Hello All, Alll are giving the same point again, ofcourse pointers are checked,before dereferncing, ofcourse all,this is why page fault occurs if corresponding physical location is not valid. and that's why pointers but *(int *)0=0 is used in LDD book in faulty module just to demonstrate that only,if such pointer derefernces kernel produces kernel OOPS ,its good to see whst this kernel OOPs exactly gives. Thanks --- Kiran Kumar <immidi_kiran@yahoo.com> wrote: > --- Preetham D Naik <pdn@sasken.com> wrote: > > SO HOW CAN NULL PTR DEREFERENCING HAPPEN IN SUCH > AN > > OS...ARE THE POINTERS > > NOT CHECKED FOR NULL!!! > > All pointers are checked for validity within the > process's address space, not just NULL. It is the > attempt to dereference the NULL pointer that throws > off the oops/segfaults rather than the > dereferencing. > > PS: All caps messages are not fine. "Don't TYPE IN > ALL > CAPS, this is read as shouting and considered rude" > to > quote ESR. > http://www.catb.org/~esr/faqs/smart-questions.html > > ===== > Regards, > Kiran Kumar Immidi > > __________________________________ > Do you Yahoo!? > Yahoo! SiteBuilder - Free web site building tool. > Try it! > http://webhosting.yahoo.com/ps/sb/ > > -- > Kernelnewbies: Help each other learn about the Linux > kernel. > Archive: > http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free web site building tool. Try it! http://webhosting.yahoo.com/ps/sb/ -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
