89c8d91e31
The termios and other changes mean the other protections needed on the driver tty arrays should be adequate. Turn it all back on. This contains pieces folded in from the fixes made to the original patches | From: Geert Uytterhoeven <geert@linux-m68k.org> (fix m68k) | From: Paul Gortmaker <paul.gortmaker@windriver.com> (fix cris) | From: Jiri Kosina <jkosina@suze.cz> (lockdep) | From: Eric Dumazet <eric.dumazet@gmail.com> (lockdep) Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
74 lines
1.5 KiB
C
74 lines
1.5 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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enum {
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TTY_MUTEX_NORMAL,
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TTY_MUTEX_NESTED,
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};
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/*
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* Getting the big tty mutex.
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*/
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static void __lockfunc tty_lock_nested(struct tty_struct *tty,
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unsigned int subclass)
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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_nested(&tty->legacy_mutex, subclass);
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}
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void __lockfunc tty_lock(struct tty_struct *tty)
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{
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return tty_lock_nested(tty, TTY_MUTEX_NORMAL);
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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_nested(tty2, TTY_MUTEX_NESTED);
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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_nested(tty, TTY_MUTEX_NESTED);
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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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