* 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
+ * 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
*
* New TIOCLINUX variants added.
* -- mj@k332.feld.cvut.cz, 19-Nov-95
- *
+ *
* Restrict vt switching via ioctl()
* -- grif@cs.ucr.edu, 5-Dec-95
*
* -- 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
+ * alloc_tty_struct() always uses kmalloc()
+ * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
*/
#include <linux/types.h>
#include <linux/selection.h>
#include <linux/kmod.h>
+#include <linux/nsproxy.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 */
+struct ktermios tty_std_termios = { /* for the benefit of tty drivers */
.c_iflag = ICRNL | IXON,
.c_oflag = OPOST | ONLCR,
.c_cflag = B38400 | CS8 | CREAD | HUPCL,
.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
ECHOCTL | ECHOKE | IEXTEN,
- .c_cc = INIT_C_CC
+ .c_cc = INIT_C_CC,
+ .c_ispeed = 38400,
+ .c_ospeed = 38400
};
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 */
-/* 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 */
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 */
+extern int pty_limit; /* Config limit on Unix98 ptys */
static DEFINE_IDR(allocated_ptys);
-static DECLARE_MUTEX(allocated_ptys_lock);
+static DEFINE_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 *);
+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,
+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);
+#ifdef CONFIG_COMPAT
+static long tty_compat_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg);
+#else
+#define tty_compat_ioctl NULL
+#endif
+static int tty_fasync(int fd, struct file *filp, int on);
+static void release_tty(struct tty_struct *tty, int idx);
+static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
+static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
+/**
+ * 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);
#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. */
#ifdef CHECK_TTY_COUNT
struct list_head *p;
int count = 0;
-
+
file_list_lock();
list_for_each(p, &tty->tty_files) {
count++;
"!= #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) {
+ while ((thead = tty->buf.head) != NULL) {
tty->buf.head = thead->next;
kfree(thead);
}
- while((thead = tty->buf.free) != NULL) {
+ 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;
}
-static struct tty_buffer *tty_buffer_alloc(size_t size)
+/**
+ * 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 = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC);
- if(p == NULL)
+ 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->read = 0;
p->char_buf_ptr = (char *)(p->data);
p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size;
-/* printk("Flip create %p\n", p); */
+ tty->buf.memory_used += size;
return p;
}
-/* Must be called with the tty_read lock held. This needs to acquire strategy
- code to decide if we should kfree or relink a given expired buffer */
+/**
+ * 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 */
-/* printk("Flip dispose %p\n", b); */
- if(b->size >= 512)
+ 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_buffer_flush - flush full tty buffers
+ * @tty: tty to flush
+ *
+ * flush all the buffers containing receive data. Caller must
+ * hold the buffer lock and must have ensured no parallel flush to
+ * ldisc is running.
+ *
+ * Locking: Caller must hold tty->buf.lock
+ */
+
+static void __tty_buffer_flush(struct tty_struct *tty)
+{
+ struct tty_buffer *thead;
+
+ while ((thead = tty->buf.head) != NULL) {
+ tty->buf.head = thead->next;
+ tty_buffer_free(tty, thead);
+ }
+ tty->buf.tail = NULL;
+}
+
+/**
+ * tty_buffer_flush - flush full tty buffers
+ * @tty: tty to flush
+ *
+ * flush all the buffers containing receive data. If the buffer is
+ * being processed by flush_to_ldisc then we defer the processing
+ * to that function
+ *
+ * Locking: none
+ */
+
+static void tty_buffer_flush(struct tty_struct *tty)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&tty->buf.lock, flags);
+
+ /* If the data is being pushed to the tty layer then we can't
+ process it here. Instead set a flag and the flush_to_ldisc
+ path will process the flush request before it exits */
+ if (test_bit(TTY_FLUSHING, &tty->flags)) {
+ set_bit(TTY_FLUSHPENDING, &tty->flags);
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ wait_event(tty->read_wait,
+ test_bit(TTY_FLUSHPENDING, &tty->flags) == 0);
+ return;
+ } else
+ __tty_buffer_flush(tty);
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+}
+
+/**
+ * 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) {
+ while ((*tbh) != NULL) {
struct tty_buffer *t = *tbh;
- if(t->size >= size) {
+ if (t->size >= size) {
*tbh = t->next;
t->next = NULL;
t->used = 0;
t->commit = 0;
t->read = 0;
- /* DEBUG ONLY */
-/* memset(t->data, '*', size); */
-/* printk("Flip recycle %p\n", t); */
+ tty->buf.memory_used += t->size;
return t;
}
tbh = &((*tbh)->next);
}
/* Round the buffer size out */
- size = (size + 0xFF) & ~ 0xFF;
- return tty_buffer_alloc(size);
+ 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;
}
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 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))
+ 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));
+ /* 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 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))
+ if (unlikely(space == 0))
break;
memcpy(tb->char_buf_ptr + tb->used, chars, space);
memcpy(tb->flag_buf_ptr + tb->used, flags, 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));
+ /* 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;
}
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 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)) {
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 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)) {
-/*
+/**
+ * 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
+ * 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);
}
/*
* 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 */
+/* Line disc dispatch table */
+static struct tty_ldisc tty_ldiscs[NR_LDISCS];
+
+/**
+ * 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;
}
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;
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 (ld->flags & LDISC_FLAG_DEFINED) {
/* If the module is being unloaded we can't use it */
if (!try_module_get(ld->owner))
- ld = NULL;
+ ld = NULL;
else /* lock it */
ld->refcount++;
- }
- else
+ } 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);
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;
* 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))
- {
+ if (test_bit(TTY_LDISC, &tty->flags)) {
ld->refcount++;
ret = 1;
}
* 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
+ * 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)
+ if (tty->ldisc.refcount == 0)
printk(KERN_ERR "tty_ldisc_ref_wait\n");
return &tty->ldisc;
}
* 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
+ * 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))
+ if (tty_ldisc_try(tty))
return &tty->ldisc;
return NULL;
}
*
* 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)
+ if (ld->refcount == 0)
printk(KERN_ERR "tty_ldisc_deref: no references.\n");
else
ld->refcount--;
- if(ld->refcount == 0)
+ if (ld->refcount == 0)
wake_up(&tty_ldisc_wait);
spin_unlock_irqrestore(&tty_ldisc_lock, flags);
}
* @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.
+ * again. Do necessary wakeups for existing sleepers.
*
* Note: nobody should set this bit except via this function. Clearing
* directly is allowed.
set_bit(TTY_LDISC, &tty->flags);
wake_up(&tty_ldisc_wait);
}
-
+
/**
* tty_set_ldisc - set line discipline
* @tty: the terminal to set
*
* 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;
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 ?
*/
return 0;
}
+ /*
+ * No more input please, we are switching. The new ldisc
+ * will update this value in the ldisc open function
+ */
+
+ tty->receive_room = 0;
+
o_ldisc = tty->ldisc;
o_tty = tty->link;
spin_lock_irqsave(&tty_ldisc_lock, flags);
if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) {
- if(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);
* 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.
+ * 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) {
+ 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)
goto restart;
}
}
-
- /* if the TTY_LDISC bit is set, then we are racing against another ldisc change */
-
+ /*
+ * 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);
/*
* Wait for ->hangup_work and ->buf.work handlers to terminate
*/
-
flush_scheduled_work();
/* Shutdown the current discipline. */
if (tty->ldisc.close)
/* 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)
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
*/
+
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)
+#ifdef CONFIG_CONSOLE_POLL
+
+/**
+ * tty_find_polling_driver - find device of a polled tty
+ * @name: name string to match
+ * @line: pointer to resulting tty line nr
+ *
+ * This routine returns a tty driver structure, given a name
+ * and the condition that the tty driver is capable of polled
+ * operation.
+ */
+struct tty_driver *tty_find_polling_driver(char *name, int *line)
+{
+ struct tty_driver *p, *res = NULL;
+ int tty_line = 0;
+ char *str;
+
+ mutex_lock(&tty_mutex);
+ /* Search through the tty devices to look for a match */
+ list_for_each_entry(p, &tty_drivers, tty_drivers) {
+ str = name + strlen(p->name);
+ tty_line = simple_strtoul(str, &str, 10);
+ if (*str == ',')
+ str++;
+ if (*str == '\0')
+ str = NULL;
+
+ if (tty_line >= 0 && tty_line <= p->num && p->poll_init &&
+ !p->poll_init(p, tty_line, str)) {
+
+ res = p;
+ *line = tty_line;
+ break;
+ }
+ }
+ mutex_unlock(&tty_mutex);
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(tty_find_polling_driver);
+#endif
+
+/**
+ * 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)
+
+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");
+ if (!tty->pgrp) {
+ printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n");
return 0;
}
- if (process_group(current) == tty->pgrp)
+ if (task_pgrp(current) == tty->pgrp)
return 0;
if (is_ignored(SIGTTOU))
return 0;
- if (is_orphaned_pgrp(process_group(current)))
+ if (is_current_pgrp_orphaned())
return -EIO;
- (void) kill_pg(process_group(current), SIGTTOU, 1);
+ kill_pgrp(task_pgrp(current), SIGTTOU, 1);
+ set_thread_flag(TIF_SIGPENDING);
return -ERESTARTSYS;
}
EXPORT_SYMBOL(tty_check_change);
-static ssize_t hung_up_tty_read(struct file * file, char __user * buf,
+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,
+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)
+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,
+static int hung_up_tty_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
}
-static struct file_operations tty_fops = {
+static long hung_up_tty_compat_ioctl(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,
+ .compat_ioctl = tty_compat_ioctl,
.open = tty_open,
.release = tty_release,
.fasync = tty_fasync,
};
#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,
.poll = tty_poll,
.ioctl = tty_ioctl,
+ .compat_ioctl = tty_compat_ioctl,
.open = ptmx_open,
.release = tty_release,
.fasync = tty_fasync,
};
#endif
-static struct file_operations console_fops = {
+static const struct file_operations console_fops = {
.llseek = no_llseek,
.read = tty_read,
.write = redirected_tty_write,
.poll = tty_poll,
.ioctl = tty_ioctl,
+ .compat_ioctl = tty_compat_ioctl,
.open = tty_open,
.release = tty_release,
.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,
.poll = hung_up_tty_poll,
.ioctl = hung_up_tty_ioctl,
+ .compat_ioctl = hung_up_tty_compat_ioctl,
.release = tty_release,
};
* 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)
+ if (ld) {
+ if (ld->write_wakeup)
ld->write_wakeup(tty);
tty_ldisc_deref(ld);
}
* 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)
+ if (ld) {
+ if (ld->flush_buffer)
ld->flush_buffer(tty);
tty_ldisc_deref(ld);
}
+ tty_buffer_flush(tty);
}
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..
+
+/**
+ * tty_reset_termios - reset terminal state
+ * @tty: tty to reset
+ *
+ * Restore a terminal to the driver default state
+ */
+
+static void tty_reset_termios(struct tty_struct *tty)
+{
+ mutex_lock(&tty->termios_mutex);
+ *tty->termios = tty->driver->init_termios;
+ tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
+ tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
+ mutex_unlock(&tty->termios_mutex);
+}
+
+/**
+ * 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(void *data)
+static void do_tty_hangup(struct work_struct *work)
{
- struct tty_struct *tty = (struct tty_struct *) data;
- struct file * cons_filp = NULL;
+ 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;
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 ? */
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. */
-
+ /*
+ * 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 != NULL) {
+ /* We may have no line discipline at this point */
if (ld->flush_buffer)
ld->flush_buffer(tty);
if (tty->driver->flush_buffer)
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 */
-
+ /*
+ * FIXME: Once we trust the LDISC code better we can wait here for
+ * ldisc completion and fix the driver call race
+ */
wake_up_interruptible(&tty->write_wait);
wake_up_interruptible(&tty->read_wait);
-
/*
* Shutdown the current line discipline, and reset it to
* N_TTY.
*/
if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
- {
- down(&tty->termios_sem);
- *tty->termios = tty->driver->init_termios;
- up(&tty->termios_sem);
- }
-
+ tty_reset_termios(tty);
/* Defer ldisc switch */
/* tty_deferred_ldisc_switch(N_TTY);
-
+
This should get done automatically when the port closes and
tty_release is called */
-
+
read_lock(&tasklist_lock);
- if (tty->session > 0) {
- do_each_task_pid(tty->session, PIDTYPE_SID, p) {
+ if (tty->session) {
+ do_each_pid_task(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;
- 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;
- } while_each_task_pid(tty->session, PIDTYPE_SID, p);
+ }
+ __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);
+ __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);
+ put_pid(p->signal->tty_old_pgrp); /* A noop */
+ if (tty->pgrp)
+ p->signal->tty_old_pgrp = get_pid(tty->pgrp);
+ spin_unlock_irq(&p->sighand->siglock);
+ } while_each_pid_task(tty->session, PIDTYPE_SID, p);
}
read_unlock(&tasklist_lock);
tty->flags = 0;
- tty->session = 0;
- tty->pgrp = -1;
+ put_pid(tty->session);
+ put_pid(tty->pgrp);
+ tty->session = NULL;
+ tty->pgrp = NULL;
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 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)
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 */
-
+ /*
+ * 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);
fput(f);
}
-void tty_hangup(struct tty_struct * tty)
+/**
+ * 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);
-void tty_vhangup(struct tty_struct * tty)
+/**
+ * tty_vhangup - process vhangup
+ * @tty: tty to hangup
+ *
+ * The user has asked via system call for the terminal to be hung up.
+ * We do this synchronously so that when the syscall returns the process
+ * is complete. That guarantee is necessary for security reasons.
+ */
+
+void tty_vhangup(struct tty_struct *tty)
{
#ifdef TTY_DEBUG_HANGUP
char buf[64];
printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf));
#endif
- do_tty_hangup((void *) tty);
+ do_tty_hangup(&tty->hangup_work);
}
+
EXPORT_SYMBOL(tty_vhangup);
-int tty_hung_up_p(struct file * filp)
+/**
+ * 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.
+/**
+ * is_tty - checker whether file is a TTY
+ * @filp: file handle that may be a tty
*
- * It performs the following functions:
+ * Check if the file handle is a tty handle.
+ */
+
+int is_tty(struct file *filp)
+{
+ return filp->f_op->read == tty_read
+ || filp->f_op->read == hung_up_tty_read;
+}
+
+static void session_clear_tty(struct pid *session)
+{
+ struct task_struct *p;
+ do_each_pid_task(session, PIDTYPE_SID, p) {
+ proc_clear_tty(p);
+ } while_each_pid_task(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.
+ * 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;
+ struct pid *tty_pgrp = NULL;
lock_kernel();
mutex_lock(&tty_mutex);
- tty = current->signal->tty;
+ tty = get_current_tty();
if (tty) {
- tty_pgrp = tty->pgrp;
+ tty_pgrp = get_pid(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);
+ } else if (on_exit) {
+ struct pid *old_pgrp;
+ spin_lock_irq(¤t->sighand->siglock);
+ old_pgrp = current->signal->tty_old_pgrp;
+ current->signal->tty_old_pgrp = NULL;
+ spin_unlock_irq(¤t->sighand->siglock);
+ if (old_pgrp) {
+ kill_pgrp(old_pgrp, SIGHUP, on_exit);
+ kill_pgrp(old_pgrp, SIGCONT, on_exit);
+ put_pid(old_pgrp);
}
mutex_unlock(&tty_mutex);
- unlock_kernel();
+ unlock_kernel();
return;
}
- if (tty_pgrp > 0) {
- kill_pg(tty_pgrp, SIGHUP, on_exit);
+ if (tty_pgrp) {
+ kill_pgrp(tty_pgrp, SIGHUP, on_exit);
if (!on_exit)
- kill_pg(tty_pgrp, SIGCONT, on_exit);
+ kill_pgrp(tty_pgrp, SIGCONT, on_exit);
+ put_pid(tty_pgrp);
}
- /* Must lock changes to tty_old_pgrp */
+ spin_lock_irq(¤t->sighand->siglock);
+ put_pid(current->signal->tty_old_pgrp);
+ current->signal->tty_old_pgrp = NULL;
+ spin_unlock_irq(¤t->sighand->siglock);
+
mutex_lock(&tty_mutex);
- current->signal->tty_old_pgrp = 0;
- tty->session = 0;
- tty->pgrp = -1;
+ /* It is possible that do_tty_hangup has free'd this tty */
+ tty = get_current_tty();
+ if (tty) {
+ put_pid(tty->session);
+ put_pid(tty->pgrp);
+ tty->session = NULL;
+ tty->pgrp = NULL;
+ } 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(task_session(current));
read_unlock(&tasklist_lock);
- mutex_unlock(&tty_mutex);
unlock_kernel();
}
+/**
+ *
+ * no_tty - Ensure the current process does not have a controlling tty
+ */
+void no_tty(void)
+{
+ struct task_struct *tsk = current;
+ if (tsk->signal->leader)
+ disassociate_ctty(0);
+ proc_clear_tty(tsk);
+}
+
+
+/**
+ * stop_tty - propagate flow control
+ * @tty: tty to stop
+ *
+ * Perform flow control to the driver. For PTY/TTY pairs we
+ * must also propagate 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 - propagate flow control
+ * @tty: tty to start
+ *
+ * Start a tty that has been stopped if at all possible. Perform
+ * any necessary wakeups and propagate 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)
}
if (tty->driver->start)
(tty->driver->start)(tty);
-
/* If we have a running line discipline it may need kicking */
tty_wakeup(tty);
- wake_up_interruptible(&tty->write_wait);
}
EXPORT_SYMBOL(start_tty);
-static ssize_t tty_read(struct file * file, char __user * buf, size_t count,
+/**
+ * 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 tty_struct *tty;
struct inode *inode;
struct tty_ldisc *ld;
tty = (struct tty_struct *)file->private_data;
- inode = file->f_dentry->d_inode;
+ inode = file->f_path.dentry->d_inode;
if (tty_paranoia_check(tty, inode, "tty_read"))
return -EIO;
if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
ld = tty_ldisc_ref_wait(tty);
lock_kernel();
if (ld->read)
- i = (ld->read)(tty,file,buf,count);
+ i = (ld->read)(tty, file, buf, count);
else
i = -EIO;
tty_ldisc_deref(ld);
return i;
}
+void tty_write_unlock(struct tty_struct *tty)
+{
+ mutex_unlock(&tty->atomic_write_lock);
+ wake_up_interruptible(&tty->write_wait);
+}
+
+int tty_write_lock(struct tty_struct *tty, int ndelay)
+{
+ if (!mutex_trylock(&tty->atomic_write_lock)) {
+ if (ndelay)
+ return -EAGAIN;
+ if (mutex_lock_interruptible(&tty->atomic_write_lock))
+ return -ERESTARTSYS;
+ }
+ return 0;
+}
+
/*
* Split writes up in sane blocksizes to avoid
* denial-of-service type attacks
const char __user *buf,
size_t count)
{
- ssize_t ret = 0, written = 0;
+ ssize_t ret, written = 0;
unsigned int chunk;
-
- if (mutex_lock_interruptible(&tty->atomic_write_lock)) {
- return -ERESTARTSYS;
- }
+
+ ret = tty_write_lock(tty, file->f_flags & O_NDELAY);
+ if (ret < 0)
+ return ret;
/*
* We chunk up writes into a temporary buffer. This
* 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))
buf = kmalloc(chunk, GFP_KERNEL);
if (!buf) {
- mutex_unlock(&tty->atomic_write_lock);
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto out;
}
kfree(tty->write_buf);
tty->write_cnt = chunk;
cond_resched();
}
if (written) {
- struct inode *inode = file->f_dentry->d_inode;
+ struct inode *inode = file->f_path.dentry->d_inode;
inode->i_mtime = current_fs_time(inode->i_sb);
ret = written;
}
- mutex_unlock(&tty->atomic_write_lock);
+out:
+ tty_write_unlock(tty);
return ret;
}
-static ssize_t tty_write(struct file * file, const char __user * buf, size_t count,
- loff_t *ppos)
+/**
+ * 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;
+ struct tty_struct *tty;
+ struct inode *inode = file->f_path.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;
+ if (!tty || !tty->driver->write ||
+ (test_bit(TTY_IO_ERROR, &tty->flags)))
+ return -EIO;
- ld = tty_ldisc_ref_wait(tty);
+ ld = tty_ldisc_ref_wait(tty);
if (!ld->write)
ret = -EIO;
else
return ret;
}
-ssize_t redirected_tty_write(struct file * file, const char __user * buf, size_t count,
- loff_t *ppos)
+ssize_t redirected_tty_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
{
struct file *p = NULL;
fput(p);
return res;
}
-
return tty_write(file, buf, count, ppos);
}
static char ptychar[] = "pqrstuvwxyzabcde";
-static inline void pty_line_name(struct tty_driver *driver, int index, char *p)
+/**
+ * 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);
+ driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name,
+ ptychar[i >> 4 & 0xf], i & 0xf);
}
-static inline void tty_line_name(struct tty_driver *driver, int index, char *p)
+/**
+ * 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;
+ struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc;
+ struct ktermios *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 we don't have a tty here on a slave open, it's because
+ * the master already started the close process and there's
+ * no relation between devpts file and tty anymore.
+ */
+ if (!tty && driver->subtype == PTY_TYPE_SLAVE) {
+ retval = -EIO;
+ goto end_init;
+ }
+ /*
+ * It's safe from now on because init_dev() is called with
+ * tty_mutex held and release_dev() won't change tty->count
+ * or tty->flags without having to grab tty_mutex
+ */
if (tty && driver->subtype == PTY_TYPE_MASTER)
tty = tty->link;
} else {
* 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 the allocated memory released. (Except that the termios
* and locked termios may be retained.)
*/
ltp = o_ltp = NULL;
tty = alloc_tty_struct();
- if(!tty)
+ if (!tty)
goto fail_no_mem;
initialize_tty_struct(tty);
tty->driver = driver;
}
if (!*tp_loc) {
- tp = (struct termios *) kmalloc(sizeof(struct termios),
- GFP_KERNEL);
+ tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
if (!tp)
goto free_mem_out;
*tp = driver->init_termios;
}
if (!*ltp_loc) {
- ltp = (struct termios *) kmalloc(sizeof(struct termios),
- GFP_KERNEL);
+ ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL);
if (!ltp)
goto free_mem_out;
- memset(ltp, 0, sizeof(struct termios));
}
if (driver->type == TTY_DRIVER_TYPE_PTY) {
}
if (!*o_tp_loc) {
- o_tp = (struct termios *)
- kmalloc(sizeof(struct termios), GFP_KERNEL);
+ o_tp = kmalloc(sizeof(struct ktermios), 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);
+ o_ltp = kzalloc(sizeof(struct ktermios), 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)) {
+ 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_tty->link = tty;
}
- /*
+ /*
* All structures have been allocated, so now we install them.
- * Failures after this point use release_mem to clean up, so
+ * Failures after this point use release_tty to clean up, so
* there's no need to null out the local pointers.
*/
- if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+ 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;
+ /* Compatibility until drivers always set this */
+ tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
+ tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
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 we fail here just call release_tty to clean up. No need
+ * to decrement the use counts, as release_tty doesn't care.
*/
if (tty->ldisc.open) {
if (driver->type == TTY_DRIVER_TYPE_PTY &&
driver->subtype == PTY_TYPE_MASTER) {
/*
- * special case for PTY masters: only one open permitted,
+ * special case for PTY masters: only one open permitted,
* and the slave side open count is incremented as well.
*/
if (tty->count) {
tty->driver = driver; /* N.B. why do this every time?? */
/* FIXME */
- if(!test_bit(TTY_LDISC, &tty->flags))
+ 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;
retval = -ENOMEM;
goto end_init;
- /* call the tty release_mem routine to clean out this slot */
+ /* call the tty release_tty routine to clean out this slot */
release_mem_out:
- printk(KERN_INFO "init_dev: ldisc open failed, "
- "clearing slot %d\n", idx);
- release_mem(tty, idx);
+ if (printk_ratelimit())
+ printk(KERN_INFO "init_dev: ldisc open failed, "
+ "clearing slot %d\n", idx);
+ release_tty(tty, idx);
goto end_init;
}
-/*
- * Releases memory associated with a tty structure, and clears out the
- * driver table slots.
+/**
+ * release_one_tty - 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)
+static void release_one_tty(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);
- }
+ struct ktermios *tp;
if (!devpts)
tty->driver->ttys[idx] = NULL;
+
if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
tp = tty->termios;
if (!devpts)
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);
}
+/**
+ * release_tty - release tty structure memory
+ *
+ * Release both @tty and a possible linked partner (think pty pair),
+ * and decrement the refcount of the backing module.
+ *
+ * Locking:
+ * tty_mutex - 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_tty(struct tty_struct *tty, int idx)
+{
+ struct tty_driver *driver = tty->driver;
+
+ if (tty->link)
+ release_one_tty(tty->link, idx);
+ release_one_tty(tty, idx);
+ module_put(driver->owner);
+}
+
/*
* Even releasing the tty structures is a tricky business.. We have
* to be very careful that the structures are all released at the
* 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)
+static void release_dev(struct file *filp)
{
struct tty_struct *tty, *o_tty;
int pty_master, tty_closing, o_tty_closing, do_sleep;
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"))
+ if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode,
+ "release_dev"))
return;
check_tty_count(tty, "release_dev");
idx, tty->name);
return;
}
- if (o_tty->termios_locked !=
+ 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",
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 &&
"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
+ * 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) {
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
* 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)
+ if (tty_closing)
set_bit(TTY_CLOSING, &tty->flags);
- if(o_tty_closing)
+ if (o_tty_closing)
set_bit(TTY_CLOSING, &o_tty->flags);
/*
* 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);
}
/* 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
/*
* 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)
- {
+ 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);
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);
+ 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);
(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);
+ tty_set_termios_ldisc(o_tty, N_TTY);
}
/*
- * The release_mem function takes care of the details of clearing
+ * The release_tty function takes care of the details of clearing
* the slots and preserving the termios structure.
*/
- release_mem(tty, idx);
+ release_tty(tty, idx);
#ifdef CONFIG_UNIX98_PTYS
/* Make this pty number available for reallocation */
if (devpts) {
- down(&allocated_ptys_lock);
+ mutex_lock(&allocated_ptys_lock);
idr_remove(&allocated_ptys, idx);
- up(&allocated_ptys_lock);
+ mutex_unlock(&allocated_ptys_lock);
}
#endif
}
-/*
- * tty_open and tty_release keep up the tty count that contains the
- * number of opens done on a tty. We cannot use the inode-count, as
- * different inodes might point to the same tty.
+/**
+ * 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)
+
+static int tty_open(struct inode *inode, struct file *filp)
{
struct tty_struct *tty;
int noctty, retval;
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)) {
- if (!current->signal->tty) {
+ if (device == MKDEV(TTYAUX_MAJOR, 0)) {
+ 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)) {
+ if (device == MKDEV(TTY_MAJOR, 0)) {
extern struct tty_driver *console_driver;
driver = console_driver;
index = fg_console;
goto got_driver;
}
#endif
- if (device == MKDEV(TTYAUX_MAJOR,1)) {
+ if (device == MKDEV(TTYAUX_MAJOR, 1)) {
driver = console_device(&index);
if (driver) {
/* Don't let /dev/console block */
}
filp->f_flags = saved_flags;
- if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN))
+ if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) &&
+ !capable(CAP_SYS_ADMIN))
retval = -EBUSY;
if (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 == NULL)
+ __proc_set_tty(current, tty);
+ spin_unlock_irq(¤t->sighand->siglock);
+ mutex_unlock(&tty_mutex);
+ tty_audit_opening();
return 0;
}
#ifdef CONFIG_UNIX98_PTYS
-static int ptmx_open(struct inode * inode, struct file * filp)
+/**
+ * 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;
nonseekable_open(inode, filp);
/* find a device that is not in use. */
- down(&allocated_ptys_lock);
+ mutex_lock(&allocated_ptys_lock);
if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) {
- up(&allocated_ptys_lock);
+ mutex_unlock(&allocated_ptys_lock);
return -ENOMEM;
}
idr_ret = idr_get_new(&allocated_ptys, NULL, &index);
if (idr_ret < 0) {
- up(&allocated_ptys_lock);
+ mutex_unlock(&allocated_ptys_lock);
if (idr_ret == -EAGAIN)
return -ENOMEM;
return -EIO;
}
if (index >= pty_limit) {
idr_remove(&allocated_ptys, index);
- up(&allocated_ptys_lock);
+ mutex_unlock(&allocated_ptys_lock);
return -EIO;
}
- up(&allocated_ptys_lock);
+ mutex_unlock(&allocated_ptys_lock);
mutex_lock(&tty_mutex);
retval = init_dev(ptm_driver, index, &tty);
mutex_unlock(&tty_mutex);
-
+
if (retval)
goto out;
check_tty_count(tty, "tty_open");
retval = ptm_driver->open(tty, filp);
- if (!retval)
+ if (!retval) {
+ tty_audit_opening();
return 0;
+ }
out1:
release_dev(filp);
return retval;
out:
- down(&allocated_ptys_lock);
+ mutex_lock(&allocated_ptys_lock);
idr_remove(&allocated_ptys, index);
- up(&allocated_ptys_lock);
+ mutex_unlock(&allocated_ptys_lock);
return retval;
}
#endif
-static int tty_release(struct inode * inode, struct file * filp)
+/**
+ * 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);
return 0;
}
-/* No kernel lock held - fine */
-static unsigned int tty_poll(struct file * filp, poll_table * wait)
+/**
+ * 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_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"))
+ if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll"))
return 0;
-
+
ld = tty_ldisc_ref_wait(tty);
if (ld->poll)
ret = (ld->poll)(tty, filp, wait);
return ret;
}
-static int tty_fasync(int fd, struct file * filp, int on)
+static int tty_fasync(int fd, struct file *filp, int on)
{
- struct tty_struct * tty;
+ 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"))
+ if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync"))
return 0;
-
+
retval = fasync_helper(fd, filp, on, &tty->fasync);
if (retval <= 0)
return retval;
if (on) {
+ enum pid_type type;
+ struct pid *pid;
if (!waitqueue_active(&tty->read_wait))
tty->minimum_to_wake = 1;
- retval = f_setown(filp, (-tty->pgrp) ? : current->pid, 0);
+ if (tty->pgrp) {
+ pid = tty->pgrp;
+ type = PIDTYPE_PGID;
+ } else {
+ pid = task_pid(current);
+ type = PIDTYPE_PID;
+ }
+ retval = __f_setown(filp, pid, type, 0);
if (retval)
return retval;
} else {
return 0;
}
+/**
+ * tiocsti - fake input character
+ * @tty: tty to fake input into
+ * @p: pointer to character
+ *
+ * Fake input to a tty device. Does the necessary locking and
+ * input management.
+ *
+ * FIXME: does not honour flow control ??
+ *
+ * Locking:
+ * Called functions take tty_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 0;
}
-static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg)
+/**
+ * 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)
+ 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)))
- return 0;
+ goto done;
+
#ifdef CONFIG_VT
if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) {
- int rc;
-
- acquire_console_sem();
- rc = vc_resize(tty->driver_data, tmp_ws.ws_col, tmp_ws.ws_row);
- release_console_sem();
- if (rc)
+ 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);
+ if (tty->pgrp)
+ kill_pgrp(tty->pgrp, SIGWINCH, 1);
+ if ((real_tty->pgrp != tty->pgrp) && real_tty->pgrp)
+ kill_pgrp(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 && (task_session(current) == tty->session))
+ return ret;
- if (current->signal->leader &&
- (current->signal->session == tty->session))
- return 0;
+ 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 (tty->session > 0) {
+ if (!current->signal->leader || current->signal->tty) {
+ ret = -EPERM;
+ goto unlock;
+ }
+
+ if (tty->session) {
/*
* This tty is already the controlling
* tty for another session group!
*/
- if ((arg == 1) && capable(CAP_SYS_ADMIN)) {
+ if (arg == 1 && capable(CAP_SYS_ADMIN)) {
/*
* Steal it away
*/
-
read_lock(&tasklist_lock);
- do_each_task_pid(tty->session, PIDTYPE_SID, p) {
- p->signal->tty = NULL;
- } while_each_task_pid(tty->session, PIDTYPE_SID, p);
+ session_clear_tty(tty->session);
read_unlock(&tasklist_lock);
- } else
- return -EPERM;
- }
- task_lock(current);
- current->signal->tty = tty;
- task_unlock(current);
- current->signal->tty_old_pgrp = 0;
- tty->session = current->signal->session;
- tty->pgrp = process_group(current);
- return 0;
+ } 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)
{
/*
*/
if (tty == real_tty && current->signal->tty != real_tty)
return -ENOTTY;
- return put_user(real_tty->pgrp, p);
+ return put_user(pid_vnr(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;
+ struct pid *pgrp;
+ pid_t pgrp_nr;
int retval = tty_check_change(real_tty);
if (retval == -EIO)
return retval;
if (!current->signal->tty ||
(current->signal->tty != real_tty) ||
- (real_tty->session != current->signal->session))
+ (real_tty->session != task_session(current)))
return -ENOTTY;
- if (get_user(pgrp, p))
+ if (get_user(pgrp_nr, p))
return -EFAULT;
- if (pgrp < 0)
+ if (pgrp_nr < 0)
return -EINVAL;
- if (session_of_pgrp(pgrp) != current->signal->session)
- return -EPERM;
- real_tty->pgrp = pgrp;
- return 0;
+ rcu_read_lock();
+ pgrp = find_vpid(pgrp_nr);
+ retval = -ESRCH;
+ if (!pgrp)
+ goto out_unlock;
+ retval = -EPERM;
+ if (session_of_pgrp(pgrp) != task_session(current))
+ goto out_unlock;
+ retval = 0;
+ put_pid(real_tty->pgrp);
+ real_tty->pgrp = get_pid(pgrp);
+out_unlock:
+ rcu_read_unlock();
+ return retval;
}
+/**
+ * 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)
{
/*
*/
if (tty == real_tty && current->signal->tty != real_tty)
return -ENOTTY;
- if (real_tty->session <= 0)
+ if (!real_tty->session)
return -ENOTTY;
- return put_user(real_tty->session, p);
+ return put_user(pid_vnr(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);
}
+/**
+ * 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 (tty_write_lock(tty, 0) < 0)
+ return -EINTR;
tty->driver->break_ctl(tty, -1);
- if (!signal_pending(current)) {
+ if (!signal_pending(current))
msleep_interruptible(duration);
- }
tty->driver->break_ctl(tty, 0);
+ tty_write_unlock(tty);
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;
/*
* Split this up, as gcc can choke on it otherwise..
*/
-int tty_ioctl(struct inode * inode, struct file * file,
+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)
* Break handling by driver
*/
if (!tty->driver->break_ctl) {
- switch(cmd) {
+ 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 TIOCSBRK:
case TIOCCBRK:
case TCSBRK:
- case TCSBRKP:
+ case TCSBRKP:
retval = tty_check_change(tty);
if (retval)
return retval;
}
switch (cmd) {
- case TIOCSTI:
- return tiocsti(tty, p);
- case TIOCGWINSZ:
- return tiocgwinsz(tty, p);
- case TIOCSWINSZ:
- return tiocswinsz(tty, real_tty, p);
- case TIOCCONS:
- return real_tty!=tty ? -EINVAL : tioccons(file);
- case FIONBIO:
- return fionbio(file, p);
- case TIOCEXCL:
- set_bit(TTY_EXCLUSIVE, &tty->flags);
- return 0;
- case TIOCNXCL:
- clear_bit(TTY_EXCLUSIVE, &tty->flags);
- return 0;
- case TIOCNOTTY:
- if (current->signal->tty != tty)
- return -ENOTTY;
- if (current->signal->leader)
- disassociate_ctty(0);
- task_lock(current);
- current->signal->tty = NULL;
- task_unlock(current);
- return 0;
- case TIOCSCTTY:
- return tiocsctty(tty, arg);
- case TIOCGPGRP:
- return tiocgpgrp(tty, real_tty, p);
- case TIOCSPGRP:
- return tiocspgrp(tty, real_tty, p);
- case TIOCGSID:
- return tiocgsid(tty, real_tty, p);
- case TIOCGETD:
- /* FIXME: check this is ok */
- return put_user(tty->ldisc.num, (int __user *)p);
- case TIOCSETD:
- return tiocsetd(tty, p);
+ 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;
+ no_tty();
+ 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);
+ 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);
+ /*
+ * Break handling
+ */
+ case TIOCSBRK: /* Turn break on, unconditionally */
+ tty->driver->break_ctl(tty, -1);
+ return 0;
- case TIOCMSET:
- case TIOCMBIC:
- case TIOCMBIS:
- return tty_tiocmset(tty, file, cmd, p);
+ 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);
+ case TCFLSH:
+ switch (arg) {
+ case TCIFLUSH:
+ case TCIOFLUSH:
+ /* flush tty buffer and allow ldisc to process ioctl */
+ tty_buffer_flush(tty);
+ break;
+ }
+ break;
}
if (tty->driver->ioctl) {
retval = (tty->driver->ioctl)(tty, file, cmd, arg);
return retval;
}
+#ifdef CONFIG_COMPAT
+static long tty_compat_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ struct tty_struct *tty = file->private_data;
+ struct tty_ldisc *ld;
+ int retval = -ENOIOCTLCMD;
+
+ if (tty_paranoia_check(tty, inode, "tty_ioctl"))
+ return -EINVAL;
+
+ if (tty->driver->compat_ioctl) {
+ retval = (tty->driver->compat_ioctl)(tty, file, cmd, arg);
+ if (retval != -ENOIOCTLCMD)
+ return retval;
+ }
+
+ ld = tty_ldisc_ref_wait(tty);
+ if (ld->compat_ioctl)
+ retval = ld->compat_ioctl(tty, file, cmd, arg);
+ tty_ldisc_deref(ld);
+
+ return retval;
+}
+#endif
/*
* 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
* Nasty bug: do_SAK is being called in interrupt context. This can
* deadlock. We punt it up to process context. AKPM - 16Mar2001
*/
-static void __do_SAK(void *arg)
+void __do_SAK(struct tty_struct *tty)
{
#ifdef TTY_SOFT_SAK
tty_hangup(tty);
#else
- struct tty_struct *tty = arg;
struct task_struct *g, *p;
- int session;
+ struct pid *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);
+ session = tty->session;
+
+ tty_ldisc_flush(tty);
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) {
+ do_each_pid_task(session, PIDTYPE_SID, p) {
printk(KERN_NOTICE "SAK: killed process %d"
- " (%s): p->signal->session==tty->session\n",
- p->pid, p->comm);
+ " (%s): task_session_nr(p)==tty->session\n",
+ task_pid_nr(p), p->comm);
send_sig(SIGKILL, p, 1);
- } while_each_task_pid(session, PIDTYPE_SID, p);
+ } while_each_pid_task(session, PIDTYPE_SID, p);
/* Now kill any processes that happen to have the
* tty open.
*/
do_each_thread(g, p) {
if (p->signal->tty == tty) {
printk(KERN_NOTICE "SAK: killed process %d"
- " (%s): p->signal->session==tty->session\n",
- p->pid, p->comm);
+ " (%s): task_session_nr(p)==tty->session\n",
+ task_pid_nr(p), p->comm);
send_sig(SIGKILL, p, 1);
continue;
}
*/
spin_lock(&p->files->file_lock);
fdt = files_fdtable(p->files);
- for (i=0; i < fdt->max_fds; i++) {
+ for (i = 0; i < fdt->max_fds; i++) {
filp = fcheck_files(p->files, i);
if (!filp)
continue;
filp->private_data == tty) {
printk(KERN_NOTICE "SAK: killed process %d"
" (%s): fd#%d opened to the tty\n",
- p->pid, p->comm, i);
+ task_pid_nr(p), p->comm, i);
force_sig(SIGKILL, p);
break;
}
#endif
}
+static void do_SAK_work(struct work_struct *work)
+{
+ struct tty_struct *tty =
+ container_of(work, struct tty_struct, SAK_work);
+ __do_SAK(tty);
+}
+
/*
* The tq handling here is a little racy - tty->SAK_work may already be queued.
* Fortunately we don't need to worry, because if ->SAK_work is already queued,
{
if (!tty)
return;
- PREPARE_WORK(&tty->SAK_work, __do_SAK, tty);
schedule_work(&tty->SAK_work);
}
EXPORT_SYMBOL(do_SAK);
-/*
- * This routine is called out of the software interrupt to flush data
- * from the buffer chain to the line discipline.
+/**
+ * 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(void *private_)
+
+static void flush_to_ldisc(struct work_struct *work)
{
- struct tty_struct *tty = (struct tty_struct *) private_;
+ 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;
return;
spin_lock_irqsave(&tty->buf.lock, flags);
+ /* So we know a flush is running */
+ set_bit(TTY_FLUSHING, &tty->flags);
head = tty->buf.head;
if (head != NULL) {
tty->buf.head = NULL;
tty_buffer_free(tty, tbuf);
continue;
}
+ /* Ldisc or user is trying to flush the buffers
+ we are feeding to the ldisc, stop feeding the
+ line discipline as we want to empty the queue */
+ if (test_bit(TTY_FLUSHPENDING, &tty->flags))
+ break;
if (!tty->receive_room) {
schedule_delayed_work(&tty->buf.work, 1);
break;
disc->receive_buf(tty, char_buf, flag_buf, count);
spin_lock_irqsave(&tty->buf.lock, flags);
}
+ /* Restore the queue head */
tty->buf.head = head;
}
+ /* We may have a deferred request to flush the input buffer,
+ if so pull the chain under the lock and empty the queue */
+ if (test_bit(TTY_FLUSHPENDING, &tty->flags)) {
+ __tty_buffer_flush(tty);
+ clear_bit(TTY_FLUSHPENDING, &tty->flags);
+ wake_up(&tty->read_wait);
+ }
+ clear_bit(TTY_FLUSHING, &tty->flags);
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.
- */
-
-int tty_termios_baud_rate(struct termios *termios)
-{
- unsigned int cbaud;
-
- cbaud = termios->c_cflag & CBAUD;
-
- if (cbaud & CBAUDEX) {
- cbaud &= ~CBAUDEX;
-
- if (cbaud < 1 || cbaud + 15 > n_baud_table)
- termios->c_cflag &= ~CBAUDEX;
- else
- cbaud += 15;
- }
- return baud_table[cbaud];
-}
-
-EXPORT_SYMBOL(tty_termios_baud_rate);
-
-/**
- * tty_get_baud_rate - get tty bit rates
- * @tty: tty to query
- *
- * Returns the baud rate as an integer for this terminal. The
- * termios lock must be held by the caller and the terminal bit
- * flags may be updated.
- */
-
-int tty_get_baud_rate(struct tty_struct *tty)
-{
- int baud = tty_termios_baud_rate(tty->termios);
-
- if (baud == 38400 && tty->alt_speed) {
- if (!tty->warned) {
- printk(KERN_WARNING "Use of setserial/setrocket to "
- "set SPD_* flags is deprecated\n");
- tty->warned = 1;
- }
- baud = tty->alt_speed;
- }
-
- return baud;
-}
-
-EXPORT_SYMBOL(tty_get_baud_rate);
-
/**
* tty_flip_buffer_push - terminal
* @tty: tty to push
*
* 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)
spin_unlock_irqrestore(&tty->buf.lock, flags);
if (tty->low_latency)
- flush_to_ldisc((void *) tty);
+ flush_to_ldisc(&tty->buf.work.work);
else
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->session = NULL;
+ tty->pgrp = NULL;
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);
- init_MUTEX(&tty->termios_sem);
+ INIT_DELAYED_WORK(&tty->buf.work, flush_to_ldisc);
+ 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);
+ 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, NULL);
+ INIT_WORK(&tty->SAK_work, do_SAK_work);
}
/*
* 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.
+ * 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).
+ * 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.
+ * 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 class_device *tty_register_device(struct tty_driver *driver,
- unsigned index, struct device *device)
+
+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;
else
tty_line_name(driver, index, name);
- return class_device_create(tty_class, NULL, dev, device, "%s", 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
+ * tty_unregister_device - unregister a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
*
- * If a tty device is registered with a call to tty_register_device() then
- * this function must be made when the tty device is gone.
+ * 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)
{
- class_device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index);
+ device_destroy(tty_class,
+ MKDEV(driver->major, driver->minor_start) + index);
}
EXPORT_SYMBOL(tty_register_device);
{
struct tty_driver *driver;
- driver = kmalloc(sizeof(struct tty_driver), GFP_KERNEL);
+ driver = kzalloc(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 */
kfree(driver);
}
-void tty_set_operations(struct tty_driver *driver, struct tty_operations *op)
+void tty_set_operations(struct tty_driver *driver,
+ const struct tty_operations *op)
{
driver->open = op->open;
driver->close = op->close;
driver->write_room = op->write_room;
driver->chars_in_buffer = op->chars_in_buffer;
driver->ioctl = op->ioctl;
+ driver->compat_ioctl = op->compat_ioctl;
driver->set_termios = op->set_termios;
driver->throttle = op->throttle;
driver->unthrottle = op->unthrottle;
driver->write_proc = op->write_proc;
driver->tiocmget = op->tiocmget;
driver->tiocmset = op->tiocmset;
+#ifdef CONFIG_CONSOLE_POLL
+ driver->poll_init = op->poll_init;
+ driver->poll_get_char = op->poll_get_char;
+ driver->poll_put_char = op->poll_put_char;
+#endif
}
int tty_register_driver(struct tty_driver *driver)
{
int error;
- int i;
+ 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 (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
+ p = kzalloc(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);
+ error = alloc_chrdev_region(&dev, driver->minor_start,
+ driver->num, driver->name);
if (!error) {
driver->major = MAJOR(dev);
driver->minor_start = MINOR(dev);
}
} else {
dev = MKDEV(driver->major, driver->minor_start);
- error = register_chrdev_region(dev, driver->num,
- (char*)driver->name);
+ error = register_chrdev_region(dev, driver->num, driver->name);
}
if (error < 0) {
kfree(p);
if (p) {
driver->ttys = (struct tty_struct **)p;
- driver->termios = (struct termios **)(p + driver->num);
- driver->termios_locked = (struct termios **)(p + driver->num * 2);
+ driver->termios = (struct ktermios **)(p + driver->num);
+ driver->termios_locked = (struct ktermios **)
+ (p + driver->num * 2);
} else {
driver->ttys = NULL;
driver->termios = NULL;
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;
if (!driver->put_char)
driver->put_char = tty_default_put_char;
-
+
+ mutex_lock(&tty_mutex);
list_add(&driver->tty_drivers, &tty_drivers);
-
- if ( !(driver->flags & TTY_DRIVER_DYNAMIC_DEV) ) {
- for(i = 0; i < driver->num; i++)
+ mutex_unlock(&tty_mutex);
+
+ 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);
int tty_unregister_driver(struct tty_driver *driver)
{
int i;
- struct termios *tp;
+ struct ktermios *tp;
void *p;
if (driver->refcount)
unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
driver->num);
-
+ mutex_lock(&tty_mutex);
list_del(&driver->tty_drivers);
+ mutex_unlock(&tty_mutex);
/*
* Free the termios and termios_locked structures because
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);
+
+static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+{
+ if (tty) {
+ /* We should not have a session or pgrp to here but.... */
+ put_pid(tty->session);
+ put_pid(tty->pgrp);
+ tty->session = get_pid(task_session(tsk));
+ tty->pgrp = get_pid(task_pgrp(tsk));
+ }
+ put_pid(tsk->signal->tty_old_pgrp);
+ tsk->signal->tty = tty;
+ tsk->signal->tty_old_pgrp = NULL;
+}
+
+static 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;
+}
+EXPORT_SYMBOL_GPL(get_current_tty);
/*
* Initialize the console device. This is called *early*, so
(void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
/*
- * set up the console device so that later boot sequences can
+ * 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)();
}
}
-#ifdef CONFIG_VT
-extern int vty_init(void);
-#endif
-
static int __init tty_class_init(void)
{
tty_class = class_create(THIS_MODULE, "tty");
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");
- class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
+ 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");
- class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, "console");
+ 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");
- class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
+ device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), "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");
- class_device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+ device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), "tty0");
vty_init();
#endif
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff