On 2/6/25 11:11, Christoph Lameter (Ampere) wrote: > I also see that KASAN_HW_TAGS exist but this means that the tags can only > be used with CONFIG_KASAN which is a kernel configuration for debug > purposes. > > What we are interested in is a *production* implementation with minimal > software overhead that will be the default on ARM64 if the appropriate > hardware is detected. Ahh, interesting. I'd assumed that once folks had in-hardware tag checks that they'd just turn on CONFIG_KASAN and be happy. Guess not! > That in turn will hopefully allow other software instrumentation > that is currently used to keep small objects secure and in turn > creates overhead. OK, so KASAN as-is is too broad. Are you saying that the kernel _currently_ have "software instrumentation" like SLAB redzoning/poisoning and you'd like to see MTE used to replace those? Are you just interested in small objects? What counts as small? I assume it's anything roughly <PAGE_SIZE.
