Re: Personal aarch64 FreeBSD OS build gets SIGSEGV during: ./pmu-events/jevents arm64 /usr/main-src/lib/libpmc/pmu-events/arch libpmc_event [cause identified]

On Sun, Sep 20, 2026 at 10:46 PM Mark Millard <marklmi@yahoo.com> wrote:
>
> On 9/20/26 18:54, Mark Millard wrote:
> > On 9/20/26 11:13, Mark Millard wrote:
> >> [I have CC'd a could of authors with recent libpmc commits. I did not
> >> list any recent libc authors.]
> >>
> >> . . .
> >>
> >
> > I found the type of problem --but it is not a obvious extension of
> > the prior material: META_MODE recorded something that indicates the
> > actual problem . . .
> >
> > /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/lib/libpmc/pmu-events/jevents.pieo.meta:R
> > 12651 /usr/include/fts.h
> >
> > The build is using the /usr/include/fts.h from the live old system
> > while trying to build the new system.
> >
> > Given the FTSENT change of layout from old to new, that does not
> > work. Also, this is not something that clearing out /usr/obj/ . . .
> > and rebuilding fixes.
> >
> > The build of lib/libpmc/pmu-events/jevents.* should get the fts.h
> > file from the source tree being built, in my case I was working in
> > /usr/main-src/ so:
> >
> > # find -s /usr/main-src/ -name fts.h -print
> > /usr/main-src/include/fts.h
> >
> > lists a path to the file that should have been used for the build.
> >
> > I expect that this would be a libpmc development issue, not a fts
> > development issue for who solves it.
> >
> >
> > Also: this turns out to not be an arm specific problem.
> >
> >
>
> The problematic include handling for building system updates extends far
> beyond the specific example in jevents.pieo.meta : All but 8 of the many
> include file usages were strictly tied to the old live system instead of
> to the new system's source tree (to some degree):
> (The ones that mention main-src are those that involve the source tree
> that I was doing the build for.)
>
> # grep -e /include/ -e '\.h$'
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/lib/libpmc/pmu-events/jevents.pieo.meta
> R 12651 /usr/include/sys/param.h
> R 12651 /usr/include/sys/_null.h
> R 12651 /usr/include/sys/_param.h
> R 12651 /usr/include/sys/types.h
> R 12651
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/tmp/legacy/usr/include/sys/cdefs.h
> R 12651
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/tmp/legacy/usr/include/sys/_decls.h
> R 12651
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/tmp/legacy/usr/include/sys/_visible.h
> R 12651 /usr/include/machine/endian.h
> R 12651 /usr/include/sys/_types.h
> R 12651 /usr/include/machine/_types.h
> R 12651 /usr/include/sys/_endian.h
> R 12651 /usr/include/sys/_offsetof.h
> R 12651 /usr/include/sys/_pthreadtypes.h
> R 12651 /usr/include/sys/_stdint.h
> R 12651 /usr/include/sys/bitcount.h
> R 12651 /usr/include/sys/select.h
> R 12651 /usr/include/sys/_sigset.h
> R 12651 /usr/include/sys/_timeval.h
> R 12651 /usr/include/sys/timespec.h
> R 12651 /usr/include/sys/_timespec.h
> R 12651 /usr/include/sys/syslimits.h
> R 12651 /usr/include/sys/signal.h
> R 12651 /usr/include/sys/_sigaltstack.h
> R 12651 /usr/include/sys/_sigval.h
> R 12651 /usr/include/machine/_limits.h
> R 12651 /usr/include/machine/signal.h
> R 12651 /usr/include/machine/param.h
> R 12651 /usr/include/sys/_align.h
> R 12651 /usr/include/sys/limits.h
> R 12651 /usr/include/sys/_maxphys.h
> R 12651 /usr/include/sys/resource.h
> R 12651 /usr/include/sys/stat.h
> R 12651 /usr/include/sys/time.h
> R 12651 /usr/include/sys/_clock_id.h
> R 12651 /usr/include/time.h
> R 12651 /usr/include/xlocale/_time.h
> R 12651 /usr/include/ctype.h
> R 12651 /usr/include/_ctype.h
> R 12651 /usr/include/runetype.h
> R 12651 /usr/include/xlocale/_ctype.h
> R 12651 /usr/include/dirent.h
> R 12651 /usr/include/sys/dirent.h
> R 12651 /usr/include/errno.h
> R 12651 /usr/include/libgen.h
> R 12651 /usr/include/limits.h
> R 12651 /usr/include/stdarg.h
> R 12651 /usr/include/sys/_stdarg.h
> R 12651
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/tmp/legacy/usr/include/stddef.h
> R 12651 /usr/include/stddef.h
> R 12651 /usr/include/stdio.h
> R 12651 /usr/include/stdlib.h
> R 12651 /usr/include/string.h
> R 12651 /usr/include/strings.h
> R 12651 /usr/include/xlocale/_strings.h
> R 12651 /usr/include/xlocale/_string.h
> R 12651 /usr/include/unistd.h
> R 12651 /usr/include/sys/unistd.h
> R 12651 /usr/include/ftw.h
> R 12651 /usr/main-src/lib/libpmc/pmu-events/list.h
> R 12651 /usr/main-src/lib/libpmc/pmu-events/jsmn.h
> R 12651 /usr/main-src/lib/libpmc/pmu-events/json.h
> R 12651 /usr/include/stdbool.h
> R 12651 /usr/main-src/lib/libpmc/pmu-events/pmu-events.h
> R 12651 /usr/include/fts.h
>
>
> Some of those may be lower risk of incompatible changes than others but
> the general trend is not good for doing system builds when layout
> changes or other incompatibilities are introduced.
>
> Of course, there are some things that are built for operation on the
> older system instead of the newer one. So the classification is case by
> case across the various *.meta files.
>
>
> Taking a quick stab at finding other examples (incomplete because of the
> failed build):
>
> # find -s /usr/obj/BUILDs/main-CA76-nodbg-clang/ -name \*.meta -exec
> grep -l -e ' /usr/include/' {} \; | grep -v /tmp/obj-tools/
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/bin/csh/gethost.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/bin/sh/mknodes.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/bin/sh/mksyntax.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/host-osreldate.h.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/lib/libmagic/mkmagic.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/lib/libpmc/pmu-events/jevents.pieo.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/lib/libpmc/pmu-events/jsmn.pieo.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/lib/libpmc/pmu-events/json.pieo.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/lib/ncurses/tinfo/make_hash.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/lib/ncurses/tinfo/make_keys.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/rescue/rescue/usr/main-src/bin/csh/gethost.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/rescue/rescue/usr/main-src/bin/sh/mknodes.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/rescue/rescue/usr/main-src/bin/sh/mksyntax.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/share/syscons/scrnmaps/armscii8-2haik8.mk.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/share/syscons/scrnmaps/iso-8859-1_to_cp437.mk.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/share/syscons/scrnmaps/iso-8859-4_for_vga9.mk.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/share/syscons/scrnmaps/iso-8859-7_to_cp437.mk.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/share/syscons/scrnmaps/koi8-r2cp866.mk.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/share/syscons/scrnmaps/koi8-u2cp866u.mk.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/share/syscons/scrnmaps/us-ascii_to_cp437.mk.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/usr.bin/awk/maketab.meta
> /usr/obj/BUILDs/main-CA76-nodbg-clang/usr/main-src/arm64.aarch64/usr.bin/vi/catalog/dump.meta
>
>
> --
> ===
> Mark Millard
> marklmi at yahoo.com

Interesting find.  And I can reproduce it, partially.  If I build
16.0-CURRENT from a 15.1 host, and look at the generated symbols:

> objdump -T /usr/obj/.../amd64.amd64/lib/libpmc/pmu-events/jevents.full | grep fts_
0000000000000000      DF *UND*  0000000000000000 (FBSD_1.5)   fts_open
0000000000000000      DF *UND*  0000000000000000 (FBSD_1.5)   fts_read
0000000000000000      DF *UND*  0000000000000000 (FBSD_1.5)   fts_close

I see the FBSD_1.5 version of those symbols.  It should be FBSD_1.9
instead.  Indeed, if I build from a 16.0 host I do see the FBSD_1.9
symbols.  So the build is definitely wrong.  But that doesn't quite
explain why you would get a segfault.  Linking to the FBSD_1.5 symbols
while using the old header files should work fine.  So I wonder if the
build is somehow including a mixture of old header files and new ones.
That would explain a segfault.