On 10/25/21 08:45, Martin Sebor via Libc-alpha wrote:
> Based on my code inspection of _mid_memalign in malloc.c I think
> a change that would more accurately reflect the implementation
> is one that described that when alignment is not a power of two
> it's bumped up to next larger power of two, and adjusted
> the EINVAL condition appropriately.

Let's not document this implementation detail, as it might tie us down 
unnecessarily in the future.

> I believe the DR460 change went into C17.  Here's an early C2x
> draft from 2018 publicly available on the WG14 site that should
> still be very close to C17:
> 
>   http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2310.pdf

This says that aligned_alloc "shall fail" if the alignment is not a 
valid alignment supported by the implementation. This means the current 
glibc alloc_aligned behavior does not conform to C17 and should be fixed 
so that it does. Something like the attached (untested) patch, say.