Linux executable picks up FreeBSD library over linux one and breaks

[Nikos Ntarmos]

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On Sat, Dec 01, 2007 at 11:01:46PM +0000, Robert Watson wrote:
> 
> On Sat, 1 Dec 2007, Alexander Leidinger wrote:
> 
> >Have a look at the search order of libs in linux. Correlate this with
> >the fact that when in linux an access is done to e.g. /lib/libX.so.y
> >which means that the linuxulator first looks if
> >/compat/linux/lib/libX.so.y is there, and if it isn't it looks if
> >/lib/libX.so.y is available.
> >
> >AFAIR a work around is to add a link in
> >/compat/linux/usr/lib/librt.so.1 -> /lib/librt.so.1
> >
> >I want to do something like this in the FC4 port, but hadn't time to
> >do it and test it so far.
> 
> It sounds like the real problem is that there are some cases where we
> don't want the Linuxulator to merge the underlying and Linux views of
> the file system -- we don't want the union of /compat/linux/lib and
> /lib, we just want /compat/linux/lib?

The problem mainly arises when a library appears earlier in the search
path in the underlying view of the file system than in the Linux view.
(e.g. there is no /compat/linux/path1/lib/libX.so.y but there is a
/path2/libX.so.y and path2 appears before path1 in the ld search path).
X-related libraries are a good example; since we moved to a
${LOCALBASE}-based X hierarchy, all X-based dynamically-linked linux
binaries pick up the native X libraries (i.e. from /usr/local/lib),
unless advised otherwise (e.g. via
LD_LIBRARY_PATH=/compat/linux/usr/X11R6/lib:$LD_LIBRARY_PATH).

Symbolic links do work. Another solution is to rearrange dynamic
libraries under /compat/linux so that they match the FreeBSD hierarchy
(and teach ld-linux to use the same search path as the native loader).
And yet another solution is to teach the linuxolator to first do an
exhaustive search for libraries under /compat/linux and only then fall
back to native ones (this seems similar to the above LD_LIBRARY_PATH
incantation).

Just my $0.02.

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Comment: Nikos Ntarmos <ntarmos at ceid.upatras.gr>

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