Subject: Re: [PATCH iproute2] Fix compilation with kernel headers < 3.4

From: Thomas De Schampheleire <[email-masked]>
Date: Mon, 26 Feb 2018 21:32:58 +0100

On Mon, Feb 26, 2018 at 09:46:41PM +0200, Serhey Popovych wrote:
> Since commit 596b1c94aa38e21b7a8c8562e8b61ccb744255d2, iproute2 uses types
> __kernel_long_t and __kernel_ulong_t but does not provide internal
> definitions for it.
> 
> This means that compilation using kernel headers that are older than 3.4
> (where these types were added) will fail. This situation may be uncommon for
> native compilation, but not uncommon for cross compilation where the
> toolchains may be a bit older.
> 
> Provide the necessary types internally if not provided by the kernel
> headers to fix compilation in such cases.
> 
> Co-Developed-by: Serhii Popovych <[email-masked]>
> Signed-off-by: Thomas De Schampheleire <[email-masked]>
> Signed-off-by: Serhey Popovych <[email-masked]>
> ---
>  include/linux/sysinfo.h |   14 ++++++++++++++
>  misc/ss.c               |   10 ++++++++++
>  2 files changed, 24 insertions(+)
>  create mode 100644 include/linux/sysinfo.h
> 
> diff --git a/include/linux/sysinfo.h b/include/linux/sysinfo.h
> new file mode 100644
> index 0000000..766de8d
> --- /dev/null
> +++ b/include/linux/sysinfo.h
> @@ -0,0 +1,14 @@
> +#ifndef _SYSINFO_COMPAT_H
> +#define _SYSINFO_COMPAT_H
> +
> +/* In case the kernel header asm/posix_types.h is too old (< 3.4) to provide
> + * __kernel_long_t, provide it here
> + */
> +#ifndef __kernel_long_t
> +typedef long		__kernel_long_t;
> +typedef unsigned long	__kernel_ulong_t;
> +#endif
> +
> +#include_next <linux/sysinfo.h>
> +
> +#endif /* _SYSINFO_COMPAT_H */
> diff --git a/misc/ss.c b/misc/ss.c
> index e047f9c..de5a673 100644
> --- a/misc/ss.c
> +++ b/misc/ss.c
> @@ -46,6 +46,16 @@
>  #include <linux/sctp.h>
>  #include <linux/vm_sockets_diag.h>
>  
> +#ifndef AF_VSOCK
> +#define AF_VSOCK	40
> +#if defined(AF_MAX) && AF_MAX < 41
> +#undef AF_MAX
> +#endif
> +#ifndef AF_MAX
> +#define AF_MAX		41
> +#endif /* AF_MAX */
> +#endif /* AF_VSOCK */
> +
>  #define MAGIC_SEQ 123456
>  #define BUF_CHUNK (1024 * 1024)
>  #define LEN_ALIGN(x) (((x) + 1) & ~1)

Thanks, this patch works fine in my use case too.

I can't judge the changes in ss.c. I did not see such problems, but my toolchain
is based on 3.3 kernel headers.

Best regards,
Thomas