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RE: [PATCH 1/3] elf: Allow dlopen of filter object to work [BZ #16272]
- From: David Kilroy <David dot Kilroy at arm dot com>
- To: Florian Weimer <fweimer at redhat dot com>
- Cc: "libc-alpha at sourceware dot org" <libc-alpha at sourceware dot org>, nd <nd at arm dot com>
- Date: Tue, 22 Oct 2019 08:27:48 +0000
- Subject: RE: [PATCH 1/3] elf: Allow dlopen of filter object to work [BZ #16272]
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> Florian Weimer
> * David Kilroy:
>
> >> The Solaris documentation does not mention symbol filtering
> (constraining
> >> the set of exported symbols) at run time. This kind of filtering is
> achieved at
> >> run time because the link editor only looks at symbols in the filter and
> does
> >> not consult the filtee.
> >
> > My assumption was that on Solaris only the symbols mentioned in the
> filter
> > actually get bound at runtime. I haven't looked at what would have to be
> done
> > to support that behaviour. I'm sounds non-trivial :)
>
> I expected that based on the name of the feature, but the Solaris
> documentation does not support that. It's only clear that they filter
> at link time.
[I just wanted to respond to this part of your email here. I'll respond to the
rest via Szabolcs email.]
The web page does say "The runtime linker uses the filtee to resolve any
symbols defined by filter.so.1. If the filtee is not found, or a filter symbol
is not found in the filtee, the filter is skipped for this symbol lookup."
Regards,
Dave.