On Fri, 2017-03-10 at 06:17 -0800, Andy Lutomirski wrote: > On Fri, Mar 10, 2017 at 3:33 AM, Stas Sergeev <stsp@xxxxxxx> wrote: > > 10.03.2017 05:39, Andy Lutomirski пишет: > > > >> On Thu, Mar 9, 2017 at 2:10 PM, Stas Sergeev <stsp@xxxxxxx> wrote: > >>> > >>> 09.03.2017 04:15, Ricardo Neri пишет: > >>> > >>>> On Wed, 2017-03-08 at 08:46 -0800, Andy Lutomirski wrote: > >>>>> > >>>>> On Wed, Mar 8, 2017 at 8:29 AM, Stas Sergeev <stsp@xxxxxxx> wrote: > >>>>>> > >>>>>> 08.03.2017 19:06, Andy Lutomirski пишет: > >>>>>>> > >>>>>>> On Wed, Mar 8, 2017 at 6:08 AM, Stas Sergeev <stsp@xxxxxxx> wrote: > >>>>>>>> > >>>>>>>> 08.03.2017 03:32, Ricardo Neri пишет: > >>>>>>>>> > >>>>>>>>> These are the instructions covered by UMIP: > >>>>>>>>> * SGDT - Store Global Descriptor Table > >>>>>>>>> * SIDT - Store Interrupt Descriptor Table > >>>>>>>>> * SLDT - Store Local Descriptor Table > >>>>>>>>> * SMSW - Store Machine Status Word > >>>>>>>>> * STR - Store Task Register > >>>>>>>>> > >>>>>>>>> This patchset initially treated tasks running in virtual-8086 > >>>>> > >>>>> mode as a > >>>>>>>>> > >>>>>>>>> special case. However, I received clarification that DOSEMU[8] > >>>>> > >>>>> does not > >>>>>>>>> > >>>>>>>>> support applications that use these instructions. > >>>>>>> > >>>>>>> Can you remind me what was special about it? It looks like you > >>>>> > >>>>> still > >>>>>>> > >>>>>>> emulate them in v8086 mode. > >>>>>> > >>>>>> Indeed, sorry, I meant prot mode here. :) > >>>>>> So I wonder what was cited to be special about v86. > >>>> > >>>> Initially my patches disabled UMIP on virtual-8086 instructions, without > >>>> regards of protected mode (i.e., UMIP was always enabled). I didn't have > >>>> emulation at the time. Then, I added emulation code that now covers > >>>> protected and virtual-8086 modes. I guess it is not special anymore. > >>> > >>> But isn't SLDT&friends just throw UD in v86? > >>> How does UMIP affect this? How does your patch affect > >>> this? > >> > >> Er, right. Ricardo, your code may need fixing. But don't you have a > >> test case for this? > > > > Why would you need one? > > Or do you really want to allow these instructions > > in v86 by the means of emulation? If so - this wasn't > > clearly stated in the patch description, neither it was > > properly discussed, it seems. > > What I meant was: if the patches incorrectly started making these > instructions work in vm86 mode where they used to cause a vm86 exit, > then that's a bug that the selftest should have caught. Yes, this is the case. I will fix this behavior... and update the test cases. -- To unsubscribe from this list: send the line "unsubscribe linux-msdos" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
