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Re: [PATCH] nss_files: Fix /etc/aliases null pointer dereference [BZ #24059]
* Szabolcs Nagy:
> * Florian Weimer <fweimer@redhat.com> [2019-02-01 18:32:23 +0100]:
>> * Szabolcs Nagy:
>> >
>> > libnss_files.so.2 is not listed as explicit dependency
>> > for some reason so it is not loaded at program startup,
>> > but after chroot is entered, but it's not available in
>> > the chroot so the first api call fails.
>>
>> There's already this in nss/Makefile:
>>
>> $(objpfx)tst-nss-files-alias-truncated: $(objpfx)/libnss_files.so
>>
>> I expected this causes a DT_NEEDED entry to be added to the executable,
>> so it is loaded upon startup, outside of the chroot.
>
> it seems debian/ubuntu gcc always passes --as-needed to the linker
> https://wiki.debian.org/ToolChain/DSOLinking
Nice find. Yes, that completely explains it.
> so either a reference is needed to the lib or
> -Wl,--no-as-needed lib -Wl,--as-needed
> ldflag to force a DT_NEEDED.
Hmm. Should we put this on the general linker command line for tests?
Are there any cases where we actually want --as-needed behavior for
objects linked into tests?
> ..or copy the lib to the chroot.
The test-in-container framework does not work on our currrent reference
machines, even as root. 8-(
In other tests, I have used dlopen before the chroot. I could adjust
this test accordingly, but it adds needless complexity in my opinion.