Gaurav Dhiman (gauravd_linux@xxxxxxxxx) wrote: > > Hi Jan, > > Well can you put some light why this code is not good. > I know that using the top most level functions of any > system call in kernel (like sys_open, sys_close, any > function whcih starts with "sys_") will put alot of > extra overload and might not be the optimum way to do > things in kernel, but i think functionality wise it > will be same, as these function handle all the > senarios need to be handled. > > I think its the easiest and safest way but definitely > not the optimum way, so we shud not use such things in > production code, but they can be used for experimental > or learning codes. Jan will explain surely better than me but I think he would explain this: http://lxr.linux.no/source/fs/open.c#L942 http://lxr.linux.no/source/fs/open.c#L839 The 'struct files_struct' is local to the process. struct files_struct * files = current->files; So in this case and module_init(), it is local to 'insmod' process and all work is done in the same time. But imagine, fd is initialize in init_module. And the write into file is called later by another process. So, It is broken, because current macro will retrieve struct files for _the_ process with will be other than one initialize by 'insmod'. Perhaps I say mistakes, but I am open to learn _why_ and _where_. -- ~Christophe -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
