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.
Many thanks.
Gordan