Re: [klibc] [PATCH net-next] net: uapi: Provide an UAPI definition of 'struct sockaddr'

[H. Peter Anvin]

On 2026-01-20 14:31, Arnd Bergmann wrote:
>> 
> I must have accidentally cut that from my reply, sorry.
> Looking at it again now, I think I ran into problems with the
> flexible array that was removed from the in-kernel sockaddr
> structure in commit 2b5e9f9b7e41 ("net: Convert struct sockaddr
> to fixed-size "sa_data[14]""), so there is a good chance it works
> now with the (once more) fixed-size version.
> 
> The other problem is that the structures that embed 'sockaddr'
> are used a lot inside of the kernel, in particular in 'ifreq',
> so changing the uapi sockaddr to __kernel_sockaddr requires
> additional changes wherever the struct members are passed
> by reference.
>

Well, the kernel should do what opting-in libcs do:

#define sockaddr __kernel_sockaddr

or

struct sockaddr { struct __kernel_sockaddr; };

... now when we have ms extensions turned on. Unfortunately gcc/clang don't
support them without the option even with __extension__, so user space is
limited to using macros.

	-hpa