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tty: Revert the tty locking series, it needs more work

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This reverts the tty layer change to use per-tty locking, because it's
not correct yet, and fixing it will require some more deep surgery.

The main revert is d29f3ef39b ("tty_lock: Localise the lock"), but
there are several smaller commits that built upon it, they also get
reverted here. The list of reverted commits is:

  fde86d3108 - tty: add lockdep annotations
  8f6576ad47 - tty: fix ldisc lock inversion trace
  d3ca8b64b9 - pty: Fix lock inversion
  b1d679afd7 - tty: drop the pty lock during hangup
  abcefe5fc3 - tty/amiserial: Add missing argument for tty_unlock()
  fd11b42e35 - cris: fix missing tty arg in wait_event_interruptible_tty call
  d29f3ef39b - tty_lock: Localise the lock

The revert had a trivial conflict in the 68360serial.c staging driver
that got removed in the meantime.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds
2012-06-02 15:21:43 -07:00
parent 233e562eac
commit f309532bf3
14 changed files with 119 additions and 191 deletions
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23
include/linux/tty.h
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@@ -268,7 +268,6 @@ struct tty_struct {
struct mutex ldisc_mutex;
struct tty_ldisc *ldisc;
struct mutex legacy_mutex;
struct mutex termios_mutex;
spinlock_t ctrl_lock;
/* Termios values are protected by the termios mutex */
@@ -606,12 +605,8 @@ extern long vt_compat_ioctl(struct tty_struct *tty,
/* tty_mutex.c */
/* functions for preparation of BKL removal */
extern void __lockfunc tty_lock(struct tty_struct *tty);
extern void __lockfunc tty_unlock(struct tty_struct *tty);
extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
struct tty_struct *tty2);
extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
struct tty_struct *tty2);
extern void __lockfunc tty_lock(void) __acquires(tty_lock);
extern void __lockfunc tty_unlock(void) __releases(tty_lock);
/*
* this shall be called only from where BTM is held (like close)
@@ -626,9 +621,9 @@ extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
long timeout)
{
tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
tty_unlock(); /* tty->ops->close holds the BTM, drop it while waiting */
tty_wait_until_sent(tty, timeout);
tty_lock(tty);
tty_lock();
}
/*
@@ -643,16 +638,16 @@ static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
*
* Do not use in new code.
*/
#define wait_event_interruptible_tty(tty, wq, condition) \
#define wait_event_interruptible_tty(wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) { \
__wait_event_interruptible_tty(tty, wq, condition, __ret); \
__wait_event_interruptible_tty(wq, condition, __ret); \
} \
__ret; \
})
#define __wait_event_interruptible_tty(tty, wq, condition, ret) \
#define __wait_event_interruptible_tty(wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
@@ -661,9 +656,9 @@ do { \
if (condition) \
break; \
if (!signal_pending(current)) { \
tty_unlock(tty); \
tty_unlock(); \
schedule(); \
tty_lock(tty); \
tty_lock(); \
continue; \
} \
ret = -ERESTARTSYS; \