Re: firefox-37, where to put

[Reco <recoverym4n@gmail.com>]

 Hi.

On Thu, 2 Apr 2015 15:06:42 -0400
Gene Heskett <gheskett@wdtv.com> wrote:

> "ldd" says its not an executable, but then says ldd itself is not, 
> while "file" says its (ldd) a Bourne Again SHell script.
> 
> Am I compromized?

Let's see what all fuss is about.

First, 

wget -q
http://ftp.mozilla.org/pub/mozilla.org/firefox/releases/37.0/linux-x86_64/en-US/firefox-37.0.tar.bz2

Second,

wget -q
ftp.mozilla.org/pub/mozilla.org/firefox/releases/37.0/SHA512SUMS

Third,

sha512sum firefox-37.0.tar.bz2

Fourth,

grep
665f856cd9f69db2122c6d5bf25305e0ffa60bb56f342be9512cbe81e912c0966a7e100ce2d0e30bf978cf94fcf43a2de4c8afa6834ebd46ff7b292f6eec3224
SHA512SUMS

And hurray, I've apparently got Genuine™ Mozilla Firefox 37.

Next,

tar xf firefox-37.0.tar.bz2 && cd firefox

And, finally

$ file firefox
firefox: ELF 64-bit LSB executable, x86-64, version 1 (SYSV),
dynamically linked (uses shared libs), for GNU/Linux 2.6.18, BuildID
[sha1]=0xd9c52e07232a78690be6d991546a12bb3668601d, stripped

$ file --mime-type firefox 
firefox: application/x-executable

So, it's definitely a binary. Yet,

$ ldd ./firefox
        not a dynamic executable

Why? That's why:

$ pwd
/tmp/firefox
$ mount | grep /tmp
tmpfs on /tmp type tmpfs
(rw,nosuid,nodev,noexec,relatime,size=12234980k)

Notice *noexec* here.


You see, ldd actually tries to execute a file (by using special hack in
ld.so, so that's OK). And of course, if you put an executable at
no-executable mountpoint, not only you won't be able to run it, ldd
also ceases to work.

And yes, ldd is a shell script. A customary way to prepend hacky
environment variables to executables is using shell wrappers. ldd is
just one of those.

Still, if ldd fails you - use objdump:

$ objdump -x firefox | grep NEED
  NEEDED               libpthread.so.0
  NEEDED               libdl.so.2
  NEEDED               librt.so.1
  NEEDED               libstdc++.so.6
  NEEDED               libm.so.6
  NEEDED               libgcc_s.so.1
  NEEDED               libc.so.6
  NEEDED               ld-linux-x86-64.so.2
  VERNEED              0x00000000004036c8
  VERNEEDNUM           0x0000000000000007


tl;dr version - move your firefox directory to filesystem mounted with
exec. Problem should solve itself.

Reco