On Thu, Oct 01, 2020 at 09:52:31PM +0200, Petr Vorel wrote:
> + update code where needed (include <linux/sysinfo.h> in code which
> included <linux/kernel.h> only to get struct sysinfo or SI_LOAD_SHIFT).
>
> The reason is to avoid indirect <linux/sysinfo.h> include when using
> some network headers: <linux/netlink.h> or others [1] ->
> <linux/kernel.h> -> <linux/sysinfo.h>.
>
> This indirect include causes redefinition of struct sysinfo when
> included both <sys/sysinfo.h> and some of network headers:
>
> In file included from x86_64-buildroot-linux-musl/sysroot/usr/include/linux/kernel.h:5,
> from x86_64-buildroot-linux-musl/sysroot/usr/include/linux/netlink.h:5,
> from ../include/tst_netlink.h:14,
> from tst_crypto.c:13:
> x86_64-buildroot-linux-musl/sysroot/usr/include/linux/sysinfo.h:8:8: error: redefinition of ‘struct sysinfo’
> struct sysinfo {
> ^~~~~~~
> In file included from ../include/tst_safe_macros.h:15,
> from ../include/tst_test.h:93,
> from tst_crypto.c:11:
> x86_64-buildroot-linux-musl/sysroot/usr/include/sys/sysinfo.h:10:8: note: originally defined here
>
> [1] or <linux/sysctl.h>, <linux/ethtool.h>, <linux/mroute6.h>, <linux/ethtool.h>
>
> Suggested-by: Rich Felker <dalias@xxxxxxxxxx>
> Signed-off-by: Petr Vorel <petr.vorel@xxxxxxxxx>
> ---
> Hi,
>
> this looks to be long standing problem: python-psutil [2], iproute2 [3],
> even for glibc in the past [4] and it tried to be solved before [5].
>
> This will require glibc fix after:
You can't do this; it breaks the existing contract with glibc. New
kernel headers can't force a glibc upgrade. You just have to get rid
of use of <linux/kernel.h> elsewhere in the uapi headers. It was a
mistake that <linux/sysinfo.h> was ever separated out of
<linux/kernel.h> since it didn't (and couldn't) fix the contract that
<linux/kernel.h> exposes struct sysinfo (and that it's misnamed). But
it's no big deal. This can all be fixed without any breakage anywhere
just by not using it.
Rich
