Re: [PATCH v2] hv_netvsc: Replace one-element array with flexible array member

[Przemek Kitszel]

On 1/17/25 01:17, Jakub Kicinski wrote:
> On Thu, 16 Jan 2025 13:39:52 -0800 Roman Kisel wrote:
> > On 1/16/2025 1:19 PM, Thorsten Blum wrote:
> > > Replace the deprecated one-element array with a modern flexible array
> > > member in the struct nvsp_1_message_send_receive_buffer_complete.
> > >
> > > Use struct_size_t(,,1) instead of sizeof() to maintain the same size.

I would add a struct-specific macro or at least put the info into this
struct' doc, that "there is legacy API requirement to allocate at least
one element for the flex array member".

> > Thanks!
> >
> > > Compile-tested only.
> >
> > The code change looks good to me now. I'll build a VM with this change
> > to clear my conscience (maybe the change triggers a compiler bug,
> > however unlikely that sounds) before replying with any tags. Likely next
> > Monday, but feel free to beat me to it, or perhaps, someone else will
> > tag this as reviewed by them and/or tested by them.
>
> Doesn't look like a real bug fix, so would be good to get some signal

If the actual usage would be with more than 1 element UBSAN will
complain.

> soon. The merge window is soon so we'll likely close the trees very
> very soon ..