On Thu, Aug 12, 2021 at 10:57 AM Marco Elver <elver@xxxxxxxxxx> wrote: > > On Wed, 11 Aug 2021 at 21:21, <andrey.konovalov@xxxxxxxxx> wrote: > > From: Andrey Konovalov <andreyknvl@xxxxxxxxx> > > > > Multiple KASAN tests do writes past the allocated objects or writes to > > freed memory. Turn these writes into reads to avoid corrupting memory. > > Otherwise, these tests might lead to crashes with the HW_TAGS mode, as it > > neither uses quarantine nor redzones. > > > > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxx> > > Reviewed-by: Marco Elver <elver@xxxxxxxxxx> > > although if you need a write primitive somewhere that doesn't corrupt > memory, you could use atomic_add() or atomic_or() of 0. Although > technically that's a read-modify-write. Interesting idea. I'd say let's keep the volatile reads for now, and change them if we encounter any problem with those. > For generic mode one issue is > that these are explicitly instrumented and not through the compiler, > which is only a problem if you're testing the compiler emits the right > instrumentation. On a related point, it seems we have no KASAN tests to check atomic operations. Filed https://bugzilla.kernel.org/show_bug.cgi?id=214055 for this. Thanks!
