> -----Original Message----- > From: Pali Rohár [mailto:pali.ro...@gmail.com] > Sent: Tuesday, October 10, 2017 2:12 PM > To: Limonciello, Mario <mario_limoncie...@dell.com> > Cc: dvh...@infradead.org; Andy Shevchenko <andy.shevche...@gmail.com>; > LKML <linux-kernel@vger.kernel.org>; platform-driver-...@vger.kernel.org; > Andy Lutomirski <l...@kernel.org>; quasi...@google.com; r...@rjwysocki.net; > mj...@google.com; h...@lst.de; Greg KH <g...@kroah.com> > 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.
