The job_control() check in n_tty_read() has nearly identical purpose and results as tty_check_change(). Both functions' purpose is to determine if the current task's pgrp is the foreground pgrp for the tty, and if not, to signal the current pgrp.
Introduce __tty_check_change() which takes the signal to send and performs the shared operations for job control() and tty_check_change(). Signed-off-by: Peter Hurley <[email protected]> --- drivers/tty/n_tty.c | 26 ++------------------------ drivers/tty/tty_io.c | 46 ++++++++++++++++++++++++---------------------- include/linux/tty.h | 1 + 3 files changed, 27 insertions(+), 46 deletions(-) diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 20932cc..bd383c4 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -2147,37 +2147,15 @@ extern ssize_t redirected_tty_write(struct file *, const char __user *, static int job_control(struct tty_struct *tty, struct file *file) { - struct pid *pgrp; - /* Job control check -- must be done at start and after every sleep (POSIX.1 7.1.1.4). */ /* NOTE: not yet done after every sleep pending a thorough check of the logic of this change. -- jlc */ /* don't stop on /dev/console */ - if (file->f_op->write == redirected_tty_write || - current->signal->tty != tty) + if (file->f_op->write == redirected_tty_write) return 0; - rcu_read_lock(); - pgrp = task_pgrp(current); - - spin_lock_irq(&tty->ctrl_lock); - if (!tty->pgrp) - printk(KERN_ERR "n_tty_read: no tty->pgrp!\n"); - else if (pgrp != tty->pgrp) { - spin_unlock_irq(&tty->ctrl_lock); - if (is_ignored(SIGTTIN) || is_current_pgrp_orphaned()) { - rcu_read_unlock(); - return -EIO; - } - kill_pgrp(pgrp, SIGTTIN, 1); - rcu_read_unlock(); - set_thread_flag(TIF_SIGPENDING); - return -ERESTARTSYS; - } - spin_unlock_irq(&tty->ctrl_lock); - rcu_read_unlock(); - return 0; + return __tty_check_change(tty, SIGTTIN); } diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 02785d8..eb210d7 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -390,10 +390,10 @@ EXPORT_SYMBOL_GPL(tty_find_polling_driver); * Locking: ctrl_lock */ -int tty_check_change(struct tty_struct *tty) +int __tty_check_change(struct tty_struct *tty, int sig) { unsigned long flags; - struct pid *pgrp; + struct pid *pgrp, *tty_pgrp; int ret = 0; if (current->signal->tty != tty) @@ -403,33 +403,35 @@ int tty_check_change(struct tty_struct *tty) pgrp = task_pgrp(current); spin_lock_irqsave(&tty->ctrl_lock, flags); - - if (!tty->pgrp) { - printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); - goto out_unlock; - } - if (pgrp == tty->pgrp) - goto out_unlock; + tty_pgrp = tty->pgrp; spin_unlock_irqrestore(&tty->ctrl_lock, flags); - if (is_ignored(SIGTTOU)) - goto out_rcuunlock; - if (is_current_pgrp_orphaned()) { - ret = -EIO; - goto out_rcuunlock; + if (tty_pgrp && pgrp != tty->pgrp) { + if (is_ignored(sig)) { + if (sig == SIGTTIN) + ret = -EIO; + } else if (is_current_pgrp_orphaned()) + ret = -EIO; + else { + kill_pgrp(pgrp, sig, 1); + set_thread_flag(TIF_SIGPENDING); + ret = -ERESTARTSYS; + } } - kill_pgrp(pgrp, SIGTTOU, 1); - rcu_read_unlock(); - set_thread_flag(TIF_SIGPENDING); - ret = -ERESTARTSYS; - return ret; -out_unlock: - spin_unlock_irqrestore(&tty->ctrl_lock, flags); -out_rcuunlock: rcu_read_unlock(); + + if (!tty_pgrp) { + pr_warn("%s: tty_check_change: sig=%d, tty->pgrp == NULL!\n", + tty_name(tty), sig); + } + return ret; } +int tty_check_change(struct tty_struct *tty) +{ + return __tty_check_change(tty, SIGTTOU); +} EXPORT_SYMBOL(tty_check_change); static ssize_t hung_up_tty_read(struct file *file, char __user *buf, diff --git a/include/linux/tty.h b/include/linux/tty.h index c2889f4..533d7f6 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -423,6 +423,7 @@ extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, const char *routine); extern const char *tty_name(const struct tty_struct *tty); extern void tty_wait_until_sent(struct tty_struct *tty, long timeout); +extern int __tty_check_change(struct tty_struct *tty, int sig); extern int tty_check_change(struct tty_struct *tty); extern void __stop_tty(struct tty_struct *tty); extern void stop_tty(struct tty_struct *tty); -- 2.6.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
