On Wed, Feb 18, 2015 at 10:15:03AM +0100, Marek Polacek wrote:
> We're lacking the POINTER_DIFF_EXPR, which means that ptr - 1 is in fact
> ptr + very_big_number. This can result in bogus run-time error when the
> objsz checking is turned on. Jakub suggested to not to issue the error
> if (ptr > ptr + offset) is true. So this patch attemps to do that, along
> with some optimizations for the common case.
>
> Bootstrap-ubsan passed, bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2015-02-17 Marek Polacek <pola...@redhat.com>
>
> PR sanitizer/65081
> * ubsan.c (OBJSZ_MAX_OFFSET): Define.
> (ubsan_expand_objsize_ifn): Don't emit run-time check if the offset
> is in range [-16K, -1]. Don't issue run-time error if
> (ptr > ptr + offset).
>
> * c-c++-common/ubsan/pr65081.c: New test.
Ok, thanks.
Jakub
