Re: Newer hwcap failures

["H.J. Lu" <hjl.tools@gmail.com>]

On Fri, Jan 29, 2021 at 4:30 AM Adhemerval Zanella via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
>
>
> On 29/01/2021 07:51, Szabolcs Nagy wrote:
> > The 01/29/2021 11:48, Florian Weimer wrote:
> >> * Szabolcs Nagy:
> >>
> >>> The 01/29/2021 10:20, Florian Weimer via Libc-alpha wrote:
> >>>> * Adhemerval Zanella:
> >>>>
> >>>>> The issue is test-container is copying the ld.so.cache from system into
> >>>>> testroot and thus _dl_sysdep_read_whole_file does not fail.
> >>>>>
> >>>>> For 32-bit builds, there is not ld.so.cache then _dl_sysdep_read_whole_file
> >>>>> fails and further ldconfig does not change the process map (since
> >>>>> _dl_load_cache_lookup won't reload the cache after an initial failure).
> >>>>>
> >>>>> That's explain why I am seeing this only on system with default 64-bit
> >>>>> userland.  I don't know exactly why I haven't see this before, neither
> >>>>> if it were some testing regression added recently.
> >>>>
> >>>> I can't reproduce this (with an x86-64 host and a multilib toolchain).
> >>>> Does it require an i386 chroot to reproduce?
> >>>
> >>> i see those tests fail with a config.make that has
> >>>
> >>> cross-compiling = maybe
> >>>
> >>> then /etc/ld.so.cache is missing from the install
> >>> directory (since ldconfig is not run)
> >>>
> >>> i normally use a i686-linux-gnu toolchain on an
> >>> x86_64 machine to test i686, not a chroot/container.
> >>> in an i686 container with native gcc the tests pass.
> >>
> >> Hmm, how do you get that maybe?  Do you rebuild ./configure using
> >> autoconf 2.70 or later?
> >>
> >> I see this in the configure file we ship:
> >>
> >> # There might be people who depend on the old broken behavior: `$host'
> >> # used to hold the argument of --host etc.
> >> # FIXME: To remove some day.
> >> build=$build_alias
> >> host=$host_alias
> >> target=$target_alias
> >>
> >> # FIXME: To remove some day.
> >> if test "x$host_alias" != x; then
> >>   if test "x$build_alias" = x; then
> >>     cross_compiling=maybe
> >>   elif test "x$build_alias" != "x$host_alias"; then
> >>     cross_compiling=yes
> >>   fi
> >> fi
> >>
> >> I configure glibc with --build=i686-linux-gnu, and that gives me
> >> “cross-compiling = no” in config.make.
> >
> > hm ok i use --host=i686-linux-gnu but not build
> > may be i should add --build too.
> >
> > (but in case of real cross compiling when i
> > run the tests with cross-wrapper+ssh then i
> > cannot change the --build and the tests will
> > fail)
> >
>
> In my environment I use '--build=x86_64-linux-gnu --host=i686-linux-gnu' and
> CFLAGS="x86_64-glibc-linux-gnu-gcc -m32" with a multiarch gcc built with
> build-many-glibcs.py:

I use

BUILD_CC="gcc" CC="gcc -m32" CXX="g++ -m32" CFLAGS="-O2 -g
-march=i686" /export/gnu/import/git/sources/glibc/configure
--prefix=/usr --without-selinux --target=i686-linux --build=i686-linux
--host=i686-linux --enable-hardcoded-path-in-tests

to test i686 on x86-64.

> $ x86_64-glibc-linux-gnu-gcc -v
> [...]
> Configure with: [...]  --with-multilib-list=m64,m32,mx32 [...]
>
> This results in:
>
> $ grep cross-compiling config.make
> cross-compiling = yes
>
> In most cases it does not interfere because cache won't be used. But I
> still think we should fix to the test that actually check ldconfig
> and ld.so.cache.
>
> My idea to handle it is to add a new 'ldconfig' rule to *.script to
> trigger a new ld.so.cache creation for container tests.



-- 
H.J.