[Bug binutils/18487] New: ARM "special symbols" reported in preference to more useful ones

[bavisonpmbz at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=18487

            Bug ID: 18487
           Summary: ARM "special symbols" reported in preference to more
                    useful ones
           Product: binutils
           Version: 2.24
            Status: NEW
          Severity: normal
          Priority: P2
         Component: binutils
          Assignee: unassigned at sourceware dot org
          Reporter: bavisonpmbz at gmail dot com
  Target Milestone: ---

addr2line has changed its behaviour so that it reports "special symbols" where
they are colocated with normal ones. By "special symbols" I mean $a, $t, $d
which are inserted into ARM objects wherever there is a boundary between
ARM-state and Thumb-state code and data. Typically there are many of these in
any given object file.

The one that tripped me up can be illustrated as follows. In addr2line 2.22:

$ objdump -d ./test | grep _fini | tail -n1 | cut -d" " -f1 | xargs addr2line
-fe ./test | head -n1
_fini

And with the same ./test binary but addr2line 2.24:

$ objdump -d ./test | grep _fini | tail -n1 | cut -d" " -f1 | xargs addr2line
-fe ./test | head -n1
$a

I can't find any evidence that this was a deliberate change, though if it was
it would be useful to have a switch to restore the previous behaviour. As it
stands, it has completely broken gperftools profiling.

If anyone knows any good workarounds (e.g. how to strip the special symbols out
of the object file) I'd love to hear, thanks.

-- 
You are receiving this mail because:
You are on the CC list for the bug.