title: binfmt-support - not allowing me to echo to register
body: <p>I am using ubuntu linux. Trying to add support of ARM interpreter to binfmt.
  I am getting permission denied error.</p>
  
  <p>Just added support to binfmt on my machine :---</p>
  
  <pre><code>sudo apt-get install binfmt-support
  </code></pre>
  
  <p>ls in directory binfmt_misc :--</p>
  
  <pre><code>ignite@ignite:/proc/sys/fs/binfmt_misc$ ls 
  python2.7  python3.2  register  status
  </code></pre>
  
  <p>binfmt_misc Filesystem is correctly mounted :---</p>
  
  <pre><code>ignite@ignite:/proc/sys/fs/binfmt_misc$ mount
  /dev/sda8 on / type ext4 (rw,errors=remount-ro)
  proc on /proc type proc (rw,noexec,nosuid,nodev)
  sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
  none on /sys/fs/fuse/connections type fusectl (rw)
  none on /sys/kernel/debug type debugfs (rw)
  none on /sys/kernel/security type securityfs (rw)
  udev on /dev type devtmpfs (rw,mode=0755)
  devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
  tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
  none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
  none on /run/shm type tmpfs (rw,nosuid,nodev)
  none on /run/user type tmpfs (rw,noexec,nosuid,nodev,size=104857600,mode=0755)
  binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
  gvfsd-fuse on /run/user/ignite/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,user=ignite)
  </code></pre>
  
  <p>module is up &amp; running :---</p>
  
  <pre><code>ignite@ignite:/proc/sys/fs/binfmt_misc$ cat /proc/modules | grep binfmt*
  binfmt_misc 17260 1 - Live 0x00000000
  </code></pre>
  
  <p>Status is showing enabled :-----</p>
  
  <pre><code>ignite@ignite:/proc/sys/fs/binfmt_misc$ cat status 
  enabled
  </code></pre>
  
  <p>Error at the time of echo to register file even using <code>sudo</code> :---</p>
  
  <pre><code>ignite@ignite:/proc/sys/fs/binfmt_misc$ sudo echo ':arm:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/var/local/rpi/qemu/bin/qemu-arm:' &gt; /proc/sys/fs/binfmt_misc/register
  bash: /proc/sys/fs/binfmt_misc/register: Permission denied
  </code></pre>
  
  <p>Why it is not allowing me to echo to register, even as sudo ?</p>
  
  <p>Edit :---<br>
  This command is working, arm folder is created :---</p>
  
  <pre><code>ignite@ignite$ echo "echo ':arm:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-arm:' &gt; /proc/sys/fs/binfmt_misc/register" | sudo sh
  
  ignite@ignite:/proc/sys/fs/binfmt_misc$ ls
  arm  python2.7  python3.2  register  status
  
  
  ignite@ignite:/proc/sys/fs/binfmt_misc$ cat arm 
  enabled
  interpreter /usr/local/bin/qemu-arm
  flags: 
  offset 0
  magic 7f454c4601010100000000000000000002002800
  mask ffffffffffffff00fffffffffffffffffeffffff
  </code></pre>
  
  <p>But i am not able to run arm executable. This is an <code>pre compiled program</code> of hello world.</p>
  
  <pre><code>ignite@ignite:~/testing$ file a.out 
  a.out: ELF 32-bit LSB executable, ARM, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 3.6.3, not stripped
  ignite@ignite:~/testing$ ./a.out 
  /lib/ld-linux-armhf.so.3: No such file or directory
  </code></pre>
  
  <p>Do i have to perform chroot to execute this arm executable<code>?</code></p>