On Fri, Jun 14, 2024 at 12:08 PM Jason A. Donenfeld [off-list ref] wrote:

Provide a generic C vDSO getrandom() implementation, which operates on
an opaque state returned by vgetrandom_alloc() and produces random bytes
the same way as getrandom(). This has a the API signature:

  ssize_t vgetrandom(void *buffer, size_t len, unsigned int flags, void *opaque_state);

Last time around, I mentioned some potential issues with this function
signature, and I didn't see any answer.  My specific objection was to
the fact that the caller passes in a pointer but not a length, and
this potentially makes reasoning about memory safety awkward,
especially if anything like CRIU is involved.

--Andy