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https://github.com/torvalds/linux
synced 2024-09-25 14:01:32 +00:00
d29f3ef39b
In each remaining case the tty_lock is associated with a specific tty. This means we can now lock on a per tty basis. We do need tty_lock_pair() for the pty case. Uglier but still a step in the right direction. [fixed up calls in 3 missing drivers - gregkh] Signed-off-by: Alan Cox <alan@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
63 lines
1.2 KiB
C
63 lines
1.2 KiB
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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/* Legacy tty mutex glue */
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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(struct tty_struct *tty)
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{
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if (tty->magic != TTY_MAGIC) {
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printk(KERN_ERR "L Bad %p\n", tty);
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WARN_ON(1);
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return;
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}
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tty_kref_get(tty);
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mutex_lock(&tty->legacy_mutex);
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}
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EXPORT_SYMBOL(tty_lock);
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void __lockfunc tty_unlock(struct tty_struct *tty)
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{
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if (tty->magic != TTY_MAGIC) {
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printk(KERN_ERR "U Bad %p\n", tty);
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WARN_ON(1);
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return;
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}
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mutex_unlock(&tty->legacy_mutex);
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tty_kref_put(tty);
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}
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EXPORT_SYMBOL(tty_unlock);
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/*
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* Getting the big tty mutex for a pair of ttys with lock ordering
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* On a non pty/tty pair tty2 can be NULL which is just fine.
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*/
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void __lockfunc tty_lock_pair(struct tty_struct *tty,
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struct tty_struct *tty2)
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{
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if (tty < tty2) {
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tty_lock(tty);
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tty_lock(tty2);
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} else {
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if (tty2 && tty2 != tty)
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tty_lock(tty2);
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tty_lock(tty);
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}
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}
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EXPORT_SYMBOL(tty_lock_pair);
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void __lockfunc tty_unlock_pair(struct tty_struct *tty,
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struct tty_struct *tty2)
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{
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tty_unlock(tty);
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if (tty2 && tty2 != tty)
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tty_unlock(tty2);
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}
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EXPORT_SYMBOL(tty_unlock_pair);
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