* alloc_tty_struct() always uses kmalloc() -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
*/
-#include <linux/config.h>
#include <linux/types.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/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 <asm/bitops.h>
#include <linux/kbd_kern.h>
#include <linux/vt_kern.h>
#include <linux/selection.h>
-#include <linux/devfs_fs_kernel.h>
-#include <linux/vs_cvirt.h>
#include <linux/kmod.h>
+#include <linux/vs_base.h>
+#include <linux/vs_cvirt.h>
#undef TTY_DEBUG_HANGUP
LIST_HEAD(tty_drivers); /* linked list of tty drivers */
-/* Semaphore to protect creating and releasing a tty. This is shared with
+/* Mutex to protect creating and releasing a tty. This is shared with
vt.c for deeply disgusting hack reasons */
-DECLARE_MUTEX(tty_sem);
+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);
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 ptmx_open(struct inode *, struct file *);
static int tty_release(struct inode *, struct file *);
int tty_ioctl(struct inode * inode, struct file * file,
unsigned int cmd, unsigned long arg);
static int tty_fasync(int fd, struct file * filp, int on);
-extern void rs_360_init(void);
static void release_mem(struct tty_struct *tty, int idx);
+/**
+ * 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)
{
- struct tty_struct *tty;
-
- tty = kmalloc(sizeof(struct tty_struct), GFP_KERNEL);
- if (tty)
- memset(tty, 0, sizeof(struct tty_struct));
- return tty;
+ 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. */
EXPORT_SYMBOL(tty_name);
-inline int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
+int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
const char *routine)
{
#ifdef TTY_PARANOIA_CHECK
"!= #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)
{
- down(&tty->termios_sem);
+ mutex_lock(&tty->termios_mutex);
tty->termios->c_line = num;
- up(&tty->termios_sem);
+ mutex_unlock(&tty->termios_mutex);
}
/*
* callers who will do ldisc lookups and cannot sleep.
*/
-static spinlock_t tty_ldisc_lock = SPIN_LOCK_UNLOCKED;
+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 */
+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)
{
return -EINVAL;
spin_lock_irqsave(&tty_ldisc_lock, flags);
- if (new_ldisc) {
- tty_ldiscs[disc] = *new_ldisc;
- tty_ldiscs[disc].num = disc;
- tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED;
- tty_ldiscs[disc].refcount = 0;
- } else {
- if(tty_ldiscs[disc].refcount)
- ret = -EBUSY;
- else
- tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED;
- }
+ 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;
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;
- if (disc < N_TTY || disc >= NR_LDISCS)
- BUG();
+ BUG_ON(disc < N_TTY || disc >= NR_LDISCS);
spin_lock_irqsave(&tty_ldisc_lock, flags);
ld = &tty_ldiscs[disc];
- if(ld->refcount == 0)
- BUG();
- ld->refcount --;
+ BUG_ON(ld->refcount == 0);
+ ld->refcount--;
module_put(ld->owner);
spin_unlock_irqrestore(&tty_ldisc_lock, flags);
}
EXPORT_SYMBOL_GPL(tty_ldisc_put);
-void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
+/**
+ * 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;
* 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)
* 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)
* 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)
*
* 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;
- if(ld == NULL)
- BUG();
+ BUG_ON(ld == NULL);
spin_lock_irqsave(&tty_ldisc_lock, flags);
if(ld->refcount == 0)
*
* 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;
+ 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:
- if (tty->ldisc.num == ldisc)
- return 0; /* We are already in the desired discipline */
-
ld = tty_ldisc_get(ldisc);
/* Eduardo Blanco <ejbs@cs.cs.com.uy> */
/* Cyrus Durgin <cider@speakeasy.org> */
if (ld == NULL)
return -EINVAL;
- o_ldisc = tty->ldisc;
+ /*
+ * 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)
- {
- /* Free the new ldisc we grabbed. Must drop the lock
- first. */
+ 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);
- /*
- * 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;
+ ld = tty_ldisc_ref_wait(tty);
+ tty_ldisc_deref(ld);
goto restart;
}
- clear_bit(TTY_LDISC, &tty->flags);
- clear_bit(TTY_DONT_FLIP, &tty->flags);
+
+ 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->flip.work);
+
+ work = cancel_delayed_work(&tty->buf.work);
/*
- * Wait for ->hangup_work and ->flip.work handlers to terminate
+ * Wait for ->hangup_work and ->buf.work handlers to terminate
*/
flush_scheduled_work();
*/
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->flip.work, 1);
+ if (work)
+ schedule_delayed_work(&tty->buf.work, 1);
return retval;
}
-/*
- * This routine returns a tty driver structure, given a device number
+/**
+ * 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
*/
-struct tty_driver *get_tty_driver(dev_t device, int *index)
+
+static struct tty_driver *get_tty_driver(dev_t device, int *index)
{
struct tty_driver *p;
return NULL;
}
-/*
- * If we try to write to, or set the state of, a terminal and we're
- * not in the foreground, send a SIGTTOU. If the signal is blocked or
- * ignored, go ahead and perform the operation. (POSIX 7.2)
+/**
+ * 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 cmd == TIOCSPGRP ? -ENOTTY : -EIO;
}
-static struct file_operations tty_fops = {
+static const struct file_operations tty_fops = {
.llseek = no_llseek,
.read = tty_read,
.write = tty_write,
};
#ifdef CONFIG_UNIX98_PTYS
-static struct file_operations ptmx_fops = {
+static const struct file_operations ptmx_fops = {
.llseek = no_llseek,
.read = tty_read,
.write = tty_write,
};
#endif
-static struct file_operations console_fops = {
+static const struct file_operations console_fops = {
.llseek = no_llseek,
.read = tty_read,
.write = redirected_tty_write,
.fasync = tty_fasync,
};
-static struct file_operations hung_up_tty_fops = {
+static const struct file_operations hung_up_tty_fops = {
.llseek = no_llseek,
.read = hung_up_tty_read,
.write = hung_up_tty_write,
.release = tty_release,
};
-static spinlock_t redirect_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(redirect_lock);
static struct file *redirect;
/**
EXPORT_SYMBOL_GPL(tty_ldisc_flush);
-/*
- * This can be called by the "eventd" kernel thread. That is process synchronous,
- * but doesn't hold any locks, so we need to make sure we have the appropriate
- * locks for what we're doing..
+/**
+ * do_tty_hangup - actual handler for hangup events
+ * @data: 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
*/
-void do_tty_hangup(void *data)
+static void do_tty_hangup(void *data)
{
struct tty_struct *tty = (struct tty_struct *) data;
struct file * cons_filp = NULL;
check_tty_count(tty, "do_tty_hangup");
file_list_lock();
/* This breaks for file handles being sent over AF_UNIX sockets ? */
- list_for_each_entry(filp, &tty->tty_files, f_list) {
+ 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)
*/
if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
{
- down(&tty->termios_sem);
+ mutex_lock(&tty->termios_mutex);
*tty->termios = tty->driver->init_termios;
- up(&tty->termios_sem);
+ mutex_unlock(&tty->termios_mutex);
}
/* Defer ldisc switch */
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)
+ if (!p->signal->leader) {
+ spin_unlock_irq(&p->sighand->siglock);
continue;
- send_group_sig_info(SIGHUP, SEND_SIG_PRIV, p);
- send_group_sig_info(SIGCONT, SEND_SIG_PRIV, p);
+ }
+ __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);
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
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
}
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);
-/*
- * This function is typically called only by the session leader, when
- * it wants to disassociate itself from its controlling tty.
+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
*
- * It performs the following functions:
+ * 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.
+ * 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;
- struct task_struct *p;
int tty_pgrp = -1;
+ int session;
lock_kernel();
- tty = current->signal->tty;
+ 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 {
- if (current->signal->tty_old_pgrp) {
- kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit);
- kill_pg(current->signal->tty_old_pgrp, SIGCONT, on_exit);
+ 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;
}
kill_pg(tty_pgrp, SIGCONT, on_exit);
}
+ spin_lock_irq(¤t->sighand->siglock);
current->signal->tty_old_pgrp = 0;
- tty->session = 0;
- tty->pgrp = -1;
+ 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);
- do_each_task_pid(current->signal->session, PIDTYPE_SID, p) {
- p->signal->tty = NULL;
- } while_each_task_pid(current->signal->session, PIDTYPE_SID, p);
+ 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)
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)
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)
{
tty_ldisc_deref(ld);
unlock_kernel();
if (i > 0)
- inode->i_atime = CURRENT_TIME;
+ inode->i_atime = current_fs_time(inode->i_sb);
return i;
}
* denial-of-service type attacks
*/
static inline ssize_t do_tty_write(
- ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char __user *, size_t),
+ ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t),
struct tty_struct *tty,
struct file *file,
- const unsigned char __user *buf,
+ const char __user *buf,
size_t count)
{
ssize_t ret = 0, written = 0;
+ unsigned int chunk;
- if (down_interruptible(&tty->atomic_write)) {
+ /* FIXME: O_NDELAY ... */
+ if (mutex_lock_interruptible(&tty->atomic_write_lock)) {
return -ERESTARTSYS;
}
- if ( test_bit(TTY_NO_WRITE_SPLIT, &tty->flags) ) {
+
+ /*
+ * 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();
- written = write(tty, file, buf, count);
+ ret = write(tty, file, tty->write_buf, size);
unlock_kernel();
- } else {
- for (;;) {
- unsigned long size = max((unsigned long)PAGE_SIZE*2, 16384UL);
- if (size > count)
- size = count;
- lock_kernel();
- ret = write(tty, file, 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 (ret <= 0)
+ break;
+ written += ret;
+ buf += ret;
+ count -= ret;
+ if (!count)
+ break;
+ ret = -ERESTARTSYS;
+ if (signal_pending(current))
+ break;
+ cond_resched();
}
if (written) {
- file->f_dentry->d_inode->i_mtime = CURRENT_TIME;
+ struct inode *inode = file->f_dentry->d_inode;
+ inode->i_mtime = current_fs_time(inode->i_sb);
ret = written;
}
- up(&tty->atomic_write);
+ 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)
{
if (!ld->write)
ret = -EIO;
else
- ret = do_tty_write(ld->write, tty, file,
- (const unsigned char __user *)buf, count);
+ ret = do_tty_write(ld->write, tty, file, buf, count);
tty_ldisc_deref(ld);
return ret;
}
static char ptychar[] = "pqrstuvwxyzabcde";
-static inline void pty_line_name(struct tty_driver *driver, int index, char *p)
+/**
+ * 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 */
ptychar[i >> 4 & 0xf], i & 0xf);
}
-static inline void tty_line_name(struct tty_driver *driver, int index, char *p)
+/**
+ * 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 semaphore, so it's
- * really quite straightforward. The semaphore locking can probably be
+ * 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 need to acquire the tty semaphore to avoid
- * race conditions. For now, play it safe.
- */
- down(&tty_sem);
+ int retval = 0;
/* check whether we're reopening an existing tty */
if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
success:
*ret_tty = tty;
- /* All paths come through here to release the semaphore */
+ /* All paths come through here to release the mutex */
end_init:
- up(&tty_sem);
return retval;
/* Release locally allocated memory ... nothing placed in slots */
free_mem_out:
- if (o_tp)
- kfree(o_tp);
+ kfree(o_tp);
if (o_tty)
free_tty_struct(o_tty);
- if (ltp)
- kfree(ltp);
- if (tp)
- kfree(tp);
+ kfree(ltp);
+ kfree(tp);
free_tty_struct(tty);
fail_no_mem:
goto end_init;
}
-/*
- * Releases memory associated with a tty structure, and clears out the
- * driver table slots.
+/**
+ * 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 tty_struct *tty, *o_tty;
int pty_master, tty_closing, o_tty_closing, do_sleep;
- int devpts_master, devpts;
+ int devpts;
int idx;
char buf[64];
unsigned long flags;
pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_MASTER);
devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0;
- devpts_master = pty_master && devpts;
o_tty = tty->link;
#ifdef TTY_PARANOIA_CHECK
* 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));
printk(KERN_WARNING "release_dev: %s: read/write wait queue "
"active!\n", tty_name(tty, buf));
+ mutex_unlock(&tty_mutex);
schedule();
}
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
* tty.
*/
if (tty_closing || o_tty_closing) {
- struct task_struct *p;
-
read_lock(&tasklist_lock);
- do_each_task_pid(tty->session, PIDTYPE_SID, p) {
- p->signal->tty = NULL;
- } while_each_task_pid(tty->session, PIDTYPE_SID, p);
+ session_clear_tty(tty->session);
if (o_tty)
- do_each_task_pid(o_tty->session, PIDTYPE_SID, p) {
- p->signal->tty = NULL;
- } while_each_task_pid(o_tty->session, PIDTYPE_SID, p);
+ 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;
* race with the set_ldisc code path.
*/
clear_bit(TTY_LDISC, &tty->flags);
- clear_bit(TTY_DONT_FLIP, &tty->flags);
- cancel_delayed_work(&tty->flip.work);
+ cancel_delayed_work(&tty->buf.work);
/*
- * Wait for ->hangup_work and ->flip.work handlers to terminate
+ * Wait for ->hangup_work and ->buf.work handlers to terminate
*/
flush_scheduled_work();
}
-/*
- * 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.
+/**
+ * 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)
*
- * 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.
*
- * 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;
noctty = filp->f_flags & O_NOCTTY;
index = -1;
retval = 0;
+
+ mutex_lock(&tty_mutex);
if (device == MKDEV(TTYAUX_MAJOR,0)) {
- if (!current->signal->tty)
+ tty = get_current_tty();
+ if (!tty) {
+ mutex_unlock(&tty_mutex);
return -ENXIO;
- driver = current->signal->tty->driver;
- index = current->signal->tty->index;
+ }
+ 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 int fg_console;
extern struct tty_driver *console_driver;
driver = console_driver;
index = fg_console;
noctty = 1;
goto got_driver;
}
+ mutex_unlock(&tty_mutex);
return -ENODEV;
}
driver = get_tty_driver(device, &index);
- if (!driver)
+ 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->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) {
- task_lock(current);
- current->signal->tty = tty;
- task_unlock(current);
- current->signal->tty_old_pgrp = 0;
- tty->session = current->signal->session;
- tty->pgrp = process_group(current);
- }
+ 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;
}
up(&allocated_ptys_lock);
+ mutex_lock(&tty_mutex);
retval = init_dev(ptm_driver, index, &tty);
+ mutex_unlock(&tty_mutex);
+
if (retval)
goto out;
return 0;
out1:
release_dev(filp);
+ return retval;
out:
down(&allocated_ptys_lock);
idr_remove(&allocated_ptys, index);
}
#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();
return 0;
}
-/* No kernel lock held - fine */
+/**
+ * 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;
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;
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)
{
- if (copy_to_user(arg, &tty->winsize, sizeof(*arg)))
- return -EFAULT;
- return 0;
+ 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)
{
if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
return -EFAULT;
+
+ mutex_lock(&tty->termios_mutex);
if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg)))
- return 0;
+ goto done;
+
#ifdef CONFIG_VT
if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) {
- unsigned int currcons = tty->index;
- int rc;
-
- acquire_console_sem();
- rc = vc_resize(currcons, tmp_ws.ws_col, tmp_ws.ws_row);
- release_console_sem();
- if (rc)
- return -ENXIO;
+ 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(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 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)
{
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)
{
- task_t *p;
-
+ int ret = 0;
if (current->signal->leader &&
(current->signal->session == tty->session))
- return 0;
+ 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)
- return -EPERM;
+ if (!current->signal->leader || current->signal->tty) {
+ ret = -EPERM;
+ goto unlock;
+ }
+
if (tty->session > 0) {
/*
* This tty is already the controlling
/*
* Steal it away
*/
-
read_lock(&tasklist_lock);
- do_each_task_pid(tty->session, PIDTYPE_SID, p) {
- p->signal->tty = NULL;
- } while_each_task_pid(tty->session, PIDTYPE_SID, p);
+ session_clear_tty(tty->session);
read_unlock(&tasklist_lock);
- } else
- return -EPERM;
+ } else {
+ ret = -EPERM;
+ goto unlock;
+ }
}
- task_lock(current);
- current->signal->tty = tty;
- task_unlock(current);
- current->signal->tty_old_pgrp = 0;
- tty->session = current->signal->session;
- tty->pgrp = process_group(current);
- return 0;
+ 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)
{
pid_t pgrp;
return put_user(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;
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)
{
/*
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;
return tty_set_ldisc(tty, ldisc);
}
-static int send_break(struct tty_struct *tty, int duration)
+/**
+ * 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)) {
- set_current_state(TASK_INTERRUPTIBLE);
- schedule_timeout(duration);
+ msleep_interruptible(duration);
}
tty->driver->break_ctl(tty, 0);
+ mutex_unlock(&tty->atomic_write_lock);
if (signal_pending(current))
return -EINTR;
return 0;
}
-static int
-tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p)
+/**
+ * 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;
return retval;
}
-static int
-tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd,
+/**
+ * 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_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)
return -ENOTTY;
if (current->signal->leader)
disassociate_ctty(0);
- task_lock(current);
- current->signal->tty = NULL;
- task_unlock(current);
+ proc_clear_tty(current);
return 0;
case TIOCSCTTY:
return tiocsctty(tty, arg);
tty->driver->break_ctl(tty, 0);
return 0;
case TCSBRK: /* SVID version: non-zero arg --> no break */
- /*
- * XXX is the above comment correct, or the
- * code below correct? Is this ioctl used at
- * all by anyone?
+ /* 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, HZ/4);
+ return send_break(tty, 250);
return 0;
case TCSBRKP: /* support for POSIX tcsendbreak() */
- return send_break(tty, arg ? arg*(HZ/10) : HZ/4);
+ return send_break(tty, arg ? arg*100 : 250);
case TIOCMGET:
return tty_tiocmget(tty, file, p);
tty_hangup(tty);
#else
struct tty_struct *tty = arg;
- struct task_struct *p;
+ 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;
+ session = tty->session;
/* We don't want an ldisc switch during this */
disc = tty_ldisc_ref(tty);
tty->driver->flush_buffer(tty);
read_lock(&tasklist_lock);
+ /* Kill the entire session */
do_each_task_pid(session, PIDTYPE_SID, p) {
- if (p->signal->tty == tty || session > 0) {
+ printk(KERN_NOTICE "SAK: killed process %d"
+ " (%s): p->signal->session==tty->session\n",
+ p->pid, p->comm);
+ send_sig(SIGKILL, p, 1);
+ } 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);
}
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);
- for (i=0; i < p->files->max_fds; i++) {
+ fdt = files_fdtable(p->files);
+ for (i=0; i < fdt->max_fds; i++) {
filp = fcheck_files(p->files, i);
if (!filp)
continue;
printk(KERN_NOTICE "SAK: killed process %d"
" (%s): fd#%d opened to the tty\n",
p->pid, p->comm, i);
- send_sig(SIGKILL, p, 1);
+ force_sig(SIGKILL, p);
break;
}
}
spin_unlock(&p->files->file_lock);
}
task_unlock(p);
- } while_each_task_pid(session, PIDTYPE_SID, p);
+ } while_each_thread(g, p);
read_unlock(&tasklist_lock);
#endif
}
EXPORT_SYMBOL(do_SAK);
-/*
- * This routine is called out of the software interrupt to flush data
- * from the flip buffer to the line discipline.
+/**
+ * flush_to_ldisc
+ * @private_: 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(void *private_)
{
struct tty_struct *tty = (struct tty_struct *) private_;
- unsigned char *cp;
- char *fp;
- int count;
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;
- if (test_bit(TTY_DONT_FLIP, &tty->flags)) {
- /*
- * Do it after the next timer tick:
- */
- schedule_delayed_work(&tty->flip.work, 1);
- goto out;
- }
- spin_lock_irqsave(&tty->read_lock, flags);
- if (tty->flip.buf_num) {
- cp = tty->flip.char_buf + TTY_FLIPBUF_SIZE;
- fp = tty->flip.flag_buf + TTY_FLIPBUF_SIZE;
- tty->flip.buf_num = 0;
- tty->flip.char_buf_ptr = tty->flip.char_buf;
- tty->flip.flag_buf_ptr = tty->flip.flag_buf;
- } else {
- cp = tty->flip.char_buf;
- fp = tty->flip.flag_buf;
- tty->flip.buf_num = 1;
- tty->flip.char_buf_ptr = tty->flip.char_buf + TTY_FLIPBUF_SIZE;
- tty->flip.flag_buf_ptr = tty->flip.flag_buf + TTY_FLIPBUF_SIZE;
+ 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;
}
- count = tty->flip.count;
- tty->flip.count = 0;
- spin_unlock_irqrestore(&tty->read_lock, flags);
-
- disc->receive_buf(tty, cp, fp, count);
-out:
- tty_ldisc_deref(disc);
-}
-
-/*
- * Call the ldisc flush directly from a driver. This function may
- * return an error and need retrying by the user.
- */
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
-int tty_push_data(struct tty_struct *tty, unsigned char *cp, unsigned char *fp, int count)
-{
- int ret = 0;
- struct tty_ldisc *disc;
-
- disc = tty_ldisc_ref(tty);
- if(test_bit(TTY_DONT_FLIP, &tty->flags))
- ret = -EAGAIN;
- else if(disc == NULL)
- ret = -EIO;
- else
- disc->receive_buf(tty, cp, fp, count);
tty_ldisc_deref(disc);
- return ret;
-
}
/*
* 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)
* 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)
*
* 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((void *) tty);
else
- schedule_delayed_work(&tty->flip.work, 1);
+ schedule_delayed_work(&tty->buf.work, 1);
}
EXPORT_SYMBOL(tty_flip_buffer_push);
-/*
- * This subroutine initializes a tty structure.
+
+/**
+ * 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->flip.char_buf_ptr = tty->flip.char_buf;
- tty->flip.flag_buf_ptr = tty->flip.flag_buf;
- INIT_WORK(&tty->flip.work, flush_to_ldisc, tty);
- init_MUTEX(&tty->flip.pty_sem);
- init_MUTEX(&tty->termios_sem);
+ tty->overrun_time = jiffies;
+ tty->buf.head = tty->buf.tail = NULL;
+ tty_buffer_init(tty);
+ INIT_WORK(&tty->buf.work, flush_to_ldisc, tty);
+ 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, tty);
- sema_init(&tty->atomic_read, 1);
- sema_init(&tty->atomic_write, 1);
+ 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, 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, 0, &ch, 1);
+ tty->driver->write(tty, &ch, 1);
}
-static struct class_simple *tty_class;
+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.
+ * 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 class 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_NO_DEVFS bit set. If that
- * bit is not set, this function should not be called.
+ * 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: ??
*/
-void tty_register_device(struct tty_driver *driver, unsigned index,
- struct device *device)
+
+struct class_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;
+ return ERR_PTR(-EINVAL);
}
- devfs_mk_cdev(dev, S_IFCHR | S_IRUSR | S_IWUSR,
- "%s%d", driver->devfs_name, index + driver->name_base);
-
if (driver->type == TTY_DRIVER_TYPE_PTY)
pty_line_name(driver, index, name);
else
tty_line_name(driver, index, name);
- class_simple_device_add(tty_class, dev, device, name);
+
+ return class_device_create(tty_class, NULL, dev, device, "%s", 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
+ * 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.
*
- * If a tty device is registered with a call to tty_register_device() then
- * this function must be made when the tty device is gone.
+ * Locking: ??
*/
+
void tty_unregister_device(struct tty_driver *driver, unsigned index)
{
- devfs_remove("%s%d", driver->devfs_name, index + driver->name_base);
- class_simple_device_remove(MKDEV(driver->major, driver->minor_start) + index);
+ class_device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index);
}
EXPORT_SYMBOL(tty_register_device);
driver->cdev.owner = driver->owner;
error = cdev_add(&driver->cdev, dev, driver->num);
if (error) {
- cdev_del(&driver->cdev);
unregister_chrdev_region(dev, driver->num);
driver->ttys = NULL;
driver->termios = driver->termios_locked = NULL;
list_add(&driver->tty_drivers, &tty_drivers);
- if ( !(driver->flags & TTY_DRIVER_NO_DEVFS) ) {
+ if ( !(driver->flags & TTY_DRIVER_DYNAMIC_DEV) ) {
for(i = 0; i < driver->num; i++)
tty_register_device(driver, i, NULL);
}
driver->termios_locked[i] = NULL;
kfree(tp);
}
- if (!(driver->flags & TTY_DRIVER_NO_DEVFS))
+ if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV))
tty_unregister_device(driver, i);
}
p = driver->ttys;
#ifdef CONFIG_EARLY_PRINTK
disable_early_printk();
#endif
-#ifdef CONFIG_SERIAL_68360
- /* This is not a console initcall. I know not what it's doing here.
- So I haven't moved it. dwmw2 */
- rs_360_init();
-#endif
- call = &__con_initcall_start;
- while (call < &__con_initcall_end) {
+ call = __con_initcall_start;
+ while (call < __con_initcall_end) {
(*call)();
call++;
}
static int __init tty_class_init(void)
{
- tty_class = class_simple_create(THIS_MODULE, "tty");
+ tty_class = class_create(THIS_MODULE, "tty");
if (IS_ERR(tty_class))
return PTR_ERR(tty_class);
return 0;
if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
panic("Couldn't register /dev/tty driver\n");
- devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 0), S_IFCHR|S_IRUGO|S_IWUGO, "tty");
- class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
+ class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
cdev_init(&console_cdev, &console_fops);
if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
panic("Couldn't register /dev/console driver\n");
- devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 1), S_IFCHR|S_IRUSR|S_IWUSR, "console");
- class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 1), NULL, "console");
+ class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, "console");
#ifdef CONFIG_UNIX98_PTYS
cdev_init(&ptmx_cdev, &ptmx_fops);
if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
panic("Couldn't register /dev/ptmx driver\n");
- devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 2), S_IFCHR|S_IRUGO|S_IWUGO, "ptmx");
- class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
+ class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
#endif
#ifdef CONFIG_VT
if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
panic("Couldn't register /dev/tty0 driver\n");
- devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR, "vc/0");
- class_simple_device_add(tty_class, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+ class_device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
vty_init();
+ out_vt:
#endif
return 0;
}