Niels Möller <ni...@lysator.liu.se> writes:

> Daiki Ueno <u...@gnu.org> writes:
>
>> Added `mark_bytes_undefined (1, &ciphertext[key->size]);` to the test
>> cases doing encryption.
>
> I'm afraid that isn't right. For one, mark_bytes_undefined is
> conditioned so it only has any effect when running the sc tests. Second,
> it will not produce any warnings for writes, which I think is what we'd
> like to detect here. I think the options are:
>
> 1. Just don't allocate any extra byte, and valgrind's should arrange for
>    alerts on out-of-bounds writes without anything special.
>
> 2. Allocate an extra byte, write some random value before the call, and
>    check that the value is unchanged after the call (some other tests
>    do that sort of thing, it's simple, old fashioned, and doesn't depend
>    on valgrind).
>
> 3. Allocate an extra byte, and mark it using VALGRIND_MAKE_MEM_NOACCESS
>    (wrapped in some macro depending on the memcheck.h configure check).
>    I don't think that gives any real benefit over valgrind's default
>    behavior with (1), but might make sense if done in combination with
>    (2).

Sorry for the confusion and thank you for the explanation; now I get it.
I pushed a change along the of option (2).  Could you take a look again?

Regards,
-- 
Daiki Ueno
_______________________________________________
nettle-bugs mailing list -- nettle-bugs@lists.lysator.liu.se
To unsubscribe send an email to nettle-bugs-le...@lists.lysator.liu.se

Reply via email to