Re: [PATCH] scripts/mod/modpost: For CentOS 7/old binutils compatibility

[Nicolas Schier <nicolas.schier@linux.dev>]

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On Thu, Aug 07, 2025 at 09:22:38AM -0700 Nathan Chancellor wrote:
> On Thu, Aug 07, 2025 at 12:51:59PM +0200, Nicolas Schier wrote:
> > On Tue, Jul 29, 2025 at 12:19:46AM +0800, Haoran lee wrote:
> > > 
> > > Signed-off-by: Haoran Lee <470658536@qq.com>
> > > ---
> > 
> > Please note that empty commit descriptions will not be accepted.
> 
> Agreed, a clear description of the issue (including an error message)
> and logic of the fix is needed.
> 
> > >  scripts/mod/modpost.c | 26 ++++++++++++++++++++++++++
> > >  1 file changed, 26 insertions(+)
> > > 
> > > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
> > > index 5ca7c268294e..216647e2f301 100644
> > > --- a/scripts/mod/modpost.c
> > > +++ b/scripts/mod/modpost.c
> > > @@ -30,6 +30,32 @@
> > >  
> > >  #define MODULE_NS_PREFIX "module:"
> > >  
> > > +/* CentOS 7 / old binutils compatibility */
> > 
> > Since v6.16-rc1 the minimum binutils version has been lifted to 
> > binutils-2.30 [1].
> > 
> > [1]: https://git.kernel.org/torvalds/c/118c40b7b50340bf7ff7e0adee8e3
> > 
> > Which binutils version do you have at CentOS 7 ?
> 
> These values come from glibc's elf.h if I understand correctly, so I
> think this is more about compatibility with versions of glibc that do
> not have these relocations defined, rather than binutils.
> 
> It appears these were all added in glibc 2.18 over ten years ago [1],
> whereas CentOS 7 appears to use glibc 2.17. There is some prior art to
> adding elf.h constants to modpost.c when they are not defined by elf.h
> but I am not sure if it is worth it in this case, as CentOS 7 has been
> EOL for over a year at this point (and I suspect the binutils / GCC
> version is already prohibitive for working on mainline).

ah, look what I found: https://lore.kernel.org/linux-kbuild/20240704134812.1511315-2-masahiroy@kernel.org/

According repology.org, CentOS 7 brings gcc 4.8.5 while v6.16 requires at
least gcc 8.  I am pretty sure that this patch will not be sufficient for
re-adding support for CentOS 7 - I doubt that its worth the effort.

Kind regards,
Nicolas

> If we do want to add these relocation defines, I think they should be
> added in order of their numerical value. I do not have a strong opinion
> either way.
> 
> [1]: https://sourceware.org/git/?p=glibc.git;a=commit;h=08cbd996d33114ca50644d060fbe3a08260430fb



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