On Thu, Jan 06, 2005 at 06:53:42PM +0100, Andi Kleen wrote: > [cc list trimmed] > > On Thu, Jan 06, 2005 at 06:26:13PM +0100, Petr Vandrovec wrote: > > > Why are you issuing 64bit ioctls from 32bit applications? > > > > There are three reasons (main reason is that vmware is 32bit app, but it is > > how > > things are currently laid out; even if there will be 64bit app, 32bit > > versions are > > already in use and people wants to use them on 64bit kernels): > > > > * USB. usbfs API is written in a way which does not allow you to safely > > wrap > > it in "generic" 32->64 layer, and attempts to do it in non-generic way in > > usbfs > > code itself did not look feasible year ago. Even on current 64bit kernels > > it is not > > possible to issue raw USB operations from 32bit apps, and I do not believe > > that > > it is going to change - after all, just issuing ioctl through 64bit path > > from application > > which is aware of 64bit kernel is quite simple, much simpler than any > > attempt to > > make kernel dual-interface. > > Agree that's a problem. We just need an alternative interface here > or I try to come up with an x86-64 specific hack (I think it's possible > to do the compatibility x86-64 specific, just not in compat code for > all architectures who have truly separated user/kernel address spaces) > > I hope the USB people will eventually add a better interface here. > Greg?
Yes, we've been talking about a usbfs2 for a long time now, but no one has stepped up and done the work. It would look a lot like gadgetfs, which only has a limited number of ioctls needed for its operation. But I don't see where the problem is unique to usbfs here, don't we properly use the 32->64bit ioctl conversion code to solve this kind of issue? Are we using it incorrectly? thanks, greg k-h ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
