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| author | Alan Cox <alan@lxorguk.ukuu.org.uk> | 2008-04-30 00:53:30 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-30 08:29:40 -0700 |
| commit | 47f86834bbd4193139d61d659bebf9ab9d691e37 (patch) | |
| tree | 6724b07e24929eba5c6df31f07871d9d6b4aa296 /include/linux/tty.h | |
| parent | 04f378b198da233ca0aca341b113dc6579d46123 (diff) | |
| download | linux-47f86834bbd4193139d61d659bebf9ab9d691e37.tar.gz linux-47f86834bbd4193139d61d659bebf9ab9d691e37.tar.bz2 linux-47f86834bbd4193139d61d659bebf9ab9d691e37.zip | |
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 <alan@redhat.com>
Cc: 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 'include/linux/tty.h')
| -rw-r--r-- | include/linux/tty.h | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/include/linux/tty.h b/include/linux/tty.h index 4d3702bade03..381085e45cca 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; |