On Thu, Mar 16, 2017 at 11:45:17AM +0900, Greg Kroah-Hartman wrote:
> On Wed, Mar 15, 2017 at 10:44:28AM +1100, Tobin C. Harding wrote:
> > Driver code is non-uniform in its use of error return codes, identical
> > failures are returning different error codes. Return is on failure
> > when checking struct magic numbers. Error codes used include -ENODEV,
> > -ENXIO, -EIO, and -EFAULT.
> >
> > Use -ENXIO. Justification is that usual call includes a check that the
> > struct is non-NULL OR'd with check on the magic number.
> >
> > #define ENXIO 6 /* No such device or address */
> >
> > Seems like a good fit. Also this choice results in the minimum number
> > of files touched.
> >
> > Pick one error code, ENXIO. Change all functions to use the same error
> > return code for the cases of failed magic number checks.
> >
> > Signed-off-by: Tobin C. Harding <me@xxxxxxxx>
> > ---
> > drivers/staging/dgnc/dgnc_mgmt.c | 2 +-
> > drivers/staging/dgnc/dgnc_tty.c | 44 ++++++++++++++++++++--------------------
> > 2 files changed, 23 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/staging/dgnc/dgnc_mgmt.c b/drivers/staging/dgnc/dgnc_mgmt.c
> > index ee8a626..f134222 100644
> > --- a/drivers/staging/dgnc/dgnc_mgmt.c
> > +++ b/drivers/staging/dgnc/dgnc_mgmt.c
> > @@ -187,7 +187,7 @@ long dgnc_mgmt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> > ch = dgnc_board[board]->channels[channel];
> >
> > if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
> > - return -ENODEV;
> > + return -ENXIO;
>
> No, this really means the device is gone. And the whole ->magic stuff
> needs to just be deleted, it's not needed at all.
Can I please confirm, all these magic number checks are useless?
Module: drivers/staging/dgnc
if (!tty || tty->magic != TTY_MAGIC)
un = tty->driver_data;
if (!un || un->magic != DGNC_UNIT_MAGIC)
ch = un->un_ch;
if (!ch || ch->magic != DGNC_CHANNEL_MAGIC)
I realize you may not be able to answer this without leaving your
email client. If so, please feel free to ignore the question. I'll
drop it if I don't get a reply.
thanks,
Tobin.
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