From eca41044268887838fa122aa24475df8f23d614c Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 22 Jun 2009 18:42:03 +0100 Subject: [PATCH] n_r3964: fix lock imbalance There is omitted BKunL in r3964_read. Centralize the paths to one point with one unlock. Signed-off-by: Jiri Slaby Signed-off-by: Alan Cox Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- drivers/char/n_r3964.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/drivers/char/n_r3964.c b/drivers/char/n_r3964.c index d2e93e34322..2e99158ebb8 100644 --- a/drivers/char/n_r3964.c +++ b/drivers/char/n_r3964.c @@ -1062,7 +1062,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, struct r3964_client_info *pClient; struct r3964_message *pMsg; struct r3964_client_message theMsg; - int count; + int ret; TRACE_L("read()"); @@ -1074,8 +1074,8 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, if (pMsg == NULL) { /* no messages available. */ if (file->f_flags & O_NONBLOCK) { - unlock_kernel(); - return -EAGAIN; + ret = -EAGAIN; + goto unlock; } /* block until there is a message: */ wait_event_interruptible(pInfo->read_wait, @@ -1085,29 +1085,31 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, /* If we still haven't got a message, we must have been signalled */ if (!pMsg) { - unlock_kernel(); - return -EINTR; + ret = -EINTR; + goto unlock; } /* deliver msg to client process: */ theMsg.msg_id = pMsg->msg_id; theMsg.arg = pMsg->arg; theMsg.error_code = pMsg->error_code; - count = sizeof(struct r3964_client_message); + ret = sizeof(struct r3964_client_message); kfree(pMsg); TRACE_M("r3964_read - msg kfree %p", pMsg); - if (copy_to_user(buf, &theMsg, count)) { - unlock_kernel(); - return -EFAULT; + if (copy_to_user(buf, &theMsg, ret)) { + ret = -EFAULT; + goto unlock; } - TRACE_PS("read - return %d", count); - return count; + TRACE_PS("read - return %d", ret); + goto unlock; } + ret = -EPERM; +unlock: unlock_kernel(); - return -EPERM; + return ret; } static ssize_t r3964_write(struct tty_struct *tty, struct file *file, -- 2.32.0.93.g670b81a890