On Fri, Oct 21, 2005 at 08:32:25AM -0400, Bagalkote, Sreenivas wrote: > >Jeff Garzik wrote: > >> Do you know where there are some clear guidelines on the use of > >> pointers in a structure passed to an ioctl to lessen (or bypass) > >> 32<->64 compat ioctl thunking? > > > >Its impossible. If you pass pointers, you need to thunk. > >(Not even passing pointers via sysfs can avoid this.) > >Consider running a 32-bit app (with 32-bit pointers and 32-bit > >ABI) on a 64-bit kernel. > > The drivers/scsi/megaraid/megaraid_mm.c simply calls regular ioctl > from within the compat_ioctl, though it does copy to and from the > userland pointers. This is done by adding appropriate padding. Yes. This is what is meant by "thunk". - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
