lock_irqsave(&tty->buf.lock, flags); |
| head = tty->buf.head; |
| if (head != NULL) { |
| tty->buf.head = NULL; |
| for (;;) { |
| int count = head->commit - head->read; |
| if (!count) { |
| if (head->next == NULL) |
| break; |
| tbuf = head; |
| head = head->next; |
| tty_buffer_free(tty, tbuf); |
| continue; |
| } |
| if (!tty->receive_room) { |
| schedule_delayed_work(&tty->buf.work, 1); |
| break; |
| } |
| if (count > tty->receive_room) |
| count = tty->receive_room; |
| char_buf = head->char_buf_ptr + head->read; |
| flag_buf = head->flag_buf_ptr + head->read; |
| head->read += count; |
| spin_unlock_irqrestore(&tty->buf.lock, flags); |
| disc->receive_buf(tty, char_buf, flag_buf, count); |
| spin_lock_irqsave(&tty->buf.lock, flags); |
| } |
| tty->buf.head = head; |
| } |
| spin_unlock_irqrestore(&tty->buf.lock, flags); |
| |
| 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. |
| * |
| * Locking: none |
| */ |
| |
| 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. |
| * |
| * Locking: none |
| */ |
| |
| 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. |
| * |
| * Locking: tty buffer lock. Driver locks in low latency mode. |
| */ |
| |
| void tty_flip_buffer_push(struct tty_struct *tty) |
| { |
| unsigned long flags; |
| spin_lock_irqsave(&tty->buf.lock, flags); |
| if (tty->buf.tail != NULL) |
| tty->buf.tail->commit = tty->buf.tail->used; |
| spin_unlock_irqrestore(&tty->buf.lock, flags); |
| |
| if (tty->low_latency) |
| flush_to_ldisc(&tty->buf.work.work); |
| else |
| schedule_delayed_work(&tty->buf.work, 1); |
| } |
| |
| EXPORT_SYMBOL(tty_flip_buffer_push); |
| |
| |
| /** |
| * initialize_tty_struct |
| * @tty: tty to initialize |
| * |
| * This subroutine initializes a tty structure that has been newly |
| * allocated. |
| * |
| * Locking: none - tty in question must not be exposed at this point |
| */ |
| |
| 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->buf.head = tty->buf.tail = NULL; |
| tty_buffer_init(tty); |
| INIT_DELAYED_WORK(&tty->buf.work, flush_to_ldisc); |
| init_MUTEX(&tty->buf.pty_sem); |
| mutex_init(&tty->termios_mutex); |
| init_waitqueue_head(&tty->write_wait); |
| init_waitqueue_head(&tty->read_wait); |
| INIT_WORK(&tty->hangup_work, do_tty_hangup); |
| mutex_init(&tty->atomic_read_lock); |
| mutex_init(&tty->atomic_write_lock); |
| spin_lock_init(&tty->read_lock); |
| INIT_LIST_HEAD(&tty->tty_files); |
| INIT_WORK(&tty->SAK_work, 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 *tty_class; |
| |
| /** |
| * tty_register_device - register a tty device |
| * @driver: the tty driver that describes the tty device |
| * @index: the index in the tty driver for this tty device |
| * @device: a struct device that is associated with this tty device. |
| * This field is optional, if there is no known struct device |
| * for this tty device it can be set to NULL safely. |
| * |
| * Returns a pointer to the struct device for this tty device |
| * (or ERR_PTR(-EFOO) on error). |
| * |
| * This call is required to be made to register an individual tty device |
| * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If |
| * that bit is not set, this function should not be called by a tty |
| * driver. |
| * |
| * Locking: ?? |
| */ |
| |
| struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
| struct device *device) |
| { |
| char name[64]; |
| dev_t dev = MKDEV(driver->major, driver->minor_start) + index; |
| |
| if (index >= driver->num) { |
| printk(KERN_ERR "Attempt to register invalid tty line number " |
| " (%d).\n", index); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| if (driver->type == TTY_DRIVER_TYPE_PTY) |
| pty_line_name(driver, index, name); |
| else |
| tty_line_name(driver, index, name); |
| |
| return device_create(tty_class, device, dev, 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 called when the tty device is gone. |
| * |
| * Locking: ?? |
| */ |
| |
| void tty_unregister_device(struct tty_driver *driver, unsigned index) |
| { |
| device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index); |
| } |
| |
| EXPORT_SYMBOL(tty_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, |
| const 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) { |
| 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_DYNAMIC_DEV) ) { |
| 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_DYNAMIC_DEV)) |
| 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); |
| |
| dev_t tty_devnum(struct tty_struct *tty) |
| { |
| return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; |
| } |
| EXPORT_SYMBOL(tty_devnum); |
| |
| void proc_clear_tty(struct task_struct *p) |
| { |
| spin_lock_irq(&p->sighand->siglock); |
| p->signal->tty = NULL; |
| spin_unlock_irq(&p->sighand->siglock); |
| } |
| EXPORT_SYMBOL(proc_clear_tty); |
| |
| void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
| { |
| if (tty) { |
| tty->session = tsk->signal->session; |
| tty->pgrp = process_group(tsk); |
| } |
| tsk->signal->tty = tty; |
| tsk->signal->tty_old_pgrp = 0; |
| } |
| |
| void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
| { |
| spin_lock_irq(&tsk->sighand->siglock); |
| __proc_set_tty(tsk, tty); |
| spin_unlock_irq(&tsk->sighand->siglock); |
| } |
| |
| struct tty_struct *get_current_tty(void) |
| { |
| struct tty_struct *tty; |
| WARN_ON_ONCE(!mutex_is_locked(&tty_mutex)); |
| tty = current->signal->tty; |
| /* |
| * session->tty can be changed/cleared from under us, make sure we |
| * issue the load. The obtained pointer, when not NULL, is valid as |
| * long as we hold tty_mutex. |
| */ |
| barrier(); |
| return tty; |
| } |
| |
| /* |
| * 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 |
| 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_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"); |
| device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), "tty"); |
| |
| cdev_init(&console_cdev, &console_fops); |
| if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || |
| register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) |
| panic("Couldn't register /dev/console driver\n"); |
| device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), "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"); |
| device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), "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"); |
| device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), "tty0"); |
| |
| vty_init(); |
| #endif |
| return 0; |
| } |
| module_init(tty_init); |