Re: [PATCH] kunit/fortify: Validate __alloc_size attribute results

[Kees Cook]

On Wed, Oct 19, 2022 at 02:29:44PM +0800, David Gow wrote:
> [13:55:44] # alloc_size_test: EXPECTATION FAILED at lib/fortify_kunit.c:91
> [13:55:44] Expected __builtin_dynamic_object_size(p, 1) == expected, but
> [13:55:44] __builtin_dynamic_object_size(p, 1) == -1
> [13:55:44] expected == 51
> [13:55:44] __alloc_size() not working with kmalloc_node(size++, gfp,
> NUMA_NO_NODE)

So, this turned out to be a rat-hole de-ja-vu. The short version is "I
was using Clang 16 where this doesn't manifest", and the long version is
"some inline attributes are broke on all versions of GCC[1] and on Clang
until version 16". :(

I will send the work-around series I've put together to address it. At
the end of the day I now have a WAY more robust set of __alloc_size
KUnit tests. :P

-Kees

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96503

-- 
Kees Cook