On 12/21/2015 05:24 PM, Andrew Morton wrote: >>> Should we use c99 initializer instead to make it future-proof? >> > >> > I didn't do that to make these sort of failures obvious. In this case, if we would have >> > used an initializer and it would default to the "wrong" values it would be much harder >> > to find this bug. >> > > If we're to make that approach useful and debuggable we should poison > the structure at the outset with some well-known and crazy pattern. Or > use kasan. We sort of do. Consider stack garbage as "poison"... This bug was found using UBSan which complained that a bool suddenly had the value of '64'. If we go back to the scenario I've described, and the struct would have been initialized on declaration, you'd have a much harder time finding it rather than letting our existing and future tools find it. Thanks, Sasha -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>