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| author | Alan Cox <alan@linux.intel.com> | 2012-08-08 16:30:13 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-10 12:55:47 -0700 |
| commit | 89c8d91e31f267703e365593f6bfebb9f6d2ad01 (patch) | |
| tree | b115c7738762abe4a8a6374debb4991382b2f785 /drivers/tty/pty.c | |
| parent | dc6802a771e91050fb686dfeeb9de4c6c9cadb79 (diff) | |
| download | linux-stable-89c8d91e31f267703e365593f6bfebb9f6d2ad01.tar.gz linux-stable-89c8d91e31f267703e365593f6bfebb9f6d2ad01.tar.bz2 linux-stable-89c8d91e31f267703e365593f6bfebb9f6d2ad01.zip | |
tty: localise the lock
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>
Diffstat (limited to 'drivers/tty/pty.c')
| -rw-r--r-- | drivers/tty/pty.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index d6579a9064c4..4399f1dbd131 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -47,6 +47,7 @@ static void pty_close(struct tty_struct *tty, struct file *filp) wake_up_interruptible(&tty->read_wait); wake_up_interruptible(&tty->write_wait); tty->packet = 0; + /* Review - krefs on tty_link ?? */ if (!tty->link) return; tty->link->packet = 0; @@ -62,9 +63,9 @@ static void pty_close(struct tty_struct *tty, struct file *filp) mutex_unlock(&devpts_mutex); } #endif - tty_unlock(); + tty_unlock(tty); tty_vhangup(tty->link); - tty_lock(); + tty_lock(tty); } } @@ -617,26 +618,27 @@ static int ptmx_open(struct inode *inode, struct file *filp) return retval; /* find a device that is not in use. */ - tty_lock(); + mutex_lock(&devpts_mutex); index = devpts_new_index(inode); - tty_unlock(); if (index < 0) { retval = index; goto err_file; } + mutex_unlock(&devpts_mutex); + mutex_lock(&tty_mutex); - mutex_lock(&devpts_mutex); tty = tty_init_dev(ptm_driver, index); - mutex_unlock(&devpts_mutex); - tty_lock(); - mutex_unlock(&tty_mutex); if (IS_ERR(tty)) { retval = PTR_ERR(tty); goto out; } + /* The tty returned here is locked so we can safely + drop the mutex */ + mutex_unlock(&tty_mutex); + set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ tty_add_file(tty, filp); @@ -649,16 +651,17 @@ static int ptmx_open(struct inode *inode, struct file *filp) if (retval) goto err_release; - tty_unlock(); + tty_unlock(tty); return 0; err_release: - tty_unlock(); + tty_unlock(tty); tty_release(inode, filp); return retval; out: + mutex_unlock(&tty_mutex); devpts_kill_index(inode, index); - tty_unlock(); err_file: + mutex_unlock(&devpts_mutex); tty_free_file(filp); return retval; } |