diff options
| -rw-r--r-- | drivers/tty/tty_io.c | 65 |
1 files changed, 48 insertions, 17 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 2661e86..3feca40 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -534,18 +534,21 @@ EXPORT_SYMBOL_GPL(tty_wakeup); /** * tty_signal_session_leader - sends SIGHUP to session leader + * @tty controlling tty + * @exit_session if non-zero, signal all foreground group processes * - * Send SIGHUP and SIGCONT to the session leader and its - * process group. + * Send SIGHUP and SIGCONT to the session leader and its process group. + * Optionally, signal all processes in the foreground process group. * * Returns the number of processes in the session with this tty * as their controlling terminal. This value is used to drop * tty references for those processes. */ -static int tty_signal_session_leader(struct tty_struct *tty) +static int tty_signal_session_leader(struct tty_struct *tty, int exit_session) { struct task_struct *p; int refs = 0; + struct pid *tty_pgrp = NULL; read_lock(&tasklist_lock); if (tty->session) { @@ -565,6 +568,7 @@ static int tty_signal_session_leader(struct tty_struct *tty) __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); put_pid(p->signal->tty_old_pgrp); /* A noop */ spin_lock(&tty->ctrl_lock); + tty_pgrp = get_pid(tty->pgrp); if (tty->pgrp) p->signal->tty_old_pgrp = get_pid(tty->pgrp); spin_unlock(&tty->ctrl_lock); @@ -573,6 +577,12 @@ static int tty_signal_session_leader(struct tty_struct *tty) } read_unlock(&tasklist_lock); + if (tty_pgrp) { + if (exit_session) + kill_pgrp(tty_pgrp, SIGHUP, exit_session); + put_pid(tty_pgrp); + } + return refs; } @@ -598,7 +608,7 @@ static int tty_signal_session_leader(struct tty_struct *tty) * tasklist_lock to walk task list for hangup event * ->siglock to protect ->signal/->sighand */ -static void __tty_hangup(struct tty_struct *tty) +static void __tty_hangup(struct tty_struct *tty, int exit_session) { struct file *cons_filp = NULL; struct file *filp, *f = NULL; @@ -647,7 +657,7 @@ static void __tty_hangup(struct tty_struct *tty) */ tty_ldisc_hangup(tty); - refs = tty_signal_session_leader(tty); + refs = tty_signal_session_leader(tty, exit_session); /* Account for the p->signal references we killed */ while (refs--) tty_kref_put(tty); @@ -696,7 +706,7 @@ static void do_tty_hangup(struct work_struct *work) struct tty_struct *tty = container_of(work, struct tty_struct, hangup_work); - __tty_hangup(tty); + __tty_hangup(tty, 0); } /** @@ -734,7 +744,7 @@ void tty_vhangup(struct tty_struct *tty) printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); #endif - __tty_hangup(tty); + __tty_hangup(tty, 0); } EXPORT_SYMBOL(tty_vhangup); @@ -758,6 +768,27 @@ void tty_vhangup_self(void) } /** + * tty_vhangup_session - hangup session leader exit + * @tty: tty to hangup + * + * The session leader is exiting and hanging up its controlling terminal. + * Every process in the foreground process group is signalled SIGHUP. + * + * We do this synchronously so that when the syscall returns the process + * is complete. That guarantee is necessary for security reasons. + */ + +void tty_vhangup_session(struct tty_struct *tty) +{ +#ifdef TTY_DEBUG_HANGUP + char buf[64]; + + printk(KERN_DEBUG "%s vhangup session...\n", tty_name(tty, buf)); +#endif + __tty_hangup(tty, 1); +} + +/** * tty_hung_up_p - was tty hung up * @filp: file pointer of tty * @@ -814,18 +845,18 @@ void disassociate_ctty(int on_exit) tty = get_current_tty(); if (tty) { - struct pid *tty_pgrp = get_pid(tty->pgrp); - if (on_exit) { - if (tty->driver->type != TTY_DRIVER_TYPE_PTY) - tty_vhangup(tty); - } - tty_kref_put(tty); - if (tty_pgrp) { - kill_pgrp(tty_pgrp, SIGHUP, on_exit); - if (!on_exit) + if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) { + tty_vhangup_session(tty); + } else { + struct pid *tty_pgrp = tty_get_pgrp(tty); + if (tty_pgrp) { + kill_pgrp(tty_pgrp, SIGHUP, on_exit); kill_pgrp(tty_pgrp, SIGCONT, on_exit); - put_pid(tty_pgrp); + put_pid(tty_pgrp); + } } + tty_kref_put(tty); + } else if (on_exit) { struct pid *old_pgrp; spin_lock_irq(¤t->sighand->siglock); |