Shared library permissions in Debian-land and Red Hat-land

[Richard W.M. Jones]

On Thu, Mar 24, 2011 at 12:31:14AM -0400, Tom Lane wrote:
> Adam Williamson <awilliam at redhat.com> writes:
> > So, is it true that the convention is 0644 in Debian and 0755 in Red
> > Hat-land? If so, does anyone know why the difference, and if this needs
> > to stay different forever? Also, I presume neither of us is patching
> > several thousand shared library packages for this, so are the
> > permissions usually set by libtool or something similar, and that's
> > where the configuration is set?
> 
> I don't know all that much about the conventions for this under Linux,
> but I'm familiar with other Unix-oid platforms where shared libraries
> *must* have execute permission or they flat out don't work.

Don't forget also that shared libraries can be executable programs:

$ /lib64/libc.so.6 
GNU C Library development release version 2.13.90, by Roland McGrath et al.
Copyright (C) 2011 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Compiled by GNU CC version 4.6.0 20110301 (Red Hat 4.6.0-0.11).
Compiled on a Linux 2.6.38 system on 2011-03-07.
Available extensions:
	  Support for some architectures added on, not maintained in glibc core.
	  The C stubs add-on version 2.1.2.
	  crypt add-on version 2.1 by Michael Glad and others
	  GNU Libidn by Simon Josefsson
	  Native POSIX Threads Library by Ulrich Drepper et al
	  BIND-8.2.3-T5B
	  RT using linux kernel aio
libc ABIs: UNIQUE IFUNC
For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.

Rich.

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