Messages in this thread | | | From | Hartley Sweeten <> | Subject | RE: [PATCH 5/7] staging: comedi: don't allow write() on async command set up for "read" | Date | Thu, 30 Oct 2014 18:07:43 +0000 |
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On Thursday, October 30, 2014 5:43 AM, Ian Abbott wrote: > If a Comedi asynchronous command has been set up for data transfer in > the "read" direction on the current "write" subdevice (for those > subdevices that support both directions), don't allow the "write" file > operation as that would mess with the data in the comedi data buffer > that is written by the low-level comedi hardware driver. > > Signed-off-by: Ian Abbott <abbotti@mev.co.uk> > --- > drivers/staging/comedi/comedi_fops.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c > index 6805ec9..6328965 100644 > --- a/drivers/staging/comedi/comedi_fops.c > +++ b/drivers/staging/comedi/comedi_fops.c > @@ -2075,6 +2075,10 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, > retval = -EACCES; > goto out; > } > + if (!(async->cmd.flags & CMDF_WRITE)) { > + retval = -EINVAL; > + goto out; > + } > > add_wait_queue(&async->wait_head, &wait); > on_wait_queue = true; > @@ -2146,6 +2150,10 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, > retval = -EACCES; > break; > } > + if (!(async->cmd.flags & CMDF_WRITE)) { > + retval = -EINVAL; > + break; > + }
Same question as with PATCH 4/7.
Is this test needed in the while () loop. Also, are the s->busy tests needed here?
> continue; > }
Regards, Hartley
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