> 2. Going from size_t to unsigned int is ABI breakage. This is mitigated
>    on CPU architectures that share 32-bit/64-bit registers (i.e. rax/eax
>    on x86-64 and r0/x0/w0 on aarch64). There's no guarantee this works
>    on all architectures, especially when the calling convention passes
>    arguments on the stack.

Good news, I realized that io_uring_prep_getxattr() and friends are
static inline functions. ABI breakage doesn't come into play because
they are compiled into the application.

The const char * to char * API breakage issue still remains but there's
a pretty good chance that real applications already pass in char *.

Thanks,
Stefan