diff options
| author | Alan Cox <alan@lxorguk.ukuu.org.uk> | 2008-04-30 00:53:31 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-30 08:29:40 -0700 |
| commit | 5d0fdf1e01899805b6c2c0b789a707dcb731b1ea (patch) | |
| tree | 19827c7b3cf365c0b403741ead6c7bc317cad51b /drivers/char/tty_io.c | |
| parent | 575537b3248ee9b7578a3bb3df33fcdda2bfc4d5 (diff) | |
tty_io: fix remaining pid struct locking
This fixes the last couple of pid struct locking failures I know about.
[oleg@tv-sign.ru: clean up do_task_stat()]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char/tty_io.c')
| -rw-r--r-- | drivers/char/tty_io.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index c8aa318eaa1..2460c4c7616 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -3174,6 +3174,27 @@ unlock: } /** + * tty_get_pgrp - return a ref counted pgrp pid + * @tty: tty to read + * + * Returns a refcounted instance of the pid struct for the process + * group controlling the tty. + */ + +struct pid *tty_get_pgrp(struct tty_struct *tty) +{ + unsigned long flags; + struct pid *pgrp; + + spin_lock_irqsave(&tty->ctrl_lock, flags); + pgrp = get_pid(tty->pgrp); + spin_unlock_irqrestore(&tty->ctrl_lock, flags); + + return pgrp; +} +EXPORT_SYMBOL_GPL(tty_get_pgrp); + +/** * tiocgpgrp - get process group * @tty: tty passed by user * @real_tty: tty side of the tty pased by the user if a pty else the tty @@ -3187,13 +3208,18 @@ unlock: static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) { + struct pid *pid; + int ret; /* * (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; - return put_user(pid_vnr(real_tty->pgrp), p); + pid = tty_get_pgrp(real_tty); + ret = put_user(pid_vnr(pid), p); + put_pid(pid); + return ret; } /** |