On Wed, Dec 05, 2012 at 04:39:49PM +0000, Serban Constantinescu wrote: > >I was wondering when someone would notice that this code was not going > >to work for this type of system, nice to see that you are working to fix > >it up. But, I'll reask Dan's question here, why not use the compat32 > >ioctl interface instead? Shouldn't that be the easier way to do this? > > Binder uses a 2 layer ioctl structure i.e. you can't know from the top > of the ioctl handler the size of the incoming package. How is this different from all other ioctl handlers in drivers? > Therefore adding a wrapper for a 64bit kernel is not an option. Really? Have you tried? And the wrapper isn't for the 64bit kernel, it's the other way around, see the compat32 ioctl code for details. > Should a 64bit Android ever appear we would probably want to support > 32bit legacy applications. I agree, this should be fixed, but please do so in the way that we fixed the rest of the kernel for this problem, don't do it in a custom way please. > For this we will need the same binder/ashmem driver to service both a > 32bit application as well as a 64bit application in a 64bit kernel. > Therefore I guess the way forward will be to support 32bit file systems > in a 64bit kernel without any change to the existing user space > (implemented in this patch) and at some point extend the ioctl range > with the needed functionality for 64bit user space. Filesystems shouldn't have anything to do with the problems, it's the mode that the kernel is running in here, right? > >Also, one meta comment, never use the uint32_t types, use the native > >kernel types (u32 and the like.) If you are crossing the user/kernel > >boundry, use the other correct types for those data structures (__u32 > >and the like). What you did here is mix and match things so much that I > >really can't verify that it is all correct. > > I have tried to in-line my changes with the types already used in the > driver but I will update to using the suggested types. Feel free to send a patch first, to fix up the types in the drivers, and then build on it, if you wish to make it easier for you. I imagine this will be a patch series anyway, if you wish to make it easy for us to review (hint, you do...) thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
