From 57c563bf78f50d8a43e7ffe0087bc43dc0f188aa Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Fri, 19 Feb 2016 16:13:54 +0000 Subject: staging: comedi: COMEDI_BUFINFO: return error if no active command The `COMEDI_BUFINFO` ioctl is used to advance the current position in the buffer and/or get the current buffer position. If no asynchronous command is active (started via the file object that issued this ioctl), this information is meaningless. Change it to return an error (`-EINVAL`) in this case. Prior to this change, if a command was started via a different file object, the ioctl returned `-EACCES`, but now it will return `-EINVAL`, which is consistent with the current behavior of the "read" and "write" file operation handlers. Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/comedi_fops.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) (limited to 'drivers/staging/comedi') diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index b7c9270f9e92..a9fabf7a1000 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1123,24 +1123,8 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, async = s->async; - if (!async) { - dev_dbg(dev->class_dev, - "subdevice does not have async capability\n"); - bi.buf_write_ptr = 0; - bi.buf_read_ptr = 0; - bi.buf_write_count = 0; - bi.buf_read_count = 0; - bi.bytes_read = 0; - bi.bytes_written = 0; - goto copyback; - } - if (!s->busy) { - bi.bytes_read = 0; - bi.bytes_written = 0; - goto copyback_position; - } - if (s->busy != file) - return -EACCES; + if (!async || s->busy != file) + return -EINVAL; if (!(async->cmd.flags & CMDF_WRITE)) { /* command was set up in "read" direction */ @@ -1165,7 +1149,6 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, bi.bytes_read = 0; } -copyback_position: bi.buf_write_count = async->buf_write_count; bi.buf_write_ptr = async->buf_write_ptr; bi.buf_read_count = async->buf_read_count; @@ -1174,7 +1157,6 @@ copyback_position: if (become_nonbusy) do_become_nonbusy(dev, s); -copyback: if (copy_to_user(arg, &bi, sizeof(bi))) return -EFAULT; -- cgit v1.2.3-55-g7522