Re: [PATCH v2 0/4] PowerPC64 static-pie

[Alan Modra <amodra@gmail.com>]

On Fri, Apr 08, 2022 at 07:27:32PM -0300, Tulio Magno Quites Machado Filho wrote:
> Alan Modra via Libc-alpha <libc-alpha@sourceware.org> writes:
> 
> > This is a repost of the series at
> > https://sourceware.org/pipermail/libc-alpha/2022-January/135598.html
> > incorporating review comments.
> >
> > Changes are:
> > - subject lines changed to comply with glibc commit log standards
> > - patch 1/4 log now mentions making a couple of symbols hidden
> > - patch 2/4 makes at_platform available to early ifunc resolvers
> >   as well as hwcap.
> > - patch 3/4 log mentions stinfo->init and stinfo->fini being unused
> > - patch 4/4 PI_STATIC_AND_HIDDEN comment explains what is going on
> >
> > patch 2/4 is the only code change from the previous series.  Testsuite
> > results now show no regressions on powerpc64le-linux.
> 
> I'm still seeing the following failures on powerpc64le-linux:
> 
> FAIL: elf/tst-tls1-static-non-pie
> FAIL: gmon/tst-gmon-static
> FAIL: gmon/tst-gmon-static-gprof
> 
> Am I missing anything?
> 
> I used different GCC and Binutils versions ranging between:
>  - GCC v8 and v11
>  - Binutils 2.30 and 2.38 (2020-03-04)

I was testing with mainline binutils and gcc (gcc-12 20220122).  It is
quite likeley that bleeding edge tools are required for static-pie on
ppc64le.  I'll see if I can recreate some of your results, in
particular with 2.38 binutils.  Mainline ppc64 binutils has a patch
that changes linker behaviour for absolute symbols.  I haven't
backported that patch, or the DT_RELR support, to the 2.38 branch
because those changes might result in breakage.  I'd rather let them
mature a while on mainline.

Here are the results I was seeing with both static-pie and relr
support enabled for ppc64 vs. basline glibc.  Same toolchain for both
glibc builds.

--- base_results   2022-03-04 04:36:09.71152949 -0600
+++ staticpierelr_results   2022-03-04 04:36:17.263676034 -0600
@@ -24,7 +24,7 @@
 UNSUPPORTED: time/tst-settimeofday
 Summary of test results:
       3 FAIL
-   4798 PASS
+   4802 PASS
      19 UNSUPPORTED
      16 XFAIL
       2 XPASS

The three fails common to both test runs were
FAIL: math/test-ibm128-llround
FAIL: math/test-ibm128-y1
FAIL: nptl/tst-pthread-gdb-attach-static
The extra PASSes are new DT_RELR tests I think.

> Anyway, this is a summary of what I think about these patches:
> 
> - Patch 1: Looks good to me.
> - Patch 2: Looks good to me.
> - Patch 3: Looks good to me after a minor change.
> - Patch 4: Hopefully I'm just missing a detail. Otherwise, I believe we should
>            delay it until the previous issues are fixed.

Thanks, I'm happy to leave out patch 4 for the time being, and perhaps
change it so that --enable-static-pie on the configure line is needed
for ppc64.

First three pushed along with the dl_vdso_vsym tweak, but I did see
this weird warning, whatever that means..

alan@squeak:~/src/glibc-current$ git push origin 1a85970f41ea1e5abe6da2298a5e8fedcea26b70:master
Enumerating objects: 62, done.
Counting objects: 100% (62/62), done.
Delta compression using up to 32 threads
Compressing objects: 100% (37/37), done.
Writing objects: 100% (39/39), 6.06 KiB | 6.06 MiB/s, done.
Total 39 (delta 33), reused 0 (delta 0), pack-reused 0
remote: Traceback (most recent call last):
remote:   File "/usr/local/bin/irkerhook.py", line 545, in <module>
remote:     ship(extractor, commit, not notify)
remote:   File "/usr/local/bin/irkerhook.py", line 467, in ship
remote:     privmsg = unicode(metadata)
remote:   File "/usr/local/bin/irkerhook.py", line 99, in __unicode__
remote:     if e.code == 401:
remote: AttributeError: 'URLError' object has no attribute 'code'
remote: *** !!! WARNING: /git/glibc.git/hooks-bin/post-receive returned code: 1.
To ssh://sourceware.org/git/glibc.git
   c0efbf8920..1a85970f41  1a85970f41ea1e5abe6da2298a5e8fedcea26b70 -> master

-- 
Alan Modra
Australia Development Lab, IBM