Re: [PATCH] vsock/test: fix failures due to wrong SO_RCVLOWAT parameter

[Stefano Garzarella]

On Thu, Oct 24, 2024 at 10:00:47AM -0500, Konstantin Shkolnyy wrote:
> On 10/24/2024 03:43, Stefano Garzarella wrote:
> > Other setsockopt() in the tests where we use unsigned long are
> > SO_VM_SOCKETS_* but they are expected to be unsigned, so we should be
> > fine.
>
> It's actually not "signed vs unsigned", but a "size + endianess" problem.

I see, thanks!

> Also, looking at SO_VM_SOCKETS_* code in the test, it uses unsigned 
> long and size_t which (I believe) will both shrink to 4 bytes on 32-bit 
> machines, while the corresponding kernel code in af_vsock.c uses u64.  
> It looks to me that this kernel code will be unhappy to receive just 4 
> bytes when it expects 8.

In include/uapi/linux/vm_sockets.h we talk about unsigned long long for 
SO_VM_SOCKETS_*, that IIUC also on 32-bit machines should be on 64bit, 
so the kernel code looks okay, but the tests should be improved, right?

Thanks,
Stefano