Re: Question about "asm/rwonce.h: No such file or directory"

[Masahiro Yamada]

On Wed, Nov 13, 2019 at 5:36 PM Xiao Yang <ice_yangxiao@xxxxxxx> wrote:
>
> On 11/13/19 3:53 PM, Masahiro Yamada wrote:
> > On Wed, Nov 13, 2019 at 4:17 PM Xiao Yang <ice_yangxiao@xxxxxxx> wrote:
> >> On 11/13/19 2:57 PM, Masahiro Yamada wrote:
> >>> Sorry, I really do not understand what you are doing.
> >>>
> >>> include/linux/compiler.h is only for kernel-space.
> >>> Shrug if a user-land program includes it.
> >> Hi Masahiro,
> >>
> >> For building tools/bpf, it is good to fix the compiler error by Daniel's
> >> patch(i.e. use linux/filter from linux header).
> >>
> >> linux/compiler.h may be used by other code in kernel.  Is it possible to
> >> trigger the same error when the other code
> >>
> >> including linux/compiler.h is built? Is this kind of code able to find
> >> the location of <asm/rwonce.h>?
> >
> > <asm/rwonce.h> is also kernel-only header.
> >
> > The kernel code can find <asm/rwonce.h>, but user-land code cannot.
>
> Hi Masahiro,
>
> Sorry, I am not familar with it.
>
> Thanks a lot for your explanation and I have seen the LINUXINCLUDE
> variable in Makefile.
>
> I will try to send a patch as Daniel suggested.
>
> Best Regards,
>
> Xiao Yang
>

Hmm, digging into the git history,
this include path was added by the following commit:


commit d7475de58575c904818efa369c82e88c6648ce2e
Author: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
Date:   Wed Nov 11 14:24:27 2015 -0800

    tools/net: Use include/uapi with __EXPORTED_HEADERS__

    Use the local uapi headers to keep in sync with "recently" added #define's
    (e.g. SKF_AD_VLAN_TPID).  Refactored CFLAGS, and bpf_asm doesn't need -I.

    Fixes: 3f356385e8a4 ("filter: bpf_asm: add minimal bpf asm tool")
    Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
    Acked-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>



I am not sure how big a deal it is,
but it could be a problem on old distros??



-- 
Best Regards
Masahiro Yamada