slapd-mtread crash on ppc64{,el} in stretch/sid

[Ryan Tandy <ryan@nardis.ca>]

Hi debian-powerpc,

Would a ppc64(el) porter be able to help me look at #866122? I have 
requested a porterbox account but it's not gone through yet, and I am 
unable to reproduce the issue at all in a qemu VM.

The openldap test suite is failing on ppc64 and ppc64el in stretch and 
unstable: the slapd-mtread helper program segfaults (exit 139) in a 
certain test case.

It looks like the builds tend to succeed on jessie's kernel and fail on 
stretch's kernel:

* 2.4.44+dfsg-4 failed on ppc64el-osuosl-01
 - kernel 4.9.0-2-powerpc64le
 - gcc-6_6.3.0-13
 - binutils_2.28-3
* 2.4.44+dfsg-5 succeeded on ppc64el-unicamp-01
 - kernel 3.16.0-4-powerpc64le
 - gcc-6_6.3.0-18
 - binutils_2.28-5
* 2.4.44+dfsg-6 failed on ppc64el-osuosl-01
 - kernel 4.9.0-3-powerpc64le
 - gcc-6_6.3.0-19
 - binutils_2.28-6
* 2.4.44+dfsg-7 failed on ppc64el-unicamp-01
 - kernel 4.9.0-3-powerpc64le
 - gcc-6_6.3.0-19
 - binutils binutils_2.28-6

with one exception:

* 2.4.44+dfsg-5~bpo8+1 succeeded on ppc64el-osuosl-01
 - kernel 4.9.0-3-powerpc64le
 - gcc-4.9_4.9.2-10
 - binutils_2.25-5+deb8u1

The steps to build and run just the failing test are:

 apt-get build-dep openldap
 apt-get source openldap
 cd openldap-*/
 DEB_BUILD_OPTIONS=nocheck dpkg-buildpackage -T build
 cd debian/build/tests
 ./run -b bdb test060-mt-hot

The slapd-mtread output is in debian/build/tests/testrun/mtread.out.
The testrun folder also contains other logs and files from the test run.
The slapd-mtread source is in tests/progs/slapd-mtread.c.

Thanks in advance for any help you can offer.

Ryan