On Fri, Feb 21, 2025 at 3:45 PM Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx> wrote: > > >What's the purpose of this config option? I think we can just change > >the value of the KASAN_SHADOW_SCALE_SHIFT define when KASAN_SW_TAGS is > >enabled. > > Well, I was aiming at later adding the "default 5 if KASAN_SW_TAGS_DENSE", and > this way it would look much cleaner than the: > > if KASAN_SW_TAGS > if KASAN_SW_TAGS_DENSE > KASAN_SHADOW_SCALE_SHIFT = 5 > else > KASAN_SHADOW_SCALE_SHIFT = 4 > else > KASAN_SHADOW_SCALE_SHIFT = 3 I think this is fine. It's still better than adding a non-configurable config option. > But now that I think of it, it should be possible to overwrite the > KASAN_SHADOW_SCALE_SHIFT from non-arch code if dense mode is enabled. This should also work. Especially since the dense mode will probably work for arm64 as well. But let's keep this series self-contained. > That's a topic for the next series but I'd imagine all architectures would > normally use the 16 memory bytes / shadow byte and if they'd care for the dense > mode they'd go for 32 memory bytes / shadow byte. Or do you think that's a > faulty assumption? Probably, but for sure I don't know, not that many architectures that care about memory tagging yet :)
