Arch Linux

Alpaca

Member

Registered: 2013-10-09

Posts: 1

binfmt_misc: Interpreter is not running

I'm trying to set up my system so that I can execute ARM binaries using qemu. The emulator works when

$ file hello
hello: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), statically linked, for GNU/Linux 2.6.27, not stripped

$ qemu-arm-static hello
Hello, World!

$ ./hello
bash: ./hello: cannot execute binary file

I have double checked that my kernel has support for it

$ cat /proc/config.gz | gunzip | grep BINFMT_MISC
CONFIG_BINFMT_MISC=y

And as far as I can tell, it is all configured correctly

$ cat /proc/sys/fs/binfmt_misc/status
enabled

$ cat /proc/sys/fs/binfmt_misc/qemu-arm
enabled
interpreter mask \xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff
flags: 
extension .offset 0

$ update-binfmts --display qemu-arm
qemu-arm (enabled):
     package = package qemu-user-static
        type = interpreter /usr/bin/qemu-arm-static
      offset = credentials yes
       magic = offset 0
        mask = magic \x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00
 interpreter = mask \xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff
    detector =

I even double checked the magic...

$ xxd hello | head -n2
0000000: 7f45 4c46 0101 0100 0000 0000 0000 0000  .ELF............
0000010: 0200 2800 0100 0000 008b 0000 3400 0000  ..(.........4...

I have an up-to-date Arch install with kernel 3.11.4-1.

What else can I check to get this working? I am clearly missing something...

-- EDIT --

Ok, so it seems that update-binfmt is lying to me. I just manually registered the handler and it worked fine. It also reports that the interpreter is correct when when looking in

/proc/sys/fs/binfmt_misc/

$ cat qemu-arm-static 
enabled
interpreter /usr/bin/qemu-arm-static
flags: 
offset 0
magic 7f454c4601010100000000000000000002002800

I will see if I can find out why that is.

Last edited by Alpaca (2013-10-09 07:46:45)

pinsl

Member

Registered: 2016-02-07

Posts: 7

Re: binfmt_misc: Interpreter is not running

This issue seems to still be relevant. The problem might be that when registered with systemd-binfmt the F flag is not set:

$ doas systemctl restart systemd-binfmt.service
$ cat /proc/sys/fs/binfmt_misc/qemu-arm
enabled
interpreter /usr/bin/qemu-arm
flags:
offset 0
magic 7f454c4601010100000000000000000002002800
mask ffffffffffffff00fffffffffffffffffeffffff
$ chroot /tmp/raspios-armhf-root/
chroot: failed to run command '/bin/bash': No such file or directory
$ /usr/lib/systemd/systemd-binfmt --unregister

$ cat /usr/lib/binfmt.d/qemu-arm-static.conf > /proc/sys/fs/binfmt_misc/register
$ cat /proc/sys/fs/binfmt_misc/qemu-arm
enabled
interpreter /usr/bin/qemu-arm-static
flags: F
offset 0
magic 7f454c4601010100000000000000000002002800
mask ffffffffffffff00fffffffffffffffffeffffff
$ chroot /tmp/raspios-armhf-root/
root@clt-dsk-t-6010:/#

Last edited by pinsl (2022-09-19 09:23:00)