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path: root/drivers/char/tty_io.c
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Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r--drivers/char/tty_io.c87
1 files changed, 47 insertions, 40 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 53d3d066554..98b126c2ded 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -130,7 +130,7 @@ LIST_HEAD(tty_drivers); /* linked list of tty drivers */
/* Semaphore to protect creating and releasing a tty. This is shared with
vt.c for deeply disgusting hack reasons */
-DECLARE_MUTEX(tty_sem);
+DEFINE_MUTEX(tty_mutex);
#ifdef CONFIG_UNIX98_PTYS
extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */
@@ -354,7 +354,7 @@ int tty_buffer_request_room(struct tty_struct *tty, size_t size)
EXPORT_SYMBOL_GPL(tty_buffer_request_room);
-int tty_insert_flip_string(struct tty_struct *tty, unsigned char *chars, size_t size)
+int tty_insert_flip_string(struct tty_struct *tty, const unsigned char *chars, size_t size)
{
int copied = 0;
do {
@@ -376,9 +376,9 @@ int tty_insert_flip_string(struct tty_struct *tty, unsigned char *chars, size_t
return copied;
}
-EXPORT_SYMBOL_GPL(tty_insert_flip_string);
+EXPORT_SYMBOL(tty_insert_flip_string);
-int tty_insert_flip_string_flags(struct tty_struct *tty, unsigned char *chars, char *flags, size_t size)
+int tty_insert_flip_string_flags(struct tty_struct *tty, const unsigned char *chars, const char *flags, size_t size)
{
int copied = 0;
do {
@@ -543,14 +543,12 @@ void tty_ldisc_put(int disc)
struct tty_ldisc *ld;
unsigned long flags;
- if (disc < N_TTY || disc >= NR_LDISCS)
- BUG();
+ BUG_ON(disc < N_TTY || disc >= NR_LDISCS);
spin_lock_irqsave(&tty_ldisc_lock, flags);
ld = &tty_ldiscs[disc];
- if(ld->refcount == 0)
- BUG();
- ld->refcount --;
+ BUG_ON(ld->refcount == 0);
+ ld->refcount--;
module_put(ld->owner);
spin_unlock_irqrestore(&tty_ldisc_lock, flags);
}
@@ -645,8 +643,7 @@ void tty_ldisc_deref(struct tty_ldisc *ld)
{
unsigned long flags;
- if(ld == NULL)
- BUG();
+ BUG_ON(ld == NULL);
spin_lock_irqsave(&tty_ldisc_lock, flags);
if(ld->refcount == 0)
@@ -1097,8 +1094,8 @@ static void do_tty_hangup(void *data)
p->signal->tty = NULL;
if (!p->signal->leader)
continue;
- send_group_sig_info(SIGHUP, SEND_SIG_PRIV, p);
- send_group_sig_info(SIGCONT, SEND_SIG_PRIV, p);
+ 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);
@@ -1188,11 +1185,11 @@ void disassociate_ctty(int on_exit)
lock_kernel();
- down(&tty_sem);
+ mutex_lock(&tty_mutex);
tty = current->signal->tty;
if (tty) {
tty_pgrp = tty->pgrp;
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
tty_vhangup(tty);
} else {
@@ -1200,7 +1197,7 @@ void disassociate_ctty(int on_exit)
kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit);
kill_pg(current->signal->tty_old_pgrp, SIGCONT, on_exit);
}
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
unlock_kernel();
return;
}
@@ -1211,7 +1208,7 @@ void disassociate_ctty(int on_exit)
}
/* Must lock changes to tty_old_pgrp */
- down(&tty_sem);
+ mutex_lock(&tty_mutex);
current->signal->tty_old_pgrp = 0;
tty->session = 0;
tty->pgrp = -1;
@@ -1222,7 +1219,7 @@ void disassociate_ctty(int on_exit)
p->signal->tty = NULL;
} while_each_task_pid(current->signal->session, PIDTYPE_SID, p);
read_unlock(&tasklist_lock);
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
unlock_kernel();
}
@@ -1306,7 +1303,7 @@ static inline ssize_t do_tty_write(
ssize_t ret = 0, written = 0;
unsigned int chunk;
- if (down_interruptible(&tty->atomic_write)) {
+ if (mutex_lock_interruptible(&tty->atomic_write_lock)) {
return -ERESTARTSYS;
}
@@ -1329,7 +1326,7 @@ static inline ssize_t do_tty_write(
if (count < chunk)
chunk = count;
- /* write_buf/write_cnt is protected by the atomic_write semaphore */
+ /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
if (tty->write_cnt < chunk) {
unsigned char *buf;
@@ -1338,7 +1335,7 @@ static inline ssize_t do_tty_write(
buf = kmalloc(chunk, GFP_KERNEL);
if (!buf) {
- up(&tty->atomic_write);
+ mutex_unlock(&tty->atomic_write_lock);
return -ENOMEM;
}
kfree(tty->write_buf);
@@ -1374,7 +1371,7 @@ static inline ssize_t do_tty_write(
inode->i_mtime = current_fs_time(inode->i_sb);
ret = written;
}
- up(&tty->atomic_write);
+ mutex_unlock(&tty->atomic_write_lock);
return ret;
}
@@ -1442,8 +1439,8 @@ static inline void tty_line_name(struct tty_driver *driver, int index, char *p)
/*
* WSH 06/09/97: Rewritten to remove races and properly clean up after a
- * failed open. The new code protects the open with a semaphore, so it's
- * really quite straightforward. The semaphore locking can probably be
+ * failed open. The new code protects the open with a mutex, so it's
+ * really quite straightforward. The mutex locking can probably be
* relaxed for the (most common) case of reopening a tty.
*/
static int init_dev(struct tty_driver *driver, int idx,
@@ -1640,7 +1637,7 @@ fast_track:
success:
*ret_tty = tty;
- /* All paths come through here to release the semaphore */
+ /* All paths come through here to release the mutex */
end_init:
return retval;
@@ -1837,7 +1834,7 @@ static void release_dev(struct file * filp)
/* Guard against races with tty->count changes elsewhere and
opens on /dev/tty */
- down(&tty_sem);
+ mutex_lock(&tty_mutex);
tty_closing = tty->count <= 1;
o_tty_closing = o_tty &&
(o_tty->count <= (pty_master ? 1 : 0));
@@ -1868,7 +1865,7 @@ static void release_dev(struct file * filp)
printk(KERN_WARNING "release_dev: %s: read/write wait queue "
"active!\n", tty_name(tty, buf));
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
schedule();
}
@@ -1934,7 +1931,7 @@ static void release_dev(struct file * filp)
read_unlock(&tasklist_lock);
}
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
/* check whether both sides are closing ... */
if (!tty_closing || (o_tty && !o_tty_closing))
@@ -2040,11 +2037,11 @@ retry_open:
index = -1;
retval = 0;
- down(&tty_sem);
+ mutex_lock(&tty_mutex);
if (device == MKDEV(TTYAUX_MAJOR,0)) {
if (!current->signal->tty) {
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
return -ENXIO;
}
driver = current->signal->tty->driver;
@@ -2070,18 +2067,18 @@ retry_open:
noctty = 1;
goto got_driver;
}
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
return -ENODEV;
}
driver = get_tty_driver(device, &index);
if (!driver) {
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
return -ENODEV;
}
got_driver:
retval = init_dev(driver, index, &tty);
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
if (retval)
return retval;
@@ -2167,9 +2164,9 @@ static int ptmx_open(struct inode * inode, struct file * filp)
}
up(&allocated_ptys_lock);
- down(&tty_sem);
+ mutex_lock(&tty_mutex);
retval = init_dev(ptm_driver, index, &tty);
- up(&tty_sem);
+ mutex_unlock(&tty_mutex);
if (retval)
goto out;
@@ -2675,7 +2672,7 @@ static void __do_SAK(void *arg)
tty_hangup(tty);
#else
struct tty_struct *tty = arg;
- struct task_struct *p;
+ struct task_struct *g, *p;
int session;
int i;
struct file *filp;
@@ -2696,8 +2693,18 @@ static void __do_SAK(void *arg)
tty->driver->flush_buffer(tty);
read_lock(&tasklist_lock);
+ /* Kill the entire session */
do_each_task_pid(session, PIDTYPE_SID, p) {
- if (p->signal->tty == tty || session > 0) {
+ printk(KERN_NOTICE "SAK: killed process %d"
+ " (%s): p->signal->session==tty->session\n",
+ p->pid, p->comm);
+ send_sig(SIGKILL, p, 1);
+ } while_each_task_pid(session, PIDTYPE_SID, p);
+ /* Now kill any processes that happen to have the
+ * tty open.
+ */
+ do_each_thread(g, p) {
+ if (p->signal->tty == tty) {
printk(KERN_NOTICE "SAK: killed process %d"
" (%s): p->signal->session==tty->session\n",
p->pid, p->comm);
@@ -2724,7 +2731,7 @@ static void __do_SAK(void *arg)
rcu_read_unlock();
}
task_unlock(p);
- } while_each_task_pid(session, PIDTYPE_SID, p);
+ } while_each_thread(g, p);
read_unlock(&tasklist_lock);
#endif
}
@@ -2915,8 +2922,8 @@ static void initialize_tty_struct(struct tty_struct *tty)
init_waitqueue_head(&tty->write_wait);
init_waitqueue_head(&tty->read_wait);
INIT_WORK(&tty->hangup_work, do_tty_hangup, tty);
- sema_init(&tty->atomic_read, 1);
- sema_init(&tty->atomic_write, 1);
+ mutex_init(&tty->atomic_read_lock);
+ mutex_init(&tty->atomic_write_lock);
spin_lock_init(&tty->read_lock);
INIT_LIST_HEAD(&tty->tty_files);
INIT_WORK(&tty->SAK_work, NULL, NULL);