On Thu, Feb 9, 2023 at 4:26 PM Rich Felker <dalias@libc.org> wrote:
> The concept of this seems fine, but if the limit was previously 255 on
> supported kernel versions, why stop at 253? It doesn't really cost
> anything to go up large enough that the 255 would work too.

I can use 255.

> As a technical detail, I'd probably also just put the full size
> expression in the [], then use sizeof when you need it later. As
> written, this change makes chbuf[] formally a VLA. The compiler
> probably optimizes it to the same code as if it wasn't a VLA, but
> there's no good reason for it to be a VLA.

Using sizeof with the original buffer would have effectively fixed
this issue, the extra "+1" in the number of chbuf elements adds 16
extra bytes to the buffer on x86_64, which would have been sufficient
to hold the extra fds.  It might as well be explicit though so it
doesn't get reduced in the future.

Attached v2.