Re: [PATCH] thermal: core: Move initial num_trips assignment before memcpy()

Kees Cook
2024-02-27T17:00:47Z

On Tue, Feb 27, 2024 at 05:47:44PM +0100, Daniel Lezcano wrote:
> Ok my misunderstanding was I thought sizeof() was calling _bdos under the
> hood, so when calling sizeof(flex_array), it was returning the computed size
> inferring from the __counted_by field.

Yeah, sizeof() has a very limited scope. __builtin_object_size() has
more flexibility (via the 2nd argument, "type"), but it was still
compile-time only. __builtin_dynamic_object_size() was added to bring
runtime evaluations into the mix (initially to support the alloc_size
attribute, and now includes the counted_by attribute too).

--
Kees Cook