abilist.awk: Treat .tdata like .tbss and reject unknown combinations.

Mathieu Desnoyers ran into an issue with his rseq patch where he
was the first person to add weak thread-local data and this
resulted in an ABI list update with entries like this:
"GLIBC_2.29 w ? D .tdata 0000000000000020".

The weakness of the symbol has nothing to do with the DSOs ABI
and so we should not write anything about weak symbols here. The
.tdata entries should be treated exactly like .tbss entries and
the output should have been: "GLIBC_2.29 __rseq_abi T 0x20"

This change makes abilist.awk handle .tdata just like .tbss,
while at the same time adding an error case for the default, and
the unknown line cases.  We never want anyone to be able to add
such entries to any ABI list files and should see an immediate
error and consult with experts.

Tested by Mathieu Desnoyers <mathieu.desnoyers@efficios.com> with
the rseq patch set and 'make update-all-abi'.

Tested myself with 'make update-all-abi' on x86_64 with no
changes.

Signed-off-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index c4dae980a2..b5ed08254c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2018-11-26  Carlos O'Donell  <carlos@redhat.com>
+
+	* scripts/abilist.awk: Handle .tdata. Error for unknown combinations.
+	Error for unknown lines.
+
 2018-11-26  Joseph Myers  <joseph@codesourcery.com>
 
 	* scripts/build-many-glibcs.py (Context.fix_glibc_timestamps):