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f309532bf3
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 d29f3ef39be4 ("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:
fde86d310886 - tty: add lockdep annotations
8f6576ad476b - tty: fix ldisc lock inversion trace
d3ca8b64b97e - pty: Fix lock inversion
b1d679afd766 - tty: drop the pty lock during hangup
abcefe5fc357 - tty/amiserial: Add missing argument for tty_unlock()
fd11b42e3598 - cris: fix missing tty arg in wait_event_interruptible_tty call
d29f3ef39be4 - 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>
33 lines
659 B
C
33 lines
659 B
C
#include <linux/tty.h>
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#include <linux/module.h>
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#include <linux/kallsyms.h>
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#include <linux/semaphore.h>
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#include <linux/sched.h>
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/*
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* The 'big tty mutex'
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*
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* This mutex is taken and released by tty_lock() and tty_unlock(),
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* replacing the older big kernel lock.
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* It can no longer be taken recursively, and does not get
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* released implicitly while sleeping.
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*
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* Don't use in new code.
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*/
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static DEFINE_MUTEX(big_tty_mutex);
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/*
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* Getting the big tty mutex.
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*/
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void __lockfunc tty_lock(void)
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{
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mutex_lock(&big_tty_mutex);
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}
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EXPORT_SYMBOL(tty_lock);
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void __lockfunc tty_unlock(void)
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{
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mutex_unlock(&big_tty_mutex);
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}
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EXPORT_SYMBOL(tty_unlock);
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