On Wed, May 09, 2012 at 11:20:07AM +0100, Ian Abbott wrote: > On 2012-05-09 00:55, H Hartley Sweeten wrote: > >On Tuesday, May 08, 2012 4:41 PM, H Hartley Sweeten wrote: > >> > >>The structs' comedi_insn, coomedi_insnlist, comedi_cmd, > >>comedi_chaninfo, and comedi_rangeinfo are all passed to > >>the kernel from user space using ioctl commands. They > >>are then copied to kernel space using copy_from_user() > >>before the data is passed to the drivers. > >> > >>The __user annotation should not be used with variables > >>inside the struct. This produces a lot of sparse warnings > >>like: > >> > >>warning: dereference of noderef expression > >> > >>Signed-off-by: H Hartley Sweeten<hsweeten@xxxxxxxxxxxxxxxxxxx> > >>Cc: Ian Abbott<abbotti@xxxxxxxxx> > >>Cc: Mori Hess<fmhess@xxxxxxxxxxxxxxxxxxxxx> > >>Cc: Greg Kroah-Hartman<gregkh@xxxxxxxxxxxxxxxxxxx> > >> > >>--- > >> > >>Note: This patch exposes some new warnings about different > >>address space. These will be addressed. > > > >Please ignore this patch. > > > >It appears the annotations in the struct definitions are correct. > > Personally, I think you were on the mark with the patch. It's > better to avoid using __user in comedi.h so it can be used as-is in > user-space. All of the structures in comedi.h are used in user-space > (although Comedilib uses its own version of comedi.h without all the > typedef eliminations that have been done in "staging") and some of > them are also deep-copied into kernel-space objects of the same > type, where the pointers in the structs would no longer be > user-space pointers. When the kernel exports .h files, stuff like this should work "automatically", so there is no need to not put __user markings. So please, yes, continue to work to get this correct, it is very essencial to ensure we don't mess stuff up. thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
