This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH 2/2] malloc: make malloc fail with requests larger than PTRDIFF_MAX
On Fri, 21 Dec 2018, Adhemerval Zanella wrote:
> What about:
>
> * Memory allocation functions malloc, calloc, realloc, reallocarray, valloc,
> pvalloc, memaling, and posix_memalignfail now fail with requests larger
Typos "memaling", "posix_memalignfail".
> than PTRDIFF_MAX. This is to avoid potential undefined behavior with
> pointer subtraction within the allocated object, where results might
> in ptrdiff_t type overflow.
"might overflow the ptrdiff_t type".
> Does gcc provide an attribute to indicate first argument is the expected
> result, so it can match the attribute with argument type instead of
> function returned one? Otherwise I think we will need to suppress it
> from posix_memalign.
No, the alloc_size attribute is inapplicable to posix_memalign.
--
Joseph S. Myers
joseph@codesourcery.com