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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-29 15:47:40 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-29 15:47:40 +0100 |
| commit | 0eae4686a128d87503863a261e84887750c8bc68 (patch) | |
| tree | 54a82e36439c0aca8e6a4389c5ea683b2887b1ab /drivers/tty | |
| parent | 4b0a2c5ff7215206ea6135a405f17c5f6fca7d00 (diff) | |
| download | linux-0eae4686a128d87503863a261e84887750c8bc68.tar.bz2 | |
Revert "tty: pty: Fix race condition between release_one_tty and pty_write"
This reverts commit b9ca5f8560af244489b4a1bc1ae88b341f24bc95 as 0-day
shows it has a circular locking dependency.
Fixes: b9ca5f8560af ("tty: pty: Fix race condition between release_one_tty and pty_write")
Reported-by: kernel test robot <lkp@intel.com>
Cc: Sahara <keun-o.park@darkmatter.ae>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/pty.c | 7 | ||||
| -rw-r--r-- | drivers/tty/tty_io.c | 3 |
2 files changed, 0 insertions, 10 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index ef72031ab5b9..00099a8439d2 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -116,12 +116,6 @@ static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) if (tty->stopped) return 0; - mutex_lock(&tty_mutex); - if (to->magic != TTY_MAGIC) { - mutex_unlock(&tty_mutex); - return -EIO; - } - if (c > 0) { spin_lock_irqsave(&to->port->lock, flags); /* Stuff the data into the input queue of the other end */ @@ -131,7 +125,6 @@ static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) tty_flip_buffer_push(to->port); spin_unlock_irqrestore(&to->port->lock, flags); } - mutex_unlock(&tty_mutex); return c; } diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index c27777f3b8c4..5fa250157025 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1448,13 +1448,10 @@ static void release_one_tty(struct work_struct *work) struct tty_driver *driver = tty->driver; struct module *owner = driver->owner; - mutex_lock(&tty_mutex); if (tty->ops->cleanup) tty->ops->cleanup(tty); tty->magic = 0; - mutex_unlock(&tty_mutex); - tty_driver_kref_put(driver); module_put(owner); |