Re: [PATCH] Allow different paths for static and shared libraries

[Rich Felker <dalias@libc.org>]

On Sun, May 31, 2015 at 06:51:42PM -0300, Ismael Luceno wrote:
> On Sun, 31 May 2015 12:30:34 -0400
> Rich Felker <dalias@libc.org> wrote:
> > On Sun, May 31, 2015 at 06:10:54AM -0300, Ismael Luceno wrote:
> > > On Sun, 31 May 2015 03:31:57 -0400
> > > Rich Felker <dalias@libc.org> wrote:
> > > > On Sun, May 31, 2015 at 04:24:25AM -0300, Ismael Luceno wrote:
> > > > > Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>
> > > > > ---
> > > > >  Makefile  | 5 ++++-
> > > > >  configure | 3 +++
> > > > >  2 files changed, 7 insertions(+), 1 deletion(-)
> > > > > [...]
> > > > 
> > > > Is there a motivation/intended-usage-case for this patch?
> > > 
> > > libc.so must be available at boot, while the static libraries don't
> > > need to, so installing to different paths comes useful.
> > 
> > In that case I think you're not looking for the semantics of slibdir
> > but rather using it as a mechanism to make ldso available before
> > libdir is mounted.
> > 
> > Note that having libc.so and libc.a in different dirs is very
> > problematic/dangerous at linking time. If the dir containing libc.a is
> > searched first, then it will get linked into dynamic-linked binaries
> > and very bad things will happen.
> > 
> > I think this is probably yet another case of wanting ldso to be the
> > canonical file and libc.so to be a symlink to it (reversing symlink
> > direction). This issue has come up many times before but I always
> > forget how it was resolved (or not) and why nothing changed...
> 
> A ld script in place of libc.so, containing "GROUP ( /lib/libc.so )",
> would workaround that.

Are you sure? I think that would result in a dependency for
"/lib/libc.so" getting put in the binary rather than one for
"libc.so", and that's also a serious bug.

Rich