On Fri, 4 Jul 2008 17:38:25 -0700 "bhanu nani" <bhanu.lnxnew@xxxxxxxxx> wrote: > if I have an ioctl that passes me some data in a structure which I > have to process and return the result as a field in the structure. > Is it acceptable if I copy the entire structure with copy_to_user() > instead of copying only the field with with put_user()? > Because doing so I am overwriting the user data which is ok for my > application but does Linux treat overwriting data in this fashion? This is a fairly normal thing. However, you will want to make sure that your data structure is the same on 32 and 64 bit systems, because someone may end up using it on a 64 bit kernel in the future, with a 32 bit program. PPC64 tends to run 32 bit PPC programs, after all. So you'll want to make sure the data structure uses data types that are the same on 32 and 64 bit (like u32) instead of data types that change depending on how the system is compiled (like unsigned long). -- All rights reversed. -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
