On Wed, 24 Mar 2010 22:19:24 +0100 Andrea Arcangeli <aarcange@xxxxxxxxxx> wrote: > > > It's a bit strange to test this when we're about to oops anyway. The > > > oops will tell us the same thing. > > > > ...except that we've seen a fair number of null pointer dereference > > exploits that have told us something altogether different. Are we > > *sure* we don't want to test for null pointers...? > > Examples? Maybe WARN_ON != oops, but VM_BUG_ON still an oops that is > and without serial console it would go lost too. I personally don't > see how it's needed. I don't quite understand the question; are you asking for examples of exploits? http://lwn.net/Articles/347006/ http://lwn.net/Articles/360328/ http://lwn.net/Articles/342330/ ... As to whether this particular test makes sense, I don't know. But the idea that we never need to test about-to-be-dereferenced pointers for NULL does worry me a bit. jon -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>