On Tue, 10 Oct 2017 19:24:11 +0000 <mario.limoncie...@dell.com> wrote:
> > -----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. Maybe but you can still write the test correctly using >= instead. Alan
