On Thu, Jul 26, 2007 at 05:14:14AM +0400, Dajie Tan wrote: > >> Yeah,this change is to enhance the robust of oprofile. When using > >> performace counter manually(writting control register in a module, no > >> need to use the oprofile),I usually make kernel panic if I do not > >> initialize the oprofile and enable the overflow interrupt carelessly. > >> So, this change can avoid this panic. :D > > > >This panic is good and should stay. It shows that you've made a mistake. > > > >john > > > > This panic is caused by accessing a null pointer.Do you think that > accessing a null > pointer is allowed in a robust system ? Of course it isn't. From the perspective of us kernel maintainers patches that add such checks are a red flag which raise concerns about the correctness of the caller of the function. So if a patch like this is submitted the first thing that is likely to happen is that we will ask why the check is needed. It does not mean such a patch is fundamentally a no-no but the code will be looked at a little harder. Ralf
