On 2016-03-14 22:25, Gordan Bobic wrote:
> On 2016-03-14 22:14, Michael Howard wrote:
>> On 14/03/2016 21:47, Gordan Bobic wrote:
>>> On 2016-03-14 21:41, Michael Howard wrote:
>>>> On 14/03/2016 17:16, Gordan Bobic wrote:
>>>>> On 2016-03-14 17:13, Michael Howard wrote:
>>>>>> On 14/03/2016 16:56, Gordan Bobic wrote:
>>>>>>> On 2016-03-14 15:00, Gordan Bobic wrote:
>>>>>>>> On 2016-03-01 22:32, Michael Howard wrote:
>>>>>>>>> On 01/03/2016 22:26, Richard W.M. Jones wrote:
>>>>>>>>>> On Mon, Feb 29, 2016 at 03:20:03PM +0000, Michael Howard
>>>>>>>>>> wrote:
>>>>>>>>>>> Just to let you know, I can't get this to work. aarch64 is
>>>>>>>>>>> supposed
>>>>>>>>>>> to be binary compatible, with the correct libraries
>>>>>>>>>>> installed, but
>>>>>>>>>>> I'm thinking the cpu isn't.
>>>>>>>>>>>
>>>>>>>>>>> All I get is 'cannot execute binary file: Exec format error',
>>>>>>>>>>> regardless of what I try.
>>>>>>>>>> As I understand it the problem is page size - 64K was chosen
>>>>>>>>>> by
>>>>>>>>>> Red Hat for aarch64, where as 4K is the norm on armv7.
>>>>>>>>>>
>>>>>>>>>> Anyway, you can run a 32 bit VM and it works well -- in fact a
>>>>>>>>>> lot
>>>>>>>>>> faster than regular 32 bit armv7 hardware.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Yes, with CONFIG_ARM64_4K_PAGES=y and CONFIG_COMPAT=y, 32 bit
>>>>>>>>> binaries run fine.
>>>>>>>>
>>>>>>>> I built a kernel with these options enabled, but chrooting into
>>>>>>>> an
>>>>>>>> armv5tel subtree segfaults immediately. :-(
>>>>>>>>
>>>>>>>> # grep -E "CONFIG_COMPAT=|CONFIG_ARM64_4K_PAGES="
>>>>>>>> /boot/config-4.4.5
>>>>>>>> CONFIG_ARM64_4K_PAGES=y
>>>>>>>> CONFIG_COMPAT=y
>>>>>>>>
>>>>>>>> # chroot /orcone/docker/rsel6/
>>>>>>>> Segmentation fault
>>>>>>>>
>>>>>>>> The chroot is armv5tel soft-float, which I think should work.
>>>>>>>> Oddly, I see no mention of a segfault in dmesg or in
>>>>>>>> /var/log/messages
>>>>>>>> on the host...
>>>>>>>>
>>>>>>>> # strace chroot /orcone/docker/media/
>>>>>>>> execve("/sbin/chroot", ["chroot", "/orcone/docker/media/"], [/*
>>>>>>>> 18 vars */]) = 0
>>>>>>>> brk(0) = 0x153eb000
>>>>>>>> mmap(NULL, 4096, PROT_READ|PROT_WRITE,
>>>>>>>> MAP_PRIVATE|MAP_ANONYMOUS, -1,
>>>>>>>> 0) = 0x7f98108000
>>>>>>>> faccessat(AT_FDCWD, "/etc/ld.so.preload", R_OK) = -1 ENOENT (No
>>>>>>>> such
>>>>>>>> file or directory)
>>>>>>>> openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
>>>>>>>> fstat(3, {st_mode=S_IFREG|0644, st_size=23876, ...}) = 0
>>>>>>>> mmap(NULL, 23876, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f98102000
>>>>>>>> close(3) = 0
>>>>>>>> openat(AT_FDCWD, "/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
>>>>>>>> read(3,
>>>>>>>> "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0\267\0\1\0\0\0\270\r\2\0\0\0\0\0"...,
>>>>>>>> 832) = 832
>>>>>>>> fstat(3, {st_mode=S_IFREG|0755, st_size=1801536, ...}) = 0
>>>>>>>> mmap(NULL, 1528796, PROT_READ|PROT_EXEC,
>>>>>>>> MAP_PRIVATE|MAP_DENYWRITE, 3,
>>>>>>>> 0) = 0x7f97f66000
>>>>>>>> mprotect(0x7f980c2000, 65536, PROT_NONE) = 0
>>>>>>>> mmap(0x7f980d2000, 24576, PROT_READ|PROT_WRITE,
>>>>>>>> MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x15c000) = 0x7f980d2000
>>>>>>>> mmap(0x7f980d8000, 13276, PROT_READ|PROT_WRITE,
>>>>>>>> MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f980d8000
>>>>>>>> close(3) = 0
>>>>>>>> mmap(NULL, 4096, PROT_READ|PROT_WRITE,
>>>>>>>> MAP_PRIVATE|MAP_ANONYMOUS, -1,
>>>>>>>> 0) = 0x7f98101000
>>>>>>>> mmap(NULL, 4096, PROT_READ|PROT_WRITE,
>>>>>>>> MAP_PRIVATE|MAP_ANONYMOUS, -1,
>>>>>>>> 0) = 0x7f98100000
>>>>>>>> mmap(NULL, 4096, PROT_READ|PROT_WRITE,
>>>>>>>> MAP_PRIVATE|MAP_ANONYMOUS, -1,
>>>>>>>> 0) = 0x7f980ff000
>>>>>>>> mprotect(0x7f980d2000, 16384, PROT_READ) = 0
>>>>>>>> mprotect(0x41f000, 4096, PROT_READ) = 0
>>>>>>>> mprotect(0x7f9810b000, 4096, PROT_READ) = 0
>>>>>>>> munmap(0x7f98102000, 23876) = 0
>>>>>>>> brk(0) = 0x153eb000
>>>>>>>> brk(0x1540c000) = 0x1540c000
>>>>>>>> brk(0) = 0x1540c000
>>>>>>>> openat(AT_FDCWD, "/usr/lib/locale/locale-archive",
>>>>>>>> O_RDONLY|O_CLOEXEC) = 3
>>>>>>>> fstat(3, {st_mode=S_IFREG|0644, st_size=109669264, ...}) = 0
>>>>>>>> mmap(NULL, 109669264, PROT_READ, MAP_PRIVATE, 3, 0) =
>>>>>>>> 0x7f916cf000
>>>>>>>> close(3) = 0
>>>>>>>> chroot("/orcone/docker/media/") = 0
>>>>>>>> chdir("/") = 0
>>>>>>>> execve("/bin/bash", ["/bin/bash", "-i"], [/* 18 vars */]) =
>>>>>>>> -1053305918634065933
>>>>>>>> --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
>>>>>>>> +++ killed by SIGSEGV +++
>>>>>>>> Segmentation fault
>>>>>>>>
>>>>>>>>
>>>>>>>> What am I doing differently?
>>>>>>>
>>>>>>> Just to make sure we are as much on the same page as possible,
>>>>>>> here
>>>>>>> is the minimal chroot I am trying:
>>>>>>> http://ftp.redsleeve.org/pub/el6-staging/rootfs/rsel6-minimal.tar.xz
>>>>>>>
>>>>>>> Built from the latest RedSleeve 6 binaries using:
>>>>>>> yum --installroot=/some/path install @core
>>>>>>>
>>>>>>> Can you extract that into an empty folder and chroot into it
>>>>>>> from your aarch64 CentOS 7 install? Does it work for you or
>>>>>>> does it segfault?
>>>>>>>
>>>>>>> If it works for you, any chance you could post your kernel
>>>>>>> config somewhere? It's the only thing I can think of that
>>>>>>> could plausibly be causeing the discrepancy (I am on 4.4.5
>>>>>>> and IIRC you were on 4.5rc).
>>>>>>
>>>>>> Downloading now but it will be a couple of hours before I can
>>>>>> check it out.
>>>>>
>>>>> Thanks, most appreciated. You may want to re-download, as I
>>>>> literally
>>>>> just replaced with tar ball with a more compressed version. If that
>>>>> happened
>>>>> during your download, what you get may end up being corrupted
>>>>> (check whether
>>>>> it matches the md5 checksum).
>>>>
>>>> I did re-download, just in case. It all works here as expected.
>>>>
>>>> [root at mp30 ~]# chroot ~/CHROOT2
>>>> [root at mp30 ~]# echo "nameserver 192.168.1.2" > /etc/resolv.conf
>>>> [root at mp30 /]# yum search linux
>>>> base | 3.8 kB
>>>> 00:00
>>>> updates | 3.0 kB
>>>> 00:00
>>>> ============================== N/S Matched: linux
>>>> ==============================
>>>> libselinux.armv5tel : SELinux library and simple utilities
>>>> libselinux-utils.armv5tel : SELinux libselinux utilies
>>>> python-linux-procfs.noarch : Linux /proc abstraction classes
>>>> selinux-policy.noarch : SELinux policy configuration
>>>> selinux-policy-doc.noarch : SELinux policy documentation
>>>> selinux-policy-minimum.noarch : SELinux minimum base policy
>>>> selinux-policy-mls.noarch : SELinux mls base policy
>>>> selinux- SELinux policy compiler
>>>> epel-release.noarch : Extra Packages for Enterprise Linux repository
>>>> : configuration
>>>> filesystem.armv5tel : The basic directory layout for a Linux system
>>>> iptables.armv5tel : Tools for managing Linux kernel packet filtering
>>>> : capabilities
>>>> libsemanage.armv5tel : SELinux binary policy manipulation library
>>>> libsepol.armv5tel : SELinux binary policy manipulation library
>>>> man-pages.noarch : Man (manual) pages from the Linux Documentation
>>>> Project
>>>> man-pages-cs.noarch : Czech man pages from the Linux Documentation
>>>> Project
>>>> man-pages-es.noarch : Spanish man pages from the Linux Documentation
>>>> Project
>>>> man-pages-fr.noarch : French version of the Linux man-pages
>>>> man-pages-it.noarch : Italian man (manual) pages from the Linux
>>>> Documentation
>>>> : Project
>>>> man-pages-pl.noarch : Polish man pages from the Linux Documentation
>>>> Project
>>>> man-pages-ru.noarch : Russian man pages from the Linux Documentation
>>>> Project
>>>> man-pages-uk.noarch : Ukrainian man pages from the Linux
>>>> Documentation Project
>>>> policycoreutils.armv5tel : SELinux policy core utilities
>>>> redhat-bookmarks.noarch : Red Hat Enterprise Linux bookmarks
>>>> redhat-indexhtml.noarch : Browser default start page for Red Hat
>>>> Enterprise
>>>> : Linux
>>>> redsleeve-release.armv5tel : Red Sleeve Enterprise Linux release
>>>> file
>>>> rhel-guest-image-6.noarch : Red Hat Enterprise Linux Guest Images
>>>> util-linux-ng.armv5tel : A collection of basic system utilities
>>>>
>>>> Name and summary matches only, use "search all" for everything.
>>>> [root at mp30 /]# exit
>>>> [root at mp30 ~]#
>>>
>>> That is most puzzling. Any chance you could please post your kernel
>>> config file
>>> (pastebin it or similar)? I'd like to try to build one exactly the
>>> same and see
>>> if I can get it working.
>>
>> No problem;
>>
>> http://pastebin.com/4mrgmNGv
>>
>> If all else fails (don't see why it should) I can put up the binary
>> and modules so you can triple check. I didn't build an RPM as I came
>> across a packaging problem, an aarch64/UTS_MACHINE issue I believe and
>> I had no idea how to solve it nor could I spend any real time
>> investigating it.
>
> Thanks for this. I'm building a new kernel with your config now. Hoping
> to
> report success in the morning. :)
I forgot how fast this thing builds the kernel. :)
I'm happy to say that 4.5.0 release kernel works fine, and I can run
chroots!
Thanks for your help Michael, I really appreciate it.
Now to see if I can make the same thing work with the LT 4.4.x kernel...
Gordan