> -----Original Message----- > From: Pali Rohár [mailto:pali.rohar@xxxxxxxxx] > Sent: Tuesday, October 10, 2017 2:12 PM > To: Limonciello, Mario <Mario_Limonciello@xxxxxxxx> > Cc: dvhart@xxxxxxxxxxxxx; Andy Shevchenko <andy.shevchenko@xxxxxxxxx>; > LKML <linux-kernel@xxxxxxxxxxxxxxx>; platform-driver-x86@xxxxxxxxxxxxxxx; > Andy Lutomirski <luto@xxxxxxxxxx>; quasisec@xxxxxxxxxx; rjw@xxxxxxxxxxxxx; > mjg59@xxxxxxxxxx; hch@xxxxxx; Greg KH <greg@xxxxxxxxx> > Subject: Re: [PATCH v6 13/14] platform/x86: wmi: create character devices when > requested by drivers > > On Monday 09 October 2017 17:51:51 Mario Limonciello wrote: > > + /* make sure we're not calling a higher instance than exists*/ > > + if (_IOC_NR(cmd) > wblock->gblock.instance_count - 1) > > + return -EINVAL; > > Is this condition really working? instance_count is unsigned, cmd is > also unsigned... and when instance_count is zero, then IIRC error would > not be thrown. > But instance count can't be zero. MOF would fall apart with a zero instance count. If a broken BIOS was shipped with an instance count of zero bigger problems would have happened.
