Re: [PATCH iproute2] iproute2: Fix undeclared __kernel_long_t type build error in RHEL 6.8

On Fri, Dec 01, 2017 at 08:48:07AM -0800, Stephen Hemminger wrote:

On Fri,  1 Dec 2017 13:04:51 +0200
Leon Romanovsky [off-list ref] wrote:

quoted

From: Leon Romanovsky <redacted>

Add asm/posix_types.h header file to the list of needed includes,
because the headers files in RHEL 6.8 are too old and doesn't
have declaration of __kernel_long_t.

In file included from ../include/uapi/linux/kernel.h:5,
                 from ../include/uapi/linux/netfilter/x_tables.h:4,
                 from ../include/xtables.h:20,
                 from em_ipset.c:26:
../include/uapi/linux/sysinfo.h:9: error: expected specifier-qualifier-list before ‘__kernel_long_t’

Cc: Riad Abo Raed <redacted>
Cc: Guy Ergas <redacted>
Signed-off-by: Leon Romanovsky <redacted>

I see the problem, but the solution of dragging in posix_types.h
would be too much of a long term maintenance issue.
All the headers in uapi are regularly generated from upstream
kernel headers; I don't want to start making exceptions.

Is it just the xtables stuff (which has always been problematic)?

Actually, the only place where __kernel_long_t and __kernel_ulong_t
appear is struct sysinfo in include/uapi/linux/sysinfo.h and this
structure isn't even used anywhere in iproute2 source (not even in the
include/uapi/linux/kernel.h file which includes <linux/sysinfo.h>).

So one could work around the problem by defining _LINUX_SYSINFO_H but
that seems a bit dirty hack.

Michal Kubecek