On Tue, Aug 31, 2010 at 10:16 AM, Vasiliy Kulikov <segooon@xxxxxxxxx> wrote: > On Tue, Aug 31, 2010 at 18:08 +0200, Julia Lawall wrote: >> On Tue, 31 Aug 2010, walter harms wrote: >> > > if (strncmp(model, "PowerBook", strlen("PowerBook")) != 0 && >> > > strncmp(model, "iBook", strlen("iBook")) != 0 && >> > > strcmp(model, "PowerMac7,2") != 0 && >> > > >> > >> > is there any rule that says when to use strncmp ? it seems perfecly valid to use strcpy here >> > (what is done in the last cmp). >> >> Perhaps there are some characters after eg PowerBook that one doesn't want >> to compare with? > > It seems to me that model has no '\0' in the end. If model is got from > the hardware then we should double check it - maybe harware is buggy. > Otherwise we'll overflow model. Model does have \0 at the end. This code is using strncmp to purposefully ignore the model suffix. > But why strcmp(model, "PowerMac7,2")? IMO it should be replaced > with strncmp(). We use strcmp when parsing the device tree because the the length of the model property string is unknown and in most cases we *must* match the exact entire string, such as with this PowerMac7,2 example. Using strncmp would also happen to match with something like "PowerMac7,2345" which is not the desired behaviour. g. -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html