On Fri, Jun 29, 2018 at 1:26 PM, Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx> wrote: > On Fri, Jun 29, 2018 at 12:04:22PM +0100, Dave Martin wrote: >> >> Can sparse be hacked to identify pointer subtractions where the pointers >> are cannot be statically proved to point into the same allocation? Re all the comments about finding all the places where we do pointer subtraction/comparison: I might be wrong, but I doubt you can easily do that with static analysis. What we could do is to try to detect all such subtractions/comparisons dynamically. The idea is to instrument all pointer/ulong subtraction/comparison instructions and try to detect tags mismatch. And then run some workload (e.g. syzkaller) to trigger more kernel code. The question is how much false positives we would get, since I imagine there would be a number of cases when we compare some random ulongs. -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
