diff options
author | Marcel Ziswiler <marcel.ziswiler@toradex.com> | 2021-07-07 01:19:43 +0200 |
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committer | Marcel Ziswiler <marcel.ziswiler@toradex.com> | 2021-07-07 01:19:43 +0200 |
commit | d900385139e5aa8d584dee92c87bb85d0226253e (patch) | |
tree | 26aa082f242221c535f2d8aa03b0c314c713e8ea /drivers/tty/tty_io.c | |
parent | 56168452b2a2fa8b4efc664d9fcb08536486a1ba (diff) | |
parent | 200ecf5055dfba12b9bff6984830a7cdddee8ab1 (diff) |
Merge tag 'v4.4.274' into toradex_vf_4.4-next
Linux 4.4.274
Diffstat (limited to 'drivers/tty/tty_io.c')
-rw-r--r-- | drivers/tty/tty_io.c | 59 |
1 files changed, 41 insertions, 18 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index b7effcfee91d..bdb25b23e8d3 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -537,8 +537,8 @@ static void __proc_set_tty(struct tty_struct *tty) put_pid(tty->session); put_pid(tty->pgrp); tty->pgrp = get_pid(task_pgrp(current)); - spin_unlock_irqrestore(&tty->ctrl_lock, flags); tty->session = get_pid(task_session(current)); + spin_unlock_irqrestore(&tty->ctrl_lock, flags); if (current->signal->tty) { tty_debug(tty, "current tty %s not NULL!!\n", current->signal->tty->name); @@ -929,21 +929,24 @@ void disassociate_ctty(int on_exit) spin_lock_irq(¤t->sighand->siglock); put_pid(current->signal->tty_old_pgrp); current->signal->tty_old_pgrp = NULL; - tty = tty_kref_get(current->signal->tty); + spin_unlock_irq(¤t->sighand->siglock); + if (tty) { unsigned long flags; + + tty_lock(tty); spin_lock_irqsave(&tty->ctrl_lock, flags); put_pid(tty->session); put_pid(tty->pgrp); tty->session = NULL; tty->pgrp = NULL; spin_unlock_irqrestore(&tty->ctrl_lock, flags); + tty_unlock(tty); tty_kref_put(tty); } else tty_debug_hangup(tty, "no current tty\n"); - spin_unlock_irq(¤t->sighand->siglock); /* Now clear signal->tty under the lock */ read_lock(&tasklist_lock); session_clear_tty(task_session(current)); @@ -2601,14 +2604,19 @@ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t return -ENOTTY; if (retval) return retval; - if (!current->signal->tty || - (current->signal->tty != real_tty) || - (real_tty->session != task_session(current))) - return -ENOTTY; + if (get_user(pgrp_nr, p)) return -EFAULT; if (pgrp_nr < 0) return -EINVAL; + + spin_lock_irq(&real_tty->ctrl_lock); + if (!current->signal->tty || + (current->signal->tty != real_tty) || + (real_tty->session != task_session(current))) { + retval = -ENOTTY; + goto out_unlock_ctrl; + } rcu_read_lock(); pgrp = find_vpid(pgrp_nr); retval = -ESRCH; @@ -2618,12 +2626,12 @@ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t if (session_of_pgrp(pgrp) != task_session(current)) goto out_unlock; retval = 0; - spin_lock_irq(&tty->ctrl_lock); put_pid(real_tty->pgrp); real_tty->pgrp = get_pid(pgrp); - spin_unlock_irq(&tty->ctrl_lock); out_unlock: rcu_read_unlock(); +out_unlock_ctrl: + spin_unlock_irq(&real_tty->ctrl_lock); return retval; } @@ -2635,21 +2643,31 @@ out_unlock: * * 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) { + unsigned long flags; + pid_t sid; + /* * (tty == real_tty) is a cheap way of * testing if the tty is NOT a master pty. */ if (tty == real_tty && current->signal->tty != real_tty) return -ENOTTY; + + spin_lock_irqsave(&real_tty->ctrl_lock, flags); if (!real_tty->session) - return -ENOTTY; - return put_user(pid_vnr(real_tty->session), p); + goto err; + sid = pid_vnr(real_tty->session); + spin_unlock_irqrestore(&real_tty->ctrl_lock, flags); + + return put_user(sid, p); + +err: + spin_unlock_irqrestore(&real_tty->ctrl_lock, flags); + return -ENOTTY; } /** @@ -2744,14 +2762,14 @@ out: * @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. + * is supported. Return -ENOTTY if it is not available. * * Locking: none (up to the driver) */ static int tty_tiocmget(struct tty_struct *tty, int __user *p) { - int retval = -EINVAL; + int retval = -ENOTTY; if (tty->ops->tiocmget) { retval = tty->ops->tiocmget(tty); @@ -2769,7 +2787,7 @@ static int tty_tiocmget(struct tty_struct *tty, int __user *p) * @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. + * is supported. Return -ENOTTY if it is not available. * * Locking: none (up to the driver) */ @@ -2781,7 +2799,7 @@ static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, unsigned int set, clear, val; if (tty->ops->tiocmset == NULL) - return -EINVAL; + return -ENOTTY; retval = get_user(val, p); if (retval) @@ -3061,10 +3079,14 @@ void __do_SAK(struct tty_struct *tty) struct task_struct *g, *p; struct pid *session; int i; + unsigned long flags; if (!tty) return; - session = tty->session; + + spin_lock_irqsave(&tty->ctrl_lock, flags); + session = get_pid(tty->session); + spin_unlock_irqrestore(&tty->ctrl_lock, flags); tty_ldisc_flush(tty); @@ -3100,6 +3122,7 @@ void __do_SAK(struct tty_struct *tty) task_unlock(p); } while_each_thread(g, p); read_unlock(&tasklist_lock); + put_pid(session); #endif } |