Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx> writes: > On Fri, 2017-03-31 at 16:11 +0200, Alexandre Julliard wrote: >> Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx> writes: >> >> > On Thu, 2017-03-30 at 13:10 +0300, Stas Sergeev wrote: >> >> 30.03.2017 08:14, Ricardo Neri пишет: >> >> In fact, smsw has an interesting property, which is that >> >> no one will ever want to disable its in-kernel emulation >> >> to provide its own. >> >> So while I'll try to estimate its usage, emulating it in kernel >> >> will not be that problematic in either case. >> > >> > Ah good to know! >> > >> >> As for protected mode, if wine only needs sgdt/sidt, then >> >> again, no one will want to disable its emulation. Not the >> >> case with sldt, but AFAICS wine doesn't need sldt, and so >> >> we can leave sldt without a fixups. Is my understanding >> >> correct? >> > >> > This is my understanding as well. I could not find any use of sldt in >> > wine. Alexandre, would you mind confirming? >> >> Some versions of the Themida software protection are known to use sldt >> as part of the virtual machine detection code [1]. The check currently >> fails because it expects the LDT to be zero, so the app is already >> broken, but sldt segfaulting would still cause a crash where there >> wasn't one before. >> >> However, I'm only aware of one application using this, and being able to >> catch and emulate sldt ourselves would actually give us a chance to fix >> this app in newer Wine versions, so I'm not opposed to having it >> segfault. > > Great! Then this is in line with what we are aiming to do with dosemu2: > not emulate str and sldt. >> >> In fact it would be nice to be able to make sidt/sgdt/etc. segfault >> too. I know a new syscall is a pain, but as far as Wine is concerned, >> being able to opt out from any emulation would be potentially useful. > > I see. I guess for now there should not be a problem with emulating > sidt/sgdt/smsw, right? In this way we don't break current versions of > winehq and programs using it. In a phase two we can introduce the > syscall so that kernel fixups can be disabled. Does this make sense? Yes, that makes sense. -- Alexandre Julliard julliard@xxxxxxxxxx -- 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
