diff options
Diffstat (limited to 'drivers/char/n_r3964.c')
| -rw-r--r-- | drivers/char/n_r3964.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/char/n_r3964.c b/drivers/char/n_r3964.c index 6b918b80f73e..3f6486e9f1ec 100644 --- a/drivers/char/n_r3964.c +++ b/drivers/char/n_r3964.c @@ -1075,12 +1075,15 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, TRACE_L("read()"); + lock_kernel(); + pClient = findClient(pInfo, task_pid(current)); if (pClient) { pMsg = remove_msg(pInfo, pClient); if (pMsg == NULL) { /* no messages available. */ if (file->f_flags & O_NONBLOCK) { + unlock_kernel(); return -EAGAIN; } /* block until there is a message: */ @@ -1090,8 +1093,10 @@ 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) + if (!pMsg) { + unlock_kernel(); return -EINTR; + } /* deliver msg to client process: */ theMsg.msg_id = pMsg->msg_id; @@ -1102,12 +1107,15 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file, kfree(pMsg); TRACE_M("r3964_read - msg kfree %p", pMsg); - if (copy_to_user(buf, &theMsg, count)) + if (copy_to_user(buf, &theMsg, count)) { + unlock_kernel(); return -EFAULT; + } TRACE_PS("read - return %d", count); return count; } + unlock_kernel(); return -EPERM; } @@ -1156,6 +1164,8 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file, pHeader->locks = 0; pHeader->owner = NULL; + lock_kernel(); + pClient = findClient(pInfo, task_pid(current)); if (pClient) { pHeader->owner = pClient; @@ -1173,6 +1183,8 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file, add_tx_queue(pInfo, pHeader); trigger_transmit(pInfo); + unlock_kernel(); + return 0; } |