On Sat, Oct 10, 2020 at 2:41 PM Sudip Mukherjee <sudipm.mukher...@gmail.com> wrote: > > On Sat, Oct 10, 2020 at 1:08 AM Sudip Mukherjee > <sudipm.mukher...@gmail.com> wrote: > > > > On Fri, Oct 9, 2020 at 5:57 AM Greg KH <gre...@linuxfoundation.org> wrote: > > > > > > On Thu, Oct 08, 2020 at 11:57:13PM +0530, Harshal Chaudhari wrote: > > > > Checking the argument passed to the ioctl is valid > > > > or not. if not then return -EINVAL. > > > > > > Along the the comments that Arnd made, this is not the correct value to > > > be returning from an ioctl when you don't pass in the correct command.
Thanks Greg for the comment. i am checking with value -EFAULT now, i will get back to you with changes as consideration of Arnd comments. > > > And it doesn't match what your patch says, please be consistent. I just want to perform the Argument check here only. back then i was trying with access_ok() as well, but access_ok() return success even if i passed a NULL pointer. so that's why i removed it from here. > > > And do you have this device to be able to test your changes? Yes I have a device and I tested these changes with the few ioctls. > > I will test this tomorrow. But from an initial look, its going to > > break ppdev. There are few ioctls which don't need any arguments. > > No, sorry. I missed the check for _IOC_NONE. > Tested on a desktop which has a parallel port with a very basic test > code of open->claim->write->release->close and it still works. Thanks a lot Sudip for your time. > -- > Regards > Sudip
