I did a bit more digging, and rebuilding 4.9.153 with CONFIG_COMPAT and a few related options, had an effect - no longer do I get "exec format error" - now it just outright segfaults. 4.4.172 works perfectly. I'm using clean mainline kernels with no additional patches. chrooting to aarch64 chroots works. On Sat, Jan 26, 2019 at 6:07 PM Stephen John Smoogen <smooge at gmail.com> wrote: > > > On Sat, 26 Jan 2019 at 18:45, Gordan Bobic <gordan at redsleeve.org> wrote: > >> Yes, they are "wrong", but not "WRONG!". >> >> As I (possibly poorly) explained, I'm running on an aarch64 machine, but >> am trying to run armv5tel and armv7hl chroots. >> I just dug out an old kernel I was using (4.4.72) and I can now chroot >> just fine. >> >> So it's something that changed in the kernel, but I'm not sure what else >> it could be other than the page size (which I already checked). >> >> I'm going to build the latest 4.4.172 with my 4.4.72 config and see if >> that works. If it does, I'll try to make oldconfig that on 4.9.153 and try >> again, see if that breaks things again. I was just hoping there might be an >> option I missed in 4.9 that enables/disables downward compatibility. >> >> > The places I have seen where this breaks before was > * it works on only specific aarch64 devices > * it works but only after you update the firmware to a newer vendor > version (because the kernel expects that to fix something else) > * it is a regression and needs to be fixed. > > [The first one was where someone remembered it working but forgot they > were working on XYZ box and then replicated in ABC and found the arch > didn't have that.] > > I am expecting it is going to be 3... but I would check on 2 also. > > > >> Gordan >> >> On Sat, Jan 26, 2019 at 5:41 PM Stephan GUILLOUX < >> stephan.guilloux at free.fr> wrote: >> >>> Wrong architecture binaries, in the chroot'ed folder ? >>> >>> What do you get with: >>> >>> file <chroot>/bin/bash >>> >>> On 26-Jan-19 17:49, Gordan Bobic wrote: >>> > It's been so long since I last had to do this, that it looks like a >>> > kernel update somewhere along the way broke this for me. :-( >>> > >>> > What happens now: >>> > >>> > # chroot rs7 >>> > chroot: failed to run command ‘/bin/bash’: Exec format error >>> > >>> > I could have sworn that this was all I needed to make this work last >>> time: >>> > # grep 4K_PAGES config-4.9.153-1.el7.centos.aarch64 >>> > CONFIG_ARM64_4K_PAGES=y >>> > # CONFIG_ARM64_64K_PAGES is not set >>> > >>> > Unfortunately, now trying to chroot into either hard-float or >>> > soft-float chroot results in the exec format error. >>> > >>> > Looking at time stamps of various things, I had this working with >>> > 4.4.70, but have since switched to 4.9.x kernels. Any thoughts on what >>> > changed between 4.4 and 4.9 would be most appreciated. >>> > >>> > What am I missing? >>> > >>> > _______________________________________________ >>> > Arm-dev mailing list >>> > Arm-dev at centos.org >>> > https://lists.centos.org/mailman/listinfo/arm-dev >>> _______________________________________________ >>> Arm-dev mailing list >>> Arm-dev at centos.org >>> https://lists.centos.org/mailman/listinfo/arm-dev >>> >> _______________________________________________ >> Arm-dev mailing list >> Arm-dev at centos.org >> https://lists.centos.org/mailman/listinfo/arm-dev >> > > > -- > Stephen J Smoogen. > > _______________________________________________ > Arm-dev mailing list > Arm-dev at centos.org > https://lists.centos.org/mailman/listinfo/arm-dev > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/arm-dev/attachments/20190126/fa377722/attachment-0006.html>