On 12/11/23 23:11, Andrey Konovalov wrote: > On Wed, Dec 6, 2023 at 3:45 PM Marco Elver <elver@xxxxxxxxxx> wrote: >> >> The is_kfence_address() implementation tolerates tagged addresses, >> i.e. if it receives a tagged non-kfence address, it will never return >> true. So just to be sure, it can't happen that a genuine kfence address would then become KASAN tagged and handed out, and thus when tested by is_kfence_address() it would be a false negative? >> The KASAN_HW_TAGS patches and KFENCE patches were in development >> concurrently, and at the time there was some conflict resolution that >> happened when both were merged. The >> is_kfence_address(kasan_reset_tag(..)) initially came from [1] but was >> squashed into 2b8305260fb. >> >> [1] https://lore.kernel.org/all/9dc196006921b191d25d10f6e611316db7da2efc.1611946152.git.andreyknvl@xxxxxxxxxx/ >> >> Andrey, do you recall what issue you encountered that needed kasan_reset_tag()? > > I don't remember at this point, but this could have been just a safety measure. > > If is_kfence_address tolerates tagged addresses, we should be able to > drop these kasan_reset_tag calls. Will drop it once the above is confirmed. Thanks!
