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

[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?

Thanks,
Namhyung