RE: [PATCH v3] Support glibc multiple namespace extension

["Metzger, Markus T" <markus.t.metzger@intel.com>]

Hello Kevin,

>This is indeed wrong and leads to
>
>      if (li->l_prev != prev_lm)
>	{
>	  warning (_("Corrupted shared library list: %s != %s"),
>		   paddress (target_gdbarch (), prev_lm),
>		   paddress (target_gdbarch (), li->l_prev));
>	  return 0;
>	}
>
>in svr4_read_so_list().  Assigning prev_lm to zero avoided the warning for
>the first library in another namespace.  I added more test cases to detect
>this reliably.
>
>I'll try organizing SVr4 DSOs in per-namespace lists.

That works.  During testing I noticed

	Invalid cast.
	warning: Probes-based dynamic linker interface failed.
	Reverting to original interface.

on dlcose().  This can also be reproduced with gdb.base/unload.exp
and upstream GDB.  I have not looked into this, yet.

This is not detected by the test system and I'm not sure whether we
actually want to consider falling back to the old interface a test fail.
The invalid cast error we probably want to detect.

I added support for detecting this invalid cast and the corrupted
library list warning in gdb_continue_to_breakpoint.

I still need to extend the library-list-svr4 XML to cover namespaces
before I send an updated patch.  I'll be out the next week so this
will take a while.

I currently check the XML version and put everything into a special
namespace on the GDB side.  We cannot use incremental updates
this way but we're backwards compatible.  The final version will
support both the new format with namespaces and incremental
updates and the old format without.

Regards,
Markus.

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