last_100_frees.stp on aarch64 is crashing while doing sprint_ubacktrace()

[Mark Wielaard]

On Mon, 2015-06-22 at 10:47 -0400, William Cohen wrote:
> I have built the systemtap code with the patch below and exercising with:
> 
> while [ 1 ]; do /root/systemtap_write/install/bin/stap
> systemtap.examples/memory/last_100_frees.stp -B CONFIG_DEBUG_INFO=y -c
> "/root/systemtap_write/install/bin/stap -V"
> -d /root/systemtap_write/install/bin/stap --ldd;done

Thanks for testing. I also tested locally (on x86_64) that exelib.exp,
which uses the unwinder extensively, works as expected. Patch committed
as:

commit 81bde8f873216c116988a98a0804dd79009b3d40
Author: Mark Wielaard <mjw@redhat.com>
Date:   Mon Jun 22 16:57:59 2015 +0200

  runtime/unwind.c: Also sanity check DWARF regno for DW_CFA_restore[_extended].
    
  When processCFI wanted to restore a register state to its initial value it
  wasn't checking whether the register was actually interesting (or existing).
  DWARF_REG_MAP might return a marker (9999) that we don't know or don't care
  about this register. This was checked in all the set_*_rule functions, but
  not in the case we reset the rule of the register. Add this check also for
  DW_CFA_restore[_extended].

Thanks,

Mark