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 ~]#
--
Mike Howard