On 14/03/2016 23:39, Gordan Bobic wrote:
> On 2016-03-14 22:58, Gordan Bobic wrote:
>> 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...
>
> Using that same config with 4.4.5 (make oldconfig, take all defaults)
> also works.
> There must have been an extra config option that I missed the first
> time around.
Excellent.
--
Mike Howard