Re: [BUG] bpftool: Build failure due to opensslv.h

[Namhyung Kim <namhyung@kernel.org>]

On Thu, Nov 20, 2025 at 09:24:49AM +0000, Quentin Monnet wrote:
> 2025-11-19 17:56 UTC-0800 ~ Namhyung Kim <namhyung@kernel.org>
> > Hello,
> > 
> > On Tue, Oct 28, 2025 at 10:20:22AM +0000, Alan Maguire wrote:
> >> On 28/10/2025 09:05, Quentin Monnet wrote:
> >>> 2025-10-27 11:27 UTC-0700 ~ Namhyung Kim <namhyung@kernel.org>
> >>>> On Mon, Oct 27, 2025 at 11:41:01AM +0000, Quentin Monnet wrote:
> >>>>> 2025-10-26 21:01 UTC-0700 ~ Namhyung Kim <namhyung@kernel.org>
> >>>>>> Hello,
> >>>>>>
> >>>>>> I'm seeing a build failure like below in Fedora 40 and others.  I'm not
> >>>>>> sure if it's reported already but it failed to build perf tools due to
> >>>>>> errors in the bootstrap bpftool.
> >>>>>>
> >>>>>>     CC      /build/util/bpf_skel/.tmp/bootstrap/sign.o
> >>>>>>   sign.c:16:10: fatal error: openssl/opensslv.h: No such file or directory
> >>>>>>      16 | #include <openssl/opensslv.h>
> >>>>>>         |          ^~~~~~~~~~~~~~~~~~~~
> >>>>>>   compilation terminated.
> >>>>>>   make[3]: *** [Makefile:256: /build/util/bpf_skel/.tmp/bootstrap/sign.o] Error 1
> >>>>>>   make[3]: *** Waiting for unfinished jobs....
> >>>>>>   make[2]: *** [Makefile.perf:1213: /build/util/bpf_skel/.tmp/bootstrap/bpftool] Error 2
> >>>>>>   make[1]: *** [Makefile.perf:289: sub-make] Error 2
> >>>>>>   make: *** [Makefile:76: all] Error 2
> >>>>>>
> >>>>>> I think it's from the recent signing change.  I'm not familiar with
> >>>>>> openssl but I guess there's a proper feature check for it.  Is this a
> >>>>>> known issue?
> >>>>>
> >>>>>
> >>>>> Hi Namhyung,
> >>>>
> >>>> Hello!
> >>>>
> >>>>>
> >>>>> This looks related to the program signing change indeed, commit
> >>>>> 40863f4d6ef2 ("bpftool: Add support for signing BPF programs")
> >>>>> introduced a dependency on OpenSSL's development headers for bpftool.
> >>>>> It's not gated behind a feature check. On Fedora, I think the headers
> >>>>> come with openssl-devel, do you have this package installed?
> >>>>
> >>>> No I don't, but I guess it should be able to build on such systems.  Or
> >>>> is it required for bpftool?  Anyway I feel like it should have a feature
> >>>> check and appropriate error messages.
> >>>>
> >>>
> >>> +Cc KP
> >>>
> >>> We usually have feature checks when optional features bring in new
> >>> dependencies for bpftool, but we haven't discussed it this time. My
> >>> understanding was that program signing is important enough that it
> >>> should always be present in newer versions of bpftool, making OpenSSL
> >>> one of the required dependencies going forward.
> >>>
> >>> We don't currently have feature checks to tell when required
> >>> dependencies are missing for bpftool (it's just the build failing, in
> >>> that case). I know perf does a great job at it, we could look into it
> >>> for bpftool, too.
> >>>
> >>
> >> One issue here is that some distros package openssl v3 such that the
> >> #include files are in /usr/include/openssl3 and libraries in
> >> /usr/lib64/openssl3 so that older versions can co-exist. Maybe we could
> >> figure out a feature test that handles that too?
> > 
> > What's the state of this?  Is the fix in the bpf tree now?
> 
> 
> Hi Namhyung, Alan just submitted a v2 of his patch (targetting
> bpf-next), see:
> 
> https://lore.kernel.org/all/20251120084754.640405-2-alan.maguire@oracle.com/
 
Hello Quentin,

I'm afraid it doesn't fix my issue.  It seems to fix another problem
about the error API.  But I still see the build failure.

Thanks,
Namhyung