Re: [PATCH v06 15/36] uapi linux/socket.h: include sys/socket.h in user space

[Arnd Bergmann]

On Wed, Aug 9, 2017 at 1:00 AM, Dmitry V. Levin <ldv@xxxxxxxxxxxx> wrote:
> On Sun, Aug 06, 2017 at 06:44:06PM +0200, Mikko Rapeli wrote:
>> This libc header has sockaddr definition in user space.
>>
>> Fixes user space compilation errors like these from kernel headers including
>> only linux/socket.h:
>>
>> error: field âifru_addrâ has incomplete type
>> struct sockaddr ifru_addr;
>> error: field â_sockaddrâ has incomplete type
>> struct sockaddr  _sockaddr;
>> error: invalid application of âsizeofâ to incomplete type âstruct sockaddrâ
>>
>> With this following uapi headers now compile in user space:
>>
>> rdma/rdma_user_rxe.h
>> linux/vm_sockets.h
>> linux/ncp_fs.h
>> linux/nfc.h
>> linux/phonet.h
>>

>>
>> +#ifndef __KERNEL__
>> +#include <sys/socket.h>
>> +#endif
>
> This is scary because of infamous libc vs uapi interoperability issues.
> Couldn't we fix affected headers instead?

Yes, I think that would be better. Maybe we can introduce a
'struct __kernel_sockaddr' in include/uapi/linux/socket.h to
go along with __kernel_sa_family_t and __kernel_sockaddr_storage,
and then use those types in the other kernel headers?

       Arnd