diff options
Diffstat (limited to 'drivers/char/tty_io.c')
| -rw-r--r-- | drivers/char/tty_io.c | 65 |
1 files changed, 44 insertions, 21 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index a96f26a63fa2..de37ebc3a4cf 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -1503,6 +1503,15 @@ int tty_hung_up_p(struct file * filp) EXPORT_SYMBOL(tty_hung_up_p); +/** + * is_tty - checker whether file is a TTY + */ +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; @@ -1726,6 +1735,23 @@ static ssize_t tty_read(struct file * file, char __user * buf, size_t count, 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 @@ -1737,13 +1763,12 @@ static inline ssize_t do_tty_write( const char __user *buf, size_t count) { - ssize_t ret = 0, written = 0; + ssize_t ret, written = 0; unsigned int chunk; - /* FIXME: O_NDELAY ... */ - 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 @@ -1776,8 +1801,8 @@ static inline ssize_t do_tty_write( 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; @@ -1812,7 +1837,8 @@ static inline ssize_t do_tty_write( inode->i_mtime = current_fs_time(inode->i_sb); ret = written; } - mutex_unlock(&tty->atomic_write_lock); +out: + tty_write_unlock(tty); return ret; } @@ -2016,11 +2042,9 @@ static int init_dev(struct tty_driver *driver, int idx, } if (!*ltp_loc) { - ltp = (struct ktermios *) kmalloc(sizeof(struct ktermios), - GFP_KERNEL); + ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); if (!ltp) goto free_mem_out; - memset(ltp, 0, sizeof(struct ktermios)); } if (driver->type == TTY_DRIVER_TYPE_PTY) { @@ -2049,11 +2073,9 @@ static int init_dev(struct tty_driver *driver, int idx, } if (!*o_ltp_loc) { - o_ltp = (struct ktermios *) - kmalloc(sizeof(struct ktermios), GFP_KERNEL); + o_ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); if (!o_ltp) goto free_mem_out; - memset(o_ltp, 0, sizeof(struct ktermios)); } /* @@ -2660,6 +2682,7 @@ got_driver: __proc_set_tty(current, tty); spin_unlock_irq(¤t->sighand->siglock); mutex_unlock(&tty_mutex); + tty_audit_opening(); return 0; } @@ -2722,8 +2745,10 @@ static int ptmx_open(struct inode * inode, struct file * filp) 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; @@ -3163,14 +3188,13 @@ static int tiocsetd(struct tty_struct *tty, int __user *p) static int send_break(struct tty_struct *tty, unsigned int duration) { - if (mutex_lock_interruptible(&tty->atomic_write_lock)) + 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); - mutex_unlock(&tty->atomic_write_lock); + tty_write_unlock(tty); if (signal_pending(current)) return -EINTR; return 0; @@ -3739,9 +3763,8 @@ struct tty_driver *alloc_tty_driver(int lines) { 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 */ |