From 47f86834bbd4193139d61d659bebf9ab9d691e37 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 30 Apr 2008 00:53:30 -0700 Subject: redo locking of tty->pgrp Historically tty->pgrp and friends were pid_t and the code "knew" they were safe. The change to pid structs opened up a few races and the removal of the BKL in places made them quite hittable. We put tty->pgrp under the ctrl_lock for the tty. Signed-off-by: Alan Cox Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/tty.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/tty.h b/include/linux/tty.h index 4d3702bade0..381085e45cc 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -184,21 +184,22 @@ struct tty_struct { struct tty_ldisc ldisc; struct mutex termios_mutex; spinlock_t ctrl_lock; + /* Termios values are protected by the termios mutex */ struct ktermios *termios, *termios_locked; char name[64]; - struct pid *pgrp; + struct pid *pgrp; /* Protected by ctrl lock */ struct pid *session; unsigned long flags; int count; - struct winsize winsize; + struct winsize winsize; /* termios mutex */ unsigned char stopped:1, hw_stopped:1, flow_stopped:1, packet:1; unsigned char low_latency:1, warned:1; - unsigned char ctrl_status; + unsigned char ctrl_status; /* ctrl_lock */ unsigned int receive_room; /* Bytes free for queue */ struct tty_struct *link; struct fasync_struct *fasync; - struct tty_bufhead buf; + struct tty_bufhead buf; /* Locked internally */ int alt_speed; /* For magic substitution of 38400 bps */ wait_queue_head_t write_wait; wait_queue_head_t read_wait; @@ -212,6 +213,7 @@ struct tty_struct { /* * The following is data for the N_TTY line discipline. For * historical reasons, this is included in the tty structure. + * Mostly locked by the BKL. */ unsigned int column; unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1; -- cgit v1.2.3