Re: iohelp handle_io_release_conch doesn't lock shared page

[Marcus Brinkmann]

On Sat, May 11, 2002 at 04:40:36PM -0400, Roland McGrath wrote:
> AFAIK other systems do not always
> provide this guarantee, e.g. none I'm aware of do for NFS; I don't know
> whether other current systems in fact make the guarantee for disk files.)
> I'm not saying it's not a worthwhile thing to have, but just to put in
> perspective how much hassle and other inefficiencies it might really be worth.

Linux doesn't allow any writes to shared libraries or executables that are
currently running:

ulysses:/bin# LC_ALL=C /bin/sh -c "cat > /bin/bash"
/bin/sh: /bin/bash: Text file busy

For shared libraries, we use MAP_COPY.  Maybe we can use this for
executables, too?

This opinion might be ignorant of any hair that is involved with exec ;)

Thanks,
Marcus

-- 
`Rhubarb is no Egyptian god.' Debian http://www.debian.org brinkmd@debian.org
Marcus Brinkmann              GNU    http://www.gnu.org    marcus@gnu.org
Marcus.Brinkmann@ruhr-uni-bochum.de
http://www.marcus-brinkmann.de