v0.15.0 tests/replace-add-needed.sh fails on ppc64le on CentOS/RHEL/Rocky 8

[robert-scheck]

tests/replace-add-needed.sh of patchelf 0.15.0 fails during make check on ppc64le on CentOS/RHEL/Rocky 8:

[…]
make  check-TESTS
make[2]: Entering directory '/builddir/build/BUILD/patchelf-0.15.0/tests'
make[3]: Entering directory '/builddir/build/BUILD/patchelf-0.15.0/tests'
PASS: plain-fail.sh
PASS: plain-run.sh
PASS: shrink-rpath.sh
PASS: set-interpreter-short.sh
PASS: set-interpreter-long.sh
PASS: set-rpath.sh
PASS: add-rpath.sh
PASS: no-rpath.sh
PASS: big-dynstr.sh
PASS: set-rpath-library.sh
PASS: soname.sh
PASS: shrink-rpath-with-allowed-prefixes.sh
PASS: set-rpath-rel-map.sh
PASS: force-rpath.sh
PASS: plain-needed.sh
PASS: output-flag.sh
PASS: too-many-strtab.sh
PASS: no-rpath-pie-powerpc.sh
PASS: build-id.sh
PASS: invalid-elf.sh
PASS: endianness.sh
PASS: contiguous-note-sections.sh
PASS: no-gnu-hash.sh
PASS: grow-file.sh
PASS: no-dynamic-section.sh
PASS: args-from-file.sh
PASS: basic-flags.sh
PASS: set-empty-rpath.sh
PASS: phdr-corruption.sh
PASS: replace-needed.sh
FAIL: replace-add-needed.sh
PASS: add-debug-tag.sh
PASS: no-rpath-amd64.sh
PASS: no-rpath-armel.sh
PASS: no-rpath-armhf.sh
PASS: no-rpath-hurd-i386.sh
PASS: no-rpath-i386.sh
PASS: no-rpath-ia64.sh
PASS: no-rpath-kfreebsd-amd64.sh
PASS: no-rpath-kfreebsd-i386.sh
PASS: no-rpath-mips.sh
PASS: no-rpath-mipsel.sh
PASS: no-rpath-powerpc.sh
PASS: no-rpath-s390.sh
PASS: no-rpath-sh4.sh
PASS: no-rpath-sparc.sh
============================================================================
Testsuite summary for patchelf 0.15.0
============================================================================
# TOTAL: 46
# PASS:  45
# SKIP:  0
# XFAIL: 0
# FAIL:  1
# XPASS: 0
# ERROR: 0
============================================================================
See tests/test-suite.log
============================================================================

Unfortunately, tests/replace-add-needed.sh.log was not that helpful:

$ cat tests/replace-add-needed.sh.log
FAIL replace-add-needed.sh (exit status: 1)
$ 

However, using -x in tests/replace-add-needed.sh lead to this:

[…]
+ sed -e 's/ -e/ -ex/' -i tests/replace-add-needed.sh
+ cd tests
+ ./replace-add-needed.sh
++ basename ./replace-add-needed.sh .sh
+ SCRATCH=scratch/replace-add-needed
++ readlink -f ../src/patchelf
+ PATCHELF=/builddir/build/BUILD/patchelf-0.15.0/src/patchelf
+ rm -rf scratch/replace-add-needed
+ mkdir -p scratch/replace-add-needed
+ cp simple scratch/replace-add-needed/
+ cp libfoo.so scratch/replace-add-needed/
+ cp libbar.so scratch/replace-add-needed/
+ cd scratch/replace-add-needed
++ ldd ./simple
++ awk '/ => / { print $3 }'
++ grep -E '(libc.so|ld-musl)'
+ libcldd=

Interesting…so what does e.g. ldd /usr/bin/ls actually look like on ppc64le on CentOS/RHEL/Rocky 8?

$ ldd /usr/bin/ls
	linux-vdso64.so.1 (0x00007fffb5b20000)
	libselinux.so.1 => /lib64/libselinux.so.1 (0x00007fffb5a40000)
	libcap.so.2 => /lib64/libcap.so.2 (0x00007fffb5a10000)
	libc.so.6 => /lib64/glibc-hwcaps/power9/libc-2.28.so (0x00007fffb5800000)
	libpcre2-8.so.0 => /lib64/libpcre2-8.so.0 (0x00007fffb5750000)
	libdl.so.2 => /lib64/libdl.so.2 (0x00007fffb5720000)
	/lib64/ld64.so.2 (0x00007fffb5b30000)
	libpthread.so.0 => /lib64/glibc-hwcaps/power9/libpthread-2.28.so (0x00007fffb56d0000)
$ 

Ah, it's glibc-hwcaps! While CentOS/RHEL/Rocky 8 has -mcpu=power8 -mtune=power8 during build-time for packages, there are optimizations using glibc-hwcaps when running on POWER9 ISA. See also:

• https://www.phoronix.com/news/Glibc-2.33-Coming-HWCAPS
• https://lwn.net/Articles/844831/
• https://sourceware.org/pipermail/libc-alpha/2020-May/113757.html
• https://sourceware.org/pipermail/libc-alpha/2020-June/115250.html